#!/usr/bin/env bun
/**
 * Development watch script for Bun
 * 
 * Watches src/ for changes, rebuilds on change, and restarts the server.
 * This is necessary because we must compile TypeScript first due to circular
 * TypeORM entity dependencies that Bun's TS loader cannot handle directly.
 */

import { watch } from "fs";
import { spawn } from "child_process";
import consola from "consola";

let serverProcess: ReturnType<typeof spawn> | null = null;
let isRebuilding = false;
let pendingRestart = false;
let debounceTimer: NodeJS.Timeout | null = null;
let watcherReady = false;

function killServer() {
  return new Promise<void>((resolve) => {
    if (serverProcess) {
      consola.info("Stopping server...");
      serverProcess.kill();
      serverProcess = null;
      // Wait for port to be fully released (longer on Windows)
      setTimeout(resolve, 2000);
    } else {
      resolve();
    }
  });
}

function startServer() {
  consola.info("Starting server...");
  serverProcess = spawn("bun", ["dist/app.js"], {
    stdio: "inherit",
    shell: true,
  });

  serverProcess.on("error", (err) => {
    consola.error("Server process error:", err);
  });

  serverProcess.on("exit", (code) => {
    if (code !== null && code !== 0 && code !== 143) {
      consola.error(`Server exited with code ${code}`);
    }
  });

  // Enable watcher after initial server start
  if (!watcherReady) {
    setTimeout(() => {
      watcherReady = true;
      consola.success("👀 Watching for file changes...");
    }, 1000);
  }
}

async function rebuild() {
  if (isRebuilding) {
    pendingRestart = true;
    return;
  }

  isRebuilding = true;
  pendingRestart = false;

  consola.info("Rebuilding...");
  await killServer();

  const buildProcess = spawn("bun", ["run", "build"], {
    stdio: "inherit",
    shell: true,
  });

  buildProcess.on("exit", (code) => {
    isRebuilding = false;

    if (code === 0) {
      consola.success("Build complete!");
      startServer();

      if (pendingRestart) {
        consola.info("Change detected during build, rebuilding again...");
        setTimeout(() => rebuild(), 100);
      }
    } else {
      consola.error(`Build failed with code ${code}`);
    }
  });
}

// Initial build and start
consola.info("🔄 Development mode - watching for changes...");
rebuild();

// Watch src/ for changes (including subdirectories)
const watcher = watch(
  "./src",
  { recursive: true },
  (eventType, filename) => {
    if (!watcherReady) return; // Ignore changes during initial build
    
    if (filename && filename.endsWith(".ts")) {
      // Ignore test files and declaration files
      if (filename.endsWith(".spec.ts") || filename.endsWith(".d.ts")) {
        return;
      }
      
      // Debounce: wait 500ms for multiple rapid changes
      if (debounceTimer) {
        clearTimeout(debounceTimer);
      }
      
      debounceTimer = setTimeout(() => {
        consola.info(`File changed: ${filename}`);
        rebuild();
      }, 500);
    }
  }
);

// Cleanup on exit
process.on("SIGINT", () => {
  consola.info("\nShutting down...");
  if (debounceTimer) clearTimeout(debounceTimer);
  killServer();
  watcher.close();
  process.exit(0);
});

process.on("SIGTERM", () => {
  if (debounceTimer) clearTimeout(debounceTimer);
  killServer();
  watcher.close();
  process.exit(0);
});