import 'package:flutter/material.dart';
import 'package:tatlock_ui/features/front_hall/data/models/environment_model.dart'
    as api;
import 'package:tatlock_ui/shared/theme/stoplight_colors.dart';

/// Air Quality Index widget displaying current AQI.
///
/// Displays air quality data from the Core API environment endpoint.
/// Only render this widget when air quality data is available.
class AirQualityWidget extends StatelessWidget {
  const AirQualityWidget({
    super.key,
    this.apiData,
    this.data,
    this.compact = false,
  });

  /// Air quality data from API. Takes priority over legacy data.
  final api.AirQualityData? apiData;

  /// Legacy air quality data to display. Uses mock data if null.
  final AirQualityData? data;

  /// Whether to use compact layout.
  final bool compact;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    // Convert API data to local model, or use legacy data
    final aqi = apiData != null
        ? _fromApiData(apiData!)
        : (data ?? AirQualityData.mock());

    if (compact) {
      return _buildCompact(context, colorScheme, aqi);
    }

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisSize: MainAxisSize.min,
          children: [
            // Header
            Row(
              children: [
                Icon(
                  Icons.air,
                  size: 20,
                  color: colorScheme.onSurfaceVariant,
                ),
                const SizedBox(width: 8),
                Text(
                  'Air Quality',
                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
                        color: colorScheme.onSurfaceVariant,
                      ),
                ),
              ],
            ),
            const SizedBox(height: 16),

            // AQI Display
            Row(
              children: [
                // AQI number with colored background
                Container(
                  width: 64,
                  height: 64,
                  decoration: BoxDecoration(
                    color: aqi.level.color.withValues(alpha: 0.15),
                    borderRadius: BorderRadius.circular(12),
                    border: Border.all(
                      color: aqi.level.color.withValues(alpha: 0.3),
                      width: 2,
                    ),
                  ),
                  child: Center(
                    child: Text(
                      '${aqi.index}',
                      style:
                          Theme.of(context).textTheme.headlineMedium?.copyWith(
                                fontWeight: FontWeight.bold,
                                color: aqi.level.color,
                              ),
                    ),
                  ),
                ),
                const SizedBox(width: 16),

                // Level info
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        aqi.level.label,
                        style:
                            Theme.of(context).textTheme.titleMedium?.copyWith(
                                  fontWeight: FontWeight.w600,
                                  color: aqi.level.color,
                                ),
                      ),
                      const SizedBox(height: 4),
                      Text(
                        aqi.level.description,
                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
                              color: colorScheme.onSurfaceVariant,
                            ),
                        maxLines: 2,
                        overflow: TextOverflow.ellipsis,
                      ),
                    ],
                  ),
                ),
              ],
            ),

            // Pollutants
            if (aqi.pollutants.isNotEmpty) ...[
              const SizedBox(height: 16),
              const Divider(height: 1),
              const SizedBox(height: 12),
              Wrap(
                spacing: 16,
                runSpacing: 8,
                children: aqi.pollutants
                    .map((p) => _PollutantChip(pollutant: p))
                    .toList(),
              ),
            ],
          ],
        ),
      ),
    );
  }

  Widget _buildCompact(
    BuildContext context,
    ColorScheme colorScheme,
    AirQualityData aqi,
  ) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Container(
              width: 32,
              height: 32,
              decoration: BoxDecoration(
                color: aqi.level.color.withValues(alpha: 0.15),
                borderRadius: BorderRadius.circular(6),
              ),
              child: Center(
                child: Text(
                  '${aqi.index}',
                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
                        fontWeight: FontWeight.bold,
                        color: aqi.level.color,
                      ),
                ),
              ),
            ),
            const SizedBox(width: 8),
            Text(
              'AQI',
              style: Theme.of(context).textTheme.bodySmall?.copyWith(
                    color: colorScheme.onSurfaceVariant,
                  ),
            ),
          ],
        ),
      ),
    );
  }
}

class _PollutantChip extends StatelessWidget {
  const _PollutantChip({required this.pollutant});

  final Pollutant pollutant;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Text(
          pollutant.name,
          style: Theme.of(context).textTheme.labelSmall?.copyWith(
                color: colorScheme.outline,
              ),
        ),
        const SizedBox(width: 4),
        Text(
          '${pollutant.value.round()} ${pollutant.unit}',
          style: Theme.of(context).textTheme.bodySmall?.copyWith(
                fontWeight: FontWeight.w500,
              ),
        ),
      ],
    );
  }
}

