//! Optional Forgejo wiring — per-agent user + token provisioning,
//! config-repo mirroring, meta read-access grants. Also seeds
//! `internal/docs` — a private repo every agent gets read-only
//! collaborator access to for operator-curated shared content.
//! No-op when `hive-forge` isn't running. Full design: `docs/forge.md`.

use std::path::Path;

use anyhow::{Context, Result};
use base64::Engine;
use reqwest::StatusCode;
use tokio::process::Command;

use crate::coordinator::Coordinator;

const FORGE_CONTAINER: &str = "hive-forge";
pub(crate) const FORGE_HTTP: &str = "http://localhost:3000";
const TOKEN_NAME_PREFIX: &str = "hyperhive";
/// Where the host-side `core` admin token lives. Used by hive-c0re
/// itself to push the meta repo + drive admin API calls (org
/// creation, future webhook setup, etc.). Root-only.
const CORE_TOKEN_PATH: &str = "/var/lib/hyperhive/forge-core-token";
// Forge provisioning markers (`forge/core-avatar-set`,
// `forge/agent-configs-avatar-set`, `forge/email-aligned-<name>`) live
// in `crate::paths` — one-shot guards: the upload/align runs once, the
// marker is written, subsequent startups skip. Delete one to force its
// step to re-run.
// Avatar PNGs are loaded at runtime from
// `$HIVE_ASSETS_DIR/branding/{hyperhive,agent-configs}.png` via the
// helpers in `hive_sh4re::assets`. The `agent-configs.png` is
// rendered from its SVG during the `hyperhive-assets` derivation's
// build.
/// Forgejo org grouping every agent's config repo. Core is a site admin
/// and reads + writes every repo here. As of the agent-config-PR flow each
/// agent is a **write collaborator on its own** `agent-configs/<name>` repo —
/// the editable PR surface it pushes config-change branches to — but `main` is
/// branch-protected core-only, so only hive-c0re's verify-and-ff-push merge
/// handler lands on it (operator approval required; the agent can't push
/// `main` or self-merge). The repos remain private, so an agent still can't
/// reach *another* agent's config. `main` is fast-forward-only — hive-c0re
/// never force-pushes; the `push_config` mirror runs best-effort until the
/// PR-merge flow retires it.
const CONFIG_ORG: &str = "agent-configs";
/// Forgejo org hosting the operator-curated shared docs/skills repo
/// that every agent gets read-only access to. Agents use it as a
/// common reference without the operator having to bake content into
/// the system prompt or rely on `/shared`. Only the manager + operator
/// (i.e. `core` user) can push.
const SHARED_ORG: &str = "internal";
/// The shared docs repo inside `SHARED_ORG`. Cloneable by every agent
/// at `{FORGE_HTTP}/internal/docs.git`.
const SHARED_DOCS_REPO: &str = "docs";
/// The hive-wide knowledge repo inside `SHARED_ORG`. Public — agents
/// can fork it and open PRs without explicit collaborator grants.
/// Bind-mounted read-only into every container at `/knowledge`.
/// See `hive-c0re/src/knowledge.rs`.
const KNOWLEDGE_REPO: &str = crate::knowledge::REPO;
/// Forgejo org that owns agent-created repos. Agents can't create
/// repos with their own token (`max_repo_creation = 0`); instead hive-c0re
/// creates them here and adds the requesting agent as a **write** member
/// (not owner/admin). Because the org — not the agent — owns the repo,
/// perms stay c0re-managed and branch protection (referencing
/// [`OPERATORS_TEAM`]) can block the author from merging their own PR. This
/// is the "agents namespace" repos land in by default.
const AGENTS_ORG: &str = "agents";
/// Operator merge-gate team inside [`AGENTS_ORG`]. Provisioned **empty** by
/// hive-c0re (so perms can be set before anyone joins); the operator adds
/// herself via the forge UI / hivectl. Branch protection on agents-org repos
/// references this team by name for the merge/approval whitelist, so the
/// rule never hardcodes a specific reviewer agent (which may not exist).
const OPERATORS_TEAM: &str = "operators";
/// Hive-managed Forgejo namespaces that agent-initiated repo creation must
/// never target. `internal` is operator-curated shared content;
/// `agent-configs` + `core` are hive-c0re-internal mirror/meta namespaces.
/// (`hyperhive` is NOT managed — it's just a repo that happens to be built
/// by this hive.) hive-c0re's create path forces [`AGENTS_ORG`], so this is
/// a defensive guard against any future caller passing an explicit owner.
const HIVE_MANAGED_NAMESPACES: &[&str] = &[SHARED_ORG, CONFIG_ORG, "core"];
/// Forgejo orgs hive-c0re ensures on startup. The meta repo lives at
/// `core/meta` (the `core` user's own namespace — no org needed).
const SEEDED_ORGS: &[&str] = &[CONFIG_ORG, SHARED_ORG, AGENTS_ORG];
/// Per-agent token scopes (broad-but-not-admin). See
/// `docs/forge.md::Token scopes` for the per-scope rationale.
const TOKEN_SCOPES: &str = "read:user,write:user,read:notification,write:notification,write:repository,write:issue,write:organization,write:misc";

/// Bootstrap `core` token scopes — adds `read:admin,write:admin` on
/// top of `TOKEN_SCOPES` so the host daemon can drive
/// `/api/v1/admin/*`. Site-admin membership alone isn't enough: the
/// token's own scope gate runs before the user-permission check.
/// See `docs/forge.md::Token scopes`.
const CORE_TOKEN_SCOPES: &str = "read:admin,write:admin,read:user,write:user,read:notification,write:notification,write:repository,write:issue,write:organization,write:misc";

/// Probe whether `hive-forge` exists as a nixos-container. Cheap —
/// `nixos-container list` is just a directory scan in /etc. Routed
/// through hive-priv: `nixos-container` needs root, and hive-c0re runs
/// unprivileged (privsep).
pub async fn is_present() -> bool {
    let Ok(stdout) = crate::priv_client::list_containers().await else {
        return false;
    };
    stdout.lines().any(|l| l.trim() == FORGE_CONTAINER)
}

/// Run `forgejo admin <args>` inside the hive-forge container as the
/// forgejo user (the only uid with write access to the state dir).
/// Returns stdout on success; bails with stderr context on failure.
async fn forge_admin(args: &[&str]) -> Result<String> {
    // Route through hive-priv (root helper) because `nixos-container run`
    // uses nsenter to enter the container's namespaces, which requires root.
    // hive-c0re runs as the unprivileged `hive-core` user and cannot call
    // nsenter directly — doing so produces:
    //   nsenter: stat of /proc/<pid>/ns/user failed: Permission denied
    let (stdout, _stderr) = crate::priv_client::run_forge_admin(args)
        .await
        .with_context(|| format!("forgejo admin {} (via hive-priv)", args.join(" ")))?;
    Ok(stdout)
}

/// Pull the access token out of forgejo's success message. Format
/// has shifted across versions (table form vs. "Access token was
/// successfully created: <hex>"), so just hunt the output for the
/// first long hex-looking word.
fn extract_token(output: &str) -> Option<String> {
    output
        .split(|c: char| c.is_whitespace() || c == ',' || c == ':')
        .find(|w| w.len() >= 32 && w.chars().all(|c| c.is_ascii_hexdigit()))
        .map(str::to_owned)
}

/// Canonical email address for a hive agent's Forgejo account.
/// Must match the `user.email` set by `meta::render_flake` so commits
/// by the agent link back to their Forgejo profile page.
fn agent_email(name: &str) -> String {
    format!("{name}@hyperhive.local")
}

/// Thin Forgejo REST helper. Sends `method` to `url` with a JSON body
/// and `Authorization: token <token>`, returns the HTTP status code.
/// All Forgejo API calls that don't shell out to `forgejo admin` go
/// through here — one place for auth header, content-type, error
/// propagation, and the shared reqwest Client.
/// Returns the response status **and body**. The body lets callers log
/// *why* Forgejo rejected a request (e.g. the validation message on a
/// 422); status-only callers just bind `(status, _)`. Body read is
/// best-effort — a read error yields an empty string rather than
/// failing the whole call.
async fn forge_http(
    method: reqwest::Method,
    url: &str,
    token: &str,
    body: &str,
) -> Result<(StatusCode, String)> {
    let client = reqwest::Client::new();
    let resp = client
        .request(method, url)
        .header("Authorization", format!("token {token}"))
        .header("Content-Type", "application/json")
        .body(body.to_owned())
        .send()
        .await
        .with_context(|| format!("forge HTTP request to {url}"))?;
    let status = resp.status();
    let text = resp.text().await.unwrap_or_default();
    Ok((status, text))
}

