const { describe, it, mock, beforeEach } = require('node:test');
const assert = require('node:assert/strict');
const path = require('path');
const { EventEmitter } = require('events');

// We need to mock fs.statSync and the hoster upload functions before requiring upload-manager
// Use node:test mock.module (available in Node 22+)

describe('UploadManager', () => {
  let UploadManager;
  let mockUploadFile;
  let fakeFileSize;

  beforeEach(() => {
    fakeFileSize = 1024 * 1024; // 1 MB default

    // Clear module cache for fresh mocks each test
    delete require.cache[require.resolve('../lib/upload-manager')];

    // Mock the hosters module
    mockUploadFile = mock.fn(async (hoster, filePath, apiKey, onProgress, signal, throttle) => {
      // Simulate upload progress
      if (onProgress) {
        onProgress(fakeFileSize / 2, fakeFileSize);
        onProgress(fakeFileSize, fakeFileSize);
      }
      return { download_url: `https://${hoster}/test123`, embed_url: null, file_code: 'test123' };
    });

    // Override require for hosters
    const origRequire = module.constructor.prototype.require;
    const hosters = require('../lib/hosters');
    hosters.uploadFile = mockUploadFile;

    // Mock fs.statSync for test file paths
    const fs = require('fs');
    const origStatSync = fs.statSync;
    fs.statSync = function(p) {
      if (typeof p === 'string' && p.startsWith('/test/')) {
        return { size: fakeFileSize };
      }
      return origStatSync.call(this, p);
    };

    UploadManager = require('../lib/upload-manager');
  });

  it('emits progress events for each task', async () => {
    const mgr = new UploadManager({});
    const events = [];
    mgr.on('progress', (data) => events.push(data));

    await mgr.startBatch([
      { file: '/test/video1.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    const statuses = events.map(e => e.status);
    assert.ok(statuses.includes('queued'), 'should have queued status');
    assert.ok(statuses.includes('done'), 'should have done status');
  });

  it('emits batch-done with correct summary', async () => {
    const mgr = new UploadManager({});
    let summary = null;
    mgr.on('batch-done', (s) => { summary = s; });

    await mgr.startBatch([
      { file: '/test/video1.mp4', hoster: 'doodstream.com', apiKey: 'key1' },
      { file: '/test/video2.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(summary);
    assert.equal(summary.total, 2);
    assert.equal(summary.succeeded, 2);
    assert.equal(summary.failed, 0);
    assert.equal(summary.files.length, 2);
  });

  it('retries on failure then succeeds', async () => {
    let callCount = 0;
    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress) => {
      callCount++;
      if (callCount <= 2) throw new Error('network error');
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'https://test/ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({ 'doodstream.com': { retries: 3, parallelCount: 1, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 } });
    const statuses = [];
    mgr.on('progress', (d) => statuses.push(d.status));

    await mgr.startBatch([
      { file: '/test/video.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(statuses.includes('retrying'), 'should show retrying status');
    assert.ok(statuses.includes('done'), 'should eventually succeed');
    assert.equal(callCount, 3);
  });

  it('exhausted retries result in error', async () => {
    mockUploadFile.mock.mockImplementation(async () => {
      throw new Error('permanent failure');
    });

    const mgr = new UploadManager({ 'doodstream.com': { retries: 1, parallelCount: 1, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 } });
    let summary = null;
    mgr.on('batch-done', (s) => { summary = s; });

    await mgr.startBatch([
      { file: '/test/video.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(summary);
    assert.equal(summary.failed, 1);
    assert.equal(summary.succeeded, 0);
  });

  it('cancel aborts running uploads', async () => {
    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress, signal) => {
      // Simulate a slow upload
      await new Promise((resolve, reject) => {
        const timer = setTimeout(() => resolve({ download_url: 'x', embed_url: null, file_code: 'x' }), 10000);
        if (signal) signal.addEventListener('abort', () => { clearTimeout(timer); reject(new Error('Aborted')); });
      });
    });

    const mgr = new UploadManager({});
    let batchDone = false;
    mgr.on('batch-done', () => { batchDone = true; });

    const batchPromise = mgr.startBatch([
      { file: '/test/video.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    // Wait a bit then cancel
    await new Promise(r => setTimeout(r, 100));
    mgr.cancel();

    await batchPromise;
    assert.equal(mgr.running, false);
    assert.ok(batchDone, 'batch-done should be emitted even after cancel');
  });

  it('maxSizeMb filter skips oversized files', async () => {
    fakeFileSize = 5 * 1024 * 1024; // 5 MB

    const mgr = new UploadManager({ 'doodstream.com': { retries: 0, parallelCount: 1, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 1 } });
    const statuses = [];
    mgr.on('progress', (d) => statuses.push(d.status));

    await mgr.startBatch([
      { file: '/test/big.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(statuses.includes('skipped'), 'oversized file should be skipped');
    assert.ok(!statuses.includes('uploading'), 'should not attempt upload');
  });

  it('per-hoster semaphore limits concurrency', async () => {
    let concurrent = 0;
    let maxConcurrent = 0;

