hm-config 0.0.6

//! Layered (project/user/env) configuration and credential storage for the
//! `hm` CLI. Shared between the `hm` binary and `hm-plugin-cloud` so both sides
//! resolve config and credentials through one source of truth.

use std::path::{Path, PathBuf};

use anyhow::{Context, Result};
use figment::{
    Figment,
    providers::{Env, Format, Serialized, Toml},
};
use serde::{Deserialize, Serialize};

pub mod creds;

pub const DEFAULT_API_URL: &str = "https://api.harmont.dev";

/// Execution backend for `hm run`.
///
/// Closed set parsed at the config boundary so invalid values are rejected at
/// deserialize time instead of mis-dispatching later, and every consumer match
/// is exhaustively checked by the compiler.
///
/// The `#[display(...)]` strings are the stable lowercase wire/CLI names and
/// must match the `#[serde(rename_all = "lowercase")]` representation.
#[derive(
    Debug, Default, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, derive_more::Display,
)]
#[serde(rename_all = "lowercase")]
pub enum Backend {
    #[default]
    #[display("docker")]
    Docker,
    #[display("cloud")]
    Cloud,
}

/// Derive the SPA (dashboard) base URL from the API base.
///
/// The CLI talks to `api.harmont.dev`, but a human clicks through to the
/// dashboard at `app.harmont.dev`. A watch/login link built from the API host
/// lands on raw JSON, so every surface that emits a user-clickable URL must map
/// the host first.
///
/// Priority:
/// 1. `override_url` (e.g. the `HM_APP_URL` env override) when non-empty,
/// 2. heuristic mapping of `api.` → `app.` on the API host,
/// 3. the API base itself (last-resort dev fallback for hosts like
///    `localhost` that have no `api.`/`app.` split).
///
/// The returned URL never has a trailing slash.
#[must_use]
pub fn app_url(api: &str, override_url: Option<&str>) -> String {
    if let Some(u) = override_url.map(str::trim).filter(|u| !u.is_empty()) {
        return u.trim_end_matches('/').to_string();
    }
    let api = api.trim_end_matches('/');
    if let Some(rest) = api.strip_prefix("https://api.") {
        return format!("https://app.{rest}");
    }
    if let Some(rest) = api.strip_prefix("http://api.") {
        return format!("http://app.{rest}");
    }
    api.to_string()
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[non_exhaustive]
pub struct CloudConfig {
    pub org: Option<String>,
    pub api_url: String,
}

impl Default for CloudConfig {
    fn default() -> Self {
        Self {
            org: None,
            api_url: DEFAULT_API_URL.to_owned(),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[non_exhaustive]
pub struct Preferences {
    pub format: String,
    pub auto_watch: bool,
}

impl Default for Preferences {
    fn default() -> Self {
        Self {
            format: "human".to_owned(),
            auto_watch: false,
        }
    }
}

#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[non_exhaustive]
pub struct Config {
    #[serde(default)]
    pub backend: Backend,
    #[serde(default)]
    pub cloud: CloudConfig,
    #[serde(default)]
    pub preferences: Preferences,
}

impl Config {
    /// XDG-aware user config path (`~/.config/hm/config.toml`).
    ///
    /// # Errors
    ///
    /// Returns an error if the platform config directory cannot be determined.
    pub fn user_config_path() -> Result<PathBuf> {
        let dir = hm_util::dirs::hm_config_dir().context("could not determine config directory")?;
        Ok(dir.join("config.toml"))
    }

    /// Project-level config path: `<root>/.hm/config.toml`.
    #[must_use]
    pub fn project_config_path(project_root: &Path) -> PathBuf {
        project_root.join(".hm").join("config.toml")
    }

