import 'dart:io';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:path/path.dart' as p;
import '../services/database_helper.dart';
import '../models/palm_record.dart';

/// Simple detection data parsed from the stored Map in the database.
class _DetectionData {
  final String className;
  final double confidence;
  final Rect normalizedBox;

  const _DetectionData({
    required this.className,
    required this.confidence,
    required this.normalizedBox,
  });

  factory _DetectionData.fromMap(Map<String, dynamic> m) {
    return _DetectionData(
      className: (m['className'] ?? m['class'] ?? 'Unknown').toString(),
      confidence: (m['confidence'] as num?)?.toDouble() ?? 0.0,
      normalizedBox: Rect.fromLTRB(
        (m['x1'] as num?)?.toDouble() ?? 0.0,
        (m['y1'] as num?)?.toDouble() ?? 0.0,
        (m['x2'] as num?)?.toDouble() ?? 1.0,
        (m['y2'] as num?)?.toDouble() ?? 1.0,
      ),
    );
  }
}

class HistoryScreen extends StatefulWidget {
  const HistoryScreen({super.key});

  @override
  State<HistoryScreen> createState() => _HistoryScreenState();
}

class _HistoryScreenState extends State<HistoryScreen> {
  final DatabaseHelper _dbHelper = DatabaseHelper();
  List<PalmRecord> _records = [];
  bool _isLoading = true;

  @override
  void initState() {
    super.initState();
    _loadHistory();
  }

  Future<void> _loadHistory() async {
    final records = await _dbHelper.getAllRecords();
    setState(() {
      _records = records;
      _isLoading = false;
    });
  }

  Future<void> _resetHistory() async {
    final confirm = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text("Reset History"),
        content: const Text("Are you sure you want to clear all analysis records? This action is irreversible."),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context, false), child: const Text("Cancel")),
          TextButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text("Reset", style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );

    if (confirm == true) {
      await _dbHelper.clearAllRecords();
      _loadHistory();
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text("History cleared successfully.")),
        );
      }
    }
  }

  Color _getStatusColor(String label) {
    if (label == 'Empty_Bunch' || label == 'Abnormal') return Colors.red;
    if (label == 'Ripe' || label == 'Overripe') return Colors.green;
    return Colors.orange;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('History Vault'),
        actions: [
          if (_records.isNotEmpty)
            IconButton(
              icon: const Icon(Icons.delete_sweep),
              tooltip: 'Reset History',
              onPressed: _resetHistory,
            ),
        ],
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _records.isEmpty
              ? const Center(child: Text("No records found yet."))
              : ListView.builder(
                  itemCount: _records.length,
                  padding: const EdgeInsets.all(12),
                  itemBuilder: (context, index) {
                    final record = _records[index];
                    final statusColor = _getStatusColor(record.ripenessClass);
                    final fileName = p.basename(record.imagePath);
                    
                    return Card(
                      margin: const EdgeInsets.only(bottom: 12),
                      elevation: 3,
                      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(15)),
                      child: ListTile(
                        leading: CircleAvatar(
                          backgroundColor: statusColor.withValues(alpha: 0.2),
                          child: Icon(Icons.spa, color: statusColor),
                        ),
                        title: Text(
                          record.ripenessClass,
                          style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                        ),
                        subtitle: Text(
                          "File: $fileName\nConf: ${(record.confidence * 100).toStringAsFixed(1)}% | ${record.timestamp.toString().split('.')[0]}",
                          style: const TextStyle(fontSize: 12),
                        ),
                        trailing: const Icon(Icons.chevron_right),
                        isThreeLine: true,
                        onTap: () => _showDetails(record),
                      ),
                    );
                  },
                ),
    );
  }

  void _showDetails(PalmRecord record) {
    final fileName = p.basename(record.imagePath);
    final List<_DetectionData> detections = record.detections
        .map((d) => _DetectionData.fromMap(d))
        .toList();

