//! Per-verb subcommand modules. Each module exposes a `Args` struct
//! (clap-derived) and a `run` fn taking `(&Client, Args) -> Result<()>`.
//! Splitting one verb per module keeps each handler small and avoids
//! the bash script's monolithic `case` statement.

pub mod artifact_get;
pub mod assign;
pub mod attach;
pub mod attachment_get;
pub mod branches;
pub mod ci_log;
pub mod ci_rerun;
pub mod clone;
pub mod close;
pub mod comment;
pub mod comment_edit;
pub mod comment_show;
pub mod comments;
pub mod dependency;
pub mod diff;
pub mod issue;
pub mod issue_cmd;
pub mod issue_create;
pub mod issue_edit;
pub mod labels;
pub mod lint;
pub mod list;
pub mod milestone;
pub mod pr;
pub mod pr_assign_reviewer;
pub mod pr_cmd;
pub mod pr_commits;
pub mod pr_create;
pub mod pr_merge;
pub mod pr_reviews;
pub mod pr_status;
pub mod reopen;
pub mod repo_add_collaborator;
pub mod repo_create;
pub mod repo_labels;
pub mod repo_search;
pub mod subscription;
pub mod timeline;
pub mod tree_sha;
pub mod view;

use std::fmt::Write as _;

use anyhow::Result;
use forgejo_api::structs::Attachment;
use serde_json::{Value, json};
use time::OffsetDateTime;
use time::format_description::well_known::Rfc3339;

use crate::client::{Client, index};

/// Pretty-print a `serde_json` value to stdout with a trailing newline,
/// matching the bash script's `| jq` output shape.
pub(crate) fn print_json(v: &Value) -> Result<()> {
    let s = serde_json::to_string_pretty(v)?;
    println!("{s}");
    Ok(())
}

/// Format an optional timestamp as its RFC 3339 string — the shape the
/// raw API emitted, so output stays stable across the typed-client
/// port. `None` (and the never-in-practice unformattable timestamp)
/// map to `None` so callers keep their existing null/placeholder
/// handling.
pub(crate) fn rfc3339(ts: Option<OffsetDateTime>) -> Option<String> {
    ts.and_then(|t| t.format(&Rfc3339).ok())
}

/// Parse a `--since`/`--before` CLI argument as RFC 3339 — the inverse of
/// [`rfc3339`], so a value copied straight from this tool's own output
/// (every row prints its `created_at` in this exact shape) round-trips
/// without reformatting. A bad value gets a message naming what was
/// typed, not a bare parser error.
pub(crate) fn parse_rfc3339(s: &str) -> Result<OffsetDateTime> {
    OffsetDateTime::parse(s, &Rfc3339)
        .map_err(|e| anyhow::anyhow!("`{s}` isn't a valid RFC 3339 timestamp: {e}"))
}

/// Forgejo's per-page cap, shared by every listing verb that over-fetches
/// by one to detect truncation without an exact total (`timeline`'s
/// `--limit`, `comments`' `--since`). The API silently clamps a requested
/// page size to this value, so it's pinned explicitly rather than left as
/// a hidden default downstream math could drift out of sync with.
pub(crate) const PAGE_SIZE: u64 = 50;

/// The highest `--limit` an over-fetch-by-one truncation check
/// (`fetch_limit = limit + 1`) can still detect: `PAGE_SIZE - 1`. At
/// `limit == PAGE_SIZE` the `+1` request silently clamps to `PAGE_SIZE`
/// server-side and the truncation check goes blind exactly when there's
/// the most data to miss.
pub(crate) const MAX_LIMIT: u64 = PAGE_SIZE - 1;

/// Cap `requested` at [`MAX_LIMIT`], reporting whether it had to. Pure so
/// the boundary math is unit-testable without a network call.
pub(crate) fn clamp_limit(requested: u64) -> (u64, bool) {
    let limit = requested.min(MAX_LIMIT);
    (limit, limit < requested)
}

#[cfg(test)]
mod page_limit_tests {
    use super::{MAX_LIMIT, PAGE_SIZE, clamp_limit};

