/**
 * Orchestrator tests.
 * Tests the FeedOrchestrator class with mocked dependencies.
 */

import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import { FeedOrchestrator, type OrchestratorOptions } from './orchestrator.js';
import { calculateNextDelay, calculateJitter, createConcurrencyLimit } from './scheduler.js';
import type { IStorage } from '../interfaces/storage.interface.js';
import type { IFetcher } from '../interfaces/fetcher.interface.js';
import type { IParser } from '../interfaces/parser.interface.js';
import type { IDedup } from '../interfaces/dedup.interface.js';
import type { FeedSource, FeedItem, FetchResult, FetchError } from '../interfaces/feed.types.js';

// Mock implementations
function createMockStorage(): IStorage {
  const sources: Map<string, FeedSource> = new Map();
  const items: FeedItem[] = [];

  return {
    save: vi.fn(async (newItems: FeedItem[]) => {
      items.push(...newItems);
    }),
    getRecent: vi.fn(async (limit: number) => items.slice(0, limit)),
    getBySource: vi.fn(async (source: string, limit: number) => 
      items.filter(i => i.source === source).slice(0, limit)
    ),
    search: vi.fn(async (query: string) => 
      items.filter(i => i.title.includes(query) || (i.summary?.includes(query) ?? false))
    ),
    getFeedSources: vi.fn(async (activeOnly?: boolean) => 
      Array.from(sources.values()).filter(s => !activeOnly || s.isActive)
    ),
    getFeedSourceById: vi.fn(async (id: string) => sources.get(id) ?? null),
    saveFeedSource: vi.fn(async (source: FeedSource) => {
      sources.set(source.id, source);
    }),
    updateFeedSourceStatus: vi.fn(async (id: string, updates) => {
      const source = sources.get(id);
      if (source) {
        if (updates.lastFetchedAt !== undefined) source.lastFetchedAt = updates.lastFetchedAt;
        if (updates.lastSuccessAt !== undefined) source.lastSuccessAt = updates.lastSuccessAt;
        if (updates.consecutiveFailures !== undefined) source.consecutiveFailures = updates.consecutiveFailures;
        if (updates.isActive !== undefined) source.isActive = updates.isActive;
        source.updatedAt = new Date();
      }
    }),
    deleteFeedSource: vi.fn(async (id: string) => {
      sources.delete(id);
    }),
  };
}

function createMockFetcher(): IFetcher {
  return {
    fetch: vi.fn(async () => ({
      responses: [],
      errors: [],
      fetchedAt: new Date(),
    })),
    fetchMany: vi.fn(async () => ({
      responses: [],
      errors: [],
      fetchedAt: new Date(),
    })),
  };
}

function createMockParser(): IParser {
  return {
    parse: vi.fn(async () => []),
    supports: vi.fn(() => true),
  };
}

function createMockDedup(): IDedup {
  return {
    filter: vi.fn(async (items: FeedItem[]) => items),
    markSeen: vi.fn(async () => {}),
  };
}

function createTestFeedSource(overrides: Partial<FeedSource> = {}): FeedSource {
  const now = new Date();
  return {
    id: 'test-feed-1',
    url: 'https://example.com/feed.xml',
    name: 'Test Feed',
    format: 'rss',
    pollIntervalMs: 60000, // 1 minute
    isActive: true,
    lastFetchedAt: null,
    lastSuccessAt: null,
    consecutiveFailures: 0,
    createdAt: now,
    updatedAt: now,
    ...overrides,
  };
}

function createTestFeedItem(overrides: Partial<FeedItem> = {}): FeedItem {
  return {
    id: 'item-1',
    source: 'https://example.com/feed.xml',
    title: 'Test Article',
    url: 'https://example.com/article',
    publishedAt: new Date(),
    ...overrides,
  };
}

describe('FeedOrchestrator', () => {
  let storage: IStorage;
  let fetcher: IFetcher;
  let parser: IParser;
  let dedup: IDedup;
  let orchestrator: FeedOrchestrator;

  beforeEach(() => {
    storage = createMockStorage();
    fetcher = createMockFetcher();
    parser = createMockParser();
    dedup = createMockDedup();

    orchestrator = new FeedOrchestrator({
      storage,
      fetcher,
      parser,
      dedup,
      maxRetries: 3,
      baseRetryDelayMs: 5000,
      maxRetryDelayMs: 300000,
      concurrency: 2,
    });
  });

  afterEach(async () => {
    await orchestrator.stop();
  });

  describe('start/stop', () => {
    it('should start and poll active feeds immediately', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);

