import { describe, it, expect, beforeEach, vi } from 'vitest';
import {
  traceProducer,
  traceConsumer,
  clearOrderingState,
  type ProducerConfig,
  type ConsumerConfig,
  type DLQOptions,
  type DLQReplayOptions,
  type DLQReasonCategory,
  type OrderingConfig,
  type OutOfOrderInfo,
  type ConsumerGroupTrackingConfig,
  type RebalanceEvent,
  type PartitionAssignment,
  type ConsumerGroupState,
  type PartitionLag,
  type RebalanceType,
} from './messaging';

// Mock the trace function to capture span options
vi.mock('./functional', () => ({
  trace: vi.fn((name, factory) => {
    return (...args: unknown[]) => {
      const mockCtx = createMockContext();
      const fn = factory(mockCtx);
      return fn(...args);
    };
  }),
}));

// Mock sampling functions
vi.mock('./sampling', () => ({
  createLinkFromHeaders: vi.fn((headers) => {
    if (headers.traceparent) {
      return {
        context: {
          traceId: '00000000000000000000000000000001',
          spanId: '0000000000000001',
          traceFlags: 1,
        },
        attributes: {},
      };
    }
    return null;
  }),
  extractLinksFromBatch: vi.fn((messages) => {
    return messages
      .filter(
        (m: { headers?: Record<string, string> }) => m.headers?.traceparent,
      )
      .map(() => ({
        context: {
          traceId: '00000000000000000000000000000001',
          spanId: '0000000000000001',
          traceFlags: 1,
        },
        attributes: {},
      }));
  }),
}));

function createMockContext() {
  const attributes: Record<string, unknown> = {};
  const events: Array<{ name: string; attributes?: Record<string, unknown> }> =
    [];
  const links: unknown[] = [];

  return {
    setAttribute: vi.fn((key, value) => {
      attributes[key] = value;
    }),
    setAttributes: vi.fn((attrs) => {
      Object.assign(attributes, attrs);
    }),
    addEvent: vi.fn((name, attrs) => {
      events.push({ name, attributes: attrs });
    }),
    addLink: vi.fn((link) => {
      links.push(link);
    }),
    addLinks: vi.fn((newLinks) => {
      links.push(...newLinks);
    }),
    setStatus: vi.fn(),
    getAttributes: () => attributes,
    getEvents: () => events,
    getLinks: () => links,
    // ProducerContext methods
    getTraceHeaders: vi.fn(() => ({
      traceparent: '00-00000000000000000000000000000001-0000000000000001-01',
    })),
    getAllPropagationHeaders: vi.fn(() => ({
      traceparent: '00-00000000000000000000000000000001-0000000000000001-01',
      baggage: 'key=value',
    })),
    // ConsumerContext methods
    recordDLQ: vi.fn(),
    recordRetry: vi.fn(),
    recordReplay: vi.fn(),
    getProducerLinks: vi.fn(() => []),
  };
}

describe('Messaging Helpers', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  describe('traceProducer', () => {
    it('should create a producer function with correct span name', async () => {
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'user-events',
      };

      const producer = traceProducer(config)(
        (_ctx) => async (_event: { id: string }) => {
          return { sent: true };
        },
      );

      const result = await producer({ id: 'event-1' });
      expect(result).toEqual({ sent: true });
    });

    it('should set messaging semantic attributes', async () => {
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'user-events',
        messageIdFrom: (args) => (args[0] as { id: string }).id,
      };

      // We need to directly test the attribute setting
      // Since the trace mock doesn't persist context properly,
      // we test the config structure
      expect(config.system).toBe('kafka');
      expect(config.destination).toBe('user-events');
    });

    it('should support SQS system type', () => {
      const config: ProducerConfig = {
        system: 'sqs',
        destination: 'orders-queue',
      };

      const producer = traceProducer(config)(
        (_ctx) => async (_message: string) => {
          return { messageId: '123' };
        },
      );

      expect(producer).toBeDefined();
    });

    it('should support RabbitMQ system type', () => {
      const config: ProducerConfig = {
        system: 'rabbitmq',
        destination: 'notifications',
      };

      const producer = traceProducer(config)(
        (_ctx) => async (_message: string) => {
          return { delivered: true };
        },
      );

      expect(producer).toBeDefined();
    });

    it('should call beforeSend callback', async () => {
      const beforeSend = vi.fn();
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'events',
        beforeSend,
      };

      const producer = traceProducer(config)(
        (_ctx) => async (_event: unknown) => {
          return { sent: true };
        },
      );

      await producer({ id: '1' });
      expect(beforeSend).toHaveBeenCalled();
    });

    it('should call onError callback on failure', async () => {
      const onError = vi.fn();
      const testError = new Error('Send failed');

      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'events',
        onError,
      };

      const producer = traceProducer(config)((_ctx) => async () => {
        throw testError;
      });

      await expect(producer()).rejects.toThrow('Send failed');
      expect(onError).toHaveBeenCalledWith(testError, expect.anything());
    });

    it('should extract message ID from function extractor', () => {
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'events',
        messageIdFrom: (args) => (args[0] as { eventId: string }).eventId,
      };

      expect(typeof config.messageIdFrom).toBe('function');
      const extractor = config.messageIdFrom as (
        args: unknown[],
      ) => string | undefined;
      expect(extractor([{ eventId: 'evt-123' }])).toBe('evt-123');
    });

    it('should extract partition from function extractor', () => {
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'events',
        partitionFrom: (args) => (args[0] as { partition: number }).partition,
      };

      expect(typeof config.partitionFrom).toBe('function');
      const extractor = config.partitionFrom as (
        args: unknown[],
      ) => number | undefined;
      expect(extractor([{ partition: 3 }])).toBe(3);
    });
  });

  describe('traceConsumer', () => {
    it('should create a consumer function with correct span name', async () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'user-events',
        consumerGroup: 'my-consumer',
      };

