import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../domain/entities/quality_status.dart';
import '../providers/display_config_provider.dart';
import 'fingerprint_guide_painter.dart';

class CameraPreviewWidget extends ConsumerWidget {
  final CameraController? controller;
  final QualityStatus? qualityStatus;
  final int consecutivePasses;
  final bool canCapture;

  const CameraPreviewWidget({
    super.key,
    required this.controller,
    this.qualityStatus,
    this.consecutivePasses = 0,
    this.canCapture = false,
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final config = ref.watch(displayConfigProvider);

    // If controller is null or not initialized, show Simulation/Placeholder
    final bool showCamera =
        controller != null && controller!.value.isInitialized;

    final qs = qualityStatus;
    final isFocusGood = qs?.isFocusGood ?? false;
    final isLightingGood = qs?.isLightingGood ?? false;
    final isPositionGood = qs?.isPositionGood ?? false;
    final overallGood = qs?.canCapture ?? false;

    return Stack(
      fit: StackFit.expand,
      children: [
        if (showCamera)
          _buildCoveredCameraPreview(context, controller!)
        else
          Container(
            color: Colors.grey.shade900,
            child: const Center(
              child: Text(
                "Camera Unavailable\n(Simulation Mode)",
                textAlign: TextAlign.center,
                style: TextStyle(color: Colors.white54, fontSize: 16),
              ),
            ),
          ),

        // Fingerprint Guide (Painter)
        if (config.showGuide)
          CustomPaint(
            painter: FingerprintGuidePainter(isGoodQuality: overallGood),
            child: Container(),
          ),

        // Icon (Center Guide)
        if (config.showGuide)
          Center(
            child: Icon(
              Icons.fingerprint,
              color: overallGood
                  ? Colors.greenAccent
                  : Colors.white.withValues(alpha: 0.3),
              size: 100,
            ),
          ),

        // Quality Indicators (Top)
        if (config.showQualityIndicators)
          Positioned(
            top: 60,
            left: 0,
            right: 0,
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                _buildStatusIcon(
                  Icons.center_focus_strong,
                  "Focus",
                  isFocusGood,
                ),
                _buildStatusIcon(Icons.wb_sunny, "Light", isLightingGood),
                _buildStatusIcon(Icons.crop_free, "Position", isPositionGood),
              ],
            ),
          ),

        // Status Text (Bottom)
        if (config.showStatusText)
          Positioned(
            bottom: 120, // Above FAB
            left: 20,
            right: 20,
            child: Column(
              children: [
                if (overallGood && !canCapture)
                  Text(
                    "Hold Steady... $consecutivePasses/5",
                    style: const TextStyle(
                      color: Colors.yellowAccent,
                      fontSize: 20,
                      fontWeight: FontWeight.bold,
                      shadows: [Shadow(blurRadius: 4, color: Colors.black)],
                    ),
                  )
                else if (canCapture)
                  const Text(
                    "READY TO CAPTURE",
                    style: TextStyle(
                      color: Colors.greenAccent,
                      fontSize: 20,
                      fontWeight: FontWeight.bold,
                      shadows: [Shadow(blurRadius: 4, color: Colors.black)],
                    ),
                  )
                else
                  const Text(
                    "Adjust Finger",
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 18,
                      shadows: [Shadow(blurRadius: 4, color: Colors.black)],
                    ),
                  ),

                const SizedBox(height: 8),
                if (qs != null && config.showDebugInfo)
                  Text(
                    "Blur: ${qs.blurScore.toStringAsFixed(0)} | Bright: ${qs.brightness.toStringAsFixed(0)}",
                    style: const TextStyle(color: Colors.grey, fontSize: 12),
                  ),
              ],
            ),
          ),
      ],
    );
  }

  Widget _buildCoveredCameraPreview(
    BuildContext context,
    CameraController controller,
  ) {
    final size = MediaQuery.of(context).size;

    double scale = 1.0;
    final double screenRatio = size.aspectRatio;
    final double cameraRatio = controller.value.aspectRatio;

    // Calculate effective camera ratio displayed (swapped if portrait)
    // We assume if screen is portrait, camera preview is also rendered in portrait mode (1/ratio)
    // by the CameraPreview widget.
    final double effectiveCameraRatio = (size.width < size.height)
        ? (1 / cameraRatio)
        : cameraRatio;

    if (screenRatio > effectiveCameraRatio) {
      // Screen is wider than camera preview
      scale = screenRatio / effectiveCameraRatio;
    } else {
      // Screen is taller than camera preview
      scale = effectiveCameraRatio / screenRatio;
    }

    return Transform.scale(
      scale: scale,
      alignment: Alignment.center,
      child: Center(child: CameraPreview(controller)),
    );
  }

  Widget _buildStatusIcon(IconData icon, String label, bool isGood) {
    return Column(
      children: [
        Container(
          padding: const EdgeInsets.all(8),
          decoration: BoxDecoration(
            color: isGood
                ? Colors.green.withValues(alpha: 0.8)
                : Colors.red.withValues(alpha: 0.8),
            shape: BoxShape.circle,
          ),
          child: Icon(icon, color: Colors.white, size: 24),
        ),
        const SizedBox(height: 4),
        Text(
          label,
          style: const TextStyle(
            color: Colors.white,
            fontSize: 12,
            shadows: [Shadow(blurRadius: 2, color: Colors.black)],
          ),
        ),
      ],
    );
  }
}