import express, { type Express } from "express";
import fs from "fs";
import path from "path";
import { createServer as createViteServer, createLogger } from "vite";
import { type Server } from "http";
import viteConfig from "../vite.config";
import { nanoid } from "nanoid";

const viteLogger = createLogger();

export function log(message: string, source = "express") {
  const formattedTime = new Date().toLocaleTimeString("en-US", {
    hour: "numeric",
    minute: "2-digit",
    second: "2-digit",
    hour12: true,
  });

  console.log(`${formattedTime} [${source}] ${message}`);
}

export async function setupVite(app: Express, server: Server) {
  const serverOptions = {
    middlewareMode: true,
    hmr: { server },
    allowedHosts: true as const,
  };

  const vite = await createViteServer({
    ...viteConfig,
    configFile: false,
    customLogger: {
      ...viteLogger,
      error: (msg, options) => {
        viteLogger.error(msg, options);
        process.exit(1);
      },
    },
    server: serverOptions,
    appType: "custom",
  });

  app.use(vite.middlewares);
  app.use("*", async (req, res, next) => {
    const url = req.originalUrl;

    try {
      const clientTemplate = path.resolve(
        import.meta.dirname,
        "..",
        "client",
        "index.html",
      );

      // always reload the index.html file from disk incase it changes
      let template = await fs.promises.readFile(clientTemplate, "utf-8");
      template = template.replace(
        `src="/src/main.tsx"`,
        `src="/src/main.tsx?v=${nanoid()}"`,
      );
      const page = await vite.transformIndexHtml(url, template);
      res.status(200).set({ "Content-Type": "text/html" }).end(page);
    } catch (e) {
      vite.ssrFixStacktrace(e as Error);
      next(e);
    }
  });
}

export function serveStatic(app: Express) {
  const distPath = path.resolve(import.meta.dirname, "public");

  if (!fs.existsSync(distPath)) {
    throw new Error(
      `Could not find the build directory: ${distPath}, make sure to build the client first`,
    );
  }

  app.use(
    express.static(distPath, {
      setHeaders: (res, filePath) => {
        const relative = path.relative(distPath, filePath).replace(/\\/g, '/');

        // Service Worker must never be cached by the browser, otherwise updates
        // are delayed by up to 24 hours and users see stale app versions.
        if (relative === 'sw.js') {
          res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
          res.setHeader('Pragma', 'no-cache');
          res.setHeader('Expires', '0');
          return;
        }

        // HTML entry and manifest must be revalidated on every load.
        if (relative === 'index.html' || relative === 'manifest.json') {
          res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate, proxy-revalidate');
          res.setHeader('Pragma', 'no-cache');
          res.setHeader('Expires', '0');
          return;
        }

        // Vite hashed assets (e.g. index-AbC123Xy.js, FormEditor-fy2__RGH.js)
        // can be cached forever because the filename changes on every content change.
        // Vite uses a dash before the hash, so we match either `.hash.ext` or `-hash.ext`.
        if (/[-.][a-zA-Z0-9_-]{8,}\.(js|css|webp|png|jpg|jpeg|svg|gif|ico|woff|woff2|ttf|otf|eot)$/i.test(relative)) {
          res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
          return;
        }
      },
    }),
  );

  // fall through to index.html if the file doesn't exist
  app.use("*", (_req, res) => {
    res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate, proxy-revalidate');
    res.setHeader('Pragma', 'no-cache');
    res.setHeader('Expires', '0');
    res.sendFile(path.resolve(distPath, "index.html"));
  });
}