use anyhow::{Context, Result};
use serde::Deserialize;
use std::path::PathBuf;

#[derive(Debug, Clone, Deserialize)]
pub struct Config {
    pub listen: String,
    pub db_path: PathBuf,
    pub topology_path: PathBuf,
    /// MM-local checkout scratch dir (per-sha worktrees live here).
    pub workdir: PathBuf,
    /// MM-local releases dir (`releases/<version>/` and `current` live here).
    pub release_root: PathBuf,
    /// Scratch postgres DB url used by `migration_dry_run`. Sando drops and
    /// recreates the schema on every run, so do not point this at anything
    /// you care about.
    #[serde(default)]
    pub scratch_db_url: Option<String>,
    /// Names of cargo bin targets the server crate produces (files under
    /// `target/release/`). First entry is the primary unit (referenced from
    /// the systemd unit's ExecStart). Defaults to `["server"]`; MNW ships
    /// `["makenotwork", "mnw-admin"]`.
    #[serde(default = "default_bin_names")]
    pub bin_names: Vec<String>,
    /// Root for per-gate run logs (`<logs_root>/<version>/<gate>.log`).
    /// Served via `GET /logs/{version}/{gate}`. Defaults to `/srv/sando/logs`.
    #[serde(default = "default_logs_root")]
    pub logs_root: PathBuf,
    /// Non-binary contents to stage into each release dir alongside
    /// `bin_names`. Each entry copies `worktree/<src>` into
    /// `<release>/<dst>`. `required=false` makes a missing source a warn
    /// (older shas missing one of these don't break sando mid-bisect);
    /// `required=true` errors. Default is empty — projects opt-in via
    /// daemon config so the sando code stays project-agnostic.
    #[serde(default)]
    pub release_contents: Vec<ReleaseEntry>,
}

/// A directory or file copied from the worktree into the staged release dir.
/// Multiple entries with the same `dst` are allowed and merged (used by MNW
/// to build `docs/` from three different worktree sources).
#[derive(Debug, Clone, Deserialize)]
pub struct ReleaseEntry {
    /// Path relative to the worktree root (e.g. `server/static`).
    pub src: PathBuf,
    /// Path relative to the release dir (e.g. `static`). Parent dirs are
    /// created as needed.
    pub dst: PathBuf,
    /// If true, a missing source aborts the build. If false, log warn + skip.
    #[serde(default)]
    pub required: bool,
}

fn default_bin_names() -> Vec<String> { vec!["server".into()] }
fn default_logs_root() -> PathBuf { PathBuf::from("/srv/sando/logs") }

impl Config {
    /// Primary binary — the one the systemd unit's ExecStart points at.
    pub fn primary_bin(&self) -> &str {
        self.bin_names.first().map(|s| s.as_str()).unwrap_or("server")
    }

    pub fn load() -> Result<Self> {
        let path = std::env::var("SANDO_CONFIG").unwrap_or_else(|_| "sando-daemon.toml".into());
        let raw = std::fs::read_to_string(&path)
            .with_context(|| format!("reading daemon config at {path}"))?;
        Ok(toml::from_str(&raw)?)
    }

    #[cfg(test)]
    pub fn for_tests() -> Self {
        Self {
            listen: "127.0.0.1:0".into(),
            db_path: PathBuf::from(":memory:"),
            topology_path: PathBuf::from("/tmp/sando-test-topology.toml"),
            workdir: PathBuf::from("/tmp/sando-test-workdir"),
            release_root: PathBuf::from("/tmp/sando-test-release-root"),
            scratch_db_url: None,
            bin_names: vec!["server".into()],
            logs_root: PathBuf::from("/tmp/sando-test-logs"),
            release_contents: Vec::new(),
        }
    }
}