import fs from "node:fs";
import type { IncomingMessage, ServerResponse } from "node:http";
import path from "node:path";
import type { Connect, Plugin, ViteDevServer } from "vite";
import { spawn } from "child_process";

export function gttsPlugin(): Plugin {
  return {
    name: "gtts",
    configureServer(server: ViteDevServer) {
      // Vite dev server middlewares are connect-style: (req, res, next)
      server.middlewares.use(async (req, res, next) => {
        const reqUrl = req.url;
        if (!reqUrl) return next();

        const url = new URL(reqUrl, "http://localhost");
        if (url.pathname !== "/api/tts") return next();

        const text = url.searchParams.get("text");
        if (!text) return next();

        try {
          await gtts(text, req, res, next);
        } catch (e) {
          console.error(e, reqUrl);
          next();
        }
      });
    },
  };
}

let fileList: Record<string, number> = {};

async function gtts(
  text: string,
  req: Connect.IncomingMessage,
  res: ServerResponse<IncomingMessage>,
  next: Connect.NextFunction,
) {
  text = text.replace(/["]/g, " ");

  const saveroot = "docs/.vitepress/cache/gtts";
  fs.mkdirSync(saveroot, { recursive: true });

  const fileListJSON = path.join(saveroot, "gtts.json");

  if (Object.keys(fileList).length === 0 && fs.existsSync(fileListJSON)) {
    fileList = JSON.parse(fs.readFileSync(fileListJSON, "utf-8"));
  }

  const fileNo = fileList[text] || Object.keys(fileList).length;
  const filename = `${fileNo}.mp3`;
  const saveto = path.join(saveroot, filename);

  if (!fs.existsSync(saveto)) {
    await new Promise((resolve, reject) => {
      const p = spawn(
        "gtts-cli",
        [
          `"${text}"`,
          ...["--lang", "ko"],
          ...["--output", path.join(process.cwd(), saveto)],
        ],
        {
          stdio: "inherit",
          shell: true,
        },
      );
      p.on("error", reject).on("close", resolve);
    });
    fileList[text] = fileNo;
    console.log(`gtts: ${text} saved to ${saveto}`);

    fs.writeFileSync(fileListJSON, JSON.stringify(fileList, null, 2));
  } else {
    // console.log(`gtts: ${text} loaded from ${saveto}`);
  }

  res.setHeader("Content-Type", "audio/mpeg");
  fs.createReadStream(saveto).pipe(res);
}