    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (context) {
        return DraggableScrollableSheet(
          initialChildSize: 0.7,
          minChildSize: 0.5,
          maxChildSize: 0.95,
          expand: false,
          builder: (context, scrollController) {
            return SingleChildScrollView(
              controller: scrollController,
              padding: const EdgeInsets.all(24),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      const Text("Record Details", style: TextStyle(fontSize: 22, fontWeight: FontWeight.bold)),
                      IconButton(onPressed: () => Navigator.pop(context), icon: const Icon(Icons.close)),
                    ],
                  ),
                  const Divider(),
                  const SizedBox(height: 16),
                  
                  // Image with Bounding Boxes
                  AspectRatio(
                    aspectRatio: 1, // Assuming squared input 640x640
                    child: Container(
                      decoration: BoxDecoration(
                        color: Colors.grey.shade200,
                        borderRadius: BorderRadius.circular(12),
                      ),
                      child: record.imagePath.isNotEmpty && File(record.imagePath).existsSync()
                          ? ClipRRect(
                              borderRadius: BorderRadius.circular(12),
                              child: Stack(
                                children: [
                                  // The Image
                                  Positioned.fill(
                                    child: Image.file(File(record.imagePath), fit: BoxFit.contain),
                                  ),
                                  // The Overlays
                                  Positioned.fill(
                                    child: LayoutBuilder(
                                      builder: (context, constraints) {
                                        return Stack(
                                          children: detections.map<Widget>((d) {
                                            final rect = d.normalizedBox;
                                            final color = _getStatusColor(d.className);
                                            return Positioned(
                                              left: rect.left * constraints.maxWidth,
                                              top: rect.top * constraints.maxHeight,
                                              width: rect.width * constraints.maxWidth,
                                              height: rect.height * constraints.maxHeight,
                                              child: Container(
                                                decoration: BoxDecoration(
                                                  border: Border.all(color: color, width: 2),
                                                  borderRadius: BorderRadius.circular(4),
                                                ),
                                              ),
                                            );
                                          }).toList(),
                                        );
                                      },
                                    ),
                                  ),
                                ],
                              ),
                            )
                          : const Center(
                              child: Icon(Icons.image, size: 64, color: Colors.grey),
                            ),
                    ),
                  ),
                  
                  const SizedBox(height: 24),
                  _buildDetailItem("File Name", fileName, Colors.blueGrey),
                  _buildDetailItem("Primary Grade", record.ripenessClass, _getStatusColor(record.ripenessClass)),
                  _buildDetailItem("Total Detections", detections.length.toString(), Colors.black),
                  _buildDetailItem("Timestamp", record.timestamp.toString().split('.')[0], Colors.black87),
                  
                  const Divider(height: 32),
                  const Text("Analytical Breakdown", style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
                  const SizedBox(height: 12),
                  
                  ...detections.map((d) => Padding(
                    padding: const EdgeInsets.only(bottom: 8),
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Row(
                          children: [
                            Container(
                              width: 12,
                              height: 12,
                              decoration: BoxDecoration(
                                color: _getStatusColor(d.className),
                                shape: BoxShape.circle,
                              ),
                            ),
                            const SizedBox(width: 8),
                            Text(d.className, style: const TextStyle(fontWeight: FontWeight.w500)),
                          ],
                        ),
                        Text("${(d.confidence * 100).toStringAsFixed(1)}%", style: const TextStyle(color: Colors.grey)),
                      ],
                    ),
                  )),
                  
                  const SizedBox(height: 24),
                  const Text(
                    "Industrial Summary: This image has been verified for harvest quality. All detected bunches are categorized according to ripeness standards.",
                    style: TextStyle(fontStyle: FontStyle.italic, color: Colors.grey),
                  ),
                  const SizedBox(height: 24),
                ],
              ),
            );
          },
        );
      },
    );
  }

  Widget _buildDetailItem(String label, String value, Color valueColor) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 12),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text("$label: ", style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 16)),
          Expanded(
            child: Text(value, style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16, color: valueColor)),
          ),
        ],
      ),
    );
  }
}