const DEFAULT_KEY_CACHE = { ttlMs: 30 * 60 * 1000, max: 10_000 };

const config = {
    debug: false,
    dashboard: { core: {}, audit: {}, keyCache: { ...DEFAULT_KEY_CACHE } },
};

export async function loadConfig() {
    if (process.env.DEBUG) config.debug = process.env.DEBUG;
    if (process.env.POSTGRES_URL) config.postgresUrl = process.env.POSTGRES_URL;
    if (process.env.PUBLIC_CORE_URL) config.publicCoreUrl = process.env.PUBLIC_CORE_URL;
    if (process.env.PUBLIC_ARCHIVE_URL) config.publicArchiveUrl = process.env.PUBLIC_ARCHIVE_URL;
    if (process.env.PUBLIC_CALLBACK_URL) config.publicCallbackUrl = process.env.PUBLIC_CALLBACK_URL;
    if (process.env.SECURE_SECRET) config.secureSecret = process.env.SECURE_SECRET;
    if (process.env.DEFAULT_FEDID_URL) config.defaultFedidUrl = process.env.DEFAULT_FEDID_URL;
    if (process.env.AUTH_MODULES) {
        config.authModules = {};
        const authModules = process.env.AUTH_MODULES.split(',').map(a => a.trim());
        for (const type of authModules) {
            const authModulePath = `../modules/auth/${type}.js`;
            const { getModuleConfig } = await import(authModulePath);
            config.authModules[type] = getModuleConfig();
        }
    }
    config.appModules = {};
    let appModules = [
        'core',
        'archive',
    ];
    if (process.env.APP_MODULES) {
        appModules = process.env.APP_MODULES.split(',').map(a => a.trim());
    }
    for (const type of appModules) {
        const appModulePath = `../modules/app/${type}.js`;
        const { getModuleConfig } = await import(appModulePath);
        config.appModules[type] = getModuleConfig();
    }
    if (process.env.PDP_TYPE) config.pdpType = process.env.PDP_TYPE;
    if (process.env.PDP_URL) config.pdpUrl = process.env.PDP_URL;
    if (process.env.INSTANT_QUEUE) config.instantQueue = process.env.INSTANT_QUEUE;

    // Remote agreement-markdown caching: exponential backoff for failed fetches
    // so an invalid URL isn't retried on every referencing create. Defaults:
    // 1 minute → 1 day, factor 2, give up after 10 attempts. All overridable.
    config.agreementCache = {
        startingDelayMs: Number(process.env.AGREEMENT_CACHE_STARTING_DELAY_MS) || 60_000,
        maxDelayMs:      Number(process.env.AGREEMENT_CACHE_MAX_DELAY_MS)      || 86_400_000,
        maxRetries:      Number(process.env.AGREEMENT_CACHE_MAX_RETRIES)       || 10,
        factor:          Number(process.env.AGREEMENT_CACHE_BACKOFF_FACTOR)    || 2,
    };

    // Optional federation: source dashboard core/audit data from remote servers
    // (via their /api/v1/data/dashboard/* API + an API key) instead of locally.
    // Unset => serve from the local DB (the single-operator default).
    const keyCacheTtl = Number(process.env.DASHBOARD_KEY_CACHE_TTL_MS);
    const keyCacheMax = Number(process.env.DASHBOARD_KEY_CACHE_MAX);
    config.dashboard = {
        core: { url: process.env.DASHBOARD_CORE_URL || null, key: process.env.DASHBOARD_CORE_KEY || null },
        audit: { url: process.env.DASHBOARD_AUDIT_URL || null, key: process.env.DASHBOARD_AUDIT_KEY || null },
        keyCache: {
            ttlMs: Number.isFinite(keyCacheTtl) ? keyCacheTtl : DEFAULT_KEY_CACHE.ttlMs,
            max: Number.isFinite(keyCacheMax) && keyCacheMax > 0 ? keyCacheMax : DEFAULT_KEY_CACHE.max,
        },
    };
}

export function getConfig() {
    return config;
}