    #[test]
    fn clamp_limit_passes_small_requests_through() {
        assert_eq!(clamp_limit(10), (10, false));
        assert_eq!(clamp_limit(MAX_LIMIT), (MAX_LIMIT, false));
    }

    #[test]
    fn clamp_limit_caps_requests_above_the_boundary() {
        // Regression: `limit + 1` must never exceed Forgejo's PAGE_SIZE,
        // or the over-fetch-by-one truncation check goes silently blind.
        assert_eq!(clamp_limit(PAGE_SIZE), (MAX_LIMIT, true));
        assert_eq!(clamp_limit(1000), (MAX_LIMIT, true));
    }
}

/// Issue-vs-PR kind, for the `pr <verb>` / `issue <verb>` sub-command
/// validation.
#[derive(Clone, Copy)]
pub(crate) enum Kind {
    Pr,
    Issue,
}

/// Verify `number` is the expected kind before a kind-namespaced verb (one
/// of the generics that work on both — close/comment/labels/…) acts on it —
/// the validation win the `pr <verb>` / `issue <verb>` split buys over the
/// old generic verbs. Forgejo's `/issues/{n}` endpoint serves both issues and
/// PRs and marks PRs with a non-null `pull_request` field, so one GET
/// classifies it. Errors with a "use the other command" message on mismatch.
pub(crate) fn assert_kind(client: &Client, number: u64, expected: Kind) -> Result<()> {
    let (owner, name) = client.owner_repo()?;
    let issue = client
        .api()
        .issue_get_issue(owner, name, index(number)?)
        .send()?;
    let is_pr = issue.pull_request.is_some();
    match (expected, is_pr) {
        (Kind::Pr, false) => {
            anyhow::bail!(
                "#{number} is an issue, not a PR — use `hive-forge issue <verb> {number}`"
            )
        }
        (Kind::Issue, true) => {
            anyhow::bail!("#{number} is a PR, not an issue — use `hive-forge pr <verb> {number}`")
        }
        _ => Ok(()),
    }
}

/// Minimal RFC 3986 unreserved-set percent encoder. Covers the subset of
/// characters that show up in the values we splice into *web-route* paths
/// (the typed client encodes its own path segments) — artifact names —
/// without pulling in a fresh workspace dep. Unreserved bytes
/// (`[A-Za-z0-9-._~]`) pass through, so the common identifier case is a
/// no-op; everything else is `%XX`-escaped. Used by `artifact-get` (the
/// artifact-name path segment on the web download route).
pub(crate) fn pct_encode(s: &str) -> String {
    let mut out = String::with_capacity(s.len());
    for b in s.bytes() {
        if b.is_ascii_alphanumeric() || matches!(b, b'-' | b'_' | b'.' | b'~') {
            out.push(b as char);
        } else {
            write!(out, "%{b:02X}").unwrap();
        }
    }
    out
}

/// Render an unresolved-name list with a `did you mean` where one fits.
///
/// A filter value that doesn't resolve is a **near-miss far more often
/// than an invention** (`area/opps` for `area/ops`), and an error that
/// only lists all 18 available names makes the reader do the diff by eye
/// — on the one occasion they already know they mistyped something.
pub(crate) fn with_suggestions(unresolved: &[&str], available: &[&str]) -> String {
    unresolved
        .iter()
        .map(|u| match nearest(u, available) {
            Some(s) => format!("{u} (did you mean \"{s}\"?)"),
            None => (*u).to_owned(),
        })
        .collect::<Vec<_>>()
        .join(", ")
}

/// Closest candidate to `needle`, when one is close enough to be worth
/// suggesting.
///
/// Thresholded rather than always returning the minimum: **a wrong
/// suggestion is worse than none**, because it invites a second failed
/// attempt at a name that was never there. The bound scales with the
/// needle (a third of its length, capped at 3) so a short name doesn't
/// match half the repo and a long one still tolerates a typo or two.
fn nearest<'a>(needle: &str, candidates: &[&'a str]) -> Option<&'a str> {
    let limit = (needle.chars().count() / 3).clamp(1, 3);
    candidates
        .iter()
        .map(|c| (edit_distance(needle, c), *c))
        .filter(|(d, _)| *d <= limit)
        // Tie-break on the shorter candidate, then alphabetically, so the
        // suggestion is stable rather than dependent on the order the
        // forge happened to return its labels in.
        .min_by_key(|(d, c)| (*d, c.len(), *c))
        .map(|(_, c)| c)
}