    /// Load configuration with full layering: defaults -> user file -> project file -> env.
    ///
    /// # Errors
    ///
    /// Returns an error if the user config path cannot be determined or
    /// figment extraction fails (malformed TOML, type mismatches).
    pub fn load(project_root: Option<&Path>) -> Result<Self> {
        let user_path = Self::user_config_path()?;
        let project_path = project_root.map(Self::project_config_path);
        Self::load_from_paths(Some(&user_path), project_path.as_deref())
            .context("loading configuration")
    }

    /// Testable core: build a `Config` from explicit file paths.
    ///
    /// Layering, lowest to highest precedence: defaults -> user file ->
    /// project file -> env.
    ///
    /// Env precedence (highest): both the `HM_`-prefixed split form
    /// (`HM_CLOUD__ORG`, `HM_CLOUD__API_URL`) and the documented
    /// `HM_ORG` / `HM_API_URL` are honored; the latter map onto
    /// `cloud.org` / `cloud.api_url`.
    ///
    /// # Errors
    ///
    /// Returns an error if figment extraction fails (malformed TOML, type mismatches).
    pub fn load_from_paths(user_path: Option<&Path>, project_path: Option<&Path>) -> Result<Self> {
        let mut figment = Figment::new().merge(Serialized::defaults(Self::default()));

        if let Some(p) = user_path {
            figment = figment.merge(Toml::file(p));
        }
        if let Some(p) = project_path {
            figment = figment.merge(Toml::file(p));
        }

        figment = figment
            .merge(Env::prefixed("HM_").split("__"))
            .merge(hm_alias_env());

        Ok(figment.extract()?)
    }

    /// Persist config to `path` atomically.
    ///
    /// # Errors
    ///
    /// Returns an error if TOML serialization fails or the atomic write fails.
    pub fn save_to(&self, path: &Path) -> Result<()> {
        let serialized = toml::to_string_pretty(self).context("serializing config")?;
        hm_util::os::fs::blocking::write_atomic_restricted(
            path,
            serialized.as_bytes(),
            hm_util::os::fs::FileMode(0o644),
            hm_util::os::fs::DirMode(0o700),
        )
        .with_context(|| format!("writing {}", path.display()))
    }

    /// Save to user-level config path (`~/.config/hm/config.toml`).
    ///
    /// # Errors
    ///
    /// Returns an error if the path cannot be determined or the write fails.
    pub fn save_user(&self) -> Result<()> {
        self.save_to(&Self::user_config_path()?)
    }
}

/// Figment env provider mapping the friendly `HM_ORG` / `HM_API_URL`
/// variables onto the nested `cloud` config keys.
///
/// The cloud settings docs and `hm`'s error messages tell users to
/// `set HM_ORG=<slug>` / `HM_API_URL=<url>`, so those flat names must feed
/// the config. This binds them to `cloud.org` / `cloud.api_url` alongside the
/// generic `HM_`-prefixed split layer (`HM_CLOUD__ORG`, …).
fn hm_alias_env() -> Env {
    Env::raw()
        .only(&["HM_ORG", "HM_API_URL"])
        .map(|key| match key.as_str() {
            "HM_ORG" => "cloud.org".into(),
            "HM_API_URL" => "cloud.api_url".into(),
            other => other.into(),
        })
        .split(".")
}

#[cfg(test)]
#[allow(clippy::unwrap_used)]
mod tests {
    use super::*;
    use std::io::Write as _;
    use std::sync::{Mutex, MutexGuard};

    /// Serializes every test that resolves config through `load_*`.
    ///
    /// All `load_*` paths merge the process environment as their top layer, so
    /// a test that sets `HM_*` (via `figment::Jail`, which mutates the
    /// real process env for the duration of its closure) would otherwise leak
    /// into a concurrently-running file-layering test. Holding this lock for
    /// the whole body of any env-or-load test makes them mutually exclusive.
    static ENV_LOCK: Mutex<()> = Mutex::new(());

    fn env_guard() -> MutexGuard<'static, ()> {
        ENV_LOCK
            .lock()
            .unwrap_or_else(std::sync::PoisonError::into_inner)
    }

