import 'dart:io';
import 'dart:ui';
import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_mlkit_face_detection/google_mlkit_face_detection.dart';
import '../../core/theme.dart';
import '../../core/utils/camera_utils.dart';
import '../../widgets/atoms/custom_button.dart';
import '../../widgets/atoms/scanner_overlay.dart';

class CameraCaptureScreen extends StatefulWidget {
  const CameraCaptureScreen({Key? key}) : super(key: key);

  @override
  State<CameraCaptureScreen> createState() => _CameraCaptureScreenState();
}

class _CameraCaptureScreenState extends State<CameraCaptureScreen>
    with SingleTickerProviderStateMixin {
  CameraController? _controller;
  CameraDescription? _frontCamera;
  bool _isCameraInitialized = false;
  bool _isProcessingFrame = false;

  // Quality gate
  bool _isFaceDetected = false;
  bool _isDistanceOk = false;
  bool _isBrightnessOk = false;
  bool _isLightingUniform = false;
  bool _isPoseValid = false;
  double _faceRatio = 0.0;
  double _brightness = 0.0;
  double _lightingUniformity = 0.0;
  double _headEulerAngleY = 0.0;

  // State capture foto
  bool _isCaptureDone = false;
  XFile? _capturedPhoto;

  late FaceDetector _faceDetector;
  late AnimationController _pulseController;

  bool get _allChecksValid =>
      _isFaceDetected && _isDistanceOk && _isBrightnessOk && _isLightingUniform && _isPoseValid;

  String get _qualityMessage {
    if (_isCaptureDone) return 'Pemotretan berhasil ✓';
    if (!_isFaceDetected) return 'Arahkan wajah ke dalam bingkai';
    if (_faceRatio < 0.25) return 'Terlalu jauh, dekatkan wajah';
    if (_faceRatio > 0.75) return 'Terlalu dekat, mundur sedikit';
    if (!_isBrightnessOk) return 'Pencahayaan kurang terang';
    if (!_isLightingUniform) return 'Ada bayangan, hadap cahaya';
    if (!_isPoseValid) return 'Hadap lurus ke kamera';
    return 'Siap — ambil foto';
  }

  @override
  void initState() {
    super.initState();
    _pulseController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 800),
    )..repeat(reverse: true);

    _faceDetector = FaceDetector(
      options: FaceDetectorOptions(
        enableClassification: false,
        enableLandmarks: true,
        enableContours: false,
        enableTracking: true,
        performanceMode: FaceDetectorMode.accurate,
      ),
    );
    _initializeCamera();
  }

  Future<void> _initializeCamera() async {
    final cameras = await availableCameras();
    _frontCamera = cameras.firstWhere(
      (camera) => camera.lensDirection == CameraLensDirection.front,
      orElse: () => cameras.first,
    );

    _controller = CameraController(
      _frontCamera!,
      ResolutionPreset.medium,
      enableAudio: false,
      imageFormatGroup: Platform.isAndroid
          ? ImageFormatGroup.nv21
          : ImageFormatGroup.bgra8888,
    );

    await _controller!.initialize();

    if (!mounted) return;

    _controller!.startImageStream((CameraImage image) {
      if (!mounted || _isCaptureDone) return;
      _processFrame(image);
    });

    setState(() {
      _isCameraInitialized = true;
    });
  }

  void _processFrame(CameraImage image) async {
    if (_isProcessingFrame) return;
    _isProcessingFrame = true;

    try {
      _brightness = BrightnessUtils.calculateBrightness(image, centerOnly: true);
      _isBrightnessOk = _brightness > 70;

      _lightingUniformity = BrightnessUtils.calculateFaceUniformity(image);
      _isLightingUniform = _lightingUniformity > 0.45;

      final inputImage = CameraUtils.inputImageFromCameraImage(
        image: image,
        camera: _frontCamera!,
        rotation: CameraUtils.rotationIntToImageRotation(
            _frontCamera!.sensorOrientation),
      );

      final faces = await _faceDetector.processImage(inputImage);

      if (faces.isNotEmpty) {
        final face = faces.first;
        
        _headEulerAngleY = face.headEulerAngleY ?? 0.0;
        _isPoseValid = _headEulerAngleY.abs() < 18.0;

        final rotation = CameraUtils.rotationIntToImageRotation(_frontCamera!.sensorOrientation);
        final bool isRotated90or270 =
            rotation == InputImageRotation.rotation90deg ||
            rotation == InputImageRotation.rotation270deg;
        final double effectiveWidth = isRotated90or270
            ? image.height.toDouble()
            : image.width.toDouble();

