import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import { AwsBedrockAgentsProvider } from '../../src/providers/bedrock/agents';
import { mockProcessEnv } from '../util/utils';

// Hoisted mocks for AWS SDK
const mockSend = vi.hoisted(() => vi.fn());
const MockBedrockAgentRuntimeClient = vi.hoisted(() =>
  vi.fn(function MockBedrockAgentRuntimeClient() {
    return { send: mockSend };
  }),
);
const MockInvokeAgentCommand = vi.hoisted(() =>
  vi.fn(function MockInvokeAgentCommand(this: any, input: any) {
    Object.assign(this, input);
  }),
);
const NodeHttpHandlerMock = vi.hoisted(() =>
  vi.fn(function NodeHttpHandlerMock() {
    return {
      handle: vi.fn(),
    };
  }),
);
const ProxyAgentMock = vi.hoisted(() => vi.fn(function ProxyAgentMock() {}));

// Mock AWS SDK modules - don't use importOriginal to avoid module resolution issues
vi.mock('@aws-sdk/client-bedrock-agent-runtime', () => ({
  BedrockAgentRuntimeClient: MockBedrockAgentRuntimeClient,
  InvokeAgentCommand: MockInvokeAgentCommand,
}));

vi.mock('@smithy/node-http-handler', () => ({
  __esModule: true,
  NodeHttpHandler: NodeHttpHandlerMock,
  default: NodeHttpHandlerMock,
}));

vi.mock('proxy-agent', () => ({
  __esModule: true,
  ProxyAgent: ProxyAgentMock,
  default: ProxyAgentMock,
}));

vi.mock('../../src/cache', async (importOriginal) => {
  return {
    ...(await importOriginal()),

    getCache: vi.fn(() =>
      Promise.resolve({
        get: vi.fn(() => Promise.resolve(null)),
        set: vi.fn(),
      }),
    ),

    isCacheEnabled: vi.fn(() => false),
  };
});

const ORIGINAL_HTTP_PROXY = process.env.HTTP_PROXY;
const ORIGINAL_HTTPS_PROXY = process.env.HTTPS_PROXY;

describe('AwsBedrockAgentsProvider', () => {
  beforeEach(() => {
    vi.clearAllMocks();
    mockProcessEnv({ HTTP_PROXY: '' });
    mockProcessEnv({ HTTPS_PROXY: '' });
  });

  afterEach(() => {
    if (ORIGINAL_HTTP_PROXY === undefined) {
      mockProcessEnv({ HTTP_PROXY: undefined });
    } else {
      mockProcessEnv({ HTTP_PROXY: ORIGINAL_HTTP_PROXY });
    }
    if (ORIGINAL_HTTPS_PROXY === undefined) {
      mockProcessEnv({ HTTPS_PROXY: undefined });
    } else {
      mockProcessEnv({ HTTPS_PROXY: ORIGINAL_HTTPS_PROXY });
    }
  });

  describe('constructor', () => {
    it('should allow creation without agentAliasId but fail on callApi', async () => {
      const provider = new AwsBedrockAgentsProvider('test-agent-123');
      const result = await provider.callApi('test');
      expect(result.error).toContain('Agent Alias ID is required');
    });

    it('should create provider with agent ID from path and alias in config', () => {
      const provider = new AwsBedrockAgentsProvider('test-agent-123', {
        config: { agentId: 'test-agent-123', agentAliasId: 'test-alias' },
      });
      expect(provider.id()).toBe('bedrock-agent:test-agent-123');
    });

    it('should create provider with agent ID from config', () => {
      const provider = new AwsBedrockAgentsProvider('', {
        config: {
          agentId: 'config-agent-456',
          agentAliasId: 'test-alias',
        },
      });
      expect(provider.id()).toBe('bedrock-agent:config-agent-456');
    });