      // Mock successful fetch
      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [{
          source: source.url,
          body: '<rss><channel><item><title>Test</title><link>https://example.com/article</link></item></channel></rss>',
          contentType: 'application/rss+xml',
          statusCode: 200,
        }],
        errors: [],
        fetchedAt: new Date(),
      });

      vi.mocked(parser.parse).mockResolvedValue([createTestFeedItem()]);

      await orchestrator.start();

      // Should have fetched
      expect(fetcher.fetch).toHaveBeenCalledWith({
        url: source.url,
        expectedFormat: source.format,
      });

      // Should have updated status
      expect(storage.updateFeedSourceStatus).toHaveBeenCalledWith(
        source.id,
        expect.objectContaining({ lastFetchedAt: expect.any(Date) })
      );
    });

    it('should throw error if already running', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);
      await orchestrator.start();

      await expect(orchestrator.start()).rejects.toThrow('Orchestrator is already running');
    });

    it('should clear all timers on stop', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);
      await orchestrator.start();
      
      await orchestrator.stop();
      // Should not throw and should clear timers
      expect(true).toBe(true);
    });
  });

  describe('processFeed', () => {
    it('should process a feed successfully', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);

      const item = createTestFeedItem();

      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [{
          source: source.url,
          body: '<rss></rss>',
          contentType: 'application/rss+xml',
          statusCode: 200,
        }],
        errors: [],
        fetchedAt: new Date(),
      });

      vi.mocked(parser.parse).mockResolvedValue([item]);
      vi.mocked(dedup.filter).mockResolvedValue([item]);

      const result = await orchestrator.processFeed(source.id);

      expect(result.success).toBe(true);
      expect(result.itemsFound).toBe(1);
      expect(result.itemsNew).toBe(1);
      expect(result.sourceId).toBe(source.id);

      // Should have saved items
      expect(storage.save).toHaveBeenCalledWith([item]);
      expect(dedup.markSeen).toHaveBeenCalledWith([item]);

      // Should have updated status with success
      expect(storage.updateFeedSourceStatus).toHaveBeenCalledWith(
        source.id,
        expect.objectContaining({
          lastSuccessAt: expect.any(Date),
          consecutiveFailures: 0,
        })
      );
    });

    it('should throw error for non-existent feed', async () => {
      await expect(orchestrator.processFeed('non-existent')).rejects.toThrow('Feed source not found');
    });

    it('should handle fetch errors with retry backoff', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);

      const error: FetchError = {
        source: source.url,
        reason: 'Network timeout',
        code: 'TIMEOUT',
      };

      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [],
        errors: [error],
        fetchedAt: new Date(),
      });

      const result = await orchestrator.processFeed(source.id);

      expect(result.success).toBe(false);
      expect(result.error).toEqual(error);
      expect(result.itemsFound).toBe(0);
      expect(result.itemsNew).toBe(0);

      // Should have incremented failure count
      expect(storage.updateFeedSourceStatus).toHaveBeenCalledWith(
        source.id,
        expect.objectContaining({ consecutiveFailures: 1 })
      );

      // Should have delay with backoff
      expect(result.nextPollDelayMs).toBeGreaterThan(source.pollIntervalMs);
    });

    it('should handle parse errors', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);

      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [{
          source: source.url,
          body: 'invalid xml',
          contentType: 'application/rss+xml',
          statusCode: 200,
        }],
        errors: [],
        fetchedAt: new Date(),
      });

      vi.mocked(parser.parse).mockRejectedValue(new Error('Parse failed'));

      const result = await orchestrator.processFeed(source.id);

      expect(result.success).toBe(false);
      expect(result.error?.code).toBe('PARSE');
    });

    it('should deduplicate items', async () => {
      const source = createTestFeedSource();
      await storage.saveFeedSource(source);

      const items = [
        createTestFeedItem({ id: 'item-1' }),
        createTestFeedItem({ id: 'item-2' }),
      ];

      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [{
          source: source.url,
          body: '<rss></rss>',
          contentType: 'application/rss+xml',
          statusCode: 200,
        }],
        errors: [],
        fetchedAt: new Date(),
      });

      vi.mocked(parser.parse).mockResolvedValue(items);
      vi.mocked(dedup.filter).mockResolvedValue([items[0]!]); // Only first item is new

      const result = await orchestrator.processFeed(source.id);

      expect(result.itemsFound).toBe(2);
      expect(result.itemsNew).toBe(1);
      
