import 'dart:math' as math show max;

import 'package:flutter/material.dart';
import 'package:syncrow_web/pages/analytics/modules/occupancy/widgets/interactive_heat_map.dart';
import 'package:syncrow_web/pages/analytics/modules/occupancy/widgets/occupancy_heat_map_days.dart';
import 'package:syncrow_web/pages/analytics/modules/occupancy/widgets/occupancy_heat_map_gradient.dart';
import 'package:syncrow_web/pages/analytics/modules/occupancy/widgets/occupancy_heat_map_months.dart';
import 'package:syncrow_web/pages/analytics/modules/occupancy/widgets/occupancy_painter.dart';
import 'package:syncrow_web/utils/color_manager.dart';

class OccupancyHeatMap extends StatelessWidget {
  const OccupancyHeatMap({
    required this.heatMapData,
    required this.selectedDate,
    super.key,
  });
  final Map<DateTime, int> heatMapData;
  final DateTime selectedDate;

  static const _cellSize = 16.0;
  static const _totalWeeks = 53;

  int get _maxValue => heatMapData.isNotEmpty
      ? heatMapData.keys.map((key) => heatMapData[key] ?? 0).reduce(math.max)
      : 0;

  DateTime _getStartingDate() {
    final jan1 = DateTime.utc(selectedDate.year, 1, 1);
    final startOfWeek = jan1.subtract(Duration(days: jan1.weekday - 1));
    return startOfWeek;
  }

  List<OccupancyPaintItem> _generatePaintItems(DateTime startDate) {
    return List.generate(_totalWeeks * 7, (index) {
      final date = startDate.add(Duration(days: index));
      final value = heatMapData[date] ?? 0;
      return OccupancyPaintItem(index: index, value: value, date: date);
    });
  }

  @override
  Widget build(BuildContext context) {
    final startDate = _getStartingDate();
    final paintItems = _generatePaintItems(startDate);

    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        OccupancyHeatMapMonths(startDate: startDate, cellSize: _cellSize),
        Container(
          decoration: const BoxDecoration(
            border: Border(
              bottom: BorderSide(color: ColorsManager.grayBorder),
              top: BorderSide(color: ColorsManager.grayBorder),
            ),
          ),
          width: double.infinity,
          child: Row(
            children: [
              Expanded(
                child: FittedBox(
                  fit: BoxFit.fill,
                  child: Row(
                    children: [
                      const OccupancyHeatMapDays(cellSize: _cellSize),
                      SizedBox(
                        width: _totalWeeks * _cellSize,
                        height: 7 * _cellSize,
                        child: InteractiveHeatMap(
                          items: paintItems,
                          maxValue: _maxValue,
                          cellSize: _cellSize,
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: 20),
        OccupancyHeatMapGradient(maxValue: _maxValue),
      ],
    );
  }
}