/// Ensure a forgejo user named `name` exists. Idempotent: forgejo
/// returns a "user already exists" error which we treat as success.
/// `admin` adds `--admin` (site admin) — used for the bootstrap
/// `core` user that drives the API. `password` picks the initial
/// account password: `None` uses `--random-password` (the existing
/// agent provisioning shape — the password is never read, agents auth
/// by token); `Some(pw)` uses `--password <pw>` so the operator path
/// in `hivectl` can set a real password for matrix-style web-UI login.
async fn ensure_user_exists(name: &str, admin: bool, password: Option<&str>) -> Result<()> {
    let email = agent_email(name);
    let mut args = vec!["user", "create", "--username", name, "--email", &email];
    match password {
        Some(pw) => args.extend(["--password", pw, "--must-change-password=false"]),
        None => args.extend(["--random-password", "--must-change-password=false"]),
    }
    if admin {
        args.push("--admin");
    }
    let result = forge_admin(&args).await;
    match result {
        Ok(_) => {
            tracing::info!(%name, "forge: created user");
            Ok(())
        }
        Err(e) => {
            // Forgejo's "already exists" error wording varies; just
            // try the next step and let token issuance surface a
            // real failure if the user truly isn't there.
            let msg = format!("{e:#}");
            if msg.contains("already exists") || msg.contains("user already") {
                tracing::debug!(%name, "forge: user already exists");
                Ok(())
            } else {
                tracing::warn!(%name, error = %msg, "forge: user create unclear; trying token anyway");
                Ok(())
            }
        }
    }
}

/// Set the forgejo password for an existing user. Used by the operator
/// path in `hivectl forge create-user --password` so re-running on an
/// already-created account still updates the password (covers the
/// "I forgot the password I set last week" case + the "argus retried
/// the verb to verify the fix" case — `forgejo admin user create`
/// silently skips a password change once the account exists). Idempotent
/// from the operator's point of view: same password input → same final
/// account state.
async fn change_user_password(name: &str, password: &str) -> Result<()> {
    let args = [
        "user",
        "change-password",
        "--username",
        name,
        "--password",
        password,
    ];
    forge_admin(&args)
        .await
        .with_context(|| format!("forgejo admin user change-password {name}"))?;
    tracing::info!(%name, "forge: changed user password");
    Ok(())
}

/// Idempotently align the Forgejo account email to `agent_email(name)`.
/// Existing agents were created with `{name}@hive.local`; this corrects
/// that so git commits (which use `{name}@hyperhive`) link to profiles.
/// Best-effort: failures are warned, not propagated.
///
/// Marker-guarded: writes `EMAIL_ALIGNED_MARKER_PREFIX{name}` on first
/// success and skips the PATCH on all subsequent calls. This prevents
/// Forgejo's admin-user-edit endpoint from resetting `use_custom_avatar`
/// on every `sync_agent` tick. Delete the marker to force re-alignment.
///
/// Uses the admin REST API (`PATCH /api/v1/admin/users/{name}`) rather
/// than `forgejo admin user edit` because the CLI dropped the `edit`
/// subcommand somewhere between forgejo 8 and current. Body includes
/// `login_name` (required by Forgejo's `EditUserOption` validator) and
/// `source_id = 0` (local auth, the default for users hive-c0re creates).
async fn ensure_user_email(name: &str) {
    let marker = crate::paths::forge_email_aligned_marker(name);
    if marker.exists() {
        return;
    }
    let Some(token) = core_token() else {
        tracing::debug!(%name, "forge: skipping ensure_user_email — no core token yet");
        return;
    };
    let email = agent_email(name);
    // `login_name` is required by Forgejo's EditUserOption validator.
    // Omitting it caused Forgejo to reset use_custom_avatar on each call.
    let body = format!(r#"{{"email":"{email}","login_name":"{name}","source_id":0}}"#);
    let url = format!("{FORGE_HTTP}/api/v1/admin/users/{name}");
    match forge_http(reqwest::Method::PATCH, &url, &token, &body).await {
        Ok((status, _)) if status.is_success() => {
            if let Some(parent) = marker.parent() {
                std::fs::create_dir_all(parent).ok();
            }
            std::fs::write(&marker, "").ok();
            tracing::info!(%name, %email, "forge: user email aligned");
        }
        Ok((status, _)) if status == reqwest::StatusCode::FORBIDDEN => {
            // Core token missing admin scope — see
            // `docs/forge.md::Token scopes` migration note.
            tracing::warn!(
                %name, %email, %status,
                "forge: PATCH user email forbidden — core token likely missing admin scope. \
                 Delete {CORE_TOKEN_PATH} and restart hive-c0re to re-mint with the new scopes."
            );
        }
        Ok((status, _)) => {
            tracing::warn!(%name, %email, %status, "forge: PATCH user email returned non-success");
        }
        Err(e) => tracing::warn!(%name, error = %e, "forge: PATCH user email transport error"),
    }
}

/// Disable direct repo creation for agent `name` by setting
/// `max_repo_creation = 0` on its Forgejo account. Agents must
/// create repos *through hive-c0re* (which owns the perms), never with
/// their own token — a write-scoped token can otherwise create + own
/// repos and self-merge, bypassing the operator-only-merge policy.
///
/// `max_repo_creation = 0` means `CanCreateRepo()` is false for any
/// count (Forgejo: `MaxRepoCreation >= 0 && NumRepos >= MaxRepoCreation`),
/// so creation is refused while push / PR / clone stay intact. **Existing
/// repos are untouched** — this only blocks *new* direct creation.
///
/// Marker-guarded like [`ensure_user_email`]: the PATCH runs once per
/// agent (delete the marker to re-apply). Body carries `login_name` +
/// `source_id` for the same reason `ensure_user_email` does — omitting
/// `login_name` makes Forgejo's `EditUserOption` validator reset
/// `use_custom_avatar`. Best-effort: failures warn, don't propagate.
async fn ensure_repo_creation_disabled(name: &str) {
    let marker = crate::paths::forge_repo_creation_disabled_marker(name);
    if marker.exists() {
        return;
    }
    let Some(token) = core_token() else {
        tracing::debug!(%name, "forge: skipping ensure_repo_creation_disabled — no core token yet");
        return;
    };
    let body = format!(r#"{{"login_name":"{name}","source_id":0,"max_repo_creation":0}}"#);
    let url = format!("{FORGE_HTTP}/api/v1/admin/users/{name}");
    match forge_http(reqwest::Method::PATCH, &url, &token, &body).await {
        Ok((status, _)) if status.is_success() => {
            if let Some(parent) = marker.parent() {
                std::fs::create_dir_all(parent).ok();
            }
            std::fs::write(&marker, "").ok();
            tracing::info!(%name, "forge: disabled direct repo creation (max_repo_creation=0)");
        }
        Ok((status, _)) if status == reqwest::StatusCode::FORBIDDEN => {
            tracing::warn!(
                %name, %status,
                "forge: PATCH max_repo_creation forbidden — core token likely missing admin scope. \
                 Delete {CORE_TOKEN_PATH} and restart hive-c0re to re-mint with the new scopes."
            );
        }
        Ok((status, _)) => {
            tracing::warn!(%name, %status, "forge: PATCH max_repo_creation returned non-success");
        }
        Err(e) => {
            tracing::warn!(%name, error = %e, "forge: PATCH max_repo_creation transport error");
        }
    }
}

/// Mint a fresh access token for `name`. Token name is suffixed with
/// a monotonic clock so re-issuing doesn't collide with an existing
/// token of the same name in the DB. `scopes` is the scope string
/// passed to `forgejo admin user generate-access-token --scopes`;
/// use `TOKEN_SCOPES` for agents, `CORE_TOKEN_SCOPES` for the
/// bootstrap `core` user.
async fn mint_token(name: &str, scopes: &str) -> Result<String> {
    let token_name = format!(
        "{TOKEN_NAME_PREFIX}-{}",
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map_or(0, |d| d.as_secs())
    );
    let stdout = forge_admin(&[
        "user",
        "generate-access-token",
        "--username",
        name,
        "--token-name",
        &token_name,
        "--scopes",
        scopes,
    ])
    .await?;
    let token = extract_token(&stdout)
        .with_context(|| format!("parse token from forgejo output: {stdout:?}"))?;
    tracing::debug!(%name, %token_name, "forge: minted access token");
    Ok(token)
}

/// Mint a fresh Forgejo access token for an agent and write it to the
/// agent's state dir via hive-priv. hive-c0re runs unprivileged and
/// cannot write to agent-owned (0755) state directories directly.
async fn mint_and_persist_agent_token(name: &str) -> Result<()> {
    let token = mint_token(name, TOKEN_SCOPES).await?;
    crate::priv_client::write_agent_forge_token(name, &token)
        .await
        .with_context(|| format!("write forge-token for {name} via hive-priv"))
}

/// Mint a fresh Forgejo access token for the `core` admin user and
/// write it directly to `path`. Unlike agent tokens this path is owned
/// by hive-c0re itself (under `/var/lib/hyperhive/`), so a direct
/// write is both correct and necessary (no priv round-trip).
async fn mint_and_persist_core_token(path: &Path) -> Result<()> {
    use std::os::unix::fs::PermissionsExt;
    let token = mint_token("core", CORE_TOKEN_SCOPES).await?;
    if let Some(parent) = path.parent() {
        std::fs::create_dir_all(parent).ok();
    }
    std::fs::write(path, format!("{token}\n"))
        .with_context(|| format!("write core token to {}", path.display()))?;
    let _ = std::fs::set_permissions(path, std::fs::Permissions::from_mode(0o600));
    tracing::info!(path = %path.display(), "forge: persisted core access token");
    Ok(())
}