      // Should only save the new item
      expect(storage.save).toHaveBeenCalledWith([items[0]]);
      expect(dedup.markSeen).toHaveBeenCalledWith([items[0]]);
    });
  });

  describe('processAllFeeds', () => {
    it('should process all active feeds', async () => {
      const source1 = createTestFeedSource({ id: 'feed-1', url: 'https://example1.com/feed.xml' });
      const source2 = createTestFeedSource({ id: 'feed-2', url: 'https://example2.com/feed.xml', isActive: false });
      
      await storage.saveFeedSource(source1);
      await storage.saveFeedSource(source2);

      vi.mocked(fetcher.fetch).mockResolvedValue({
        responses: [{
          source: 'url',
          body: '<rss></rss>',
          contentType: 'application/rss+xml',
          statusCode: 200,
        }],
        errors: [],
        fetchedAt: new Date(),
      });

      vi.mocked(parser.parse).mockResolvedValue([createTestFeedItem()]);

      const results = await orchestrator.processAllFeeds();

      // Only active feeds should be processed
      expect(results.size).toBe(1);
      expect(results.has('feed-1')).toBe(true);
      expect(results.has('feed-2')).toBe(false);
    });
  });

  describe('getFeedHealth', () => {
    it('should return health status for all feeds', async () => {
      const healthyFeed = createTestFeedSource({
        id: 'healthy',
        url: 'https://healthy.com/feed.xml',
        consecutiveFailures: 0,
      });

      const unhealthyFeed = createTestFeedSource({
        id: 'unhealthy',
        url: 'https://unhealthy.com/feed.xml',
        consecutiveFailures: 5, // More than maxRetries (3)
      });

      await storage.saveFeedSource(healthyFeed);
      await storage.saveFeedSource(unhealthyFeed);

      const health = await orchestrator.getFeedHealth();

      expect(health).toHaveLength(2);

      const healthy = health.find(h => h.sourceId === 'healthy');
      const unhealthy = health.find(h => h.sourceId === 'unhealthy');

      expect(healthy?.isHealthy).toBe(true);
      expect(unhealthy?.isHealthy).toBe(false);
    });
  });
});

describe('Scheduler utilities', () => {
  describe('calculateNextDelay', () => {
    it('should return base delay when no failures', () => {
      const base = 5000;
      const delay = calculateNextDelay(0, base, 300000);
      // Allow for ±10% jitter (max 5000ms)
      expect(delay).toBeGreaterThanOrEqual(base - 5000);
      expect(delay).toBeLessThanOrEqual(base + 5000);
    });

    it('should increase delay with failures', () => {
      const base = 5000;
      const delay1 = calculateNextDelay(1, base, 300000);
      const delay2 = calculateNextDelay(2, base, 300000);
      const delay3 = calculateNextDelay(3, base, 300000);

      // Allow for ±10% jitter (max 5000ms)
      expect(delay1).toBeGreaterThanOrEqual(base * 2 - 5000);
      expect(delay2).toBeGreaterThanOrEqual(base * 4 - 5000);
      expect(delay3).toBeGreaterThanOrEqual(base * 8 - 5000);
      
      // Should generally be increasing (with some tolerance for jitter)
      expect(delay1).toBeLessThan(delay3);
    });

    it('should cap delay at maxDelay', () => {
      const maxDelay = 300000;
      const delay = calculateNextDelay(10, 5000, maxDelay);
      
      expect(delay).toBeLessThanOrEqual(maxDelay + 5000); // Max + max jitter
    });
  });

  describe('calculateJitter', () => {
    it('should return jitter within ±10% of delay', () => {
      const delay = 5000;
      const jitter = calculateJitter(delay);

      expect(Math.abs(jitter)).toBeLessThanOrEqual(delay * 0.1);
    });

    it('should cap jitter at 5000ms', () => {
      const largeDelay = 100000;
      const jitter = calculateJitter(largeDelay);

      expect(Math.abs(jitter)).toBeLessThanOrEqual(5000);
    });
  });

  describe('createConcurrencyLimit', () => {
    it('should limit concurrent operations', async () => {
      const limit = createConcurrencyLimit(2);
      let running = 0;
      let maxRunning = 0;

      const promises = Array.from({ length: 5 }, async () => {
        return limit(async () => {
          running++;
          maxRunning = Math.max(maxRunning, running);
          await new Promise(resolve => setTimeout(resolve, 50));
          running--;
        });
      });

      await Promise.all(promises);

      expect(maxRunning).toBe(2);
      expect(running).toBe(0);
    });

    it('should handle errors correctly', async () => {
      const limit = createConcurrencyLimit(2);

      const promises = [
        limit(async () => 'success'),
        limit(async () => { throw new Error('fail'); }),
      ];

      const results = await Promise.allSettled(promises);

      expect(results[0]?.status).toBe('fulfilled');
      expect(results[1]?.status).toBe('rejected');
    });
  });
});