/*
 * Copyright (C) 2025 Jakub Žitník
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

import express, { Request, Response } from "express";
import path from "path";
const app = express();
import fs from "fs/promises";
import { getCurrentInterval } from "./scheduleRules.js";
import bodyParser from "body-parser";
import cors from "cors";
import next from "next";
import { fileURLToPath } from "url";

const DB_FOLDER = path.join(process.cwd(), "volume", "db");
const WEB_FOLDER = path.join(process.cwd(), "web", "public");
const SERVE_WEB = process.env.SERVE_WEB != "false";

const VERSIONS = ["v1", "v2", "v3"];
const PORT = process.env.PORT || 3000;

// @ts-ignore
globalThis.File = class File {};

app.use(bodyParser.json());

app.use(cors({
  origin: "*",
  methods: ["GET", "POST", "OPTIONS"],
  allowedHeaders: ["Content-Type"],
}));

app.get('/', async (req: Request, res: Response) => {
  const userAgent = req.headers['user-agent'] || '';
  const isBrowser = /Mozilla|Chrome|Firefox|Safari|Edg/.test(userAgent);

  if (isBrowser && SERVE_WEB) {
    res.sendFile(path.join(WEB_FOLDER, "index.html"));
  } else {
    const dataStr = await fs.readFile(path.join(DB_FOLDER, "v1.json"), "utf8");
    const data = JSON.parse(dataStr);

    data["status"]["currentUpdateSchedule"] = getCurrentInterval();

    res.json(data);
  }
});

VERSIONS.forEach((version) => {
  app.get(`/versioned/${version}`, async (_: Request, res: Response) => {
    try {
      const filePath = path.join(DB_FOLDER, `${version}.json`);
      const dataStr = await fs.readFile(filePath, "utf8");
      const data = JSON.parse(dataStr);

      data.status.currentUpdateSchedule = getCurrentInterval();

      res.json(data);
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: "Failed to load version data" });
    }
  });
});

app.get("/status", async (_: Request, res: Response) => {
  const dataStr = await fs.readFile(path.resolve("./volume/customState.json"), {encoding: "utf8"});
  const data = JSON.parse(dataStr);

  if (data.working) {
    res.json({ working: true })
  } else {
    res.json({ working: data.working, message: data.message })
  }
})

app.get("/posts/viewer/redirect", (_: Request, res: Response) => {
  res.redirect(302, "/viewer");
})

app.post("/report", async (req: Request, res: Response): Promise<any> => {
  const { class: className, location, content } = req.body;
  if (!className || !location || !content) {
    return res.status(400).json({ error: "Missing required fields." });
  }
  if (!["TIMETABLE", "ABSENCES", "ABSENCE", "TAKES_PLACE", "OTHER"].includes(location)) {
    return res.status(400).json({ error: "Invalid location value." });
  }

  const url = process.env.REPORT_WEBHOOK_URL;

  if (!url) {
      console.error("REPORT_WEBHOOK_URL is not set.");
      return res.status(500).json({ error: "Server configuration error." });
  }

  let resp;
  try {
    resp = await fetch(url, {
      method: "POST",
      headers: {
        "Content-Type": "text/plain",
      },
      body: `${content}\n\nClass: ${className}\nLocation: ${location}`,
    });
  } catch (err: any) {
    console.error('Fetch failed:', err.message);
    console.error(err);
    throw err;
  }

  if (!resp.ok) {
    throw new Error(`Request failed`);
  }

  res.status(200).json({ message: "Report received successfully." });
});

if (SERVE_WEB) {
  const __filename = fileURLToPath(import.meta.url)
  const __dirname = path.dirname(__filename)
  const dev = process.env.NODE_ENV !== 'production'

  // @ts-ignore
  const nextApp = next({
    dev,
    dir: path.join(__dirname, '../viewer')
  })

  const handle = nextApp.getRequestHandler()

  await nextApp.prepare()

  app.all(/^\/viewer(?:$|\/.*)/, (req, res) => {
    return handle(req, res)
  })

  app.use(express.static(path.join(process.cwd(), 'web/public'), {
    index: 'index.html',
    extensions: ['html'],
  }))
}

app.listen(PORT, () => {
  console.log(`Server is running at http://localhost:${PORT}`);
});