/// Levenshtein distance, two-row DP. Small enough not to justify a
/// workspace dependency for the one place it is used.
fn edit_distance(a: &str, b: &str) -> usize {
    let b: Vec<char> = b.chars().collect();
    let mut prev: Vec<usize> = (0..=b.len()).collect();
    let mut cur = vec![0_usize; b.len() + 1];
    for (i, ca) in a.chars().enumerate() {
        cur[0] = i + 1;
        for (j, cb) in b.iter().enumerate() {
            let cost = usize::from(ca != *cb);
            cur[j + 1] = (prev[j] + cost).min(prev[j + 1] + 1).min(cur[j] + 1);
        }
        std::mem::swap(&mut prev, &mut cur);
    }
    prev[b.len()]
}

/// One reviewer's latest verdict on a PR, plus forgejo's `stale` /
/// `dismissed` bits.
///
/// `stale` is set by forgejo when the PR head commit changed after this
/// review was submitted (branch protection then wants a fresh review);
/// `dismissed` is set when the review was explicitly dismissed. Either way
/// the review no longer applies to the current head even though its `state`
/// string still reads `APPROVED` / `REQUEST_CHANGES` — so surfacing them
/// stops the CLI from reporting a no-longer-valid review as still-good, and
/// [`ReviewInfo::superseded`] rolls both into one "doesn't count" check.
///
/// ⚠️ **`stale` here is not forgejo's flag alone.** That flag is eventually
/// consistent: seconds after a push it still reports the pre-push answer, so
/// a verdict against the previous head reads as current in exactly the window
/// where someone runs the CLI right after pushing. [`latest_reviews`] therefore
/// ORs it with a direct comparison of the review's own `commit_id` against the
/// PR head — the flag is right *eventually*, the comparison is right
/// *immediately*, and either alone is worse than both.
pub(crate) struct ReviewInfo {
    pub login: String,
    pub state: String,
    pub stale: bool,
    pub dismissed: bool,
}

impl ReviewInfo {
    /// True when the review no longer applies to the current head — stale
    /// (head moved) or dismissed. Such a verdict neither blocks a merge nor
    /// counts as a fresh approval.
    pub(crate) fn superseded(&self) -> bool {
        self.stale || self.dismissed
    }
}

/// Whether this review was submitted against a commit that is no longer the
/// PR head — the race-free half of the staleness check.
///
/// Fails **closed on unknowns**, i.e. "not stale": either side missing means
/// we cannot show the head moved, and the cost of guessing wrong in that
/// direction is one redundant re-review, where the other direction would
/// silently void every verdict on the PR (blocking nothing, but reporting a
/// ready PR as unreviewed and inviting a re-request that dismisses a real
/// approval).
fn reviewed_older_head(reviewed_sha: Option<&str>, head_sha: Option<&str>) -> bool {
    let (Some(head), Some(reviewed)) = (head_sha, reviewed_sha) else {
        return false;
    };
    // Both emptiness checks matter, and for the same reason: a blank string
    // is a value the forge sent, not a sha it has. Treating one as real would
    // make every review compare unequal and mark the whole PR stale — the
    // direction this whole function exists to avoid.
    !head.is_empty() && !reviewed.is_empty() && reviewed != head
}

