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

const videoAccessLog = new Map();

const CACHE_TIMEOUT = 10 * 60 * 1000;

function createCacheManager() {
  setInterval(cleanupUnusedVideos, 5 * 60 * 1000);

  setTimeout(cleanupUnusedVideos, 30 * 1000);

  scanExistingVideos();

  console.log(
    `Video caching ${
      process.env.ENABLE_CACHING === "true" ? "enabled" : "disabled"
    }`
  );

  return function cacheMiddleware(req, res, next) {
    if (req.path.startsWith("/videocd/")) {
      const pathParts = req.path.split("/").filter(Boolean);
      if (pathParts.length >= 2) {
        const videoId = pathParts[1];
        videoAccessLog.set(videoId, Date.now());
        console.log(`Video ${videoId} accessed at ${new Date().toISOString()}`);
      }
    }

    next();
  };
}

function scanExistingVideos() {
  const videoHostDir = path.join(process.cwd(), "videohost");

  if (!fs.existsSync(videoHostDir)) {
    console.log("Video directory does not exist yet");
    return;
  }

  try {
    const videoDirs = fs.readdirSync(videoHostDir);
    const now = Date.now();

    for (const videoId of videoDirs) {
      const videoDir = path.join(videoHostDir, videoId);

      try {
        if (fs.statSync(videoDir).isDirectory()) {
          videoAccessLog.set(videoId, now);
        }
      } catch (err) {
        console.error(`Error checking directory ${videoId}: ${err.message}`);
      }
    }

    console.log(
      `Found and tracking ${videoAccessLog.size} existing video directories`
    );
  } catch (err) {
    console.error(`Error scanning video directory: ${err.message}`);
  }
}

function cleanupUnusedVideos() {
  const isCachingEnabled = process.env.ENABLE_CACHING === "true";

  if (isCachingEnabled) {
    console.log("Video caching is enabled, skipping cleanup");
    return;
  }

  console.log("Running video cache cleanup check");
  const now = Date.now();
  const videoHostDir = path.join(process.cwd(), "videohost");

  if (!fs.existsSync(videoHostDir)) {
    console.log("Video directory does not exist, nothing to clean up");
    return;
  }

  try {
    const videoDirs = fs.readdirSync(videoHostDir);

    for (const videoId of videoDirs) {
      const lastAccess = videoAccessLog.get(videoId) || 0;
      const timeSinceAccess = now - lastAccess;

      if (timeSinceAccess > CACHE_TIMEOUT) {
        const videoDir = path.join(videoHostDir, videoId);

        try {
          if (fs.statSync(videoDir).isDirectory()) {
            console.log(
              `Removing unused video directory: ${videoId} (last accessed ${Math.floor(
                timeSinceAccess / 60000
              )} minutes ago)`
            );
            fs.rmSync(videoDir, { recursive: true, force: true });
            videoAccessLog.delete(videoId);
          }
        } catch (err) {
          console.error(`Error deleting directory ${videoId}: ${err.message}`);
        }
      }
    }
  } catch (err) {
    console.error(`Error during video cache cleanup: ${err.message}`);
  }
}

module.exports = createCacheManager;