        _faceRatio = face.boundingBox.width / effectiveWidth;
        _isFaceDetected = true;
        _isDistanceOk = _faceRatio >= 0.25 && _faceRatio <= 0.75;
      } else {
        _isFaceDetected = false;
        _isDistanceOk = false;
        _isPoseValid = false;
        _faceRatio = 0.0;
      }

      if (mounted) setState(() {});
    } catch (e) {
      debugPrint("Error processing frame: $e");
    } finally {
      _isProcessingFrame = false;
    }
  }

  Future<void> _capturePhoto() async {
    if (!_allChecksValid || _isCaptureDone) return;

    try {
      await _controller!.stopImageStream();
    } catch (_) {}

    XFile? photo;
    try {
      photo = await _controller!.takePicture();
    } catch (e) {
      debugPrint("Gagal mengambil foto: $e");
      _controller!.startImageStream((CameraImage image) {
        if (!mounted || _isCaptureDone) return;
        _processFrame(image);
      });
      return;
    }

    HapticFeedback.mediumImpact();

    setState(() {
      _isCaptureDone = true;
      _capturedPhoto = photo;
    });
  }

  void _retake() {
    setState(() {
      _isCaptureDone = false;
      _capturedPhoto = null;
      _isFaceDetected = false;
      _isDistanceOk = false;
      _isPoseValid = false;
      _isLightingUniform = false;
      _isBrightnessOk = false;
    });

    _controller!.startImageStream((CameraImage image) {
      if (!mounted || _isCaptureDone) return;
      _processFrame(image);
    });
  }

  void _usePhoto() {
    if (_capturedPhoto != null) {
      Navigator.pop(context, {
        'photo': File(_capturedPhoto!.path),
      });
    }
  }

  @override
  void dispose() {
    _pulseController.dispose();
    _controller?.dispose();
    _faceDetector.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      extendBodyBehindAppBar: true,
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        elevation: 0,
        leading: IconButton(
          icon: Container(
            padding: const EdgeInsets.all(8),
            decoration: BoxDecoration(
              color: Colors.black.withOpacity(0.5),
              shape: BoxShape.circle,
            ),
            child: const Icon(Icons.close, color: Colors.white, size: 16),
          ),
          onPressed: () => Navigator.pop(context),
        ),
      ),
      body: Stack(
        children: [
          // Preview kamera atau Foto yang diambil
          if (_isCaptureDone && _capturedPhoto != null)
            SizedBox.expand(
              child: Image.file(
                File(_capturedPhoto!.path),
                fit: BoxFit.cover,
              ),
            )
          else if (_isCameraInitialized)
            SizedBox.expand(
              child: FittedBox(
                fit: BoxFit.cover,
                child: SizedBox(
                  width: _controller!.value.previewSize?.height ??
                      MediaQuery.of(context).size.width,
                  height: _controller!.value.previewSize?.width ??
                      MediaQuery.of(context).size.height,
                  child: CameraPreview(_controller!),
                ),
              ),
            )
          else
            const Center(child: CircularProgressIndicator(color: Colors.white)),


          // Scanner overlay
          ScannerOverlay(
            borderColor: _isCaptureDone
                ? AppTheme.statusGreen
                : _allChecksValid
                    ? AppTheme.statusGreen
                    : _isFaceDetected
                        ? AppTheme.statusYellow
                        : AppTheme.primaryBlue,
            isScanning: !_isCaptureDone,
          ),

          // Header info
          Positioned(
            top: MediaQuery.of(context).padding.top + kToolbarHeight + 20,
            left: 20,
            right: 20,
            child: Column(
              children: [
                Text(
                  _isCaptureDone
                      ? 'Pemotretan Selesai'
                      : 'Ambil Foto Wajah',
                  style: AppTheme.heading3.copyWith(color: Colors.white),
                ),
                const SizedBox(height: 10),
                ClipRRect(
                  borderRadius: BorderRadius.circular(20),
                  child: BackdropFilter(
                    filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
                    child: Container(
                      padding: const EdgeInsets.symmetric(
                          horizontal: 20, vertical: 10),
                      decoration: BoxDecoration(
                        color: Colors.white.withOpacity(0.15),
                        borderRadius: BorderRadius.circular(20),
                        border:
                            Border.all(color: Colors.white.withOpacity(0.3)),
                      ),
                      child: Text(
                        _qualityMessage,
                        textAlign: TextAlign.center,
                        style: AppTheme.bodyLarge.copyWith(
                          color: _isCaptureDone
                              ? AppTheme.statusGreen
                              : _allChecksValid
                                  ? AppTheme.statusGreen
                                  : Colors.white,
                          fontWeight: FontWeight.bold,
                        ),
                      ),
                    ),
                  ),
                ),

