//! Per-agent path resolution for state, harness, and credential directories.
//!
//! All agents (including the manager `root`) use `/agents/{label}/state`
//! for agent-owned durable notes, and `/agents/{label}/harness` for
//! harness-internal files (`hyperhive-events.sqlite`, `hyperhive-model`, etc.)
//! that should not clutter what claude sees as "my notes dir".
//! Claude credentials live at `$HOME/.claude` (resolves to
//! `/home/<agent-name>/.claude` because the harness service runs as a
//! non-root unix user matching the agent label — see
//! `docs/persistence.md::First-boot agent-user migration`).
//!
//! All three paths can be overridden via env vars (`HYPERHIVE_STATE_DIR`,
//! `HYPERHIVE_HARNESS_DIR`, `HYPERHIVE_CLAUDE_DIR`) for dev / test scenarios.

use std::path::PathBuf;

/// Durable state directory for the current agent. Reads `HYPERHIVE_STATE_DIR`
/// first (always set by the meta flake to `/agents/{label}/state`); falls back
/// to the same pattern derived from `HIVE_LABEL` for dev/test environments
/// where the env var may not be set.
#[must_use]
pub fn state_dir() -> PathBuf {
    if let Some(p) = std::env::var_os("HYPERHIVE_STATE_DIR") {
        return PathBuf::from(p);
    }
    let label = std::env::var("HIVE_LABEL").unwrap_or_default();
    PathBuf::from(format!("/agents/{label}/state"))
}

/// Harness-internal state directory. Holds files the harness owns
/// (`hyperhive-events.sqlite`, `hyperhive-turn-stats.sqlite`,
/// `hyperhive-model`) so they do not appear inside the agent-visible
/// `/agents/{label}/state` tree. Delegates to the shared canonical
/// resolver in `hive_sh4re::paths` so the harness + every out-of-process
/// MCP daemon resolve this identically (reads `HYPERHIVE_HARNESS_DIR`,
/// then a `harness/` sibling of `HYPERHIVE_STATE_DIR`, then
/// `/agents/{HIVE_LABEL}/harness`).
#[must_use]
pub fn harness_dir() -> PathBuf {
    hive_sh4re::paths::harness_dir()
}

/// Consolidated harness-local state db — todos + reminders + the questions
/// mirror, one table each — mutable per-agent state the harness owns, kept
/// out of the append-only `hyperhive-events.sqlite` sink. Per mara's call
/// ("not yet another sqlite! todos, reminders, questions should be like
/// three tiny tables in one 500kb sqlite"), this file is the shared home
/// for all loose-ends-v2 stores; each store's `open()` only applies its own
/// `CREATE TABLE IF NOT EXISTS`, so opening multiple stores against the
/// same path is safe (distinct table names, no schema collision).
/// All three stores (todos, reminders, questions) open this same path
/// directly (see their `open()` call sites) — distinct table names mean no
/// schema collision, so there's no need for per-store path wrapper fns here.
///
/// Before this consolidation, todos and reminders lived in their own
/// `hyperhive-todos.sqlite` / `hyperhive-reminders.sqlite` files; a
/// one-time boot migration (`db_migrate::run`) folds those into this path
/// the first time a harness boots after the upgrade.
#[must_use]
pub fn state_db() -> PathBuf {
    harness_dir().join("hyperhive-state.sqlite")
}

/// Legacy pre-consolidation todos db path, consulted only by
/// [`crate::db_migrate`] on the first boot after the upgrade.
#[must_use]
pub fn legacy_todos_db() -> PathBuf {
    harness_dir().join("hyperhive-todos.sqlite")
}

/// Legacy pre-consolidation reminders db path, consulted only by
/// [`crate::db_migrate`] on the first boot after the upgrade.
#[must_use]
pub fn legacy_reminders_db() -> PathBuf {
    harness_dir().join("hyperhive-reminders.sqlite")
}

/// Per-turn config dir for the regenerated claude-{mcp-config,settings,
/// system-prompt} files the harness drops before each turn. Set by
/// systemd via `RuntimeDirectory = "hive-config"`: a per-service runtime
/// dir owned by the agent unix user, auto-cleared on stop. Kept separate
/// from `/run/hive` (the host-owned mcp.sock bind) so the harness owns
/// its own write surface and we don't have to chown a bind-mounted dir.
/// Overridable via `HYPERHIVE_CONFIG_DIR` for dev / test scenarios.
#[must_use]
pub fn config_dir() -> PathBuf {
    if let Some(p) = std::env::var_os("HYPERHIVE_CONFIG_DIR") {
        return PathBuf::from(p);
    }
    PathBuf::from("/run/hive-config")
}

/// Claude credentials directory for the current agent. `$HOME/.claude`
/// matches what the `claude` CLI reads at runtime — the harness sees
/// the same `$HOME` set by the per-service systemd `environment`
/// declaration (`/home/<agent>`). Falls back to `/root/.claude` for
/// dev / test environments where `HOME` isn't set so the previous
/// root-by-default shape keeps working without env wiring.
/// Overridable via `HYPERHIVE_CLAUDE_DIR` for dev / test scenarios.
#[must_use]
pub fn claude_dir() -> PathBuf {
    if let Some(p) = std::env::var_os("HYPERHIVE_CLAUDE_DIR") {
        return PathBuf::from(p);
    }
    if let Some(home) = std::env::var_os("HOME") {
        let mut path = PathBuf::from(home);
        path.push(".claude");
        return path;
    }
    PathBuf::from("/root/.claude")
}