/// Ensure `name` has a forgejo user + token file. Always re-mints the
/// token so the on-disk file always reflects the current `TOKEN_SCOPES`.
/// Safe to call on every spawn and on every hive-c0re startup.
pub async fn ensure_user_for(name: &str) -> Result<()> {
    if !is_present().await {
        return Ok(());
    }
    ensure_user_exists(name, false, None).await?;
    ensure_user_email(name).await;
    mint_and_persist_agent_token(name).await
}

/// Provision a forgejo user for `name` and return the freshly-minted
/// token. Unlike [`ensure_user_for`], the token is **not** persisted to
/// disk — the caller is responsible for storing it. Used by `hivectl
/// forge create-user` for human (non-agent) accounts so we don't create
/// stray `/var/lib/hyperhive/agents/<name>/` directories for users that
/// aren't agents.
///
/// `password` picks the account password. `None` keeps the existing
/// random-throwaway shape (caller doesn't need web UI access — token
/// alone is enough). `Some(pw)` sets `pw` as the password, including
/// running `forgejo admin user change-password` if the account already
/// exists, so the operator can log into the forge web UI afterwards.
/// Idempotent: re-running with the same `Some(pw)` lands on the same
/// final state.
pub async fn provision_user_token(name: &str, password: Option<&str>) -> Result<String> {
    if !is_present().await {
        anyhow::bail!(
            "hive-forge container not running — wait for hive-c0re to start it before provisioning forge users"
        );
    }
    ensure_user_exists(name, false, password).await?;
    if let Some(pw) = password {
        // `user create` silently no-ops on an existing account, so
        // we run change-password unconditionally when the caller
        // asked for a specific password — keeps the verb idempotent
        // for "set or reset" use.
        change_user_password(name, pw).await?;
    }
    ensure_user_email(name).await;
    mint_token(name, TOKEN_SCOPES).await
}

/// Set `core`'s Forgejo avatar to the hyperhive logo once, then
/// remember it so subsequent startups don't re-upload. Best-effort
/// — any non-2xx is logged at the caller; the project runs fine
/// with the default hash identicon.
async fn ensure_core_avatar(token: &str) -> Result<()> {
    let marker = crate::paths::forge_core_avatar_marker();
    if marker.exists() {
        return Ok(());
    }
    let png_path = hive_sh4re::assets::core_avatar_png();
    let png_bytes = tokio::fs::read(&png_path)
        .await
        .with_context(|| format!("read core avatar PNG from {}", png_path.display()))?;
    let body = format!(
        r#"{{"image":"{}"}}"#,
        base64::engine::general_purpose::STANDARD.encode(&png_bytes),
    );
    let url = format!("{FORGE_HTTP}/api/v1/admin/users/core/avatar");
    let (status, _) = forge_http(reqwest::Method::POST, &url, token, &body).await?;
    if !status.is_success() {
        anyhow::bail!("set core avatar: HTTP {status}");
    }
    if let Some(parent) = marker.parent() {
        std::fs::create_dir_all(parent).ok();
    }
    std::fs::write(marker, "").ok();
    tracing::info!("forge: set core user avatar to hyperhive logo");
    Ok(())
}

/// Set the `agent-configs` org's Forgejo avatar to the
/// configs-stack glyph once. Sibling to `ensure_core_avatar`:
/// one-shot, marker-guarded, best-effort. Forgejo's per-org avatar
/// endpoint is `POST /api/v1/orgs/{org}/avatar` with a base64-PNG
/// JSON body — same shape as the admin user endpoint above.
async fn ensure_config_org_avatar(token: &str) -> Result<()> {
    let marker = crate::paths::forge_config_org_avatar_marker();
    if marker.exists() {
        return Ok(());
    }
    let png_path = hive_sh4re::assets::config_org_avatar_png();
    let png_bytes = tokio::fs::read(&png_path)
        .await
        .with_context(|| format!("read {CONFIG_ORG} avatar PNG from {}", png_path.display()))?;
    let body = format!(
        r#"{{"image":"{}"}}"#,
        base64::engine::general_purpose::STANDARD.encode(&png_bytes),
    );
    let url = format!("{FORGE_HTTP}/api/v1/orgs/{CONFIG_ORG}/avatar");
    let (status, _) = forge_http(reqwest::Method::POST, &url, token, &body).await?;
    if !status.is_success() {
        anyhow::bail!("set {CONFIG_ORG} avatar: HTTP {status}");
    }
    if let Some(parent) = marker.parent() {
        std::fs::create_dir_all(parent).ok();
    }
    std::fs::write(marker, "").ok();
    tracing::info!(
        org = CONFIG_ORG,
        "forge: set org avatar to configs-stack logo"
    );
    Ok(())
}

/// Outcome of probing whether the persisted core token still works
/// against the *current* forge. Existence on disk is not validity: a
/// token minted before a forge rebuild / re-provision is unknown to the
/// new forge's DB and 401s on every call — which silently breaks the
/// hive-ci runner-registration prefetch (it reads this same token to
/// fetch a runner registration token).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum CoreTokenCheck {
    /// Token authenticated successfully — keep using it.
    Valid,
    /// Forge explicitly rejected the token (401/403) — re-mint.
    Invalid,
    /// Couldn't determine (forge unreachable / 5xx). Don't re-mint on a
    /// transient: keep the existing token and let a later ensure pass
    /// re-check once the forge is responsive. Re-minting here would both
    /// fail (mint needs the forge too) and churn tokens needlessly.
    Indeterminate,
}

/// Map the HTTP status of the token-probe call to a [`CoreTokenCheck`].
/// Pure so the decision logic is unit-testable without a live forge.
fn classify_core_token_status(status: StatusCode) -> CoreTokenCheck {
    if status.is_success() {
        CoreTokenCheck::Valid
    } else if status == StatusCode::UNAUTHORIZED || status == StatusCode::FORBIDDEN {
        CoreTokenCheck::Invalid
    } else {
        CoreTokenCheck::Indeterminate
    }
}

/// Probe whether `token` is still accepted by the current forge with a
/// cheap authenticated `GET /api/v1/user` (covered by the core token's
/// `read:user` scope). See [`CoreTokenCheck`] for how the outcome is
/// interpreted.
async fn check_core_token(token: &str) -> CoreTokenCheck {
    let url = format!("{FORGE_HTTP}/api/v1/user");
    match forge_http(reqwest::Method::GET, &url, token, "").await {
        Ok((status, _)) => classify_core_token_status(status),
        Err(e) => {
            tracing::debug!(
                error = %e,
                "forge: core-token probe could not reach forge; treating as indeterminate"
            );
            CoreTokenCheck::Indeterminate
        }
    }
}

/// Ensure the bootstrap `core` admin user + a token at
/// `CORE_TOKEN_PATH`. The token is what hive-c0re uses for forgejo
/// API calls (org creation, meta-repo push, and the hive-ci
/// runner-registration prefetch). Returns the token.
///
/// Idempotent, but validity-aware: when a token file is already present
/// it is **probed against the current forge** before being trusted. A
/// token persisted before a forge rebuild / re-provision is stale (the
/// new forge DB doesn't know it) and would 401 every caller — so on a
/// definitive rejection the token is re-minted. A merely-unreachable
/// forge leaves the existing token in place (a later ensure pass
/// re-checks) rather than churning tokens on a transient.
async fn ensure_core_user_and_token() -> Result<String> {
    let path = std::path::Path::new(CORE_TOKEN_PATH);
    if let Ok(existing) = std::fs::read_to_string(path) {
        let trimmed = existing.trim().to_owned();
        if !trimmed.is_empty() {
            match check_core_token(&trimmed).await {
                CoreTokenCheck::Valid | CoreTokenCheck::Indeterminate => return Ok(trimmed),
                CoreTokenCheck::Invalid => {
                    tracing::warn!(
                        path = %path.display(),
                        "forge: persisted core token rejected by forge (stale after rebuild?); \
                         re-minting"
                    );
                }
            }
        }
    }
    ensure_user_exists("core", true, None).await?;
    mint_and_persist_core_token(path).await?;
    let raw = std::fs::read_to_string(path)
        .with_context(|| format!("read {CORE_TOKEN_PATH} after mint"))?;
    Ok(raw.trim().to_owned())
}

/// JSON body for a private, empty repo defaulting to `main`.
fn repo_body(name: &str) -> String {
    format!(r#"{{"name":"{name}","auto_init":false,"private":true,"default_branch":"main"}}"#)
}

/// JSON body for a public, empty repo defaulting to `main`.
fn repo_body_public(name: &str) -> String {
    format!(r#"{{"name":"{name}","auto_init":false,"private":false,"default_branch":"main"}}"#)
}

