import { createServer } from 'node:http';

import { JobQueue, SqliteStorage } from '../src/index.js';
import { cleanupDir, createDbPath, createTempDir, waitFor } from './helpers.js';

describe('JobQueue', () => {
  it('runs multi-phase jobs to completion', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['download', 'process'],
      concurrency: 1,
    });
    const events: string[] = [];

    queue.on('job:started', () => events.push('started'));
    queue.on('job:phase:completed', (_, phase) => events.push(`phase:${phase.name}`));
    queue.on('job:completed', () => events.push('completed'));

    queue.handle('download', async (_job, ctx) => {
      await ctx.progress(50, 'downloading');
      return { filePath: '/tmp/video.mp4' };
    });

    queue.handle('process', async (_job, ctx) => {
      expect(ctx.phaseResult<{ filePath: string }>('download')?.filePath).toBe('/tmp/video.mp4');
      await ctx.progress(25, 'processing');
      return { outputPath: '/tmp/video.txt' };
    });

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'completed');

      const job = queue.getJob(jobId);
      expect(job?.status).toBe('completed');
      expect(job?.phaseResults.download).toEqual({ filePath: '/tmp/video.mp4' });
      expect(job?.phaseResults.process).toEqual({ outputPath: '/tmp/video.txt' });
      expect(events).toEqual(['started', 'phase:download', 'phase:process', 'completed']);
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });

  it('retries recoverable failures and eventually completes', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['run'],
      concurrency: 1,
      retry: {
        maxAttempts: 3,
        baseDelayMs: 10,
        classifyError: async (error) =>
          error instanceof Error && error.message === 'recoverable' ? 'recoverable' : 'fatal',
      },
    });
    let attempts = 0;
    let retries = 0;

    queue.on('job:retrying', () => {
      retries += 1;
    });

    queue.handle('run', async () => {
      attempts += 1;
      if (attempts === 1) {
        throw new Error('recoverable');
      }

      return { ok: true };
    });

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'completed', { timeoutMs: 4_000 });

      const job = queue.getJob(jobId);
      expect(job?.status).toBe('completed');
      expect(job?.retryCount).toBe(1);
      expect(retries).toBe(1);
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });

  it('streams queue events as SSE', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['run'],
      concurrency: 1,
    });
    const stream = queue.createEventStream({ includeSnapshot: false });
    const reader = stream.getReader();
    const chunks: string[] = [];
    const readPromise = (async () => {
      while (true) {
        const { value, done } = await reader.read();
        if (done) {
          return;
        }

        if (value) {
          chunks.push(new TextDecoder().decode(value));
          if (chunks.some((chunk) => chunk.includes('event: job:completed'))) {
            return;
          }
        }
      }
    })();

    queue.handle('run', async (_job, ctx) => {
      await ctx.progress(100, 'done');
      return { ok: true };
    });

    try {
      await queue.enqueue({ url: 'https://example.com/video' });
      await Promise.race([
        readPromise,
        waitFor(() => chunks.some((chunk) => chunk.includes('event: job:completed')), {
          timeoutMs: 4_000,
        }),
      ]);
    } finally {
      await reader.cancel();
      await queue.shutdown();
      cleanupDir(dir);
    }

    expect(chunks.join('\n')).toContain('event: job:completed');
    expect(chunks.join('\n')).toContain('event: job:progress');
  });

  it('marks unfinished phases as cancelled when cancelling a pending job', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['download', 'process'],
      concurrency: 1,
    });

    try {
      const jobId = await queue.enqueue(
        { url: 'https://example.com/video' },
        { scheduledAt: new Date(Date.now() + 60_000) },
      );
      const cancelled = await queue.cancel(jobId);

      expect(cancelled.status).toBe('cancelled');
      expect(cancelled.phases.map((phase) => phase.status)).toEqual(['cancelled', 'cancelled']);
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });

  it('emits job:cancelled once when cancelling after a phase completes', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['download', 'process'],
      concurrency: 1,
    });
    let processStarted = false;
    let cancelledEvents = 0;

    queue.on('job:phase:completed', (job, phase) => {
      if (phase.name === 'download') {
        void queue.cancel(job.id);
      }
    });
    queue.on('job:cancelled', () => {
      cancelledEvents += 1;
    });

    queue.handle('download', async (_job, ctx) => {
      await ctx.progress(100, 'downloaded');
      return { filePath: '/tmp/video.mp4' };
    });
    queue.handle('process', async () => {
      processStarted = true;
      return { outputPath: '/tmp/video.txt' };
    });

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'cancelled');

      expect(cancelledEvents).toBe(1);
      expect(processStarted).toBe(false);
      expect(queue.getJob(jobId)?.phases.map((phase) => phase.status)).toEqual([
        'completed',
        'cancelled',
      ]);
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });

  it('waits for in-flight webhooks during shutdown', async () => {
    const dir = createTempDir();
    const deliveries: string[] = [];
    const server = createServer((request, response) => {
      let body = '';
      request.on('data', (chunk) => {
        body += chunk.toString();
      });
      request.on('end', () => {
        setTimeout(() => {
          deliveries.push(body);
          response.writeHead(202).end();
        }, 50);
      });
    });

    await new Promise<void>((resolve) => {
      server.listen(0, '127.0.0.1', () => resolve());
    });

    const address = server.address();
    if (!address || typeof address === 'string') {
      throw new Error('Server address unavailable');
    }