    #[test]
    fn app_url_maps_prod_api_to_app() {
        assert_eq!(app_url(DEFAULT_API_URL, None), "https://app.harmont.dev");
    }

    #[test]
    fn app_url_override_wins_and_trims_trailing_slash() {
        assert_eq!(
            app_url(DEFAULT_API_URL, Some("http://localhost:5173/")),
            "http://localhost:5173"
        );
    }

    #[test]
    fn app_url_empty_override_is_ignored() {
        assert_eq!(
            app_url(DEFAULT_API_URL, Some("   ")),
            "https://app.harmont.dev"
        );
    }

    #[test]
    fn app_url_falls_back_to_api_for_unmapped_host() {
        assert_eq!(
            app_url("http://localhost:4000", None),
            "http://localhost:4000"
        );
        // http api. → http app.
        assert_eq!(app_url("http://api.dev.test/", None), "http://app.dev.test");
    }

    #[test]
    fn default_config_values() {
        let cfg = Config::default();
        assert_eq!(cfg.backend, Backend::Docker);
        assert_eq!(cfg.cloud.api_url, DEFAULT_API_URL);
        assert!(cfg.cloud.org.is_none());
        assert_eq!(cfg.preferences.format, "human");
        assert!(!cfg.preferences.auto_watch);
    }

    #[test]
    fn deserialize_full_toml() {
        let toml_str = r#"
[cloud]
org = "acme"
api_url = "https://custom.api"

[preferences]
format = "json"
auto_watch = true
"#;
        let cfg: Config = toml::from_str(toml_str).unwrap();
        assert_eq!(cfg.cloud.org.as_deref(), Some("acme"));
        assert_eq!(cfg.cloud.api_url, "https://custom.api");
        assert_eq!(cfg.preferences.format, "json");
        assert!(cfg.preferences.auto_watch);
    }

    #[test]
    fn deserialize_sparse_toml() {
        let _g = env_guard();
        let toml_str = r#"
[cloud]
org = "sparse-co"
"#;
        let mut f = tempfile::NamedTempFile::new().unwrap();
        f.write_all(toml_str.as_bytes()).unwrap();

        let cfg = Config::load_from_paths(Some(f.path()), None).unwrap();
        assert_eq!(cfg.cloud.org.as_deref(), Some("sparse-co"));
        assert_eq!(cfg.cloud.api_url, DEFAULT_API_URL);
        assert_eq!(cfg.preferences.format, "human");
        assert!(!cfg.preferences.auto_watch);
    }

    #[test]
    fn deserialize_empty_toml() {
        let _g = env_guard();
        let mut f = tempfile::NamedTempFile::new().unwrap();
        f.write_all(b"").unwrap();

        let cfg = Config::load_from_paths(Some(f.path()), None).unwrap();
        assert_eq!(cfg.cloud.api_url, DEFAULT_API_URL);
        assert!(cfg.cloud.org.is_none());
        assert_eq!(cfg.preferences.format, "human");
        assert!(!cfg.preferences.auto_watch);
    }

    #[test]
    fn figment_project_overrides_user() {
        let _g = env_guard();
        let user_toml = r#"
[cloud]
org = "user-org"
api_url = "https://user.api"

[preferences]
format = "json"
"#;
        let project_toml = r#"
[cloud]
org = "project-org"
"#;

        let mut user_file = tempfile::NamedTempFile::new().unwrap();
        user_file.write_all(user_toml.as_bytes()).unwrap();

        let mut project_file = tempfile::NamedTempFile::new().unwrap();
        project_file.write_all(project_toml.as_bytes()).unwrap();

        let cfg =
            Config::load_from_paths(Some(user_file.path()), Some(project_file.path())).unwrap();

        assert_eq!(cfg.cloud.org.as_deref(), Some("project-org"));
        assert_eq!(cfg.cloud.api_url, "https://user.api");
        assert_eq!(cfg.preferences.format, "json");
    }