      const consumer = traceConsumer(config)(
        (_ctx) => async (_message: unknown) => {
          return { processed: true };
        },
      );

      const result = await consumer({ value: 'test' });
      expect(result).toEqual({ processed: true });
    });

    it('should support batch mode', async () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'user-events',
        batchMode: true,
        headersFrom: (msg) =>
          (msg as { headers: Record<string, string> }).headers,
      };

      const consumer = traceConsumer(config)(
        (_ctx) => async (messages: unknown[]) => {
          return { count: messages.length };
        },
      );

      const messages = [
        { value: 'a', headers: { traceparent: '00-abc-def-01' } },
        { value: 'b', headers: { traceparent: '00-xyz-uvw-01' } },
      ];

      const result = await consumer(messages);
      expect(result).toEqual({ count: 2 });
    });

    it('should call onError callback on failure', async () => {
      const onError = vi.fn();
      const testError = new Error('Process failed');

      const config: ConsumerConfig = {
        system: 'sqs',
        destination: 'orders',
        onError,
      };

      const consumer = traceConsumer(config)((_ctx) => async () => {
        throw testError;
      });

      await expect(consumer({})).rejects.toThrow('Process failed');
      expect(onError).toHaveBeenCalledWith(testError, expect.anything());
    });

    it('should support lag metrics configuration', () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'events',
        lagMetrics: {
          getCurrentOffset: (msg) => (msg as { offset: number }).offset,
          getEndOffset: () => Promise.resolve(1000),
          getPartition: (msg) => (msg as { partition: number }).partition,
        },
      };

      expect(config.lagMetrics).toBeDefined();
      expect(config.lagMetrics!.getCurrentOffset).toBeDefined();
      expect(config.lagMetrics!.getCurrentOffset!({ offset: 500 })).toBe(500);
    });

    it('should extract headers using string path', () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'events',
        headersFrom: 'headers',
      };

      expect(config.headersFrom).toBe('headers');
    });

    it('should extract headers using function', () => {
      const config: ConsumerConfig = {
        system: 'sqs',
        destination: 'events',
        headersFrom: (msg) => {
          const m = msg as {
            MessageAttributes: Record<string, { StringValue: string }>;
          };
          const result: Record<string, string> = {};
          for (const [k, v] of Object.entries(m.MessageAttributes || {})) {
            result[k] = v.StringValue;
          }
          return result;
        },
      };

      const extractor = config.headersFrom as (
        msg: unknown,
      ) => Record<string, string> | undefined;
      const headers = extractor({
        MessageAttributes: {
          traceparent: { StringValue: '00-abc-def-01' },
        },
      });

      expect(headers).toEqual({ traceparent: '00-abc-def-01' });
    });
  });

  describe('ProducerContext', () => {
    it('getTraceHeaders should return W3C trace context headers', () => {
      const mockCtx = createMockContext();
      const headers = mockCtx.getTraceHeaders();

      expect(headers.traceparent).toBeDefined();
      expect(headers.traceparent).toMatch(
        /^\d{2}-[a-f0-9]{32}-[a-f0-9]{16}-\d{2}$/,
      );
    });

    it('getAllPropagationHeaders should include baggage when enabled', () => {
      const mockCtx = createMockContext();
      const headers = mockCtx.getAllPropagationHeaders();

      expect(headers.traceparent).toBeDefined();
      expect(headers.baggage).toBeDefined();
    });
  });

  describe('ConsumerContext', () => {
    it('recordDLQ should be callable with basic args', () => {
      const mockCtx = createMockContext();
      mockCtx.recordDLQ('Max retries exceeded', 'orders-dlq');

      expect(mockCtx.recordDLQ).toHaveBeenCalledWith(
        'Max retries exceeded',
        'orders-dlq',
      );
    });

    it('recordRetry should be callable', () => {
      const mockCtx = createMockContext();
      mockCtx.recordRetry(2, 5);

      expect(mockCtx.recordRetry).toHaveBeenCalledWith(2, 5);
    });

    it('recordReplay should be callable', () => {
      const mockCtx = createMockContext();
      mockCtx.recordReplay({ replayAttempt: 1, dlqDwellTimeMs: 5000 });

      expect(mockCtx.recordReplay).toHaveBeenCalledWith({
        replayAttempt: 1,
        dlqDwellTimeMs: 5000,
      });
    });

    it('getProducerLinks should return links', () => {
      const mockCtx = createMockContext();
      const links = mockCtx.getProducerLinks();

      expect(mockCtx.getProducerLinks).toHaveBeenCalled();
      expect(Array.isArray(links)).toBe(true);
    });
  });

  describe('Enhanced DLQ Handling', () => {
    describe('DLQOptions types', () => {
      it('should support all reason categories', () => {
        const categories: DLQReasonCategory[] = [
          'validation',
          'processing',
          'timeout',
          'poison',
          'unknown',
        ];

        for (const category of categories) {
          const options: DLQOptions = {
            reasonCategory: category,
          };
          expect(options.reasonCategory).toBe(category);
        }
      });

      it('should support full DLQ options', () => {
        const error = new Error('Processing failed');
        const options: DLQOptions = {
          linkToProducer: true,
          reasonCategory: 'processing',
          attemptCount: 3,
          originalError: error,
          metadata: {
            customField: 'value',
            retryDelay: 1000,
            isReplayable: true,
          },
        };

        expect(options.linkToProducer).toBe(true);
        expect(options.reasonCategory).toBe('processing');
        expect(options.attemptCount).toBe(3);
        expect(options.originalError).toBe(error);
        expect(options.metadata?.customField).toBe('value');
      });

      it('should allow partial options', () => {
        const options: DLQOptions = {
          reasonCategory: 'validation',
        };

