import pg from "pg";
import logger from "./logger.js";
import { isTransientError } from "../utils/errors.js";
const { Pool } = pg;
const pool = new Pool({
    host: process.env.DATABASE_HOST || "172.17.0.1",
    port: parseInt(process.env.DATABASE_PORT || "5432", 10),
    database: process.env.DATABASE_NAME || "docfast",
    user: process.env.DATABASE_USER || "docfast",
    password: process.env.DATABASE_PASSWORD || "docfast",
    max: 10,
    idleTimeoutMillis: 10000, // Evict idle connections after 10s (was 30s) — faster cleanup of stale sockets
    connectionTimeoutMillis: 5000, // Don't wait forever for a connection
    allowExitOnIdle: false,
    keepAlive: true, // TCP keepalive to detect dead connections
    keepAliveInitialDelayMillis: 10000, // Start keepalive probes after 10s idle
});
// Handle errors on idle clients — pg.Pool automatically removes the client
// after emitting this event, so we just log it.
pool.on("error", (err, client) => {
    logger.error({ err }, "Unexpected error on idle PostgreSQL client — evicted from pool");
});
export { isTransientError } from "../utils/errors.js";
/**
 * Execute a query with automatic retry on transient errors.
 *
 * KEY FIX: On transient error, we destroy the bad connection (client.release(true))
 * so the pool creates a fresh TCP connection on the next attempt, instead of
 * reusing a dead socket from the pool.
 */
export async function queryWithRetry(queryText, params, maxRetries = 3) {
    let lastError;
    for (let attempt = 0; attempt <= maxRetries; attempt++) {
        let client;
        try {
            client = await pool.connect();
            const result = await client.query(queryText, params);
            client.release(); // Return healthy connection to pool
            return result;
        }
        catch (err) {
            // Destroy the bad connection so pool doesn't reuse it
            if (client) {
                try {
                    client.release(true);
                }
                catch (_) { /* already destroyed */ }
            }
            lastError = err;
            if (!isTransientError(err) || attempt === maxRetries) {
                throw err;
            }
            const delayMs = Math.min(1000 * Math.pow(2, attempt), 5000); // 1s, 2s, 4s (capped at 5s)
            logger.warn({ err: err.message, code: err.code, attempt: attempt + 1, maxRetries, delayMs }, "Transient DB error, destroying bad connection and retrying...");
            await new Promise(resolve => setTimeout(resolve, delayMs));
        }
    }
    throw lastError;
}
/**
 * Connect with retry — for operations that need a client (transactions).
 * On transient connect errors, waits and retries so the pool can establish
 * fresh connections to the new PgBouncer pod.
 */
export async function connectWithRetry(maxRetries = 3) {
    let lastError;
    for (let attempt = 0; attempt <= maxRetries; attempt++) {
        try {
            const client = await pool.connect();
            // Validate the connection is actually alive
            try {
                await client.query("SELECT 1");
            }
            catch (validationErr) {
                // Connection is dead — destroy it and retry
                try {
                    client.release(true);
                }
                catch (_) { }
                if (!isTransientError(validationErr) || attempt === maxRetries) {
                    throw validationErr;
                }
                const delayMs = Math.min(1000 * Math.pow(2, attempt), 5000);
                logger.warn({ err: validationErr.message, code: validationErr.code, attempt: attempt + 1 }, "Connection validation failed, destroying and retrying...");
                await new Promise(resolve => setTimeout(resolve, delayMs));
                continue;
            }
            return client;
        }
        catch (err) {
            lastError = err;
            if (!isTransientError(err) || attempt === maxRetries) {
                throw err;
            }
            const delayMs = Math.min(1000 * Math.pow(2, attempt), 5000);
            logger.warn({ err: err.message, code: err.code, attempt: attempt + 1, maxRetries, delayMs }, "Transient DB connect error, retrying...");
            await new Promise(resolve => setTimeout(resolve, delayMs));
        }
    }
    throw lastError;
}
export async function initDatabase() {
    const client = await connectWithRetry();
    try {
        await client.query(`
      CREATE TABLE IF NOT EXISTS api_keys (
        key TEXT PRIMARY KEY,
        tier TEXT NOT NULL DEFAULT 'free',
        email TEXT NOT NULL DEFAULT '',
        created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
        stripe_customer_id TEXT
      );
      CREATE INDEX IF NOT EXISTS idx_api_keys_email ON api_keys(email);
      CREATE INDEX IF NOT EXISTS idx_api_keys_stripe ON api_keys(stripe_customer_id);
      CREATE UNIQUE INDEX IF NOT EXISTS idx_api_keys_stripe_unique
        ON api_keys(stripe_customer_id) WHERE stripe_customer_id IS NOT NULL;

      CREATE TABLE IF NOT EXISTS verifications (
        id SERIAL PRIMARY KEY,
        email TEXT NOT NULL,
        token TEXT NOT NULL UNIQUE,
        api_key TEXT NOT NULL,
        created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
        verified_at TIMESTAMPTZ
      );
      CREATE INDEX IF NOT EXISTS idx_verifications_email ON verifications(email);
      CREATE INDEX IF NOT EXISTS idx_verifications_token ON verifications(token);

      CREATE TABLE IF NOT EXISTS pending_verifications (
        email TEXT PRIMARY KEY,
        code TEXT NOT NULL,
        created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
        expires_at TIMESTAMPTZ NOT NULL,
        attempts INT NOT NULL DEFAULT 0
      );

      CREATE TABLE IF NOT EXISTS usage (
        key TEXT PRIMARY KEY,
        count INT NOT NULL DEFAULT 0,
        month_key TEXT NOT NULL
      );
    `);
        logger.info("PostgreSQL tables initialized");
    }
    finally {
        client.release();
    }
}
/**
 * Clean up stale database entries:
 * - Expired pending verifications
 * - Unverified free-tier API keys (never completed verification)
 * - Orphaned usage rows (key no longer exists)
 */
export async function cleanupStaleData() {
    const results = { expiredVerifications: 0, staleKeys: 0, orphanedUsage: 0 };
    // 1. Delete expired pending verifications
    const pv = await queryWithRetry("DELETE FROM pending_verifications WHERE expires_at < NOW() RETURNING email");
    results.expiredVerifications = pv.rowCount || 0;
    // 2. Delete unverified free-tier keys (email not in verified verifications)
    const sk = await queryWithRetry(`
    DELETE FROM api_keys
    WHERE tier = 'free'
      AND email NOT IN (
        SELECT DISTINCT email FROM verifications WHERE verified_at IS NOT NULL
      )
    RETURNING key
  `);
    results.staleKeys = sk.rowCount || 0;
    // 3. Delete orphaned usage rows
    const ou = await queryWithRetry(`
    DELETE FROM usage
    WHERE key NOT IN (SELECT key FROM api_keys)
    RETURNING key
  `);
    results.orphanedUsage = ou.rowCount || 0;
    logger.info({ ...results }, `Database cleanup complete: ${results.expiredVerifications} expired verifications, ${results.staleKeys} stale keys, ${results.orphanedUsage} orphaned usage rows removed`);
    return results;
}
export { pool };
export default pool;