    it('should throw error when no agent ID is provided', () => {
      expect(
        () =>
          new AwsBedrockAgentsProvider('', {
            config: { agentAliasId: 'test-alias' } as any,
          }),
      ).toThrow(
        'Agent ID is required. Provide it in the provider path (bedrock-agent:AGENT_ID) or config.',
      );
    });

    it('should accept configuration options', () => {
      const config = {
        agentId: 'test-agent',
        agentAliasId: 'prod-alias',
        sessionId: 'session-123',
        enableTrace: true,
        memoryId: 'LONG_TERM_MEMORY',
      };
      const provider = new AwsBedrockAgentsProvider('', { config });
      // Provider adds default timeout and maxRetries
      expect(provider.config).toMatchObject(config);
    });
  });

  describe('getAgentRuntimeClient', () => {
    it('should create runtime client without custom handler by default', async () => {
      const provider = new AwsBedrockAgentsProvider('test-agent-123', {
        config: {
          agentId: 'test-agent-123',
          agentAliasId: 'test-alias',
          region: 'us-east-1',
        },
      });

      await provider.getAgentRuntimeClient();

      // client-bedrock-agent-runtime already defaults to HTTP/1.1,
      // so no custom handler is needed without proxy
      expect(NodeHttpHandlerMock).not.toHaveBeenCalled();
      expect(MockBedrockAgentRuntimeClient).toHaveBeenCalledWith({
        region: 'us-east-1',
        retryMode: 'adaptive',
        maxAttempts: 10,
      });
    });

    it('should create runtime client with proxy agent when proxy is configured', async () => {
      mockProcessEnv({ HTTPS_PROXY: 'http://proxy.example:8080' });

      const provider = new AwsBedrockAgentsProvider('test-agent-123', {
        config: {
          agentId: 'test-agent-123',
          agentAliasId: 'test-alias',
          region: 'us-east-1',
        },
      });

      await provider.getAgentRuntimeClient();

      expect(ProxyAgentMock).toHaveBeenCalled();
      expect(NodeHttpHandlerMock).toHaveBeenCalledWith({
        httpsAgent: expect.any(Object),
        requestTimeout: 300000,
      });
      const requestHandler = NodeHttpHandlerMock.mock.results.at(-1)?.value;
      expect(MockBedrockAgentRuntimeClient).toHaveBeenCalledWith({
        region: 'us-east-1',
        retryMode: 'adaptive',
        maxAttempts: 10,
        requestHandler,
      });
    });
  });

  describe('callApi', () => {
    let provider: AwsBedrockAgentsProvider;

    beforeEach(() => {
      vi.clearAllMocks();
      // Reset the hoisted mocks
      mockSend.mockReset();
      MockBedrockAgentRuntimeClient.mockClear();
      MockInvokeAgentCommand.mockClear();

      // Create provider after mocks are set up
      provider = new AwsBedrockAgentsProvider('test-agent', {
        config: {
          agentId: 'test-agent',
          agentAliasId: 'test-alias',
          region: 'us-east-1',
        },
      });
    });

    afterEach(() => {
      vi.clearAllMocks();
      vi.restoreAllMocks();
    });

    it('should require agentAliasId', async () => {
      // Create provider without agentAliasId to test error
      const providerNoAlias = new AwsBedrockAgentsProvider('test-agent', {
        config: {
          agentId: 'test-agent',
          // agentAliasId intentionally missing
        } as any,
      });

      const result = await providerNoAlias.callApi('Test prompt');

      expect(result.error).toContain('Agent Alias ID is required');
      expect(result.output).toBeUndefined();
    });

    it('should successfully invoke agent with text response', async () => {
      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('This is the agent response'),
            },
          };
        })(),
        sessionId: 'session-abc123',
        $metadata: {},
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      const result = await provider.callApi('Test prompt');

      expect(result.output).toBe('This is the agent response');
      expect(result.error).toBeUndefined();
      expect(result.metadata?.sessionId).toBe('session-abc123');
    });

    it('should handle agent with tool calls and traces', async () => {
      provider.config.enableTrace = true;