/// Converts API air quality data to local AirQualityData model.
AirQualityData _fromApiData(api.AirQualityData data) {
  final index = data.aqi ?? 0;
  final pollutants = <Pollutant>[];

  if (data.pm25 != null) {
    pollutants.add(Pollutant(name: 'PM2.5', value: data.pm25!, unit: 'µg/m³'));
  }
  if (data.pm10 != null) {
    pollutants.add(Pollutant(name: 'PM10', value: data.pm10!, unit: 'µg/m³'));
  }
  if (data.o3 != null) {
    pollutants.add(Pollutant(name: 'O₃', value: data.o3!, unit: 'ppb'));
  }
  if (data.no2 != null) {
    pollutants.add(Pollutant(name: 'NO₂', value: data.no2!, unit: 'ppb'));
  }

  return AirQualityData(
    index: index,
    level: AqiLevel.fromIndex(index),
    pollutants: pollutants,
  );
}

/// Air Quality Index levels based on US EPA standard.
enum AqiLevel {
  good(
    label: 'Good',
    description: 'Air quality is satisfactory',
    color: StoplightColors.green,
    minIndex: 0,
    maxIndex: 50,
  ),
  moderate(
    label: 'Moderate',
    description: 'Acceptable for most people',
    color: StoplightColors.orange,
    minIndex: 51,
    maxIndex: 100,
  ),
  unhealthySensitive(
    label: 'Unhealthy for Sensitive',
    description: 'May affect sensitive groups',
    color: StoplightColors.orange,
    minIndex: 101,
    maxIndex: 150,
  ),
  unhealthy(
    label: 'Unhealthy',
    description: 'Health effects for everyone',
    color: StoplightColors.red,
    minIndex: 151,
    maxIndex: 200,
  ),
  veryUnhealthy(
    label: 'Very Unhealthy',
    description: 'Serious health effects',
    color: Color(0xFF8B008B),
    minIndex: 201,
    maxIndex: 300,
  ),
  hazardous(
    label: 'Hazardous',
    description: 'Health emergency conditions',
    color: Color(0xFF800000),
    minIndex: 301,
    maxIndex: 500,
  );

  const AqiLevel({
    required this.label,
    required this.description,
    required this.color,
    required this.minIndex,
    required this.maxIndex,
  });

  final String label;
  final String description;
  final Color color;
  final int minIndex;
  final int maxIndex;

  static AqiLevel fromIndex(int index) {
    for (final level in AqiLevel.values) {
      if (index >= level.minIndex && index <= level.maxIndex) {
        return level;
      }
    }
    return AqiLevel.hazardous;
  }
}

/// Pollutant data.
class Pollutant {
  const Pollutant({
    required this.name,
    required this.value,
    required this.unit,
  });

  final String name;
  final double value;
  final String unit;
}

/// Air quality data model.
class AirQualityData {
  const AirQualityData({
    required this.index,
    required this.level,
    this.pollutants = const [],
  });

  final int index;
  final AqiLevel level;
  final List<Pollutant> pollutants;

  /// Create from index value.
  factory AirQualityData.fromIndex(int index, {List<Pollutant>? pollutants}) {
    return AirQualityData(
      index: index,
      level: AqiLevel.fromIndex(index),
      pollutants: pollutants ?? const [],
    );
  }

  /// Mock air quality data for development.
  factory AirQualityData.mock() {
    return const AirQualityData(
      index: 42,
      level: AqiLevel.good,
      pollutants: [
        Pollutant(name: 'PM2.5', value: 8.5, unit: 'µg/m³'),
        Pollutant(name: 'PM10', value: 15, unit: 'µg/m³'),
        Pollutant(name: 'O₃', value: 32, unit: 'ppb'),
      ],
    );
  }
}