/// Set an existing repo to public visibility. No-op if the repo is
/// already public. Used for `internal/knowledge` which may have been
/// created as private on an older deployment.
async fn set_repo_public(owner: &str, repo: &str, token: &str) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/repos/{owner}/{repo}");
    let (status, _) =
        forge_http(reqwest::Method::PATCH, &url, token, r#"{"private":false}"#).await?;
    match status.as_u16() {
        200 => {
            tracing::debug!(%owner, %repo, "forge: repo set to public");
            Ok(())
        }
        other => anyhow::bail!("PATCH {owner}/{repo} (set public) returned HTTP {other}"),
    }
}

/// Create `name` inside org `org` as a public repo. Idempotent.
async fn ensure_org_repo_public(org: &str, name: &str, token: &str) -> Result<()> {
    create_repo(
        &format!("{FORGE_HTTP}/api/v1/orgs/{org}/repos"),
        &repo_body_public(name),
        token,
        &format!("{org}/{name}"),
    )
    .await
}

/// POST a repo-creation request to `url` and fold "already exists"
/// (HTTP 409 / 422) into success. `label` is `<owner>/<name>` — purely
/// for log + error context.
async fn create_repo(url: &str, body: &str, token: &str, label: &str) -> Result<()> {
    let (status, _) = forge_http(reqwest::Method::POST, url, token, body).await?;
    match status.as_u16() {
        201 => {
            tracing::info!(%label, "forge: created repo");
            Ok(())
        }
        409 | 422 => {
            tracing::debug!(%label, "forge: repo already exists");
            Ok(())
        }
        other => anyhow::bail!("POST {url} ({label}) returned HTTP {other}"),
    }
}

/// Create a repo in the token-owner's own namespace. `token` belongs
/// to the user we want the repo owned by (we use `core`'s token for
/// `core/meta`). Idempotent.
pub async fn ensure_repo(name: &str, token: &str) -> Result<()> {
    create_repo(
        &format!("{FORGE_HTTP}/api/v1/user/repos"),
        &repo_body(name),
        token,
        &format!("core/{name}"),
    )
    .await
}

/// Create `name` inside org `org` (used for `agent-configs/<agent>`).
/// Idempotent.
async fn ensure_org_repo(org: &str, name: &str, token: &str) -> Result<()> {
    create_repo(
        &format!("{FORGE_HTTP}/api/v1/orgs/{org}/repos"),
        &repo_body(name),
        token,
        &format!("{org}/{name}"),
    )
    .await
}

/// Read the persisted core token, or None when the forge isn't
/// seeded yet. Cheap — just a file read.
pub fn core_token() -> Option<String> {
    std::fs::read_to_string(CORE_TOKEN_PATH)
        .ok()
        .map(|s| s.trim().to_owned())
        .filter(|s| !s.is_empty())
}

/// Push `dir` (the meta repo) to `core/meta` on the local forge.
/// Best-effort: returns Err which callers log + ignore. No-op when
/// the core token isn't present yet (forge container not provisioned).
pub async fn push_meta(dir: &Path) -> Result<()> {
    let Some(token) = core_token() else {
        return Ok(());
    };
    // Token-in-URL push. Forgejo accepts `oauth2:<token>` or just
    // any-username:<token>; using `core` matches the owner so the
    // remote name is self-describing.
    let url = format!("http://core:{token}@localhost:3000/core/meta.git");
    let out = Command::new("git")
        .current_dir(dir)
        .args(["push", "--force", &url, "HEAD:main"])
        .output()
        .await
        .context("invoke git push core/meta")?;
    if !out.status.success() {
        anyhow::bail!(
            "git push core/meta failed ({}): {}",
            out.status,
            String::from_utf8_lossy(&out.stderr).trim()
        );
    }
    tracing::info!("forge: pushed meta to core/meta");
    Ok(())
}

/// Ensure the `agent-configs/<name>` repo exists so the first
/// `push_config` doesn't 404, and wire it as the agent-editable PR surface:
/// the agent is a **write** collaborator (can push feature branches +
/// open config PRs) and `main` is branch-protected core-only (only hive-c0re's
/// merge handler lands on it; operator approval required). No-op when the forge
/// isn't running or the core token isn't minted yet. Safe to call on every
/// spawn and on every startup (all steps idempotent).
pub async fn ensure_config_repo(name: &str) -> Result<()> {
    if !is_present().await {
        return Ok(());
    }
    let Some(token) = core_token() else {
        return Ok(());
    };
    ensure_org_repo(CONFIG_ORG, name, &token).await?;
    // Agent = write collaborator: it can push config-PR branches + open PRs,
    // but the branch protection below keeps it off `main` directly.
    add_collaborator(CONFIG_ORG, name, name, "write", &token).await?;
    // Protect `main` core-only, fast-forward-only (no auto force-push).
    apply_config_repo_branch_protection(name, &token).await
}

/// Ensure the `internal/docs` repo exists. Called once at startup
/// after `ensure_org(SHARED_ORG)`. Idempotent — `ensure_org_repo`
/// treats 409 as success.
pub async fn ensure_shared_docs_repo(core_token: &str) -> Result<()> {
    ensure_org_repo(SHARED_ORG, SHARED_DOCS_REPO, core_token).await
}

/// Grant agent `name` read-only collaborator access to `internal/docs`.
/// Idempotent: HTTP 204 (already a collaborator) is treated as success.
/// Mirrors `meta_read_access` so agents can clone the shared docs repo
/// without authentication hassle.
pub async fn shared_docs_access(name: &str, core_token: &str) -> Result<()> {
    let url =
        format!("{FORGE_HTTP}/api/v1/repos/{SHARED_ORG}/{SHARED_DOCS_REPO}/collaborators/{name}");
    let body = r#"{"permission":"read"}"#;
    let out = Command::new("curl")
        .args([
            "-sS",
            "-o",
            "/dev/null",
            "-w",
            "%{http_code}",
            "-X",
            "PUT",
            "-H",
            "Content-Type: application/json",
            "-H",
            &format!("Authorization: token {core_token}"),
            "-d",
            body,
            &url,
        ])
        .output()
        .await
        .context("invoke curl PUT internal/docs/collaborators")?;
    let code = String::from_utf8_lossy(&out.stdout).trim().to_owned();
    match code.as_str() {
        "204" => {
            tracing::info!(%name, "forge: granted shared-docs read access");
            Ok(())
        }
        other => anyhow::bail!(
            "PUT {SHARED_ORG}/{SHARED_DOCS_REPO}/collaborators/{name} returned HTTP {other}"
        ),
    }
}

/// Ensure the `internal/knowledge` repo exists and is public.
/// Called once at startup after `ensure_org(SHARED_ORG)`. Idempotent.
///
/// The repo is created as public so any agent with a forge account can
/// fork it and open PRs to contribute. Existing deployments that ended
/// up with a private repo are patched to public on the next hive-c0re
/// startup via `set_repo_public`.
pub async fn ensure_knowledge_repo(core_token: &str) -> Result<()> {
    ensure_org_repo_public(SHARED_ORG, KNOWLEDGE_REPO, core_token).await?;
    // Ensure public even if the repo already existed as private (older deployment).
    set_repo_public(SHARED_ORG, KNOWLEDGE_REPO, core_token).await
}

/// Grant agent `name` read-only collaborator access to `core/meta` on
/// the forge so the agent can clone/fetch the meta flake. Idempotent:
/// HTTP 204 (already a collaborator) is treated as success.
pub async fn meta_read_access(name: &str, core_token: &str) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/repos/core/meta/collaborators/{name}");
    let body = r#"{"permission":"read"}"#;
    let out = Command::new("curl")
        .args([
            "-sS",
            "-o",
            "/dev/null",
            "-w",
            "%{http_code}",
            "-X",
            "PUT",
            "-H",
            "Content-Type: application/json",
            "-H",
            &format!("Authorization: token {core_token}"),
            "-d",
            body,
            &url,
        ])
        .output()
        .await
        .context("invoke curl PUT core/meta/collaborators")?;
    let code = String::from_utf8_lossy(&out.stdout).trim().to_owned();
    match code.as_str() {
        "204" => {
            tracing::info!(%name, "forge: granted meta read access");
            Ok(())
        }
        other => anyhow::bail!("PUT core/meta/collaborators/{name} returned HTTP {other}"),
    }
}

/// Add `http://localhost:3000/core/meta.git` as the `meta` remote in
/// the agent's proposed config repo so the agent (and the manager) can
/// fetch the meta flake from the forge. Idempotent: no-op when the
/// remote already points at the right URL, or when the proposed repo
/// does not exist yet. No-op when the forge is not running.
pub async fn ensure_meta_remote(name: &str) -> Result<()> {
    if !is_present().await {
        return Ok(());
    }
    let proposed_dir = Coordinator::agent_proposed_dir(name);
    if !proposed_dir.join(".git").exists() {
        return Ok(());
    }
    let want = format!("{FORGE_HTTP}/core/meta.git");
    let existing = crate::lifecycle::git_command()
        .current_dir(&proposed_dir)
        .args(["remote", "get-url", "meta"])
        .output()
        .await
        .context("git remote get-url meta")?;
    if existing.status.success() {
        let current = String::from_utf8_lossy(&existing.stdout).trim().to_owned();
        if current == want {
            return Ok(());
        }
        crate::lifecycle::git(&proposed_dir, &["remote", "set-url", "meta", &want]).await
    } else {
        crate::lifecycle::git(&proposed_dir, &["remote", "add", "meta", &want]).await
    }
}