        expect(options.reasonCategory).toBe('validation');
        expect(options.linkToProducer).toBeUndefined();
        expect(options.attemptCount).toBeUndefined();
      });
    });

    describe('DLQReplayOptions types', () => {
      it('should support replay options with span context', () => {
        const options: DLQReplayOptions = {
          originalDLQSpanContext: {
            traceId: '00000000000000000000000000000001',
            spanId: '0000000000000002',
            traceFlags: 1,
          },
          dlqDwellTimeMs: 3_600_000, // 1 hour
          replayAttempt: 2,
        };

        expect(options.originalDLQSpanContext?.traceId).toBe(
          '00000000000000000000000000000001',
        );
        expect(options.dlqDwellTimeMs).toBe(3_600_000);
        expect(options.replayAttempt).toBe(2);
      });

      it('should allow partial replay options', () => {
        const options: DLQReplayOptions = {
          replayAttempt: 1,
        };

        expect(options.replayAttempt).toBe(1);
        expect(options.originalDLQSpanContext).toBeUndefined();
      });
    });

    describe('recordDLQ overloads', () => {
      it('should support basic signature (reason only)', () => {
        const mockCtx = createMockContext();
        // This tests the type system accepts reason-only calls
        mockCtx.recordDLQ('Processing failed');
        expect(mockCtx.recordDLQ).toHaveBeenCalledWith('Processing failed');
      });

      it('should support reason + dlqName signature', () => {
        const mockCtx = createMockContext();
        mockCtx.recordDLQ('Schema validation failed', 'orders-dlq');
        expect(mockCtx.recordDLQ).toHaveBeenCalledWith(
          'Schema validation failed',
          'orders-dlq',
        );
      });

      it('should support reason + options signature', () => {
        const mockCtx = createMockContext();
        const options: DLQOptions = {
          reasonCategory: 'validation',
          attemptCount: 3,
        };
        mockCtx.recordDLQ('Invalid payload format', options);
        expect(mockCtx.recordDLQ).toHaveBeenCalledWith(
          'Invalid payload format',
          options,
        );
      });

      it('should support reason + dlqName + options signature', () => {
        const mockCtx = createMockContext();
        const error = new Error('Timeout exceeded');
        const options: DLQOptions = {
          reasonCategory: 'timeout',
          attemptCount: 5,
          originalError: error,
          linkToProducer: true,
          metadata: { processingTimeMs: 30_000 },
        };
        mockCtx.recordDLQ('Processing timeout', 'orders-dlq', options);
        expect(mockCtx.recordDLQ).toHaveBeenCalledWith(
          'Processing timeout',
          'orders-dlq',
          options,
        );
      });
    });

    describe('Poison pill detection', () => {
      it('should support poison category for repeated failures', () => {
        const options: DLQOptions = {
          reasonCategory: 'poison',
          attemptCount: 10,
          metadata: {
            failurePattern: 'OutOfMemoryError',
            affectedConsumers: 3,
          },
        };

        expect(options.reasonCategory).toBe('poison');
        expect(options.attemptCount).toBe(10);
      });
    });
  });

  describe('MessagingSystem types', () => {
    it('should support kafka', () => {
      const config: ProducerConfig = { system: 'kafka', destination: 'topic' };
      expect(config.system).toBe('kafka');
    });

    it('should support sqs', () => {
      const config: ProducerConfig = { system: 'sqs', destination: 'queue' };
      expect(config.system).toBe('sqs');
    });

    it('should support rabbitmq', () => {
      const config: ProducerConfig = {
        system: 'rabbitmq',
        destination: 'exchange',
      };
      expect(config.system).toBe('rabbitmq');
    });

    it('should support sns', () => {
      const config: ProducerConfig = {
        system: 'sns',
        destination: 'topic-arn',
      };
      expect(config.system).toBe('sns');
    });

    it('should support pubsub', () => {
      const config: ProducerConfig = { system: 'pubsub', destination: 'topic' };
      expect(config.system).toBe('pubsub');
    });

    it('should support custom system strings', () => {
      const config: ProducerConfig = {
        system: 'custom-mq',
        destination: 'channel',
      };
      expect(config.system).toBe('custom-mq');
    });
  });

  describe('Span naming conventions', () => {
    it('producer should use system.publish destination format', () => {
      const config: ProducerConfig = {
        system: 'kafka',
        destination: 'user-events',
      };
      // The span name is constructed as `${config.system}.publish ${config.destination}`
      const expectedSpanName = `${config.system}.publish ${config.destination}`;
      expect(expectedSpanName).toBe('kafka.publish user-events');
    });

    it('consumer (single) should use system.process destination format', () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'user-events',
      };
      const expectedSpanName = `${config.system}.process ${config.destination}`;
      expect(expectedSpanName).toBe('kafka.process user-events');
    });

    it('consumer (batch) should use system.receive destination format', () => {
      const config: ConsumerConfig = {
        system: 'kafka',
        destination: 'user-events',
        batchMode: true,
      };
      const expectedSpanName = `${config.system}.receive ${config.destination}`;
      expect(expectedSpanName).toBe('kafka.receive user-events');
    });
  });

