import { test, expect, describe, beforeEach, afterEach } from "bun:test";

// Mock MediaStream and related APIs
class MockMediaStreamTrack {
  kind: string;
  id: string;
  label: string = '';
  enabled: boolean = true;
  muted: boolean = false;
  readyState: 'live' | 'ended' = 'live';
  
  constructor(kind: string) {
    this.kind = kind;
    this.id = Math.random().toString(36);
  }

  stop() {
    this.readyState = 'ended';
  }

  clone() {
    return new MockMediaStreamTrack(this.kind);
  }
}

class MockMediaStream {
  id: string;
  active: boolean = true;
  private tracks: MockMediaStreamTrack[] = [];

  constructor(tracks?: MockMediaStreamTrack[]) {
    this.id = Math.random().toString(36);
    if (tracks) {
      this.tracks = [...tracks];
    }
  }

  getTracks() {
    return [...this.tracks];
  }

  getVideoTracks() {
    return this.tracks.filter(track => track.kind === 'video');
  }

  getAudioTracks() {
    return this.tracks.filter(track => track.kind === 'audio');
  }

  addTrack(track: MockMediaStreamTrack) {
    this.tracks.push(track);
  }

  removeTrack(track: MockMediaStreamTrack) {
    const index = this.tracks.indexOf(track);
    if (index > -1) {
      this.tracks.splice(index, 1);
    }
  }
}

class MockHTMLVideoElement {
  srcObject: MockMediaStream | null = null;
  autoplay: boolean = false;
  muted: boolean = false;
  
  play() {
    return Promise.resolve();
  }
  
  pause() {}
}

// Mock navigator.mediaDevices
let mockGetUserMediaCalls: any[] = [];
const mockGetUserMedia = (constraints: any) => {
  mockGetUserMediaCalls.push(constraints);
  const tracks = [];
  if (constraints.video) tracks.push(new MockMediaStreamTrack('video'));
  if (constraints.audio) tracks.push(new MockMediaStreamTrack('audio'));
  return Promise.resolve(new MockMediaStream(tracks));
};

(global as any).navigator = {
  mediaDevices: {
    getUserMedia: mockGetUserMedia
  }
};

// Mock document.getElementById
let getElementByIdReturn: any = null;
(global as any).document = {
  getElementById: () => getElementByIdReturn
};

// Import after mocking
import { MediaHandler } from "../../public/js/services/MediaHandler.ts";

describe("MediaHandler", () => {
  let mediaHandler: MediaHandler;
  let mockVideoElement: MockHTMLVideoElement;

  beforeEach(() => {
    mockVideoElement = new MockHTMLVideoElement();
    getElementByIdReturn = mockVideoElement;
    mockGetUserMediaCalls.length = 0; // Clear calls array
  });

  test("should initialize with video element", () => {
    mediaHandler = new MediaHandler('testVideo');
    
    // The MediaHandler should have found and stored the video element
    expect(mediaHandler.getLocalVideo()).toBe(mockVideoElement);
  });

  test("should initialize without video element", () => {
    mediaHandler = new MediaHandler();
    
    expect(mediaHandler.getLocalVideo()).toBeNull();
  });

  test("should get local stream successfully", async () => {
    mediaHandler = new MediaHandler('testVideo');
    
    const mockTracks = [
      new MockMediaStreamTrack('video'),
      new MockMediaStreamTrack('audio')
    ];
    const mockStream = new MockMediaStream(mockTracks);
    
    // Override mock to return this specific stream and track calls
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    const getUserMediaCalls: any[] = [];
    (global as any).navigator.mediaDevices.getUserMedia = (constraints: any) => {
      getUserMediaCalls.push(constraints);
      return Promise.resolve(mockStream);
    };

    const stream = await mediaHandler.getLocalStream();

    expect(getUserMediaCalls).toHaveLength(1);
    expect(getUserMediaCalls[0]).toEqual({
      video: {
        width: { ideal: 1280 },
        height: { ideal: 720 },
        frameRate: { ideal: 30 }
      },
      audio: true
    });

    expect(stream).toBe(mockStream);
    expect(mockVideoElement.srcObject).toBe(mockStream);
    
