import 'package:flutter_test/flutter_test.dart';

import 'package:qiangbao_accounting/models/bill.dart';
import 'package:qiangbao_accounting/utils/amount_util.dart';
import 'package:qiangbao_accounting/utils/bill_grouping.dart';
import 'package:qiangbao_accounting/utils/date_util.dart';

Bill bill({
  required int id,
  required String date,
  required double amount,
  required int type,
  String description = '',
}) =>
    Bill(
      id: id,
      categoryId: 1,
      categoryName: '餐饮',
      categoryIcon: '🍔',
      amount: amount,
      description: description,
      billDate: date,
      type: type,
    );

void main() {
  group('月份/周界工具', () {
    test('monthStart 取当月 1 日', () {
      expect(formatDate(monthStart(DateTime(2026, 9, 21))), '2026-09-01');
    });

    test('monthEnd 处理 28/30/31 天与闰年 2 月', () {
      expect(formatDate(monthEnd(DateTime(2026, 9, 5))), '2026-09-30');
      expect(formatDate(monthEnd(DateTime(2026, 2, 5))), '2026-02-28');
      expect(formatDate(monthEnd(DateTime(2028, 2, 5))), '2028-02-29'); // 闰年
      expect(formatDate(monthEnd(DateTime(2026, 12, 5))), '2026-12-31');
    });

    test('shiftMonth 跨年正确', () {
      expect(formatDate(shiftMonth(DateTime(2026, 1, 1), -1)), '2025-12-01');
      expect(formatDate(shiftMonth(DateTime(2026, 12, 1), 1)), '2027-01-01');
    });

    test('weekStart 返回本周一', () {
      // 2026-09-21 是周一
      expect(formatDate(weekStart(DateTime(2026, 9, 21))), '2026-09-21');
      // 周日应回到本周一（9/20 是周日 → 9/14）
      expect(formatDate(weekStart(DateTime(2026, 9, 20))), '2026-09-14');
      // 跨月：2026-10-01 是周四 → 本周一 9/28
      expect(formatDate(weekStart(DateTime(2026, 10, 1))), '2026-09-28');
    });

    test('isSameMonth', () {
      expect(isSameMonth(DateTime(2026, 9, 1), DateTime(2026, 9, 30)), isTrue);
      expect(isSameMonth(DateTime(2026, 9, 1), DateTime(2026, 10, 1)), isFalse);
    });

    test('parseBillDate 兼容 LocalDateTime', () {
      expect(parseBillDate('2026-09-21T12:30:00'), '2026-09-21');
      expect(parseBillDate('2026-09-21 12:30:00'), '2026-09-21');
      expect(parseBillDate('2026-09-21'), '2026-09-21');
    });
  });

  group('金额工具', () {
    test('formatAmount 两位小数并挡掉非法值', () {
      expect(formatAmount(12.5), '12.50');
      expect(formatAmount(null), '0.00');
      expect(formatAmount(double.nan), '0.00');
      expect(formatAmount(double.infinity), '0.00');
    });

    test('formatSignedAmount 按类型给符号（不看金额正负）', () {
      expect(formatSignedAmount(12.0, isExpense: true), '-¥12.00');
      expect(formatSignedAmount(12.0, isExpense: false), '+¥12.00');
    });

    test('percentOf 防除零', () {
      expect(percentOf(25, 100), 25);
      expect(percentOf(25, 0), 0);
      expect(percentOf(0, 0), 0);
    });
  });

  group('账单分组', () {
    test('按日期分组并分别累计支出/收入', () {
      final groups = groupBillsByDate([
        bill(id: 1, date: '2026-09-21', amount: 30, type: 1),
        bill(id: 2, date: '2026-09-21', amount: 20, type: 1),
        bill(id: 3, date: '2026-09-21', amount: 5000, type: 2),
        bill(id: 4, date: '2026-09-20', amount: 15.5, type: 1),
      ]);

      expect(groups.length, 2);
      // 保持输入顺序（后端已按日期倒序）
      expect(groups[0].date, '2026-09-21');
      expect(groups[0].bills.length, 3);
      expect(groups[0].expenseTotal, 50);
      expect(groups[0].incomeTotal, 5000);
      // 同日内不重排，保持后端 createTime 倒序
      expect(groups[0].bills.map((b) => b.id).toList(), [1, 2, 3]);

      expect(groups[1].date, '2026-09-20');
      expect(groups[1].expenseTotal, 15.5);
      expect(groups[1].incomeTotal, 0);
    });

    test('空列表返回空分组', () {
      expect(groupBillsByDate([]), isEmpty);
    });

    test('金额恒为正数时按 type 判断收支方向', () {
      final expense = bill(id: 1, date: '2026-09-21', amount: 30, type: 1);
      final income = bill(id: 2, date: '2026-09-21', amount: 30, type: 2);
      expect(expense.isExpense, isTrue);
      expect(income.isExpense, isFalse);
      expect(expense.absAmount, 30);
    });
  });

  group('Bill.fromJson 防御性', () {
    test('字段缺失/类型不符不抛异常', () {
      final b = Bill.fromJson({
        'id': '12', // 字符串数字
        'amount': '35.5', // 字符串金额
        'billDate': '2026-09-21T10:00:00',
        // categoryName / categoryIcon / type 缺失
      });
      expect(b.id, 12);
      expect(b.amount, 35.5);
      expect(b.billDate, '2026-09-21');
      expect(b.categoryName, '未分类');
      // 图标兜底值是「图标名」不再是 emoji（2026-09-24 换成自绘图标集）
      expect(b.categoryIcon, 'other');
      expect(b.type, 1); // 缺省按支出
    });

    test('type 为 2 时是收入', () {
      final b = Bill.fromJson({'id': 1, 'amount': 100, 'billDate': '2026-09-21', 'type': 2});
      expect(b.isExpense, isFalse);
    });
  });
}