/// Latest non-comment review per reviewer on a PR. Reviews come
/// oldest-first, so a later verdict from the same user supersedes an
/// earlier one; `COMMENT` / `PENDING` reviews carry no verdict and are
/// skipped. Shared by `pr-status` (health view + readiness verdict) and
/// `pr-merge` (pre-merge changes-requested gate) so the verdict semantics
/// stay in one place.
///
/// # Errors
///
/// Propagates the forge API errors from listing the PR's reviews.
pub(crate) fn latest_reviews(client: &Client, repo: &str, pr: u64) -> Result<Vec<ReviewInfo>> {
    let (owner, name) = crate::client::split_repo(repo)?;
    let pr = index(pr)?;
    // The head this PR currently points at, used to age out verdicts forgejo
    // has not marked stale yet (see `ReviewInfo`). Best-effort: on any failure
    // we fall back to forgejo's flag alone, which is today's behaviour — a
    // missing head must never make every review look superseded.
    let head_sha = client
        .api()
        .repo_get_pull_request(owner, name, pr)
        .send()
        .ok()
        .and_then(|pull| pull.head.as_ref().and_then(|h| h.sha.clone()));
    // Paginate (50/page, 10-page runaway cap — same ceiling the raw
    // client used) so a heavily re-reviewed PR doesn't truncate.
    let mut reviews = Vec::new();
    for page in 1..=10u32 {
        let (_, batch) = client
            .api()
            .repo_list_pull_reviews(owner, name, pr)
            .page(page)
            .page_size(50)
            .send()?;
        let short = batch.len() < 50;
        reviews.extend(batch);
        if short {
            break;
        }
    }
    let mut latest: Vec<ReviewInfo> = Vec::new();
    for r in &reviews {
        let Some(login) = r.user.as_ref().and_then(|u| u.login.as_deref()) else {
            continue;
        };
        let st = r.state.as_deref().unwrap_or("");
        if st == "COMMENT" || st == "PENDING" || st.is_empty() {
            continue;
        }
        let stale = r.stale.unwrap_or(false)
            || reviewed_older_head(r.commit_id.as_deref(), head_sha.as_deref());
        let dismissed = r.dismissed.unwrap_or(false);
        if let Some(slot) = latest.iter_mut().find(|info| info.login == login) {
            st.clone_into(&mut slot.state);
            slot.stale = stale;
            slot.dismissed = dismissed;
        } else {
            latest.push(ReviewInfo {
                login: login.to_owned(),
                state: st.to_owned(),
                stale,
                dismissed,
            });
        }
    }
    Ok(latest)
}

/// The current dependency list for an issue or PR — each entry names
/// another issue/PR this one is blocked on, with its `number`/`title`/
/// `state`. Forgejo's dependency endpoint works on the shared issue/PR
/// index (PRs are issues internally under the hood), so `issue show`,
/// `pr show`, and `list`'s dep-progress annotation all call this instead
/// of duplicating the fetch-and-shape step. A reviewer asked whether
/// `show`/`view` surface dependencies — they didn't (only `timeline`
/// rendered them, as history); this is the current-state complement.
/// `state` was added alongside `list`'s annotation so a caller can tell
/// open deps from closed ones without a second fetch.
///
/// # Errors
///
/// Propagates the forge API errors from listing dependencies.
pub(crate) fn dependency_summaries(
    client: &Client,
    owner: &str,
    name: &str,
    number: u64,
) -> Result<Vec<Value>> {
    let deps = client
        .api()
        .issue_list_issue_dependencies(owner, name, index(number)?)
        .send()?;
    Ok(deps
        .into_iter()
        .map(|d| json!({ "number": d.number, "title": d.title, "state": d.state }))
        .collect())
}

/// A single attachment as one display line — `[file: <name>] <url>`,
/// mirroring the `[file: ...]` marker convention `read_room` already
/// uses for matrix attachments. `None` when the attachment has no
/// download URL (shouldn't happen server-side, but a missing pointer
/// is worse silently dropped than shown as "?").
///
/// Forgejo already returns `assets` inline on the same `Comment`/`Issue`
/// fetch every render path here already makes — this just reads a field
/// that was sitting unused, the gap that made an attachment link
/// unreadable from a non-visual CLI read without guessing the UUID by
/// hand (hit in practice on the swarm-controller extraction thread).
pub(crate) fn attachment_line(a: &Attachment) -> Option<String> {
    let name = a.name.as_deref().unwrap_or("?");
    let url = a.browser_download_url.as_ref()?;
    Some(format!("[file: {name}] {url}"))
}