  // =========================================================================
  // Extensible Hooks ("Bring Your Own" System Support)
  // =========================================================================

  describe('Extensible Hooks', () => {
    describe('Producer customAttributes hook', () => {
      it('should call customAttributes hook with context and args', async () => {
        const customAttributes = vi.fn().mockReturnValue({
          'nats.subject': 'orders.created',
          'nats.stream': 'ORDERS',
        });

        const config: ProducerConfig = {
          system: 'nats' as const,
          destination: 'orders.created',
          customAttributes,
        };

        const producer = traceProducer(config)(
          (_ctx) => async (event: { orderId: string }) => {
            return { sent: true, orderId: event.orderId };
          },
        );

        await producer({ orderId: 'order-123' });
        expect(customAttributes).toHaveBeenCalled();
        // Args should include the event
        const [, args] = customAttributes.mock.calls[0];
        expect(args[0]).toEqual({ orderId: 'order-123' });
      });

      it('should support NATS-style attributes', () => {
        const config: ProducerConfig = {
          system: 'nats' as const,
          destination: 'orders.created',
          customAttributes: (_ctx, args) => ({
            'nats.subject':
              (args[0] as { subject?: string })?.subject || 'default',
            'nats.reply_to': (args[0] as { replyTo?: string })?.replyTo,
            'nats.stream': 'ORDERS',
          }),
        };

        expect(config.customAttributes).toBeDefined();
        const attrs = config.customAttributes!(createMockContext() as never, [
          { subject: 'orders.created', replyTo: '_INBOX.reply' },
        ]);
        expect(attrs['nats.subject']).toBe('orders.created');
        expect(attrs['nats.reply_to']).toBe('_INBOX.reply');
      });

      it('should support Temporal-style attributes', () => {
        const config: ProducerConfig = {
          system: 'temporal' as const,
          destination: 'orders-queue',
          customAttributes: (_ctx, args) => ({
            'temporal.workflow_id': (args[0] as { workflowId: string })
              .workflowId,
            'temporal.run_id': (args[0] as { runId: string }).runId,
            'temporal.task_queue': 'orders-queue',
          }),
        };

        expect(config.customAttributes).toBeDefined();
        const attrs = config.customAttributes!(createMockContext() as never, [
          { workflowId: 'wf-123', runId: 'run-456' },
        ]);
        expect(attrs['temporal.workflow_id']).toBe('wf-123');
        expect(attrs['temporal.run_id']).toBe('run-456');
      });
    });

    describe('Producer customHeaders hook', () => {
      it('should call customHeaders hook', async () => {
        const customHeaders = vi.fn().mockReturnValue({
          'x-correlation-id': 'corr-123',
          'x-request-id': 'req-456',
        });

        const config: ProducerConfig = {
          system: 'kafka',
          destination: 'events',
          customHeaders,
        };

        // The customHeaders is called via getFullHeaders()
        // For testing, we verify the config accepts it
        expect(config.customHeaders).toBeDefined();
      });

      it('should support Datadog-style custom headers', () => {
        const config: ProducerConfig = {
          system: 'kafka',
          destination: 'events',
          customHeaders: (ctx) => ({
            'x-datadog-trace-id': ctx.getTraceId?.() || 'unknown',
            'x-datadog-parent-id': ctx.getSpanId?.() || 'unknown',
          }),
        };

        expect(config.customHeaders).toBeDefined();
      });
    });

    describe('Consumer customAttributes hook', () => {
      it('should call customAttributes hook with context and message', async () => {
        const customAttributes = vi.fn().mockReturnValue({
          'cloudflare.queue_id': 'q-123',
          'cloudflare.attempts': 1,
        });

        const config: ConsumerConfig = {
          system: 'cloudflare_queues' as const,
          destination: 'orders-queue',
          customAttributes,
        };

        const consumer = traceConsumer(config)(
          (_ctx) => async (msg: { id: string; attempts: number }) => {
            return { processed: true, id: msg.id };
          },
        );

        await consumer({ id: 'msg-123', attempts: 1 });
        expect(customAttributes).toHaveBeenCalled();
      });

      it('should support Cloudflare Queue attributes', () => {
        const config: ConsumerConfig = {
          system: 'cloudflare_queues' as const,
          destination: 'orders',
          customAttributes: (_ctx, msg) => ({
            'cloudflare.queue_id': (msg as { id: string }).id,
            'cloudflare.timestamp_ms': Date.now(),
            'cloudflare.attempts': (msg as { attempts: number }).attempts,
          }),
        };

        expect(config.customAttributes).toBeDefined();
        const attrs = config.customAttributes!(createMockContext() as never, {
          id: 'msg-123',
          attempts: 2,
        });
        expect(attrs['cloudflare.queue_id']).toBe('msg-123');
        expect(attrs['cloudflare.attempts']).toBe(2);
      });

      it('should support Redis Streams attributes', () => {
        const config: ConsumerConfig = {
          system: 'redis_streams' as const,
          destination: 'orders:stream',
          customAttributes: (_ctx, msg) => ({
            'redis.stream_id': (msg as { streamId: string }).streamId,
            'redis.consumer_group': 'processors',
            'redis.pending_count': (msg as { pendingCount: number })
              .pendingCount,
          }),
        };

        expect(config.customAttributes).toBeDefined();
        const attrs = config.customAttributes!(createMockContext() as never, {
          streamId: '1234567890-0',
          pendingCount: 5,
        });
        expect(attrs['redis.stream_id']).toBe('1234567890-0');
      });
    });

    describe('Consumer customContextExtractor hook', () => {
      it('should support B3 format extraction', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          headersFrom: 'headers',
          customContextExtractor: (headers) => {
            const traceId = headers['x-b3-traceid'];
            const spanId = headers['x-b3-spanid'];
            const sampled = headers['x-b3-sampled'] === '1';
            if (!traceId || !spanId) return null;
            return {
              traceId,
              spanId,
              traceFlags: sampled ? 1 : 0,
              isRemote: true,
            };
          },
        };

        expect(config.customContextExtractor).toBeDefined();
        const context = config.customContextExtractor!({
          'x-b3-traceid': '00000000000000000000000000000abc',
          'x-b3-spanid': '00000000000def',
          'x-b3-sampled': '1',
        });
        expect(context).not.toBeNull();
        expect(context!.traceId).toBe('00000000000000000000000000000abc');
        expect(context!.spanId).toBe('00000000000def');
        expect(context!.traceFlags).toBe(1);
      });