    // Restore original
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
  });

  test("should handle getUserMedia error", async () => {
    mediaHandler = new MediaHandler('testVideo');
    
    const error = new Error('Camera access denied');
    
    // Override mock to reject with error
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    const originalConsoleError = console.error;
    const errorLogs: any[] = [];
    console.error = (...args: any[]) => errorLogs.push(args);
    
    (global as any).navigator.mediaDevices.getUserMedia = () => Promise.reject(error);

    await expect(mediaHandler.getLocalStream()).rejects.toThrow('Camera access denied');
    
    expect(errorLogs.length).toBeGreaterThan(0);
    expect(errorLogs[0][0]).toBe('Error accessing media devices:');
    expect(errorLogs[0][1]).toBe(error);
    
    // Restore originals
    console.error = originalConsoleError;
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
  });

  test("should stop local stream", async () => {
    mediaHandler = new MediaHandler('testVideo');
    
    const mockTracks = [
      new MockMediaStreamTrack('video'),
      new MockMediaStreamTrack('audio')
    ];
    const mockStream = new MockMediaStream(mockTracks);
    
    // Override mock to return this specific stream
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    (global as any).navigator.mediaDevices.getUserMedia = () => Promise.resolve(mockStream);

    await mediaHandler.getLocalStream();
    
    // Track the initial state of the tracks
    const initialStates = mockTracks.map(track => track.readyState);

    mediaHandler.stopLocalStream();

    // Check that all tracks were stopped (readyState should be 'ended')
    mockTracks.forEach(track => {
      expect(track.readyState).toBe('ended');
    });

    expect(mockVideoElement.srcObject).toBeNull();
    expect(mediaHandler.getCurrentStream()).toBeNull();
    
    // Restore original
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
  });

  test("should handle stopping stream when no stream exists", () => {
    mediaHandler = new MediaHandler('testVideo');
    
    expect(() => {
      mediaHandler.stopLocalStream();
    }).not.toThrow();
    
    expect(mockVideoElement.srcObject).toBeNull();
  });

  test("should get current stream", async () => {
    mediaHandler = new MediaHandler('testVideo');
    
    expect(mediaHandler.getCurrentStream()).toBeNull();

    const mockStream = new MockMediaStream([new MockMediaStreamTrack('video')]);
    
    // Override mock to return this specific stream
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    (global as any).navigator.mediaDevices.getUserMedia = () => Promise.resolve(mockStream);

    await mediaHandler.getLocalStream();
    
    // Restore original
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
    
    expect(mediaHandler.getCurrentStream()).toBe(mockStream);
  });

  test("should work without video element", async () => {
    getElementByIdReturn = null;
    mediaHandler = new MediaHandler('nonExistentVideo');
    
    const mockStream = new MockMediaStream([new MockMediaStreamTrack('video')]);
    
    // Override mock to return this specific stream
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    (global as any).navigator.mediaDevices.getUserMedia = () => Promise.resolve(mockStream);

    const stream = await mediaHandler.getLocalStream();
    
    expect(stream).toBe(mockStream);
    expect(mediaHandler.getLocalVideo()).toBeNull();
    
    // Restore original
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
  });

  test("should handle multiple calls to getLocalStream", async () => {
    mediaHandler = new MediaHandler('testVideo');
    
    const mockStream1 = new MockMediaStream([new MockMediaStreamTrack('video')]);
    const mockStream2 = new MockMediaStream([new MockMediaStreamTrack('video')]);
    
    let callCount = 0;
    const originalGetUserMedia = (global as any).navigator.mediaDevices.getUserMedia;
    (global as any).navigator.mediaDevices.getUserMedia = () => {
      callCount++;
      return Promise.resolve(callCount === 1 ? mockStream1 : mockStream2);
    };

    const stream1 = await mediaHandler.getLocalStream();
    const stream2 = await mediaHandler.getLocalStream();

    expect(stream1).toBe(mockStream1);
    expect(stream2).toBe(mockStream2);
    expect(callCount).toBe(2);
    
    // The video element should have the latest stream
    expect(mockVideoElement.srcObject).toBe(mockStream2);
    
    // Restore original
    (global as any).navigator.mediaDevices.getUserMedia = originalGetUserMedia;
  });
});