const fs = require("fs");
const http = require("http");

const config = fs.readFileSync(process.argv[2], "utf8");
const portFor = (key) => Number(new RegExp(`^${key}:\\s*"127\\.0\\.0\\.1:(\\d+)"`, "m").exec(config)?.[1]);
const pathName = /^paths:\s*\n\s+"([^"]+)":/m.exec(config)?.[1] || null;
const apiPort = portFor("apiAddress");
const metricsPort = portFor("metricsAddress");
const hlsPort = portFor("hlsAddress");
const servers = [];

function listen(port, handler) {
  const server = http.createServer(handler);
  server.listen(port, "127.0.0.1");
  servers.push(server);
}

listen(apiPort, (req, res) => {
  if (req.url !== "/v3/paths/list") return res.writeHead(404).end();
  res.setHeader("Content-Type", "application/json");
  res.end(JSON.stringify({
    itemCount: pathName ? 1 : 0,
    pageCount: 1,
    items: pathName ? [{
      name: pathName,
      ready: false,
      tracks: [],
      bytesReceived: 0,
      bytesSent: 0,
      readers: []
    }] : []
  }));
});

listen(metricsPort, (_req, res) => {
  res.setHeader("Content-Type", "text/plain");
  res.end(pathName
    ? `paths{name=${JSON.stringify(pathName)}} 1\npaths_readers{name=${JSON.stringify(pathName)}} 0\npaths_inbound_bytes{name=${JSON.stringify(pathName)}} 0\npaths_outbound_bytes{name=${JSON.stringify(pathName)}} 0\nhls_sessions 0\n`
    : "paths 0\nhls_sessions 0\n");
});

listen(hlsPort, (req, res) => {
  if (!pathName || !req.url.startsWith(`/${pathName}/`)) return res.writeHead(404).end();
  if (req.url.includes("index.m3u8")) {
    res.setHeader("Content-Type", "application/vnd.apple.mpegurl");
    return res.end("#EXTM3U\n#EXT-X-MAP:URI=\"init.mp4\"\n#EXTINF:1,\nsegment0.mp4\n");
  }
  res.setHeader("Content-Type", "video/mp4");
  res.end(Buffer.from("fake-media"));
});

function close() {
  let pending = servers.length;
  if (!pending) return process.exit(0);
  for (const server of servers) server.close(() => {
    pending -= 1;
    if (!pending) process.exit(0);
  });
  setTimeout(() => process.exit(0), 500).unref();
}

process.on("SIGINT", close);
process.on("SIGTERM", close);