/// Mirror agent `name`'s applied config repo — `main` plus every tag
/// (`proposal` / `approved` / `building` / `deployed` / `failed` /
/// `denied`) — to `agent-configs/<name>` on the local forge.
/// Best-effort: returns Err which callers log + ignore. No-op when the
/// forge isn't seeded or the applied repo doesn't exist yet.
///
/// Call this after every hive-c0re mutation of an applied repo's refs
/// so the forge copy always reflects what core actually did.
///
/// Never force-pushes. The status tags are id-suffixed
/// (`proposal/<id>`, `deployed/<id>`, …) and therefore add-only, and
/// `main` is published history — after a failed deploy rolls the LOCAL
/// applied `main` back to last-good, the forge `main` may legitimately
/// be ahead (e.g. an operator-merged config PR whose rebuild failed).
/// Rewinding it would erase that merged commit from the forge, which
/// is exactly the incident this guards against: the local repo tracks
/// "what last built", the forge tracks "what was approved", and the
/// `failed/<id>` tag records the divergence. A non-fast-forward
/// rejection of `main` is therefore expected + logged at info; the
/// tags in the same push still land (git pushes refspecs
/// independently). Any other failure is a real error.
///
/// The tokenised URL is passed straight to `git push` and deliberately
/// never stored as a named remote: the applied repo is bind-mounted
/// READ-ONLY into the manager container (`/applied`), so a token in
/// `.git/config` would leak core's admin credential to an agent.
pub async fn push_config(name: &str) -> Result<()> {
    let Some(token) = core_token() else {
        return Ok(());
    };
    let dir = Coordinator::agent_applied_dir(name);
    if !dir.join(".git").exists() {
        return Ok(());
    }
    let url = format!("http://core:{token}@localhost:3000/{CONFIG_ORG}/{name}.git");
    let out = crate::lifecycle::git_command()
        .current_dir(&dir)
        .args([
            "push",
            &url,
            "refs/heads/main:refs/heads/main",
            "refs/tags/*:refs/tags/*",
        ])
        .output()
        .await
        .context("invoke git push agent-configs")?;
    if !out.status.success() {
        let stderr = String::from_utf8_lossy(&out.stderr);
        if stderr.contains("non-fast-forward") {
            tracing::info!(
                %name,
                "forge: mirror push of main rejected (non-fast-forward) — forge main is \
                 ahead of local applied main (rolled-back deploy); leaving forge history intact"
            );
            return Ok(());
        }
        anyhow::bail!(
            "git push {CONFIG_ORG}/{name} failed ({}): {}",
            out.status,
            stderr.trim()
        );
    }
    tracing::info!(%name, "forge: mirrored applied config to agent-configs");
    Ok(())
}

/// POST `/api/v1/orgs` to create an org named `name`. Idempotent:
/// HTTP 422 ("user already exists") is treated as success.
async fn ensure_org(name: &str, admin_token: &str) -> Result<()> {
    let body = format!(r#"{{"username":"{name}"}}"#);
    let url = format!("{FORGE_HTTP}/api/v1/orgs");
    let (status, _) = forge_http(reqwest::Method::POST, &url, admin_token, &body).await?;
    match status.as_u16() {
        201 => {
            tracing::info!(%name, "forge: created org");
            Ok(())
        }
        422 | 409 => {
            tracing::debug!(%name, "forge: org already exists");
            Ok(())
        }
        other => anyhow::bail!("POST /api/v1/orgs name={name} returned HTTP {other}"),
    }
}

/// One operator-declared pull-mirror, forwarded from the nix
/// `services.hyperhive.forge.mirrors` option as JSON in
/// `HYPERHIVE_FORGE_MIRRORS`.
#[derive(serde::Deserialize)]
struct Mirror {
    /// Upstream clone URL to mirror from (e.g. `https://github.com/actions/checkout`).
    upstream: String,
    /// Local `<owner>/<repo>` the mirror is created at.
    dest: String,
}

/// Ensure each `HYPERHIVE_FORGE_MIRRORS` entry exists as a real Forgejo
/// pull-mirror. The env carries the JSON-encoded nix `forge.mirrors` list
/// (plus the CI-auto `actions/checkout` entry). Absent/empty env = no-op.
/// Per-mirror failures warn and continue — never abort the startup sweep.
async fn ensure_mirrors(admin_token: &str) {
    let raw = match std::env::var("HYPERHIVE_FORGE_MIRRORS") {
        Ok(s) if !s.trim().is_empty() => s,
        _ => return,
    };
    let mirrors: Vec<Mirror> = match serde_json::from_str(&raw) {
        Ok(m) => m,
        Err(e) => {
            tracing::warn!(error = ?e, "forge: HYPERHIVE_FORGE_MIRRORS is not valid JSON; skipping mirror seed");
            return;
        }
    };
    for m in mirrors {
        let Some((owner, repo)) = m.dest.split_once('/') else {
            tracing::warn!(dest = %m.dest, "forge: mirror dest is not <owner>/<repo>; skipping");
            continue;
        };
        // Create the dest org first (idempotent); the mirror can't land
        // without its owner existing.
        if let Err(e) = ensure_org(owner, admin_token).await {
            tracing::warn!(%owner, error = ?e, "forge: ensure_org for mirror failed");
            continue;
        }
        if let Err(e) = ensure_mirror_repo(&m.upstream, owner, repo, admin_token).await {
            tracing::warn!(dest = %m.dest, error = ?e, "forge: ensure_mirror_repo failed");
        }
    }
}

/// Periodic sync interval for pull-mirrors. Forgejo syncs mirrors
/// on-access by default, which re-introduces external DNS latency on
/// every `git clone` (the hive-ci runner shares the host netns and is
/// therefore affected by host resolver blips). A fixed periodic interval
/// isolates CI from transient DNS failures — a stale mirror is
/// acceptable; a broken clone because of a momentary DNS blip is not.
const MIRROR_INTERVAL: &str = "8h0m0s";

/// Create `owner/repo` as a pull-mirror of `upstream` via the migrate API.
/// Idempotent: if the repo already exists this function patches its
/// `mirror_interval` to ensure it matches (covers mirrors that were
/// created before the interval was introduced). A 409 on the migrate
/// POST (a race between the GET check and the POST) is also success.
async fn ensure_mirror_repo(
    upstream: &str,
    owner: &str,
    repo: &str,
    admin_token: &str,
) -> Result<()> {
    let repo_url = format!("{FORGE_HTTP}/api/v1/repos/{owner}/{repo}");
    let (status, _) = forge_http(reqwest::Method::GET, &repo_url, admin_token, "").await?;
    if status.is_success() {
        // Mirror already present. Patch interval so mirrors seeded before
        // this field was introduced (or with a different value) converge.
        let patch_body = serde_json::json!({ "mirror_interval": MIRROR_INTERVAL }).to_string();
        let (patch_status, patch_text) =
            forge_http(reqwest::Method::PATCH, &repo_url, admin_token, &patch_body).await?;
        if patch_status.is_success() {
            tracing::debug!(%owner, %repo, interval = MIRROR_INTERVAL, "forge: pull-mirror interval updated");
        } else {
            tracing::warn!(
                %owner, %repo, status = %patch_status, body = %patch_text,
                "forge: failed to set mirror_interval on existing pull-mirror"
            );
        }
        return Ok(());
    }
    // serde_json::json! → the upstream URL is escaped safely (no string
    // interpolation into the JSON body).
    let body = serde_json::json!({
        "clone_addr": upstream,
        "repo_owner": owner,
        "repo_name": repo,
        "mirror": true,
        // Periodic refresh instead of on-access sync — keeps CI isolated
        // from external DNS failures at clone time.
        "interval": MIRROR_INTERVAL,
        "service": "git",
        "private": false,
    })
    .to_string();
    let url = format!("{FORGE_HTTP}/api/v1/repos/migrate");
    let (status, text) = forge_http(reqwest::Method::POST, &url, admin_token, &body).await?;
    match status.as_u16() {
        201 => {
            tracing::info!(%owner, %repo, %upstream, interval = MIRROR_INTERVAL, "forge: created pull-mirror");
            Ok(())
        }
        // 409 = a race created it between our GET check and here (the GET
        // is the real idempotency guard). NOT 422: for the migrate endpoint
        // 422 is a validation error (bad clone_addr / service), so it must
        // surface via the bail arm, not be swallowed as "already exists".
        409 => {
            tracing::debug!(%owner, %repo, "forge: pull-mirror already exists (race)");
            Ok(())
        }
        other => {
            anyhow::bail!("POST /api/v1/repos/migrate {owner}/{repo} returned HTTP {other}: {text}")
        }
    }
}