    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress, signal) => {
      concurrent++;
      maxConcurrent = Math.max(maxConcurrent, concurrent);
      await new Promise(r => setTimeout(r, 50));
      concurrent--;
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'https://test/ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({ 'doodstream.com': { retries: 0, parallelCount: 1, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 } });

    await mgr.startBatch([
      { file: '/test/a.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/b.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/c.mp4', hoster: 'doodstream.com', apiKey: 'k' }
    ]);

    assert.equal(maxConcurrent, 1, 'should only run 1 upload at a time');
  });

  it('global parallel limit caps concurrency across hosters', async () => {
    let concurrent = 0;
    let maxConcurrent = 0;

    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress) => {
      concurrent++;
      maxConcurrent = Math.max(maxConcurrent, concurrent);
      await new Promise((resolve) => setTimeout(resolve, 40));
      concurrent--;
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: `https://${hoster}/ok`, embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({
      'doodstream.com': { retries: 0, parallelCount: 5, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 },
      'voe.sx': { retries: 0, parallelCount: 5, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 },
      'vidmoly.me': { retries: 0, parallelCount: 5, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 }
    }, {
      parallelUploadCount: 2,
      scaleParallelUploads: true
    });

    await mgr.startBatch([
      { jobId: 'job-1', file: '/test/a.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { jobId: 'job-2', file: '/test/b.mp4', hoster: 'voe.sx', apiKey: 'k' },
      { jobId: 'job-3', file: '/test/c.mp4', hoster: 'vidmoly.me', apiKey: 'k' }
    ]);

    assert.equal(maxConcurrent, 2, 'should only run 2 uploads globally at once');
  });

  it('cancelJobs aborts a selected running upload', async () => {
    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress, signal) => {
      await new Promise((resolve, reject) => {
        const timer = setTimeout(() => resolve(), 250);
        if (signal) {
          signal.addEventListener('abort', () => {
            clearTimeout(timer);
            reject(new Error('Aborted'));
          }, { once: true });
        }
      });
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'https://test/ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({});
    const statuses = [];
    mgr.on('progress', (data) => statuses.push({ jobId: data.jobId, status: data.status }));

    const batchPromise = mgr.startBatch([
      { jobId: 'selected-job', file: '/test/video.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    await new Promise((resolve) => setTimeout(resolve, 50));
    mgr.cancelJobs(['selected-job']);

    await batchPromise;
    assert.ok(statuses.some((entry) => entry.jobId === 'selected-job' && entry.status === 'aborted'));
  });

  it('addJobs returns duplicate info and still runs newly queued jobs', async () => {
    let releaseFirst = null;

    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress, signal) => {
      if (filePath.endsWith('/first.mp4')) {
        await new Promise((resolve, reject) => {
          releaseFirst = resolve;
          if (signal) {
            signal.addEventListener('abort', () => reject(new Error('Aborted')), { once: true });
          }
        });
      } else {
        await new Promise((resolve) => setTimeout(resolve, 20));
      }
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'https://test/ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({
      'doodstream.com': { retries: 0, parallelCount: 1, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 }
    });
    const statuses = [];
    mgr.on('progress', (data) => statuses.push({ jobId: data.jobId, status: data.status }));

    const batchPromise = mgr.startBatch([
      { jobId: 'job-first', file: '/test/first.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    for (let i = 0; i < 50 && !releaseFirst; i++) {
      await new Promise((resolve) => setTimeout(resolve, 10));
    }
    assert.equal(typeof releaseFirst, 'function', 'first job should be running before addJobs');

    const addResult = mgr.addJobs([
      { jobId: 'job-first', file: '/test/first.mp4', hoster: 'doodstream.com', apiKey: 'key1' },
      { jobId: 'job-second', file: '/test/second.mp4', hoster: 'doodstream.com', apiKey: 'key1' },
      { jobId: 'job-third', file: '/test/third.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.equal(addResult.added, 2);
    assert.deepEqual(addResult.alreadyInBatchJobIds, ['job-first']);

    releaseFirst();
    await batchPromise;

    assert.ok(statuses.some((entry) => entry.jobId === 'job-second' && entry.status === 'done'));
    assert.ok(statuses.some((entry) => entry.jobId === 'job-third' && entry.status === 'done'));
  });

  it('_combineSignals propagates abort from either source', () => {
    const mgr = new UploadManager({});
    const ac1 = new AbortController();
    const ac2 = new AbortController();

