import { describe, it, expect, vi, beforeEach } from 'vitest';

class MockEventStream implements AsyncGenerator<unknown, void, unknown> {
  private index = 0;
  private readonly events: unknown[];
  readonly returnSpy = vi.fn(async () => ({ done: true as const, value: undefined }));

  constructor(events: unknown[]) {
    this.events = events;
  }

  [Symbol.asyncIterator](): AsyncGenerator<unknown, void, unknown> {
    return this;
  }

  async next(): Promise<IteratorResult<unknown, void>> {
    if (this.index >= this.events.length) {
      return { done: true, value: undefined };
    }
    const value = this.events[this.index];
    this.index += 1;
    return { done: false, value };
  }

  async return(): Promise<IteratorResult<unknown, void>> {
    return this.returnSpy();
  }

  async throw(e?: unknown): Promise<IteratorResult<unknown, void>> {
    throw e;
  }
}

const { createOpencodeMock } = vi.hoisted(() => ({
  createOpencodeMock: vi.fn(),
}));

vi.mock('node:net', () => ({
  createServer: () => {
    const handlers = new Map<string, (...args: unknown[]) => void>();
    return {
      unref: vi.fn(),
      on: vi.fn((event: string, handler: (...args: unknown[]) => void) => {
        handlers.set(event, handler);
      }),
      listen: vi.fn((_port: number, _host: string, cb: () => void) => {
        cb();
      }),
      address: vi.fn(() => ({ port: 62000 })),
      close: vi.fn((cb?: (err?: Error) => void) => cb?.()),
    };
  },
}));

vi.mock('@opencode-ai/sdk/v2', () => ({
  createOpencode: createOpencodeMock,
}));

describe('OpenCodeClient stream cleanup', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it('should close SSE stream when session.idle is received', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'session.idle',
        properties: { sessionID: 'session-1' },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-1' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });

    const subscribe = vi.fn().mockResolvedValue({ stream });
    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('interactive', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
    });

    expect(result.status).toBe('done');
    expect(stream.returnSpy).toHaveBeenCalled();
    expect(disposeInstance).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
    expect(subscribe).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should close SSE stream when session.error is received', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'session.error',
        properties: {
          sessionID: 'session-2',
          error: { name: 'Error', data: { message: 'boom' } },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-2' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });

    const subscribe = vi.fn().mockResolvedValue({ stream });
    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('interactive', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
    });

    expect(result.status).toBe('error');
    expect(result.content).toContain('boom');
    expect(stream.returnSpy).toHaveBeenCalled();
    expect(disposeInstance).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
    expect(subscribe).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should continue after assistant message completed and finish on session.idle', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'message.part.updated',
        properties: {
          part: { id: 'p-1', type: 'text', text: 'done' },
          delta: 'done',
        },
      },
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-3',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
      {
        type: 'message.part.updated',
        properties: {
          part: { id: 'p-1', type: 'text', text: 'done more' },
          delta: ' more',
        },
      },
      {
        type: 'session.idle',
        properties: { sessionID: 'session-3' },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-3' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });

    const subscribe = vi.fn().mockResolvedValue({ stream });
    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await Promise.race([
      client.call('interactive', 'hello', {
        cwd: '/tmp',
        model: 'opencode/big-pickle',
      }),
      new Promise<never>((_, reject) => setTimeout(() => reject(new Error('timed out')), 500)),
    ]);

    expect(result.status).toBe('done');
    expect(result.content).toBe('done more');
    expect(disposeInstance).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
    expect(subscribe).toHaveBeenCalledWith(
      { directory: '/tmp' },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should reject question.asked without handler and continue processing', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'question.asked',
        properties: {
          id: 'q-1',
          sessionID: 'session-4',
          questions: [
            {
              question: 'Select one',
              header: 'Question',
              options: [{ label: 'A', description: 'A desc' }],
            },
          ],
        },
      },
      {
        type: 'message.part.updated',
        properties: {
          part: { id: 'p-q1', type: 'text', text: 'continued response' },
          delta: 'continued response',
        },
      },
      {
        type: 'session.idle',
        properties: { sessionID: 'session-4' },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-4' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const questionReject = vi.fn().mockResolvedValue({ data: true });

    const subscribe = vi.fn().mockResolvedValue({ stream });
    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
        question: { reject: questionReject, reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('interactive', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
    });

    expect(result.status).toBe('done');
    expect(result.content).toBe('continued response');
    expect(questionReject).toHaveBeenCalledWith(
      {
        requestID: 'q-1',
        directory: '/tmp',
      },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should answer question.asked when handler is configured', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'question.asked',
        properties: {
          id: 'q-2',
          sessionID: 'session-5',
          questions: [
            {
              question: 'Select one',
              header: 'Question',
              options: [{ label: 'A', description: 'A desc' }],
            },
          ],
        },
      },
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-5',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-5' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const questionReply = vi.fn().mockResolvedValue({ data: true });