/// Whether `ns` is a hive-managed Forgejo namespace that agent-initiated
/// repo creation must never target — `internal` (operator-curated
/// shared content) + `agent-configs` / `core` (hive-c0re-internal). The
/// create path forces [`AGENTS_ORG`], so this guards a future surface that
/// might accept an explicit owner.
#[must_use]
pub fn is_hive_managed_namespace(ns: &str) -> bool {
    HIVE_MANAGED_NAMESPACES.contains(&ns)
}

/// Provision the [`OPERATORS_TEAM`] inside [`AGENTS_ORG`] as an **empty**
/// team. Branch protection on agents-org repos references it as the
/// merge/approval whitelist; the operator adds herself as a member via the
/// forge UI / hivectl. `includes_all_repositories` so the gate applies to
/// every agent repo; `write` is enough to approve + merge. hive-c0re never
/// manages membership. Idempotent (422/409 = already exists).
async fn ensure_operators_team(token: &str) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/orgs/{AGENTS_ORG}/teams");
    let body = format!(
        r#"{{"name":"{OPERATORS_TEAM}","description":"hyperhive operators — merge gate for agent repos","permission":"write","includes_all_repositories":true,"can_create_org_repo":false}}"#
    );
    let (status, _) = forge_http(reqwest::Method::POST, &url, token, &body).await?;
    match status.as_u16() {
        201 => {
            tracing::info!("forge: created {OPERATORS_TEAM} team in {AGENTS_ORG}");
            Ok(())
        }
        409 | 422 => {
            tracing::debug!("forge: {OPERATORS_TEAM} team already exists");
            Ok(())
        }
        other => {
            anyhow::bail!("POST /orgs/{AGENTS_ORG}/teams ({OPERATORS_TEAM}) returned HTTP {other}")
        }
    }
}

/// Add `user` as a collaborator on `owner/repo` at `permission`
/// (`read` / `write` / `admin`). Idempotent: 201 (added) and 204 (already a
/// collaborator / permission updated) both count as success.
async fn add_collaborator(
    owner: &str,
    repo: &str,
    user: &str,
    permission: &str,
    token: &str,
) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/repos/{owner}/{repo}/collaborators/{user}");
    let body = format!(r#"{{"permission":"{permission}"}}"#);
    let (status, _) = forge_http(reqwest::Method::PUT, &url, token, &body).await?;
    match status.as_u16() {
        201 | 204 => {
            tracing::debug!(%owner, %repo, %user, %permission, "forge: collaborator set");
            Ok(())
        }
        other => {
            anyhow::bail!("PUT {owner}/{repo}/collaborators/{user} returned HTTP {other}")
        }
    }
}

/// Apply the operator merge-gate branch protection to `repo`'s default
/// branch: only [`OPERATORS_TEAM`] members can merge, and an
/// approving review from that team is required — so the author (a write-level
/// agent, not in the team) cannot merge its own PR. Idempotent: an existing
/// rule for the branch (200/409/422) is treated as success.
async fn apply_operator_branch_protection(repo: &str, token: &str) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/repos/{AGENTS_ORG}/{repo}/branch_protections");
    let body = format!(
        r#"{{"branch_name":"main","enable_merge_whitelist":true,"merge_whitelist_teams":["{OPERATORS_TEAM}"],"enable_approvals_whitelist":true,"approvals_whitelist_teams":["{OPERATORS_TEAM}"],"required_approvals":1,"block_on_official_review_requests":true}}"#
    );
    let (status, _) = forge_http(reqwest::Method::POST, &url, token, &body).await?;
    match status.as_u16() {
        201 => {
            tracing::info!(%repo, "forge: applied operator branch protection");
            Ok(())
        }
        200 | 409 | 422 => {
            tracing::debug!(%repo, "forge: branch protection already present");
            Ok(())
        }
        other => anyhow::bail!("POST {AGENTS_ORG}/{repo}/branch_protections returned HTTP {other}"),
    }
}

/// Apply branch protection to an `agent-configs/<name>` repo's `main` so it
/// can serve as the agent-editable, PR-merge config surface:
/// - **push + merge whitelists are `core`-only** — the agent (a write
///   collaborator) can push feature branches and open config PRs, but only
///   hive-c0re lands on `main`, via its verify-and-ff-push merge handler
///   (`run_merge_config_pr`). The agent can never push `main` directly.
/// - **operator-team approval is required** to merge, and the author (not in
///   the team) cannot self-approve.
/// - **`enable_force_push` is `false`** — `main` only ever advances by
///   fast-forward. The merge handler's `ff_push_to_main` is already a
///   non-force push, so it lands fine. The legacy `push_config` mirror DOES
///   force-push (it re-points status tags and rewinds `main` on a failed-build
///   rollback), so the protection now rejects those non-ff updates — that
///   mirror runs best-effort until the agent-opened PR-merge flow retires it.
///   (Auto force-push is intentionally not allowed: per operator directive a
///   silent force-push is a bug, not a feature.)
///
/// Idempotent: an existing rule for the branch (200/409/422) is success.
async fn apply_config_repo_branch_protection(repo: &str, token: &str) -> Result<()> {
    let url = format!("{FORGE_HTTP}/api/v1/repos/{CONFIG_ORG}/{repo}/branch_protections");
    let body = format!(
        r#"{{"branch_name":"main","enable_push_whitelist":true,"push_whitelist_usernames":["core"],"enable_merge_whitelist":true,"merge_whitelist_usernames":["core"],"enable_approvals_whitelist":true,"approvals_whitelist_teams":["{OPERATORS_TEAM}"],"required_approvals":1,"block_on_official_review_requests":true,"allow_manual_merge":true,"enable_force_push":false}}"#
    );
    let (status, resp_body) = forge_http(reqwest::Method::POST, &url, token, &body).await?;
    if status.as_u16() == 201 {
        tracing::info!(%repo, "forge: applied config-repo branch protection");
        return Ok(());
    }
    // Non-201 is ambiguous: it can mean "rule already exists" (idempotent
    // success) OR a silent rejection — e.g. a 422 where Forgejo refused
    // the request and created NO rule. The old code treated 200/409/422
    // all as success, so a rejected POST left the repo unprotected with
    // no error (the reported case: a new agent's config repo had no
    // `main` rule and nothing was logged). Don't trust the status code:
    // verify the `main` rule actually exists, and on failure surface the
    // POST's response body so the real reason is in the journal.
    let main_url = format!("{url}/main");
    let (check, _) = forge_http(reqwest::Method::GET, &main_url, token, "").await?;
    if check.as_u16() == 200 {
        tracing::debug!(%repo, %status, "forge: config-repo branch protection already present");
        Ok(())
    } else {
        anyhow::bail!(
            "branch protection for {CONFIG_ORG}/{repo} not applied: POST -> HTTP {status} \
             (body: {body}); GET main -> HTTP {check}, no `main` rule present",
            body = resp_body.trim(),
        )
    }
}

/// Create a repo for `agent` in the c0re-owned [`AGENTS_ORG`] and wire the
/// perms: the org owns it (perms stay c0re-managed), the agent is added
/// as a **write** collaborator (not owner — can push + open PRs but can't
/// bypass branch protection), and the default branch gets the operator
/// merge gate. This is the sanctioned create path now that agents can't
/// create repos directly (`max_repo_creation = 0`). Idempotent.
pub async fn create_agent_repo(agent: &str, repo: &str, core_token: &str) -> Result<String> {
    ensure_org_repo(AGENTS_ORG, repo, core_token).await?;
    add_collaborator(AGENTS_ORG, repo, agent, "write", core_token).await?;
    apply_operator_branch_protection(repo, core_token).await?;
    tracing::info!(%agent, %repo, "forge: created agent repo in {AGENTS_ORG} with operator merge gate");
    Ok(format!("{AGENTS_ORG}/{repo}"))
}

/// Per-agent forge sync: ensure the agent has a forgejo user + token,
/// a mirrored config repo, read access to `core/meta`, and the `meta`
/// remote in its proposed repo. All operations are idempotent; failures
/// are logged as warnings but don't abort the caller.
///
/// `core_token` is `core_token()` — passed in so callers that already
/// fetched it don't re-read the file. Pass `None` to skip the
/// `meta_read_access` step (safe: the access grant is best-effort).
///
/// Called by both `ensure_all()` (startup sweep) and `rebuild_agent`
/// (per-rebuild) so the two paths stay equivalent.
pub async fn sync_agent(name: &str, core_token: Option<&str>) {
    if let Err(e) = ensure_user_for(name).await {
        tracing::warn!(%name, error = ?e, "forge: ensure_user failed");
    }
    // Align email to match the git user.email set by meta::render_flake
    // so commits link to the agent's Forgejo profile. Best-effort;
    // also patches up agents created before this fix (old @hive.local).
    ensure_user_email(name).await;
    // Block direct agent-initiated repo creation: agents create
    // repos through hive-c0re, never with their own token. Idempotent +
    // marker-guarded; also covers agents provisioned before this landed.
    ensure_repo_creation_disabled(name).await;
    // Mirror the agent's applied config repo into agent-configs.
    // ensure_config_repo is idempotent; push_config catches any
    // drift since the last run — e.g. the startup migration just
    // relocated `deployed/0`, or a deploy landed while the forge
    // was down.
    if let Err(e) = ensure_config_repo(name).await {
        tracing::warn!(%name, error = ?e, "forge: ensure_config_repo failed");
    }
    if let Err(e) = push_config(name).await {
        tracing::warn!(%name, error = ?e, "forge: push_config failed");
    }
    // Grant read-only access to core/meta and wire the `meta` remote
    // into the proposed repo so agents can fetch their deployment context.
    if let Some(token) = core_token
        && let Err(e) = meta_read_access(name, token).await
    {
        tracing::warn!(%name, error = ?e, "forge: ensure_meta_read_access failed");
    }
    if let Err(e) = ensure_meta_remote(name).await {
        tracing::warn!(%name, error = ?e, "forge: ensure_meta_remote failed");
    }
    // Grant read-only access to internal/docs so the agent can clone
    // the operator-curated shared skills/runbook repo. Best-effort.
    if let Some(token) = core_token
        && let Err(e) = shared_docs_access(name, token).await
    {
        tracing::warn!(%name, error = ?e, "forge: shared_docs_access failed");
    }
    // internal/knowledge is public — no per-agent collaborator grant needed.
}