/// JSON form of an attachment list (`{"name", "url"}` per entry), for
/// `--json` output — same data [`attachment_line`] renders as text.
pub(crate) fn attachment_json(assets: Option<&[Attachment]>) -> Vec<Value> {
    assets
        .unwrap_or_default()
        .iter()
        .map(|a| {
            json!({
                "name": a.name,
                "url": a.browser_download_url.as_ref().map(ToString::to_string),
            })
        })
        .collect()
}

#[cfg(test)]
mod tests {
    use super::{pct_encode, reviewed_older_head};

    #[test]
    fn review_on_an_older_commit_is_stale() {
        // The bug this exists for: forgejo still reports `stale: false` here
        // in the seconds after a push, so the comparison has to catch it.
        assert!(reviewed_older_head(Some("81292f14"), Some("f4c47088")));
    }

    #[test]
    fn review_on_the_current_head_is_not_stale() {
        assert!(!reviewed_older_head(Some("f4c47088"), Some("f4c47088")));
    }

    /// Every unknown fails *toward* keeping the verdict. Voiding every review
    /// on a forge that stopped reporting one of these would be a far louder
    /// wrong answer than one redundant re-review.
    #[test]
    fn unknown_commit_or_head_is_not_stale() {
        assert!(!reviewed_older_head(None, Some("f4c47088")));
        assert!(!reviewed_older_head(Some("81292f14"), None));
        assert!(!reviewed_older_head(Some(""), Some("f4c47088")));
        // Absent and blank have to behave the same on BOTH sides — a blank
        // head that counted as real would mark every review on the PR stale.
        assert!(!reviewed_older_head(Some("81292f14"), Some("")));
        assert!(!reviewed_older_head(Some(""), Some("")));
    }

    #[test]
    fn pct_encode_passes_unreserved_through() {
        // Plain artifact names round-trip verbatim — no performance
        // regression on the common case.
        assert_eq!(pct_encode("damocles"), "damocles");
        assert_eq!(pct_encode("area-ops"), "area-ops");
        assert_eq!(pct_encode("area_ops"), "area_ops");
        assert_eq!(pct_encode("pr1ma-paper-pdf"), "pr1ma-paper-pdf");
    }

    #[test]
    fn pct_encode_escapes_reserved() {
        // `&` / `/` / spaces in any spliced value must escape so they
        // can't break out of the path/query segment.
        assert_eq!(pct_encode("good first issue"), "good%20first%20issue");
        assert_eq!(pct_encode("x&y"), "x%26y");
        assert_eq!(pct_encode("a/b"), "a%2Fb");
    }

    #[test]
    fn nearest_finds_the_one_character_typo() {
        let all = ["area/ops", "area/broker", "type/bug"];
        assert_eq!(super::nearest("area/opps", &all), Some("area/ops"));
        assert_eq!(super::nearest("type/bugs", &all), Some("type/bug"));
    }

    #[test]
    fn nearest_suggests_nothing_for_an_invention() {
        // The important half: a wrong suggestion invites a second failed
        // attempt at a name that was never there, so far-away input must
        // fall back to "here is everything".
        let all = ["area/ops", "area/broker", "type/bug"];
        assert_eq!(super::nearest("frontend", &all), None);
        assert_eq!(super::nearest("", &all), None);
    }

    #[test]
    fn nearest_is_stable_when_two_candidates_tie() {
        // Both are distance 1 from "v3"; the answer must not depend on
        // the order the forge returned them in.
        let forward = ["v1", "v2"];
        let reversed = ["v2", "v1"];
        assert_eq!(
            super::nearest("v3", &forward),
            super::nearest("v3", &reversed)
        );
    }

    #[test]
    fn with_suggestions_annotates_only_the_near_misses() {
        let all = ["area/ops", "type/bug"];
        let rendered = super::with_suggestions(&["area/opps", "frontend"], &all);
        assert!(
            rendered.contains(r#"area/opps (did you mean "area/ops"?)"#),
            "{rendered}"
        );
        assert!(rendered.contains("frontend"), "{rendered}");
        assert!(
            !rendered.contains(r"frontend (did you mean"),
            "invented name must not get a suggestion: {rendered}"
        );
    }
}