//! Per-agent filesystem paths used by both `hive-bash-daemon` and the
//! stdio MCP bridge.
//!
//! All paths are overridable via env vars so the operator can redirect
//! them in agent.nix when needed.

use std::path::PathBuf;

/// Default unix socket path the daemon listens on inside the agent
/// container. Lives under systemd's `RuntimeDirectory=hive-bash`
/// (a tmpfs path that disappears on container restart — the daemon
/// recreates the socket on its own boot) so the agent unix user can
/// bind without root in `/run`.
pub const DEFAULT_DAEMON_SOCKET: &str = "/run/hive-bash/socket";

/// Resolve the daemon's unix socket path. Override via `HIVE_BASH_SOCKET`.
#[must_use]
pub fn daemon_socket() -> PathBuf {
    std::env::var_os("HIVE_BASH_SOCKET")
        .map_or_else(|| PathBuf::from(DEFAULT_DAEMON_SOCKET), PathBuf::from)
}

/// Base directory for task files. Uses `HYPERHIVE_HARNESS_DIR` if set
/// (injected by hive-c0re meta flake after the harness/state split);
/// falls back to a sibling of the state dir for pre-split deployments.
#[must_use]
pub fn tasks_dir() -> PathBuf {
    let base = if let Some(p) = std::env::var_os("HYPERHIVE_HARNESS_DIR") {
        PathBuf::from(p)
    } else {
        // Pre-split fallback: derive harness/ as a sibling of state/.
        let state = std::env::var("HYPERHIVE_STATE_DIR").unwrap_or_default();
        let state_path = PathBuf::from(&state);
        state_path
            .parent()
            .map_or_else(|| PathBuf::from(state), |p| p.join("harness"))
    };
    base.join("bash-tasks")
}

/// Hyperhive control socket — the daemon writes wake signals here so
/// the harness drives a new claude turn on bash task completion.
/// Mirrors the path used by `forge_notify` and `hive-matrix-mcp`.
#[must_use]
pub fn hyperhive_socket() -> PathBuf {
    std::env::var_os("HIVE_CONTROL_SOCKET")
        .map_or_else(|| PathBuf::from("/run/hive/mcp.sock"), PathBuf::from)
}

/// Directory where MCP daemons write loose-end summary files for the harness.
/// Each daemon writes `<name>.json` here; the harness scans the dir in
/// `get_loose_ends` to surface active work from all MCPs generically.
///
/// NOTE: the base-dir resolution logic here is intentionally mirrored in
/// `hive-ag3nt/src/mcp_loose_ends.rs::loose_ends_dir()`. They can't share
/// code across crates — keep them in sync if the fallback logic changes.
#[must_use]
pub fn mcp_loose_ends_dir() -> PathBuf {
    let base = if let Some(p) = std::env::var_os("HYPERHIVE_HARNESS_DIR") {
        PathBuf::from(p)
    } else {
        let state = std::env::var("HYPERHIVE_STATE_DIR").unwrap_or_default();
        let state_path = PathBuf::from(&state);
        state_path
            .parent()
            .map_or_else(|| PathBuf::from(state), |p| p.join("harness"))
    };
    base.join("mcp-loose-ends")
}

/// Full path for a task's JSON metadata file.
#[must_use]
pub fn task_json(id: &str) -> PathBuf {
    tasks_dir().join(format!("{id}.json"))
}

/// Full path for a task's captured stdout.
#[must_use]
pub fn task_out(id: &str) -> PathBuf {
    tasks_dir().join(format!("{id}.out"))
}

/// Full path for a task's captured stderr.
#[must_use]
pub fn task_err(id: &str) -> PathBuf {
    tasks_dir().join(format!("{id}.err"))
}