/// Sweep every existing container (manager + sub-agents) and ensure
/// each has a forgejo user + token, plus an `agent-configs/<name>`
/// repo mirroring its applied config. Also seeds the `core` admin
/// user (hive-c0re's own identity for pushing the meta repo + driving
/// the API), the `agent-configs` org, and the `core/meta` repo.
/// Called once at hive-c0re startup. Per-step failures are logged
/// but don't abort the sweep.
pub async fn ensure_all() {
    if !is_present().await {
        tracing::debug!("forge: hive-forge container absent, skipping user sweep");
        return;
    }
    let core_token = match ensure_core_user_and_token().await {
        Ok(t) => Some(t),
        Err(e) => {
            tracing::warn!(error = ?e, "forge: ensure_core_user_and_token failed");
            None
        }
    };
    if let Some(token) = core_token.as_deref() {
        for org in SEEDED_ORGS {
            if let Err(e) = ensure_org(org, token).await {
                tracing::warn!(%org, error = ?e, "forge: ensure_org failed");
            }
        }
        // Seed the operator-declared pull-mirrors (nix `forge.mirrors` +
        // the CI-auto `actions/checkout`, forwarded via the
        // `HYPERHIVE_FORGE_MIRRORS` env). Each ensures its own dest org, so
        // this is independent of the SEEDED_ORGS loop above.
        ensure_mirrors(token).await;
        // Provision the operator merge-gate team (empty) inside the agents
        // org so branch protection can reference it before anyone joins
        //. The operator adds herself as a member out-of-band.
        if let Err(e) = ensure_operators_team(token).await {
            tracing::warn!(error = ?e, "forge: ensure_operators_team failed");
        }
        // Meta repo lives at core/meta — pushed from git_commit in
        // meta.rs on every deploy/lock-update. Make sure it exists
        // before the first push hits a 404.
        if let Err(e) = ensure_repo("meta", token).await {
            tracing::warn!(error = ?e, "forge: ensure_repo core/meta failed");
        }
        // Seed the shared docs repo. internal is already in
        // SEEDED_ORGS above so the org exists; ensure the repo itself.
        if let Err(e) = ensure_shared_docs_repo(token).await {
            tracing::warn!(error = ?e, "forge: ensure_shared_docs_repo failed");
        }
        // Seed the hive-wide knowledge repo.
        if let Err(e) = ensure_knowledge_repo(token).await {
            tracing::warn!(error = ?e, "forge: ensure_knowledge_repo failed");
        }
        // Clone knowledge repo locally so it can be bind-mounted into agents.
        if let Err(e) = crate::knowledge::ensure_local_clone(token).await {
            tracing::warn!(error = ?e, "knowledge: ensure_local_clone failed");
        }
        if let Err(e) = ensure_core_avatar(token).await {
            tracing::warn!(error = ?e, "forge: ensure_core_avatar failed");
        }
        if let Err(e) = ensure_config_org_avatar(token).await {
            tracing::warn!(error = ?e, "forge: ensure_config_org_avatar failed");
        }
    }
    let Ok(containers) = crate::lifecycle::list().await else {
        tracing::warn!("forge: nixos-container list failed; skipping user sweep");
        return;
    };
    for c in containers {
        let Some(name) = c.strip_prefix(crate::lifecycle::AGENT_PREFIX) else {
            continue;
        };
        sync_agent(name, core_token.as_deref()).await;
    }
}

// ---------------------------------------------------------------------------
// PR-based config-flow merge primitives (part of the
// dashboard-approve-driven config-change flow).
//
// The dashboard-approve-driven flow has hive-c0re verify an operator-approved
// config PR, then land it: ff-push the verified sha to the protected default
// branch (= the merge) and mark the PR merged manually. These three fns are
// the forge-side mechanics the c0re approve-handler (`run_merge_config_pr`)
// orchestrates; the orchestration fetches the verified sha into the agent's
// applied repo before calling `ff_push_to_main`. The core token is sourced
// internally (`core_token`), never passed in. `repo` is the agent's editable
// forge config repo in `owner/name` form (e.g. `agent-configs/<agent>`).
// ---------------------------------------------------------------------------

/// Typed failure for the merge primitives so the c0re approve-handler can
/// `match` recoverable drift (refresh the request sha + re-verify) against a
/// hard failure (fail the approval). The two drift variants carry the observed
/// sha so the handler can re-pin to it; `Other` is everything else (transport,
/// API, unexpected) and is not auto-retried.
#[derive(Debug)]
pub enum ForgeMergeError {
    /// The PR head moved off `expected` (now at `actual`), seen at
    /// mark-merged time. The handler's pre-merge `pr_head_sha` re-read is the
    /// primary drift gate; this is the belt-and-suspenders race catch.
    HeadDrift { expected: String, actual: String },
    /// `main` (`actual_head`) is not a descendant of `expected_ancestor`, so
    /// pushing the verified sha would not be a fast-forward — `main` raced.
    NotFastForward {
        expected_ancestor: String,
        actual_head: String,
    },
    /// Transport / API / unexpected failure — hard-fail, no auto-retry.
    Other(anyhow::Error),
}

impl std::fmt::Display for ForgeMergeError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::HeadDrift { expected, actual } => {
                write!(f, "PR head drifted: expected {expected}, found {actual}")
            }
            Self::NotFastForward {
                expected_ancestor,
                actual_head,
            } => write!(
                f,
                "not a fast-forward: main {actual_head} is not a descendant of {expected_ancestor}"
            ),
            Self::Other(e) => write!(f, "{e}"),
        }
    }
}

impl std::error::Error for ForgeMergeError {}

impl From<anyhow::Error> for ForgeMergeError {
    fn from(e: anyhow::Error) -> Self {
        Self::Other(e)
    }
}

/// Agent name from an `owner/name` forge repo string (the trailing segment).
fn repo_agent_name(repo: &str) -> &str {
    repo.rsplit('/').next().unwrap_or(repo)
}

/// Token-in-URL clone/push URL for a forge repo (`owner/name`). Mirrors
/// `push_config`'s pattern; the token is passed straight to git and never
/// stored as a named remote.
fn tokenised_repo_url(repo: &str, token: &str) -> String {
    format!("http://core:{token}@localhost:3000/{repo}.git")
}

/// Resolve a PR's head sha via `git ls-remote <repo> refs/pull/<pr>/head`
/// (Forgejo exposes PR heads there). Pure read, no mutation — the handler's
/// primary drift gate (compare against the approved sha), and `mark_pr_merged`
/// uses it to detect head-drift on failure.
///
/// # Errors
/// `Other` on transport failure or an empty/missing ref.
pub async fn pr_head_sha(repo: &str, pr: u64) -> Result<String, ForgeMergeError> {
    let token = core_token()
        .ok_or_else(|| ForgeMergeError::Other(anyhow::anyhow!("forge core token absent")))?;
    let url = tokenised_repo_url(repo, &token);
    let refspec = format!("refs/pull/{pr}/head");
    let out = crate::lifecycle::git_command()
        .args(["ls-remote", &url, &refspec])
        .output()
        .await
        .context("git ls-remote PR head")?;
    if !out.status.success() {
        return Err(ForgeMergeError::Other(anyhow::anyhow!(
            "git ls-remote {repo} {refspec} failed ({}): {}",
            out.status,
            String::from_utf8_lossy(&out.stderr).trim()
        )));
    }
    let stdout = String::from_utf8_lossy(&out.stdout);
    let sha = stdout
        .split_whitespace()
        .next()
        .filter(|s| !s.is_empty())
        .ok_or_else(|| {
            ForgeMergeError::Other(anyhow::anyhow!(
                "no head ref for PR #{pr} in {repo} (ls-remote empty)"
            ))
        })?;
    Ok(sha.to_string())
}