      it('should support Datadog format extraction', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          headersFrom: 'headers',
          customContextExtractor: (headers) => {
            const traceId = headers['x-datadog-trace-id'];
            const spanId = headers['x-datadog-parent-id'];
            if (!traceId || !spanId) return null;
            // Convert Datadog's decimal format to OTel hex
            return {
              traceId: BigInt(traceId).toString(16).padStart(32, '0'),
              spanId: BigInt(spanId).toString(16).padStart(16, '0'),
              traceFlags: 1,
              isRemote: true,
            };
          },
        };

        expect(config.customContextExtractor).toBeDefined();
        const context = config.customContextExtractor!({
          'x-datadog-trace-id': '123456789',
          'x-datadog-parent-id': '987654321',
        });
        expect(context).not.toBeNull();
        // 123456789 decimal = 75bcd15 hex (7 chars) → padStart(32) = 25 zeros + 7 = 32 chars
        expect(context!.traceId).toBe('000000000000000000000000075bcd15');
        // 987654321 decimal = 3ade68b1 hex (8 chars) → padStart(16) = 8 zeros + 8 = 16 chars
        expect(context!.spanId).toBe('000000003ade68b1');
      });

      it('should return null for missing headers', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          headersFrom: 'headers',
          customContextExtractor: (headers) => {
            const traceId = headers['x-b3-traceid'];
            const spanId = headers['x-b3-spanid'];
            if (!traceId || !spanId) return null;
            return { traceId, spanId, traceFlags: 1, isRemote: true };
          },
        };

        const context = config.customContextExtractor!({});
        expect(context).toBeNull();
      });
    });

    describe('Combined hooks usage', () => {
      it('should support using all hooks together for NATS', () => {
        const producerConfig: ProducerConfig = {
          system: 'nats' as const,
          destination: 'orders.created',
          customAttributes: (_ctx, args) => ({
            'nats.subject': 'orders.created',
            'nats.stream': 'ORDERS',
            'nats.sequence': (args[0] as { seq?: number })?.seq || 0,
          }),
          customHeaders: (_ctx) => ({
            'Nats-Msg-Id': `msg-${Date.now()}`,
          }),
        };

        const consumerConfig: ConsumerConfig = {
          system: 'nats' as const,
          destination: 'orders.created',
          headersFrom: 'headers',
          customAttributes: (_ctx, msg) => ({
            'nats.subject': (msg as { subject: string }).subject,
            'nats.redelivered':
              (msg as { redelivered?: boolean })?.redelivered || false,
          }),
          customContextExtractor: (headers) => {
            // NATS uses its own tracing headers
            const traceId = headers['nats-trace-id'];
            const spanId = headers['nats-span-id'];
            if (!traceId || !spanId) return null;
            return { traceId, spanId, traceFlags: 1, isRemote: true };
          },
        };

        expect(producerConfig.customAttributes).toBeDefined();
        expect(producerConfig.customHeaders).toBeDefined();
        expect(consumerConfig.customAttributes).toBeDefined();
        expect(consumerConfig.customContextExtractor).toBeDefined();
      });
    });
  });

  describe('Message Ordering Support', () => {
    beforeEach(() => {
      // Clear global ordering state between tests
      clearOrderingState();
    });

    describe('OrderingConfig types', () => {
      it('should define OrderingConfig interface correctly', () => {
        const config: OrderingConfig = {
          sequenceFrom: (msg) => (msg as { offset: number }).offset,
          partitionKeyFrom: (msg) => (msg as { key: string }).key,
          messageIdFrom: (msg) => (msg as { id: string }).id,
          detectOutOfOrder: true,
          detectDuplicates: true,
          deduplicationWindowSize: 500,
          onOutOfOrder: (_ctx, _info) => {},
          onDuplicate: (_ctx, _id) => {},
        };

        expect(config.sequenceFrom).toBeDefined();
        expect(config.partitionKeyFrom).toBeDefined();
        expect(config.messageIdFrom).toBeDefined();
        expect(config.detectOutOfOrder).toBe(true);
        expect(config.detectDuplicates).toBe(true);
        expect(config.deduplicationWindowSize).toBe(500);
      });

      it('should define OutOfOrderInfo interface correctly', () => {
        const info: OutOfOrderInfo = {
          currentSequence: 10,
          expectedSequence: 5,
          partitionKey: 'partition-1',
          gap: 5,
        };

        expect(info.currentSequence).toBe(10);
        expect(info.expectedSequence).toBe(5);
        expect(info.partitionKey).toBe('partition-1');
        expect(info.gap).toBe(5);
      });
    });

    describe('Sequence tracking', () => {
      it('should extract sequence number from message', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
          },
        };

        expect(config.ordering?.sequenceFrom?.({ offset: 42 })).toBe(42);
      });

      it('should extract partition key from message', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            partitionKeyFrom: (msg) => (msg as { key: string }).key,
          },
        };

        expect(config.ordering?.partitionKeyFrom?.({ key: 'user-123' })).toBe(
          'user-123',
        );
      });

      it('should extract message ID for deduplication', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            messageIdFrom: (msg) => (msg as { id: string }).id,
          },
        };

        expect(config.ordering?.messageIdFrom?.({ id: 'msg-abc' })).toBe(
          'msg-abc',
        );
      });
    });

    describe('Out-of-order detection', () => {
      it('should detect out-of-order messages and call callback', async () => {
        const outOfOrderCallback = vi.fn();

        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
            detectOutOfOrder: true,
            onOutOfOrder: outOfOrderCallback,
          },
        };