    #[test]
    fn backend_display_matches_wire_strings() {
        assert_eq!(Backend::Docker.to_string(), "docker");
        assert_eq!(Backend::Cloud.to_string(), "cloud");
    }

    #[test]
    fn backend_defaults_docker_and_parses_and_layers() {
        let _g = env_guard();
        // default
        assert_eq!(Config::default().backend, Backend::Docker);

        // user file sets cloud; project file sets docker -> project wins.
        let mut user_file = tempfile::NamedTempFile::new().unwrap();
        user_file.write_all(br#"backend = "cloud""#).unwrap();

        let mut project_file = tempfile::NamedTempFile::new().unwrap();
        project_file.write_all(br#"backend = "docker""#).unwrap();

        let cfg =
            Config::load_from_paths(Some(user_file.path()), Some(project_file.path())).unwrap();
        assert_eq!(cfg.backend, Backend::Docker);

        // user file alone parses "cloud".
        let cfg_user = Config::load_from_paths(Some(user_file.path()), None).unwrap();
        assert_eq!(cfg_user.backend, Backend::Cloud);
    }

    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
    async fn save_and_reload_roundtrip() {
        let _g = env_guard();
        let tmp = tempfile::tempdir().unwrap();
        let path = tmp.path().join("config.toml");
        let cfg = Config {
            cloud: CloudConfig {
                org: Some("saved-org".into()),
                ..CloudConfig::default()
            },
            ..Config::default()
        };
        cfg.save_to(&path).unwrap();

        let loaded = Config::load_from_paths(Some(&path), None).unwrap();
        assert_eq!(loaded.cloud.org.as_deref(), Some("saved-org"));
        assert_eq!(loaded.cloud.api_url, DEFAULT_API_URL);
        assert_eq!(loaded.preferences.format, "human");
    }

    #[test]
    #[allow(clippy::result_large_err)] // figment::Error is the Jail closure's error type.
    fn hm_env_overrides_cloud_keys() {
        let _g = env_guard();
        // `Jail` isolates env mutation from concurrently-running tests.
        figment::Jail::expect_with(|jail| {
            jail.set_env("HM_ORG", "env-org");
            jail.set_env("HM_API_URL", "https://env.api");

            let cfg = Config::load_from_paths(None, None).unwrap();
            assert_eq!(cfg.cloud.org.as_deref(), Some("env-org"));
            assert_eq!(cfg.cloud.api_url, "https://env.api");
            Ok(())
        });
    }

    #[test]
    #[allow(clippy::result_large_err)] // figment::Error is the Jail closure's error type.
    fn hm_env_overrides_user_file() {
        let _g = env_guard();
        // Env is the highest-precedence layer: it wins over a user file.
        figment::Jail::expect_with(|jail| {
            jail.set_env("HM_ORG", "env-org");

            jail.create_file(
                "config.toml",
                "[cloud]\norg = \"file-org\"\napi_url = \"https://file.api\"\n",
            )?;
            let user = jail.directory().join("config.toml");

            let cfg = Config::load_from_paths(Some(&user), None).unwrap();
            assert_eq!(cfg.cloud.org.as_deref(), Some("env-org"));
            // Unset env keys still come from the file.
            assert_eq!(cfg.cloud.api_url, "https://file.api");
            Ok(())
        });
    }

    #[test]
    fn figment_missing_files_still_resolve() {
        let _g = env_guard();
        let nonexistent_user = Path::new("/tmp/harmont-test-nonexistent-user/config.toml");
        let nonexistent_project = Path::new("/tmp/harmont-test-nonexistent-project/config.toml");

        let cfg =
            Config::load_from_paths(Some(nonexistent_user), Some(nonexistent_project)).unwrap();

        assert_eq!(cfg.cloud.api_url, DEFAULT_API_URL);
        assert!(cfg.cloud.org.is_none());
        assert_eq!(cfg.preferences.format, "human");
        assert!(!cfg.preferences.auto_watch);
    }
}