use std::{net::SocketAddr, path::PathBuf};

/// Runtime configuration, read from the environment (see `.env.example`).
#[derive(Debug, Clone)]
pub struct Config {
    pub bind: SocketAddr,
    pub frontend: PathBuf,
    pub templates: PathBuf,
    pub data_dir: PathBuf,
    pub database_url: String,
    pub default_domain: String,
    pub xmpp_whitelist: Vec<String>,
    pub max_sessions: usize,
    pub disable_registration: bool,
    pub default_locale: String,
    pub banner: Option<String>,
    pub info: Option<String>,
    pub debug_xmpp: bool,
    /// Development only: connect without TLS to this host:port
    pub xmpp_plaintext: Option<String>,
    /// Disconnect the XMPP sessions without any browser activity for this long
    pub session_timeout_hours: u64,
    /// Allow the picture proxy and link previews to reach private networks (development)
    pub allow_private_urls: bool,
    /// Delete the cached messages older than this many days (0: keep them),
    /// to follow the XMPP server's archive expiry
    pub message_retention_days: u32,
}

fn env(key: &str) -> Option<String> {
    std::env::var(key).ok().filter(|v| !v.is_empty())
}

impl Config {
    pub fn from_env() -> Self {
        let root = env("MOVIM_ROOT")
            .map(PathBuf::from)
            .unwrap_or_else(|| PathBuf::from(env!("CARGO_MANIFEST_DIR")));
        let data_dir = env("MOVIM_DATA_DIR")
            .map(PathBuf::from)
            .unwrap_or_else(|| root.join("data"));

        Config {
            bind: env("MOVIM_BIND")
                .unwrap_or_else(|| "127.0.0.1:8080".into())
                .parse()
                .expect("invalid MOVIM_BIND"),
            frontend: root.join("frontend"),
            templates: root.join("templates"),
            database_url: env("MOVIM_DATABASE_URL").unwrap_or_else(|| {
                format!("sqlite://{}?mode=rwc", data_dir.join("movim.sqlite").display())
            }),
            data_dir,
            default_domain: env("MOVIM_DOMAIN").unwrap_or_else(|| "movim.eu".into()),
            xmpp_whitelist: env("MOVIM_XMPP_WHITELIST")
                .map(|s| {
                    s.split(',')
                        .map(|d| d.trim().to_string())
                        .filter(|d| !d.is_empty())
                        .collect()
                })
                .unwrap_or_default(),
            max_sessions: env("MOVIM_MAX_SESSIONS")
                .and_then(|s| s.parse().ok())
                .unwrap_or(0),
            disable_registration: env("MOVIM_DISABLE_REGISTRATION").is_some_and(|v| v == "1" || v == "true"),
            default_locale: env("MOVIM_LOCALE").unwrap_or_else(|| "en".into()),
            banner: env("MOVIM_BANNER"),
            info: env("MOVIM_INFO"),
            debug_xmpp: env("MOVIM_DEBUG_XMPP").is_some_and(|v| v == "1" || v == "true"),
            xmpp_plaintext: env("MOVIM_XMPP_PLAINTEXT"),
            session_timeout_hours: env("MOVIM_SESSION_TIMEOUT_HOURS").and_then(|s| s.parse().ok()).unwrap_or(24 * 7),
            allow_private_urls: env("MOVIM_ALLOW_PRIVATE_URLS").is_some_and(|v| v == "1" || v == "true"),
            message_retention_days: env("MOVIM_MESSAGE_RETENTION_DAYS").and_then(|s| s.parse().ok()).unwrap_or(0),
        }
    }
}