    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['run'],
      concurrency: 1,
      webhook: {
        url: `http://127.0.0.1:${address.port}/hook`,
        events: ['job:completed'],
      },
    });
    let deliveredEvents = 0;

    queue.on('job:webhook:delivered', () => {
      deliveredEvents += 1;
    });
    queue.handle('run', async () => ({ ok: true }));

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'completed');

      const startedAt = Date.now();
      await queue.shutdown();

      expect(Date.now() - startedAt).toBeGreaterThanOrEqual(40);
      expect(deliveredEvents).toBe(1);
      expect(deliveries).toHaveLength(1);
    } finally {
      await new Promise<void>((resolve, reject) => {
        server.close((error) => {
          if (error) {
            reject(error);
            return;
          }

          resolve();
        });
      });
      cleanupDir(dir);
    }
  });

  it('cleans up listeners and storage when shutdown times out', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['run'],
      concurrency: 1,
    });
    const internalQueue = queue as JobQueue<{ url: string }> & {
      storage: { close: () => void };
      events: { removeAllListeners: () => void };
    };
    const closeSpy = vi.spyOn(internalQueue.storage, 'close');
    const removeAllListenersSpy = vi.spyOn(internalQueue.events, 'removeAllListeners');

    queue.handle(
      'run',
      async (_job, ctx) =>
        await new Promise((resolve) => {
          ctx.signal.addEventListener(
            'abort',
            () => {
              resolve({ ok: false });
            },
            { once: true },
          );
        }),
    );

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'active');

      await expect(queue.shutdown(10)).rejects.toThrow(/Timed out waiting for workers to drain/);
      expect(removeAllListenersSpy).toHaveBeenCalledTimes(1);
      expect(closeSpy).toHaveBeenCalledTimes(1);
    } finally {
      cleanupDir(dir);
    }
  });

  it('preserves completed phase results when retrying from partial progress', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['download', 'process'],
      concurrency: 1,
    });
    let downloadRuns = 0;
    let processRuns = 0;
    let resumedFilePath: string | undefined;

    queue.handle('download', async () => {
      downloadRuns += 1;
      return { filePath: '/tmp/video.mp4' };
    });
    queue.handle('process', async (_job, ctx) => {
      processRuns += 1;
      const filePath = ctx.phaseResult<{ filePath: string }>('download')?.filePath;

      if (processRuns === 1) {
        expect(filePath).toBe('/tmp/video.mp4');
        throw new Error('fatal');
      }

      resumedFilePath = filePath;
      return { outputPath: `${filePath}.json` };
    });

    try {
      const jobId = await queue.enqueue({ url: 'https://example.com/video' });
      await waitFor(() => queue.getJob(jobId)?.status === 'failed');

      await queue.retry(jobId, { fromStart: false });
      await waitFor(() => queue.getJob(jobId)?.status === 'completed');

      expect(downloadRuns).toBe(1);
      expect(processRuns).toBe(2);
      expect(resumedFilePath).toBe('/tmp/video.mp4');
      expect(queue.getJob(jobId)?.phaseResults.download).toEqual({ filePath: '/tmp/video.mp4' });
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });

  it('restores interrupted active jobs as failed with phase context on restart', async () => {
    const dir = createTempDir();
    const dbPath = createDbPath(dir);
    const storage = new SqliteStorage<{ url: string }>(dbPath);

    try {
      const job = storage.createJob(
        'job-1',
        { url: 'https://example.com/video' },
        [
          {
            name: 'run',
            status: 'pending',
            progress: 0,
            message: null,
            startedAt: null,
            completedAt: null,
            error: null,
          },
        ],
        {},
        1,
      );

      expect(storage.claimPendingJob(job.id)).toBe(true);
      storage.saveProgress(
        job.id,
        'run',
        [
          {
            name: 'run',
            status: 'active',
            progress: 25,
            message: 'working',
            startedAt: new Date().toISOString(),
            completedAt: null,
            error: null,
          },
        ],
        25,
        'working',
      );
      storage.close();

      const restarted = new JobQueue<{ url: string }>({
        dbPath,
        phases: ['run'],
        concurrency: 1,
      });

      try {
        const restartedJob = restarted.getJob(job.id);
        expect(restartedJob?.status).toBe('failed');
        expect(restartedJob?.error?.phase).toBe('run');
        expect(restartedJob?.error?.attempt).toBe(1);
      } finally {
        await restarted.shutdown();
      }
    } finally {
      cleanupDir(dir);
    }
  });

  it('executes scheduled jobs when their wakeup time arrives', async () => {
    const dir = createTempDir();
    const queue = new JobQueue<{ url: string }>({
      dbPath: createDbPath(dir),
      phases: ['run'],
      concurrency: 1,
    });
    const startedAt: number[] = [];
    const scheduledAt = Date.now() + 50;

    queue.handle('run', async () => {
      startedAt.push(Date.now());
      return { ok: true };
    });

    try {
      const jobId = await queue.enqueue(
        { url: 'https://example.com/video' },
        { scheduledAt: new Date(scheduledAt) },
      );
      await waitFor(() => queue.getJob(jobId)?.status === 'completed', { timeoutMs: 4_000 });

      expect(startedAt).toHaveLength(1);
      expect(startedAt[0]).toBeGreaterThanOrEqual(scheduledAt - 10);
    } finally {
      await queue.shutdown();
      cleanupDir(dir);
    }
  });
});