//! Per-agent filesystem paths used by both `hive-matrix-daemon` and the
//! stdio MCP bridge.
//!
//! All paths are overridable via env vars for dev / test scenarios and
//! to let the harness point the daemon at non-default locations when
//! the operator overrides `hyperhive.matrix.*` options.

use std::path::PathBuf;

/// Default homeserver URL when `HIVE_MATRIX_URL` isn't set. Tuwunel
/// (the local hive-matrix container) listens on `localhost:8008` by
/// default; shared host netns means every agent container resolves
/// `localhost` to the same machine.
pub const DEFAULT_HOMESERVER: &str = "http://localhost:8008";

/// Default unix socket path the daemon listens on inside the agent
/// container. The stdio MCP bridge `connect()`s here on every tool call.
/// Lives under systemd's `RuntimeDirectory=hive-matrix` (a tmpfs path
/// that disappears on container restart — fine, because the daemon
/// recreates the socket on its own boot) so the agent unix user
/// (post-#658) can bind a socket inside it without root in `/run`.
pub const DEFAULT_DAEMON_SOCKET: &str = "/run/hive-matrix/socket";

/// Resolve the matrix access-token file path. Override via
/// `HIVE_MATRIX_TOKEN_FILE`; default is `<HYPERHIVE_STATE_DIR>/matrix-token`,
/// the path `hive-c0re::matrix::ensure_user_for` writes to on agent
/// account provisioning.
#[must_use]
pub fn token_file() -> PathBuf {
    if let Some(p) = std::env::var_os("HIVE_MATRIX_TOKEN_FILE") {
        return PathBuf::from(p);
    }
    let state_dir = std::env::var("HYPERHIVE_STATE_DIR").unwrap_or_default();
    PathBuf::from(format!("{state_dir}/matrix-token"))
}

/// Resolve the homeserver URL. Override via `HIVE_MATRIX_URL`; default
/// is the in-container `localhost:8008` tuwunel.
#[must_use]
pub fn homeserver_url() -> String {
    std::env::var("HIVE_MATRIX_URL").unwrap_or_else(|_| DEFAULT_HOMESERVER.to_owned())
}

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

/// Persistent sqlite store directory for matrix-sdk's state (event
/// cache, devices, etc.). Lives under the per-agent state dir so it
/// survives container restart but gets wiped on `destroy --purge`.
#[must_use]
pub fn matrix_state_dir() -> PathBuf {
    let state_dir = std::env::var("HYPERHIVE_STATE_DIR").unwrap_or_default();
    PathBuf::from(format!("{state_dir}/matrix-sdk-state"))
}

/// Hyperhive control socket — the daemon writes wake signals here so
/// the harness drives a new claude turn on incoming matrix events.
/// Mirrors the path `forge_notify` writes to.
#[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")
}