        // Verify config is set up correctly
        expect(config.ordering?.detectOutOfOrder).toBe(true);
        expect(config.ordering?.onOutOfOrder).toBe(outOfOrderCallback);
      });

      it('should calculate gap correctly for missing messages', () => {
        // Test gap calculation: if we expect 5 but get 10, gap is 5
        const info: OutOfOrderInfo = {
          currentSequence: 10,
          expectedSequence: 5,
          gap: 10 - 5, // = 5 (5 messages missing)
        };

        expect(info.gap).toBe(5);
      });

      it('should calculate negative gap for out-of-order (earlier) messages', () => {
        // If we expect 10 but get 5 (received earlier message), gap is -5
        const info: OutOfOrderInfo = {
          currentSequence: 5,
          expectedSequence: 10,
          gap: 5 - 10, // = -5 (message from past)
        };

        expect(info.gap).toBe(-5);
      });

      it('should track sequence per partition key', () => {
        // Verify config supports partition-specific tracking
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
            partitionKeyFrom: (msg) => (msg as { partition: string }).partition,
            detectOutOfOrder: true,
          },
        };

        expect(config.ordering?.partitionKeyFrom).toBeDefined();
        expect(config.ordering?.sequenceFrom).toBeDefined();
      });
    });

    describe('Duplicate detection', () => {
      it('should detect duplicate messages and call callback', async () => {
        const duplicateCallback = vi.fn();

        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            messageIdFrom: (msg) => (msg as { id: string }).id,
            detectDuplicates: true,
            onDuplicate: duplicateCallback,
          },
        };

        // Verify config is set up correctly
        expect(config.ordering?.detectDuplicates).toBe(true);
        expect(config.ordering?.onDuplicate).toBe(duplicateCallback);
      });

      it('should use custom deduplication window size', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            messageIdFrom: (msg) => (msg as { id: string }).id,
            detectDuplicates: true,
            deduplicationWindowSize: 500,
          },
        };

        expect(config.ordering?.deduplicationWindowSize).toBe(500);
      });

      it('should default deduplication window to 1000', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            messageIdFrom: (msg) => (msg as { id: string }).id,
            detectDuplicates: true,
            // No deduplicationWindowSize - defaults to 1000
          },
        };

        expect(config.ordering?.deduplicationWindowSize).toBeUndefined();
        // The actual default (1000) is applied at runtime in extractAndProcessOrdering
      });
    });

    describe('ConsumerContext ordering methods', () => {
      it('should have isDuplicate() method in ConsumerContext interface', () => {
        // Type check - these methods are defined in ConsumerContext interface
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            detectDuplicates: true,
          },
        };

        // Verify the config is valid
        expect(config.ordering?.detectDuplicates).toBe(true);
      });

      it('should have getOutOfOrderInfo() method in ConsumerContext interface', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            detectOutOfOrder: true,
          },
        };

        expect(config.ordering?.detectOutOfOrder).toBe(true);
      });

      it('should have getSequenceNumber() method in ConsumerContext interface', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
          },
        };

        expect(config.ordering?.sequenceFrom).toBeDefined();
      });

      it('should have getPartitionKey() method in ConsumerContext interface', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          ordering: {
            partitionKeyFrom: (msg) => (msg as { key: string }).key,
          },
        };

        expect(config.ordering?.partitionKeyFrom).toBeDefined();
      });
    });

    describe('Combined ordering configuration', () => {
      it('should support full Kafka ordering configuration', () => {
        const outOfOrderCallback = vi.fn();
        const duplicateCallback = vi.fn();

        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'user-events',
          consumerGroup: 'event-processor',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
            partitionKeyFrom: (msg) => (msg as { key: string }).key,
            messageIdFrom: (msg) =>
              (msg as { headers: { idempotencyKey: string } }).headers
                .idempotencyKey,
            detectOutOfOrder: true,
            detectDuplicates: true,
            deduplicationWindowSize: 2000,
            onOutOfOrder: outOfOrderCallback,
            onDuplicate: duplicateCallback,
          },
        };

        expect(config.ordering).toBeDefined();
        expect(config.ordering?.detectOutOfOrder).toBe(true);
        expect(config.ordering?.detectDuplicates).toBe(true);
        expect(config.ordering?.deduplicationWindowSize).toBe(2000);
      });

      it('should support SQS ordering configuration with message group', () => {
        const config: ConsumerConfig = {
          system: 'sqs',
          destination: 'orders.fifo',
          ordering: {
            sequenceFrom: (msg) =>
              Number.parseInt(
                (msg as { Attributes: { SequenceNumber: string } }).Attributes
                  .SequenceNumber,
                10,
              ),
            partitionKeyFrom: (msg) =>
              (msg as { Attributes: { MessageGroupId: string } }).Attributes
                .MessageGroupId,
            messageIdFrom: (msg) => (msg as { MessageId: string }).MessageId,
            detectOutOfOrder: true,
            detectDuplicates: true,
          },
        };

        // Test extraction functions
        const sqsMessage = {
          MessageId: 'msg-123',
          Attributes: {
            SequenceNumber: '12345',
            MessageGroupId: 'order-group-1',
          },
        };

        expect(config.ordering?.sequenceFrom?.(sqsMessage)).toBe(12_345);
        expect(config.ordering?.partitionKeyFrom?.(sqsMessage)).toBe(
          'order-group-1',
        );
        expect(config.ordering?.messageIdFrom?.(sqsMessage)).toBe('msg-123');
      });

      it('should support RabbitMQ ordering configuration', () => {
        const config: ConsumerConfig = {
          system: 'rabbitmq',
          destination: 'orders',
          consumerGroup: 'order-processor',
          ordering: {
            sequenceFrom: (msg) =>
              (msg as { properties: { headers: { 'x-sequence': number } } })
                .properties.headers['x-sequence'],
            messageIdFrom: (msg) =>
              (msg as { properties: { messageId: string } }).properties
                .messageId,
            detectDuplicates: true,
          },
        };

        const rabbitMessage = {
          properties: {
            messageId: 'rabbit-msg-1',
            headers: {
              'x-sequence': 42,
            },
          },
        };