/// Full `owner/name` path of an agent's config repo on the forge — the
/// `agent-configs` org mirror that the PR-merge flow reads + fast-forwards.
pub fn config_repo(agent: &str) -> String {
    format!("{CONFIG_ORG}/{agent}")
}

/// Fetch PR #`pr`'s head into the agent's applied repo via
/// `refs/pull/<pr>/head` (which Forgejo always serves — a bare-sha fetch can
/// be refused by uploadpack policy). This makes the reviewed head an object
/// in the applied repo so the ancestor check in [`ff_push_to_main`], the
/// `git_update_ref(main, …)` in the deploy tail, and the eval-verify all
/// resolve it locally before the irreversible push.
///
/// # Errors
/// `Other` on transport failure or a non-zero git exit.
pub async fn fetch_pr_head_into_applied(repo: &str, pr: u64) -> Result<(), ForgeMergeError> {
    let token = core_token()
        .ok_or_else(|| ForgeMergeError::Other(anyhow::anyhow!("forge core token absent")))?;
    let url = tokenised_repo_url(repo, &token);
    let applied = Coordinator::agent_applied_dir(repo_agent_name(repo));
    let refspec = format!("refs/pull/{pr}/head");
    let out = crate::lifecycle::git_command()
        .current_dir(&applied)
        .args(["fetch", "--no-tags", &url, &refspec])
        .output()
        .await
        .context("git fetch PR head into applied")?;
    if !out.status.success() {
        return Err(ForgeMergeError::Other(anyhow::anyhow!(
            "git fetch {repo} {refspec} into applied failed ({}): {}",
            out.status,
            String::from_utf8_lossy(&out.stderr).trim()
        )));
    }
    Ok(())
}

/// Fast-forward the forge repo's `main` to `sha` — THE merge in the PR flow.
/// Reads `main`'s current sha (`git ls-remote … refs/heads/main`), verifies it
/// is a strict ancestor of `sha` (`git merge-base --is-ancestor`, run in the
/// agent's applied repo where the orchestration has already fetched `sha`),
/// then does a **non-force** `git push <sha>:refs/heads/main`. The ancestor
/// pre-check and the non-force push are two independent guards: either catches
/// a raced `main` (→ `NotFastForward`) rather than clobbering reviewed history.
///
/// # Errors
/// `NotFastForward` if `main` raced ahead of `sha`; `Other` on transport/other.
pub async fn ff_push_to_main(repo: &str, sha: &str) -> Result<(), ForgeMergeError> {
    let token = core_token()
        .ok_or_else(|| ForgeMergeError::Other(anyhow::anyhow!("forge core token absent")))?;
    let url = tokenised_repo_url(repo, &token);
    let applied = Coordinator::agent_applied_dir(repo_agent_name(repo));

    // Current `main` on the forge repo.
    let ls = crate::lifecycle::git_command()
        .args(["ls-remote", &url, "refs/heads/main"])
        .output()
        .await
        .context("git ls-remote main")?;
    if !ls.status.success() {
        return Err(ForgeMergeError::Other(anyhow::anyhow!(
            "git ls-remote {repo} refs/heads/main failed ({}): {}",
            ls.status,
            String::from_utf8_lossy(&ls.stderr).trim()
        )));
    }
    let ls_out = String::from_utf8_lossy(&ls.stdout);
    let main_sha = ls_out.split_whitespace().next().unwrap_or("").to_string();

    // Strict-ancestor check: `main` must be an ancestor of `sha` for a true
    // fast-forward. Skip when `main` is unborn (empty) — the push creates it.
    if !main_sha.is_empty() {
        let anc = crate::lifecycle::git_command()
            .current_dir(&applied)
            .args(["merge-base", "--is-ancestor", &main_sha, sha])
            .output()
            .await
            .context("git merge-base --is-ancestor")?;
        match anc.status.code() {
            Some(0) => {} // ancestor → fast-forward safe
            Some(1) => {
                return Err(ForgeMergeError::NotFastForward {
                    expected_ancestor: main_sha,
                    actual_head: sha.to_string(),
                });
            }
            _ => {
                return Err(ForgeMergeError::Other(anyhow::anyhow!(
                    "git merge-base --is-ancestor errored ({}): {}",
                    anc.status,
                    String::from_utf8_lossy(&anc.stderr).trim()
                )));
            }
        }
    }

    // Non-force push `sha` → `main`. Without `--force`, git rejects a
    // non-fast-forward (a race between the check above and now), surfaced as
    // `NotFastForward` rather than clobbering the remote.
    let push = crate::lifecycle::git_command()
        .current_dir(&applied)
        .args(["push", &url, &format!("{sha}:refs/heads/main")])
        .output()
        .await
        .context("git push sha:main")?;
    if !push.status.success() {
        let stderr = String::from_utf8_lossy(&push.stderr);
        if stderr.contains("non-fast-forward") || stderr.contains("fetch first") {
            return Err(ForgeMergeError::NotFastForward {
                expected_ancestor: main_sha,
                actual_head: sha.to_string(),
            });
        }
        return Err(ForgeMergeError::Other(anyhow::anyhow!(
            "git push {repo} {sha}:main failed ({}): {}",
            push.status,
            stderr.trim()
        )));
    }
    Ok(())
}

/// Mark PR `pr` as **manually merged** at `sha` (Forgejo
/// `POST …/pulls/{pr}/merge` with `Do=manually-merged`, `MergeCommitID=sha`).
/// `ff_push_to_main` must have already set `main` to `sha` (Forgejo requires
/// the branch already be at the merge commit). On a non-2xx, re-reads the PR
/// head to distinguish drift (`HeadDrift`) from a generic failure (`Other`) —
/// best-effort, since the handler's pre-merge head re-read is the real gate.
///
/// # Errors
/// `HeadDrift` if the PR head no longer matches `sha`; `Other` otherwise.
pub async fn mark_pr_merged(repo: &str, pr: u64, sha: &str) -> Result<(), ForgeMergeError> {
    let token = core_token()
        .ok_or_else(|| ForgeMergeError::Other(anyhow::anyhow!("forge core token absent")))?;
    let url = format!("{FORGE_HTTP}/api/v1/repos/{repo}/pulls/{pr}/merge");
    let body = format!(r#"{{"Do":"manually-merged","MergeCommitID":"{sha}"}}"#);
    let (status, _) = forge_http(reqwest::Method::POST, &url, &token, &body)
        .await
        .context("POST pulls/<pr>/merge (manually-merged)")?;
    if status.is_success() {
        return Ok(());
    }
    // Best-effort drift detection: if the live head no longer matches `sha`,
    // that's a head-drift race; otherwise surface as a hard failure.
    match pr_head_sha(repo, pr).await {
        Ok(actual) if actual != sha => Err(ForgeMergeError::HeadDrift {
            expected: sha.to_string(),
            actual,
        }),
        _ => Err(ForgeMergeError::Other(anyhow::anyhow!(
            "mark PR #{pr} in {repo} manually-merged at {sha} failed: HTTP {status}"
        ))),
    }
}

#[cfg(test)]
mod tests {
    use super::{CoreTokenCheck, classify_core_token_status, repo_agent_name, tokenised_repo_url};
    use reqwest::StatusCode;

    #[test]
    fn success_statuses_are_valid() {
        assert_eq!(
            classify_core_token_status(StatusCode::OK),
            CoreTokenCheck::Valid
        );
        assert_eq!(
            classify_core_token_status(StatusCode::NO_CONTENT),
            CoreTokenCheck::Valid
        );
    }

    #[test]
    fn auth_rejection_statuses_are_invalid() {
        // The whole point: a stale token (forge rebuilt out from under it)
        // 401s, and 401/403 are the only outcomes that trigger a re-mint.
        assert_eq!(
            classify_core_token_status(StatusCode::UNAUTHORIZED),
            CoreTokenCheck::Invalid
        );
        assert_eq!(
            classify_core_token_status(StatusCode::FORBIDDEN),
            CoreTokenCheck::Invalid
        );
    }

    #[test]
    fn transient_and_unexpected_statuses_are_indeterminate() {
        // Never re-mint on a transient — minting needs the forge too, and
        // churning tokens on a blip is worse than keeping the existing one.
        for s in [
            StatusCode::INTERNAL_SERVER_ERROR,
            StatusCode::BAD_GATEWAY,
            StatusCode::SERVICE_UNAVAILABLE,
            StatusCode::GATEWAY_TIMEOUT,
            StatusCode::NOT_FOUND,
        ] {
            assert_eq!(
                classify_core_token_status(s),
                CoreTokenCheck::Indeterminate,
                "status {s} should be indeterminate"
            );
        }
    }

    #[test]
    fn repo_agent_name_takes_trailing_segment() {
        assert_eq!(repo_agent_name("agent-configs/atlas"), "atlas");
        assert_eq!(repo_agent_name("atlas"), "atlas");
        assert_eq!(repo_agent_name("a/b/c"), "c");
    }

    #[test]
    fn tokenised_repo_url_shape() {
        assert_eq!(
            tokenised_repo_url("agent-configs/iris", "tok"),
            "http://core:tok@localhost:3000/agent-configs/iris.git"
        );
    }
}