    const { signal, cleanup } = mgr._combineSignals(ac1.signal, ac2.signal);
    assert.equal(signal.aborted, false);

    ac2.abort();
    assert.equal(signal.aborted, true);
    cleanup();
  });

  it('_combineSignals returns aborted signal if input already aborted', () => {
    const mgr = new UploadManager({});
    const ac1 = new AbortController();
    ac1.abort();
    const ac2 = new AbortController();

    const { signal, cleanup } = mgr._combineSignals(ac1.signal, ac2.signal);
    assert.equal(signal.aborted, true);
    cleanup();
  });

  it('_sleep resolves after delay', async () => {
    const mgr = new UploadManager({});
    const start = Date.now();
    await mgr._sleep(100);
    assert.ok(Date.now() - start >= 90);
  });

  it('_sleep rejects on abort', async () => {
    const mgr = new UploadManager({});
    const ac = new AbortController();
    setTimeout(() => ac.abort(), 10);
    await assert.rejects(mgr._sleep(5000, ac.signal), /Aborted/);
  });

  it('file not found produces descriptive error', async () => {
    // Override fs.statSync to throw ENOENT for a specific path
    const fs = require('fs');
    const origStat = fs.statSync;
    fs.statSync = function(p) {
      if (p === '/test/deleted.mp4') throw Object.assign(new Error('ENOENT'), { code: 'ENOENT' });
      return origStat.call(this, p);
    };

    const mgr = new UploadManager({});
    const errors = [];
    mgr.on('progress', (d) => { if (d.error) errors.push(d.error); });

    await mgr.startBatch([
      { file: '/test/deleted.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    fs.statSync = origStat;
    assert.ok(errors.some(e => e.includes('nicht gefunden')), `expected "nicht gefunden" error, got: ${errors.join(', ')}`);
  });

  it('zero-byte file produces descriptive error', async () => {
    fakeFileSize = 0;

    const mgr = new UploadManager({});
    const errors = [];
    mgr.on('progress', (d) => { if (d.error) errors.push(d.error); });

    await mgr.startBatch([
      { file: '/test/empty.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(errors.some(e => e.includes('0 Bytes')), `expected "0 Bytes" error, got: ${errors.join(', ')}`);
  });

  it('empty batch completes immediately with zero counts', async () => {
    const mgr = new UploadManager({});
    let summary = null;
    mgr.on('batch-done', (s) => { summary = s; });

    const start = Date.now();
    await mgr.startBatch([]);
    const elapsed = Date.now() - start;

    assert.ok(summary, 'batch-done should be emitted');
    assert.equal(summary.total, 0);
    assert.equal(summary.succeeded, 0);
    assert.equal(summary.failed, 0);
    assert.ok(elapsed < 200, `empty batch should complete fast, took ${elapsed}ms`);
  });

  it('scaleParallelUploads limits per-hoster count to global limit', async () => {
    let concurrent = 0;
    let maxConcurrent = 0;

    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress) => {
      concurrent++;
      maxConcurrent = Math.max(maxConcurrent, concurrent);
      await new Promise(r => setTimeout(r, 40));
      concurrent--;
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager(
      { 'doodstream.com': { retries: 0, parallelCount: 10, maxSpeedKbs: 0, restartBelowKbs: 0, timeIntervalSec: 0, maxSizeMb: 0 } },
      { parallelUploadCount: 2, scaleParallelUploads: true }
    );

    await mgr.startBatch([
      { file: '/test/a.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/b.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/c.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/d.mp4', hoster: 'doodstream.com', apiKey: 'k' },
      { file: '/test/e.mp4', hoster: 'doodstream.com', apiKey: 'k' }
    ]);

    assert.ok(maxConcurrent <= 2, `scaleParallelUploads should cap at 2, was ${maxConcurrent}`);
  });

  it('stats event contains expected fields', async () => {
    // Make upload take long enough for stats interval to fire
    mockUploadFile.mock.mockImplementation(async (hoster, filePath, apiKey, onProgress, signal) => {
      await new Promise(r => setTimeout(r, 1500));
      if (onProgress) onProgress(fakeFileSize, fakeFileSize);
      return { download_url: 'https://test/ok', embed_url: null, file_code: 'ok' };
    });

    const mgr = new UploadManager({});
    const statsEvents = [];
    mgr.on('stats', (d) => statsEvents.push(d));

    await mgr.startBatch([
      { file: '/test/video.mp4', hoster: 'doodstream.com', apiKey: 'key1' }
    ]);

    assert.ok(statsEvents.length > 0, 'should have received stats events');
    const stat = statsEvents[0];
    assert.ok('globalSpeedKbs' in stat);
    assert.ok('totalBytes' in stat);
    assert.ok('elapsed' in stat);
    assert.ok('activeJobs' in stat);
  });
});