        expect(config.ordering?.sequenceFrom?.(rabbitMessage)).toBe(42);
        expect(config.ordering?.messageIdFrom?.(rabbitMessage)).toBe(
          'rabbit-msg-1',
        );
      });
    });

    describe('clearOrderingState()', () => {
      it('should be exported for test isolation', () => {
        expect(typeof clearOrderingState).toBe('function');
      });

      it('should not throw when called', () => {
        expect(() => clearOrderingState()).not.toThrow();
      });

      it('should allow multiple calls', () => {
        clearOrderingState();
        clearOrderingState();
        clearOrderingState();
        // No error = success
        expect(true).toBe(true);
      });
    });

    describe('Span attributes', () => {
      it('should define expected attribute names for sequence number', () => {
        // Document expected span attributes
        const expectedAttributes = [
          'messaging.message.sequence_number',
          'messaging.message.partition_key',
          'messaging.message.id',
          'messaging.ordering.out_of_order',
          'messaging.ordering.expected_sequence',
          'messaging.ordering.gap',
          'messaging.ordering.duplicate',
        ];

        // These are the attributes set by extractAndProcessOrdering
        expect(expectedAttributes).toContain(
          'messaging.message.sequence_number',
        );
        expect(expectedAttributes).toContain('messaging.ordering.out_of_order');
        expect(expectedAttributes).toContain('messaging.ordering.duplicate');
      });

      it('should define expected event names', () => {
        const expectedEvents = ['message_out_of_order', 'message_duplicate'];

        expect(expectedEvents).toContain('message_out_of_order');
        expect(expectedEvents).toContain('message_duplicate');
      });
    });
  });

  describe('Consumer Group Tracking', () => {
    describe('ConsumerGroupTrackingConfig types', () => {
      it('should define ConsumerGroupTrackingConfig interface correctly', () => {
        const config: ConsumerGroupTrackingConfig = {
          memberId: 'consumer-1',
          groupInstanceId: 'instance-1',
          onRebalance: (_ctx, _event) => {},
          onPartitionsAssigned: (_ctx, _partitions) => {},
          onPartitionsRevoked: (_ctx, _partitions) => {},
          trackPartitionLag: true,
          trackHeartbeat: true,
          heartbeatIntervalMs: 3000,
        };

        expect(config.memberId).toBe('consumer-1');
        expect(config.groupInstanceId).toBe('instance-1');
        expect(config.trackPartitionLag).toBe(true);
        expect(config.trackHeartbeat).toBe(true);
        expect(config.heartbeatIntervalMs).toBe(3000);
      });

      it('should support function-based memberId and groupInstanceId', () => {
        let dynamicMemberId = 'consumer-initial';

        const config: ConsumerGroupTrackingConfig = {
          memberId: () => dynamicMemberId,
          groupInstanceId: () => 'static-instance',
        };

        expect(typeof config.memberId).toBe('function');
        expect((config.memberId as () => string)()).toBe('consumer-initial');

        dynamicMemberId = 'consumer-updated';
        expect((config.memberId as () => string)()).toBe('consumer-updated');
      });
    });

    describe('RebalanceEvent types', () => {
      it('should define RebalanceEvent interface correctly', () => {
        const event: RebalanceEvent = {
          type: 'assigned',
          partitions: [
            { topic: 'orders', partition: 0, offset: 100 },
            { topic: 'orders', partition: 1, offset: 200 },
          ],
          timestamp: Date.now(),
          generation: 5,
          memberId: 'consumer-1',
          reason: 'new consumer joined',
        };

        expect(event.type).toBe('assigned');
        expect(event.partitions).toHaveLength(2);
        expect(event.generation).toBe(5);
        expect(event.memberId).toBe('consumer-1');
      });

      it('should support all rebalance types', () => {
        const types: RebalanceType[] = ['assigned', 'revoked', 'lost'];

        for (const type of types) {
          const event: RebalanceEvent = {
            type,
            partitions: [],
            timestamp: Date.now(),
          };
          expect(event.type).toBe(type);
        }
      });
    });

    describe('PartitionAssignment types', () => {
      it('should define PartitionAssignment interface correctly', () => {
        const assignment: PartitionAssignment = {
          topic: 'user-events',
          partition: 3,
          offset: 12_345,
          metadata: 'leader-epoch:10',
        };

        expect(assignment.topic).toBe('user-events');
        expect(assignment.partition).toBe(3);
        expect(assignment.offset).toBe(12_345);
        expect(assignment.metadata).toBe('leader-epoch:10');
      });

      it('should allow minimal partition assignment', () => {
        const assignment: PartitionAssignment = {
          topic: 'events',
          partition: 0,
        };

        expect(assignment.topic).toBe('events');
        expect(assignment.partition).toBe(0);
        expect(assignment.offset).toBeUndefined();
      });
    });

    describe('ConsumerGroupState types', () => {
      it('should define ConsumerGroupState interface correctly', () => {
        const state: ConsumerGroupState = {
          groupId: 'order-processors',
          memberId: 'consumer-abc123',
          groupInstanceId: 'instance-1',
          assignedPartitions: [
            { topic: 'orders', partition: 0 },
            { topic: 'orders', partition: 1 },
          ],
          generation: 10,
          isActive: true,
          lastHeartbeat: Date.now(),
          state: 'stable',
        };

        expect(state.groupId).toBe('order-processors');
        expect(state.isActive).toBe(true);
        expect(state.state).toBe('stable');
        expect(state.assignedPartitions).toHaveLength(2);
      });

      it('should support all consumer group states', () => {
        const states: ConsumerGroupState['state'][] = [
          'stable',
          'preparing_rebalance',
          'completing_rebalance',
          'dead',
          'empty',
        ];

        for (const groupState of states) {
          const state: ConsumerGroupState = {
            groupId: 'test',
            assignedPartitions: [],
            isActive: groupState !== 'dead',
            state: groupState,
          };
          expect(state.state).toBe(groupState);
        }
      });
    });

