import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../providers/scanner_provider.dart';
import '../widgets/camera_preview_widget.dart';
import '../widgets/display_config_dialog.dart';
import 'dart:io' show File;
import 'package:flutter/foundation.dart';

class ScannerScreen extends ConsumerStatefulWidget {
  const ScannerScreen({super.key});

  @override
  ConsumerState<ScannerScreen> createState() => _ScannerScreenState();
}

class _ScannerScreenState extends ConsumerState<ScannerScreen> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ref.read(scannerProvider.notifier).initialize();
    });
  }

  @override
  Widget build(BuildContext context) {
    final state = ref.watch(scannerProvider);

    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        title: const Text('FingerScanner'),
        backgroundColor: Colors.transparent,
        elevation: 0,
        actions: [
          IconButton(
            icon: const Icon(Icons.settings, color: Colors.white),
            onPressed: () {
              showDialog(
                context: context,
                builder: (context) => const DisplayConfigDialog(),
              );
            },
            tooltip: "Display Settings",
          ),
          if (state is ScannerReady && !state.isSimulation)
            IconButton(
              icon: const Icon(Icons.bug_report, color: Colors.white54),
              onPressed: () =>
                  ref.read(scannerProvider.notifier).startSimulation(),
              tooltip: "Switch to Simulation",
            ),
        ],
      ),
      body: Builder(
        builder: (context) {
          if (state is ScannerInitial || state is ScannerInitializing) {
            return const Center(child: CircularProgressIndicator());
          } else if (state is ScannerReady) {
            final canCapture = state.canCapture;

            return Stack(
              children: [
                CameraPreviewWidget(
                  controller: state.controller,
                  qualityStatus: state.qualityStatus,
                  consecutivePasses: state.consecutivePasses,
                  canCapture: canCapture,
                ),
                Positioned(
                  bottom: 30,
                  left: 0,
                  right: 0,
                  child: Center(
                    child: FloatingActionButton.large(
                      onPressed: canCapture
                          ? () => ref.read(scannerProvider.notifier).scan()
                          : null,
                      backgroundColor: canCapture
                          ? Colors.white
                          : Colors.grey.shade800,
                      child: Icon(
                        Icons.camera_alt,
                        color: canCapture ? Colors.black : Colors.grey,
                      ),
                    ),
                  ),
                ),
              ],
            );
          } else if (state is ScannerScanning) {
            return Stack(
              children: [
                CameraPreviewWidget(controller: state.controller),
                Container(
                  color: Colors.black.withValues(alpha: 0.5),
                  child: const Center(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        CircularProgressIndicator(color: Colors.greenAccent),
                        SizedBox(height: 20),
                        Text(
                          "Capturing...",
                          style: TextStyle(color: Colors.white),
                        ),
                      ],
                    ),
                  ),
                ),
              ],
            );
          } else if (state is ScannerSuccess) {
            final isSimulation =
                state.result.imagePath == "simulated_capture.jpg";

            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const Icon(Icons.check_circle, color: Colors.green, size: 80),
                  const SizedBox(height: 20),
                  const Text(
                    "Scan Complete!",
                    style: TextStyle(color: Colors.white, fontSize: 24),
                  ),
                  const SizedBox(height: 10),
                  Text(
                    "Saved to: ${state.result.imagePath}",
                    style: const TextStyle(color: Colors.grey),
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: 30),
                  SizedBox(
                    height: 200,
                    child: isSimulation
                        ? const Icon(Icons.image, size: 100, color: Colors.grey)
                        : (kIsWeb
                              ? Image.network(state.result.imagePath)
                              : Image.file(File(state.result.imagePath))),
                  ),
                  const SizedBox(height: 30),
                  ElevatedButton(
                    onPressed: () {
                      ref.read(scannerProvider.notifier).reset();
                    },
                    child: const Text("Scan Again"),
                  ),
                ],
              ),
            );
          } else if (state is ScannerError) {
            return Center(
              child: Padding(
                padding: const EdgeInsets.all(32.0),
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    const Icon(
                      Icons.no_photography,
                      color: Colors.red,
                      size: 64,
                    ),
                    const SizedBox(height: 24),
                    Text(
                      state.message,
                      style: const TextStyle(color: Colors.white, fontSize: 14),
                      textAlign: TextAlign.center,
                    ),
                    const SizedBox(height: 32),
                    ElevatedButton.icon(
                      icon: const Icon(Icons.refresh),
                      label: const Text("Retry Camera"),
                      onPressed: () =>
                          ref.read(scannerProvider.notifier).tryCamera(),
                      style: ElevatedButton.styleFrom(
                        backgroundColor: Colors.white,
                        foregroundColor: Colors.black,
                        padding: const EdgeInsets.symmetric(
                          horizontal: 24,
                          vertical: 12,
                        ),
                      ),
                    ),
                    const SizedBox(height: 16),
                    TextButton(
                      onPressed: () =>
                          ref.read(scannerProvider.notifier).startSimulation(),
                      child: const Text(
                        "Run Simulation Mode Instead",
                        style: TextStyle(color: Colors.white54),
                      ),
                    ),
                  ],
                ),
              ),
            );
          }
          return const SizedBox.shrink();
        },
      ),
    );
  }
}