/**
 * Local API for MySQL. Keeps credentials off the client.
 * Run: npm run server, or npm run dev (starts API + Vite together).
 */
import "dotenv/config";
import cors from "cors";
import express from "express";
import path from "path";
import type { RowDataPacket } from "mysql2";
import mysql from "mysql2/promise";
import { registerAuthRoutes } from "./auth";
import { registerCourseVideoRoutes } from "./courseVideos";

const app = express();
app.use(express.json());
app.use(
  cors({
    origin: process.env.CORS_ORIGIN?.split(",").map((s) => s.trim()) ?? true,
  }),
);

const apiPort = Number(process.env.API_PORT ?? 3001);
const apiHost = process.env.API_HOST ?? "127.0.0.1";

function sslOption(): boolean | { rejectUnauthorized: boolean } | undefined {
  if (process.env.MYSQL_SSL !== "true") return undefined;
  if (process.env.MYSQL_SSL_INSECURE === "true") {
    return { rejectUnauthorized: false };
  }
  return true;
}

let pool: mysql.Pool | null = null;

function getPool(): mysql.Pool {
  if (pool) return pool;
  const host = process.env.MYSQL_HOST || process.env.DB_HOST;
  const user = process.env.MYSQL_USER || process.env.DB_USER;
  const database = process.env.MYSQL_DATABASE || process.env.DB_NAME;
  if (!host || !user || !database) {
    throw new Error("Set DB_HOST, DB_USER, DB_NAME (or MYSQL_*) in .env");
  }
  const portEnv = process.env.MYSQL_PORT || process.env.DB_PORT;
  pool = mysql.createPool({
    host,
    port: Number(portEnv ?? 3306),
    user,
    password: process.env.MYSQL_PASSWORD ?? process.env.DB_PASSWORD ?? "",
    database,
    waitForConnections: true,
    connectionLimit: Number(process.env.MYSQL_CONNECTION_LIMIT ?? 5),
    ssl: sslOption(),
  });
  return pool;
}

registerAuthRoutes(app, getPool);
registerCourseVideoRoutes(app, getPool);

app.use("/uploads", express.static(path.join(process.cwd(), "uploads")));

app.get("/api/health", (_req, res) => {
  res.json({ ok: true });
});

app.get("/api/db/ping", async (_req, res) => {
  try {
    const [rows] = await getPool().query<RowDataPacket[]>("SELECT 1 AS ok");
    res.json({ ok: true, rows });
  } catch (err) {
    console.error("[db/ping]", err);
    res.status(503).json({ ok: false, error: "Database unreachable" });
  }
});

app.listen(apiPort, apiHost, () => {
  console.log(`API listening on http://${apiHost}:${apiPort}`);
});