import next from "next"
import { createServer } from "http"
import { Server } from "socket.io"
import { runMigrations } from "@/lib/db/migrate"
import { mcProcessManager } from "@/lib/minecraft/process"
import { setupSocketServer } from "@/lib/socket/server"
import { auth } from "@/lib/auth/index"

const dev = process.env.NODE_ENV !== "production"
const port = Number(process.env.PORT ?? 3000)
const hostname = process.env.HOSTNAME ?? "0.0.0.0"

async function main(): Promise<void> {
  // ---- 1. Run DB migrations -------------------------------------------------
  console.log("[Server] Running database migrations…")
  await runMigrations()
  console.log("[Server] Migrations complete")

  // ---- 2. Prepare Next.js app -----------------------------------------------
  const app = next({ dev, hostname, port })
  const handle = app.getRequestHandler()
  await app.prepare()
  console.log(`[Server] Next.js ready (${dev ? "development" : "production"})`)

  // ---- 3. Create Node.js HTTP server ----------------------------------------
  const httpServer = createServer((req, res) => {
    handle(req, res).catch((err: unknown) => {
      console.error("[Server] Next.js handler error:", err)
      res.statusCode = 500
      res.end("Internal Server Error")
    })
  })

  // ---- 4. Attach Socket.io --------------------------------------------------
  const io = new Server(httpServer, {
    cors: {
      // Restrict to same origin in production; allow all in dev for convenience
      origin: dev ? "*" : (process.env.NEXTAUTH_URL ?? `http://${hostname}:${port}`),
      credentials: true,
    },
    // Use websocket transport first, fall back to polling
    transports: ["websocket", "polling"],
  })

  // Delegate namespace setup (auth middleware + event handlers) to the module
  setupSocketServer(io, auth)

  // ---- 5. Start HTTP server -------------------------------------------------
  await new Promise<void>((resolve, reject) => {
    httpServer.on("error", reject)
    httpServer.listen(port, hostname, () => {
      resolve()
    })
  })

  console.log(`[Server] Listening on http://${hostname}:${port}`)

  // ---- 6. Initialize Minecraft process manager ------------------------------
  // (Does NOT auto-start the MC server; that is controlled through the UI)
  console.log("[Server] McProcessManager initialized")

  // ---- 7. Graceful shutdown -------------------------------------------------
  const shutdown = async (signal: string): Promise<never> => {
    console.log(`\n[Server] Received ${signal}, shutting down…`)

    // Stop accepting new connections
    httpServer.close()

    // Disconnect all Socket.io clients
    await io.close()

    // Stop the Minecraft server gracefully if it is running
    const status = mcProcessManager.getStatus()
    if (status.running) {
      console.log("[Server] Stopping Minecraft server…")
      try {
        await mcProcessManager.stop(false)
      } catch {
        // If graceful stop fails, force kill
        try {
          await mcProcessManager.stop(true)
        } catch (err) {
          console.error("[Server] Force stop failed:", err)
        }
      }
    }

    console.log("[Server] Goodbye.")
    process.exit(0)
  }

  process.on("SIGTERM", () => void shutdown("SIGTERM"))
  process.on("SIGINT", () => void shutdown("SIGINT"))
}

main().catch((err: unknown) => {
  console.error("[Server] Fatal startup error:", err)
  process.exit(1)
})