    const subscribe = vi.fn().mockResolvedValue({ stream });
    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
        question: { reject: vi.fn(), reply: questionReply },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('interactive', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
      onAskUserQuestion: async () => ({ Question: 'A' }),
    });

    expect(result.status).toBe('done');
    expect(questionReply).toHaveBeenCalledWith(
      {
        requestID: 'q-2',
        directory: '/tmp',
        answers: [['A']],
      },
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should pass mapped tools to promptAsync when allowedTools is set', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-tools',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-tools' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const subscribe = vi.fn().mockResolvedValue({ stream });

    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('coder', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
      allowedTools: ['Read', 'Edit', 'Bash', 'WebSearch', 'WebFetch', 'mcp__github__search'],
    });

    expect(result.status).toBe('done');
    expect(promptAsync).toHaveBeenCalledWith(
      expect.objectContaining({
        tools: {
          read: true,
          edit: true,
          bash: true,
          websearch: true,
          webfetch: true,
          mcp__github__search: true,
        },
      }),
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should pass empty tools object to promptAsync when allowedTools is an explicit empty array', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-empty-tools',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-empty-tools' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const subscribe = vi.fn().mockResolvedValue({ stream });

    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await client.call('coder', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
      allowedTools: [],
    });

    expect(result.status).toBe('done');
    expect(promptAsync).toHaveBeenCalledWith(
      expect.objectContaining({
        tools: {},
      }),
      expect.objectContaining({ signal: expect.any(AbortSignal) }),
    );
  });

  it('should configure allow permissions for edit mode', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-perm',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-perm' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const subscribe = vi.fn().mockResolvedValue({ stream });

    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    await client.call('coder', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
      permissionMode: 'edit',
    });

    const createCallArgs = createOpencodeMock.mock.calls[0]?.[0] as { config?: Record<string, unknown> };
    const permission = createCallArgs.config?.permission as Record<string, string>;
    expect(permission.read).toBe('allow');
    expect(permission.edit).toBe('allow');
    expect(permission.write).toBe('allow');
    expect(permission.bash).toBe('allow');
    expect(permission.question).toBe('deny');
  });

  it('should pass permission ruleset to session.create', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'message.updated',
        properties: {
          info: {
            sessionID: 'session-ruleset',
            role: 'assistant',
            time: { created: Date.now(), completed: Date.now() + 1 },
          },
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-ruleset' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const subscribe = vi.fn().mockResolvedValue({ stream });

    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: vi.fn() },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    await client.call('coder', 'hello', {
      cwd: '/tmp',
      model: 'opencode/big-pickle',
      permissionMode: 'edit',
    });

    expect(sessionCreate).toHaveBeenCalledWith(expect.objectContaining({
      directory: '/tmp',
      permission: expect.arrayContaining([
        expect.objectContaining({ permission: 'edit', action: 'allow' }),
        expect.objectContaining({ permission: 'question', action: 'deny' }),
      ]),
    }));
  });

  it('should fail fast when permission reply times out', async () => {
    const { OpenCodeClient } = await import('../infra/opencode/client.js');
    const stream = new MockEventStream([
      {
        type: 'permission.asked',
        properties: {
          id: 'perm-1',
          sessionID: 'session-perm-timeout',
        },
      },
    ]);

    const promptAsync = vi.fn().mockResolvedValue(undefined);
    const sessionCreate = vi.fn().mockResolvedValue({ data: { id: 'session-perm-timeout' } });
    const disposeInstance = vi.fn().mockResolvedValue({ data: {} });
    const subscribe = vi.fn().mockResolvedValue({ stream });
    const permissionReply = vi.fn().mockImplementation(() => new Promise(() => {}));

    createOpencodeMock.mockResolvedValue({
      client: {
        instance: { dispose: disposeInstance },
        session: { create: sessionCreate, promptAsync },
        event: { subscribe },
        permission: { reply: permissionReply },
      },
      server: { close: vi.fn() },
    });

    const client = new OpenCodeClient();
    const result = await Promise.race([
      client.call('coder', 'hello', {
        cwd: '/tmp',
        model: 'opencode/big-pickle',
        permissionMode: 'edit',
      }),
      new Promise<never>((_, reject) => setTimeout(() => reject(new Error('timed out')), 8000)),
    ]);

    expect(result.status).toBe('error');
    expect(result.content).toContain('permission reply timed out');
  });
});