const express = require("express");
const cors = require("cors");
const path = require("path");
const fs = require("fs");
const { execSync } = require("child_process");
const os = require("os");

/**
 * Local development server for testing providers
 */
class DevServer {
  constructor() {
    this.app = express();
    this.port = 3001;
    this.distDir = path.join(__dirname, "dist");
    this.currentDir = path.join(__dirname);

    this.setupMiddleware();
    this.setupRoutes();
  }

  setupMiddleware() {
    // Enable CORS for mobile app
    this.app.use(
      cors({
        origin: "*",
        methods: ["GET", "POST", "OPTIONS"],
        allowedHeaders: ["Content-Type", "Authorization"],
      })
    );

    // Serve static files from dist directory
    this.app.use("/dist", express.static(this.distDir));

    // JSON parsing
    this.app.use(express.json());

    // Logging
    this.app.use((req, res, next) => {
      console.log(`${new Date().toISOString()} - ${req.method} ${req.url}`);
      next();
    });
  }

  setupRoutes() {
    // Serve manifest.json
    this.app.get("/manifest.json", (req, res) => {
      const manifestPath = path.join(this.currentDir, "manifest.json");
      console.log(`Serving manifest from: ${manifestPath}`);

      if (fs.existsSync(manifestPath)) {
        res.sendFile(manifestPath);
      } else {
        res.status(404).json({ error: "Manifest not found. Run build first." });
      }
    });

    // Serve individual provider files
    this.app.get("/dist/:provider/:file", (req, res) => {
      const { provider, file } = req.params;
      const filePath = path.join(this.distDir, provider, file);

      if (fs.existsSync(filePath)) {
        res.sendFile(filePath);
      } else {
        res.status(404).json({
          error: `File not found: ${provider}/${file}`,
          hint: "Make sure to run build first",
        });
      }
    });

    // Build endpoint - trigger rebuild
    this.app.post("/build", (req, res) => {
      try {
        console.log("🔨 Triggering rebuild...");
        execSync("node build.js", { stdio: "inherit" });
        res.json({ success: true, message: "Build completed" });
      } catch (error) {
        console.error("Build failed:", error);
        res.status(500).json({
          success: false,
          error: error.message,
        });
      }
    });

    // Status endpoint
    this.app.get("/status", (req, res) => {
      const providers = this.getAvailableProviders();
      res.json({
        status: "running",
        port: this.port,
        providers: providers.length,
        providerList: providers,
        buildTime: this.getBuildTime(),
      });
    });

    // List available providers
    this.app.get("/providers", (req, res) => {
      const providers = this.getAvailableProviders();
      res.json(providers);
    });

    // Health check
    this.app.get("/health", (req, res) => {
      res.json({ status: "healthy", timestamp: new Date().toISOString() });
    });

    // 404 handler
    this.app.use((req, res) => {
      res.status(404).json({
        error: "Not found",
        availableEndpoints: [
          "GET /manifest.json",
          "GET /dist/:provider/:file",
          "POST /build",
          "GET /status",
          "GET /providers",
          "GET /health",
        ],
      });
    });
  }

  getAvailableProviders() {
    if (!fs.existsSync(this.distDir)) {
      return [];
    }

    return fs
      .readdirSync(this.distDir, { withFileTypes: true })
      .filter((item) => item.isDirectory())
      .map((item) => item.name);
  }

  getBuildTime() {
    const manifestPath = path.join(this.rootDir, "manifest.json");
    if (fs.existsSync(manifestPath)) {
      const stats = fs.statSync(manifestPath);
      return stats.mtime.toISOString();
    }
    return null;
  }

  start() {
    // Get local IP address
    const interfaces = os.networkInterfaces();
    let localIp = "localhost";
    for (const name of Object.keys(interfaces)) {
      for (const iface of interfaces[name]) {
        if (iface.family === "IPv4" && !iface.internal) {
          localIp = iface.address;
          break;
        }
      }
      if (localIp !== "localhost") break;
    }
    this.app.listen(this.port, "0.0.0.0", () => {
      console.log(`
🚀 Vega Providers Dev Server Started!

📡 Server URL: http://localhost:${this.port}
📱 Mobile Test URL: http://${localIp}:${this.port}

💡 Usage:
  1. Run 'npm run auto' to to start the dev server ☑️
  2. Update vega app to use: http://${localIp}:${this.port}
  3. Test your providers!

🔄 Auto-rebuild: POST to /build to rebuild after changes
      `);

      // Check if build exists
      if (!fs.existsSync(this.distDir)) {
        console.log('\n⚠️  No build found. Run "node build.js" first!\n');
      }
    });
  }
}

// Start the server
const server = new DevServer();
server.start();