      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('Agent response with tool'),
            },
            trace: {
              trace: {
                orchestrationTrace: {
                  rationale: {
                    text: 'Agent reasoning about the task',
                  },
                  invocationInput: {
                    actionGroupInvocationInput: {
                      actionGroupName: 'calculator',
                      function: 'add',
                    },
                  },
                },
              },
            },
          };
          yield {
            trace: {
              trace: {
                actionGroupTrace: {
                  actionGroupInvocationOutput: {
                    text: '42',
                  },
                },
              },
            },
          };
        })(),
        sessionId: 'session-xyz789',
        $metadata: {},
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      const result = await provider.callApi('Calculate something');

      expect(result.output).toBe('Agent response with tool');
      // Trace should be the raw array from the agent response
      expect(result.metadata?.trace).toEqual([
        {
          trace: {
            orchestrationTrace: {
              rationale: {
                text: 'Agent reasoning about the task',
              },
              invocationInput: {
                actionGroupInvocationInput: {
                  actionGroupName: 'calculator',
                  function: 'add',
                },
              },
            },
          },
        },
        {
          trace: {
            actionGroupTrace: {
              actionGroupInvocationOutput: {
                text: '42',
              },
            },
          },
        },
      ]);
    });

    it('should handle memory configuration', async () => {
      provider.config.memoryId = 'LONG_TERM_MEMORY';

      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('Response with memory'),
            },
          };
        })(),
        sessionId: 'session-mem123',
        $metadata: {},
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      await provider.callApi('Test with memory');

      // Verify that the provider was configured with memory
      expect(provider.config.memoryId).toBe('LONG_TERM_MEMORY');
    });

    it('should handle API errors gracefully', async () => {
      // Override the mock to reject for this test
      (mockSend as any).mockRejectedValue(new Error('AWS API Error'));

      const result = await provider.callApi('Test prompt');

      expect(result.error).toBeDefined();
      expect(result.error).toContain('Failed to invoke agent');
      expect(result.output).toBeUndefined();
    });

    it('should handle token usage in metadata', async () => {
      // Clear previous mock and set up new response
      mockSend.mockClear();

      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('Response with tokens'),
            },
          };
        })(),
        sessionId: 'session-token123',
        $metadata: {
          usage: {
            inputTokens: 10,
            outputTokens: 20,
            totalTokens: 30,
          },
        },
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      const result = await provider.callApi('Test prompt');

      // Token usage is not currently extracted from Bedrock Agents responses
      // as the AWS SDK types don't include usage metadata
      expect(result.output).toBe('Response with tokens');
    });

    it('should use session ID from config if provided', async () => {
      provider.config.sessionId = 'fixed-session-id';

      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('Response'),
            },
          };
        })(),
        sessionId: 'response-session-id',
        $metadata: {},
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      await provider.callApi('Test prompt');

      // Verify that the fixed session ID was used
      expect(provider.config.sessionId).toBe('fixed-session-id');
    });

    it('should generate session ID if not provided', async () => {
      // Clear previous mock and set up new response
      mockSend.mockClear();

      const mockResponse = {
        completion: (async function* () {
          yield {
            chunk: {
              bytes: new TextEncoder().encode('Response'),
            },
          };
        })(),
        sessionId: 'generated-session',
        $metadata: {},
      };

      (mockSend as any).mockResolvedValue(mockResponse as any);

      const result = await provider.callApi('Test prompt');

      // Verify call was successful
      expect(result.output).toBe('Response');
      expect(result.error).toBeUndefined();
      expect(mockSend).toHaveBeenCalled();
    });
  });

  describe('toString', () => {
    it('should return formatted string representation', () => {
      const provider = new AwsBedrockAgentsProvider('my-agent', {
        config: { agentId: 'my-agent', agentAliasId: 'test-alias' },
      });
      expect(provider.toString()).toBe('[AWS Bedrock Agents Provider my-agent]');
    });
  });
});