    describe('PartitionLag types', () => {
      it('should define PartitionLag interface correctly', () => {
        const lag: PartitionLag = {
          topic: 'events',
          partition: 2,
          currentOffset: 1000,
          endOffset: 1500,
          lag: 500,
          timestamp: Date.now(),
        };

        expect(lag.topic).toBe('events');
        expect(lag.partition).toBe(2);
        expect(lag.lag).toBe(500);
        expect(lag.currentOffset).toBe(1000);
        expect(lag.endOffset).toBe(1500);
      });

      it('should calculate lag correctly', () => {
        const currentOffset = 5000;
        const endOffset = 5250;

        const lag: PartitionLag = {
          topic: 'orders',
          partition: 0,
          currentOffset,
          endOffset,
          lag: endOffset - currentOffset,
          timestamp: Date.now(),
        };

        expect(lag.lag).toBe(250);
      });
    });

    describe('Consumer config with group tracking', () => {
      it('should support full Kafka consumer group configuration', () => {
        const rebalanceCallback = vi.fn();
        const assignedCallback = vi.fn();
        const revokedCallback = vi.fn();

        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'user-events',
          consumerGroup: 'event-processor',
          consumerGroupTracking: {
            memberId: () => 'consumer-123',
            groupInstanceId: 'static-instance-1',
            onRebalance: rebalanceCallback,
            onPartitionsAssigned: assignedCallback,
            onPartitionsRevoked: revokedCallback,
            trackPartitionLag: true,
            trackHeartbeat: true,
            heartbeatIntervalMs: 3000,
          },
        };

        expect(config.consumerGroupTracking).toBeDefined();
        expect(config.consumerGroupTracking?.trackPartitionLag).toBe(true);
        expect(config.consumerGroupTracking?.trackHeartbeat).toBe(true);
      });

      it('should support minimal group tracking configuration', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          consumerGroup: 'processors',
          consumerGroupTracking: {
            memberId: 'consumer-1',
          },
        };

        expect(config.consumerGroupTracking?.memberId).toBe('consumer-1');
        expect(config.consumerGroupTracking?.trackPartitionLag).toBeUndefined();
      });
    });

    describe('Span attributes for consumer groups', () => {
      it('should define expected attribute names', () => {
        const expectedAttributes = [
          'messaging.consumer_group.rebalance.type',
          'messaging.consumer_group.rebalance.partition_count',
          'messaging.consumer_group.generation',
          'messaging.consumer_group.member_id',
          'messaging.consumer_group.rebalance.reason',
          'messaging.consumer_group.heartbeat.healthy',
          'messaging.consumer_group.heartbeat.latency_ms',
        ];

        expect(expectedAttributes).toContain(
          'messaging.consumer_group.rebalance.type',
        );
        expect(expectedAttributes).toContain(
          'messaging.consumer_group.generation',
        );
        expect(expectedAttributes).toContain(
          'messaging.consumer_group.heartbeat.healthy',
        );
      });

      it('should define expected event names', () => {
        const expectedEvents = [
          'consumer_group_assigned',
          'consumer_group_revoked',
          'consumer_group_lost',
          'consumer_group_heartbeat',
          'partition_lag_recorded',
        ];

        expect(expectedEvents).toContain('consumer_group_assigned');
        expect(expectedEvents).toContain('consumer_group_revoked');
        expect(expectedEvents).toContain('consumer_group_heartbeat');
      });
    });

    describe('Integration with other features', () => {
      it('should work alongside ordering configuration', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'orders',
          consumerGroup: 'order-processor',
          ordering: {
            sequenceFrom: (msg) => (msg as { offset: number }).offset,
            detectOutOfOrder: true,
          },
          consumerGroupTracking: {
            memberId: 'consumer-1',
            trackPartitionLag: true,
          },
        };

        expect(config.ordering).toBeDefined();
        expect(config.consumerGroupTracking).toBeDefined();
      });

      it('should work alongside lag metrics configuration', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          consumerGroup: 'processor',
          lagMetrics: {
            getCurrentOffset: (msg) => (msg as { offset: number }).offset,
            getEndOffset: () => Promise.resolve(10_000),
          },
          consumerGroupTracking: {
            memberId: 'consumer-1',
            trackPartitionLag: true,
          },
        };

        expect(config.lagMetrics).toBeDefined();
        expect(config.consumerGroupTracking).toBeDefined();
      });

      it('should work with custom attributes hook', () => {
        const config: ConsumerConfig = {
          system: 'kafka',
          destination: 'events',
          consumerGroup: 'processor',
          consumerGroupTracking: {
            memberId: 'consumer-1',
          },
          customAttributes: (_ctx, msg) => ({
            'custom.key': (msg as { key: string }).key,
          }),
        };

        expect(config.consumerGroupTracking).toBeDefined();
        expect(config.customAttributes).toBeDefined();
      });
    });

    describe('SQS and RabbitMQ support', () => {
      it('should support SQS with group tracking', () => {
        const config: ConsumerConfig = {
          system: 'sqs',
          destination: 'orders.fifo',
          consumerGroup: 'order-processor',
          consumerGroupTracking: {
            // SQS doesn't have member IDs but we can track instance
            groupInstanceId: process.env.ECS_TASK_ID || 'local',
          },
        };

        expect(config.consumerGroupTracking?.groupInstanceId).toBeDefined();
      });

      it('should support RabbitMQ with group tracking', () => {
        const config: ConsumerConfig = {
          system: 'rabbitmq',
          destination: 'orders',
          consumerGroup: 'order-consumer',
          consumerGroupTracking: {
            memberId: () => 'rabbitmq-consumer-tag-123',
          },
        };

        expect(config.consumerGroupTracking?.memberId).toBeDefined();
      });
    });
  });
});