okane/lib/ui/pages/account/breakdown_card.dart

import 'dart:math';

import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:get_it/get_it.dart';
import 'package:okane/database/collections/transaction.dart';
import 'package:okane/database/database.dart';
import 'package:okane/ui/state/core.dart';
import 'package:okane/ui/utils.dart';
import 'package:okane/ui/widgets/piechart.dart';
import 'package:okane/ui/widgets/piechart_card.dart';

const CATEGORY_INCOME = "Income";
const CATEGORY_OTHER = "Other";

typedef LegendData =
    ({Map<String, double> expenses, Map<String, Color> colors, double usable});

class LegendItem extends StatelessWidget {
  final String text;
  final Color color;

  const LegendItem({required this.text, required this.color, super.key});

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.start,
      children: [
        DecoratedBox(
          decoration: BoxDecoration(
            color: color,
            borderRadius: BorderRadius.circular(5),
          ),
          child: SizedBox(width: 10, height: 10),
        ),
        Padding(padding: EdgeInsets.only(left: 8), child: Text(text)),
      ],
    );
  }
}

class BreakdownCard extends StatelessWidget {
  const BreakdownCard({super.key});

  LegendData _computeSections(List<Transaction> transactions) {
    Map<String, double> expenses = {};
    Map<String, Color> colors = {};
    double usableMoney = 0;
    transactions.forEach((t) {
      String category;
      if (t.amount > 0) {
        category = CATEGORY_INCOME;
        colors[CATEGORY_INCOME] = Colors.green;
      } else {
        if (t.expenseCategory.value?.name == null) {
          category = CATEGORY_OTHER;
          colors[category] = Colors.red;
        } else {
          category = t.expenseCategory.value!.name;
          colors[category] = colorHash(t.expenseCategory.value!.name);
        }
      }

      expenses.update(
        category,
        (value) => value + t.amount.abs(),
        ifAbsent: () => t.amount.abs(),
      );
      usableMoney += t.amount;
    });
    return (expenses: expenses, colors: colors, usable: usableMoney);
  }

  Widget _buildCard(Widget child, String? subtitle) {
    return ResponsiveCard(
      titleText: "Expense Breakdown",
      subtitleText: subtitle,
      child: child,
    );
  }

  Widget _buildCenterText(String text) {
    return _buildCard(Center(child: Text(text)), null);
  }

  @override
  Widget build(BuildContext context) {
    final bloc = GetIt.I.get<CoreCubit>();
    return BlocBuilder<CoreCubit, CoreState>(
      builder: (context, state) {
        if (bloc.activeAccount == null) {
          return _buildCenterText("No account active");
        }

        return FutureBuilder(
          future: getLastTransactions(bloc.activeAccount!, DateTime.now(), 30),
          builder: (context, snapshot) {
            if (!snapshot.hasData) {
              return _buildCard(
                Padding(
                  padding: EdgeInsets.all(16),
                  child: SizedBox(
                    width: 150 - 16 * 2,
                    height: 150 - 16 * 2,
                    child: CircularProgressIndicator(),
                  ),
                ),
                null,
              );
            }

            final data = _computeSections(snapshot.data!);
            final sectionData =
                data.expenses.entries
                    .map(
                      (entry) => PieChartSectionData(
                        value: entry.value,
                        title: formatCurrency(entry.value, precise: false),
                        titleStyle: TextStyle(fontWeight: FontWeight.bold),
                        radius: 40,
                        color: data.colors[entry.key]!,
                      ),
                    )
                    .toList();
            if (sectionData.isEmpty) {
              return _buildCenterText("No expenses available");
            }
            return _buildCard(
              OkanePieChart(
                valueConverter: formatCurrency,
                items:
                    data.expenses.entries
                        .map(
                          (e) => (
                            title: e.key,
                            value: e.value,
                            color: colorHash(e.key),
                          ),
                        )
                        .toList(),
              ),
              "Available money: ${formatCurrency(data.usable)}",
            );
          },
        );
      },
    );
  }
}