                // Quality chips (sebelum rekam)
                if (!_isCaptureDone) ...[
                  const SizedBox(height: 10),
                  Wrap(
                    spacing: 6,
                    runSpacing: 6,
                    alignment: WrapAlignment.center,
                    children: [
                      _buildQualityChip(
                        icon: Icons.straighten,
                        label: _isFaceDetected
                            ? (_faceRatio < 0.25
                                ? 'Terlalu Jauh'
                                : _faceRatio > 0.75
                                    ? 'Terlalu Dekat'
                                    : 'Jarak ✓')
                            : 'Jarak',
                        isOk: _isDistanceOk,
                        isDetected: _isFaceDetected,
                      ),
                      _buildQualityChip(
                        icon: Icons.wb_sunny_outlined,
                        label: 'Cahaya',
                        isOk: _isBrightnessOk,
                        isDetected: _isFaceDetected,
                      ),
                      _buildQualityChip(
                        icon: Icons.blur_on,
                        label: 'Bayangan',
                        isOk: _isLightingUniform,
                        isDetected: _isFaceDetected,
                      ),
                      _buildQualityChip(
                        icon: Icons.face,
                        label: 'Hadap Depan',
                        isOk: _isPoseValid,
                        isDetected: _isFaceDetected,
                      ),
                    ],
                  ),
                ],

              ],
            ),
          ),

          // Tombol bawah
          Positioned(
            bottom: 40,
            left: 20,
            right: 20,
            child: _isCaptureDone
                ? Row(
                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                    children: [
                      Expanded(
                        child: CustomButton(
                          text: "Pindai Ulang",
                          type: ButtonType.secondary,
                          onPressed: _retake,
                          icon: Icons.refresh,
                        ),
                      ),
                      const SizedBox(width: 16),
                      Expanded(
                        child: CustomButton(
                          text: "Gunakan",
                          type: ButtonType.primary,
                          onPressed: _usePhoto,
                          icon: Icons.check,
                          backgroundColor: AppTheme.statusGreen,
                        ),
                      ),
                    ],
                  )
                : Center(
                    child: GestureDetector(
                      onTap: _allChecksValid ? _capturePhoto : null,
                          child: Container(
                            width: 76,
                            height: 76,
                            decoration: BoxDecoration(
                              shape: BoxShape.circle,
                              border: Border.all(
                                color: _allChecksValid
                                    ? Colors.white.withOpacity(0.8)
                                    : Colors.white.withOpacity(0.3),
                                width: 6,
                              ),
                              color: _allChecksValid
                                  ? AppTheme.primaryBlue.withOpacity(0.8)
                                  : Colors.white.withOpacity(0.05),
                              boxShadow: _allChecksValid
                                  ? [
                                      BoxShadow(
                                        color: AppTheme.primaryBlue.withOpacity(0.4),
                                        blurRadius: 16,
                                      )
                                    ]
                                  : null,
                            ),
                            child: const Icon(
                              Icons.face_retouching_natural,
                              color: Colors.white,
                              size: 36,
                            ),
                          ),
                        ),
                      ),
          ),
        ],
      ),
    );
  }

  Widget _buildQualityChip({
    required IconData icon,
    required String label,
    required bool isOk,
    required bool isDetected,
  }) {
    final color = !isDetected
        ? Colors.white.withOpacity(0.4)
        : isOk
            ? AppTheme.statusGreen
            : AppTheme.statusYellow;

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 5),
      decoration: BoxDecoration(
        color: color.withOpacity(0.15),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: color.withOpacity(0.4)),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            isOk && isDetected ? Icons.check_circle : icon,
            color: color,
            size: 14,
          ),
          const SizedBox(width: 4),
          Text(
            label,
            style: TextStyle(
              color: color,
              fontSize: 11,
              fontWeight: FontWeight.w600,
            ),
          ),
        ],
      ),
    );
  }
}