import { describe, it, expect } from 'vitest';
import {
  startOfDay, endOfDay, startOfMonth, endOfMonth, startOfWeek, endOfWeek,
  isSameDay, addDays, addMonths, monthGrid, weekDays, remindAt,
  bucketByDay, dayKey, renderReminder, toLocalInput, fromLocalInput,
  describeRecurrence, describeRemindBefore
} from '../../src/lib/calendar';
import type { CalendarEvent } from '../../src/types';

let seq = 0;
function ev(over: Partial<CalendarEvent> = {}): CalendarEvent {
  seq += 1;
  return {
    event_id: `e${String(seq).padStart(3, '0')}`,
    title: `事件 ${seq}`,
    description: '',
    reminder_text: '',
    agent_name: 'pi',
    to_address: '',
    recipients: [],
    delivery_mode: 'separate',
    event_time: '2026-09-03T14:30:00+08:00',
    remind_before: 0,
    recurrence: 'none',
    status: 'active',
    created_at: '2026-09-01T00:00:00Z',
    updated_at: '2026-09-01T00:00:00Z',
    created_by: 'jianf',
    ...over
  };
}

describe('日期边界', () => {
  it('startOfDay / endOfDay 用本地时区', () => {
    const d = new Date(2026, 8, 3, 14, 30, 45, 123);
    expect(startOfDay(d).getHours()).toBe(0);
    expect(startOfDay(d).getMilliseconds()).toBe(0);
    expect(endOfDay(d).getHours()).toBe(23);
    expect(endOfDay(d).getMilliseconds()).toBe(999);
    // 不修改入参
    expect(d.getHours()).toBe(14);
  });

  it('startOfMonth / endOfMonth', () => {
    const d = new Date(2026, 8, 15);
    expect(startOfMonth(d).getDate()).toBe(1);
    expect(endOfMonth(d).getDate()).toBe(30); // 9 月 30 天
    expect(endOfMonth(new Date(2026, 1, 5)).getDate()).toBe(28); // 2026 年 2 月
  });

  it('周从周一开始，周日归到上一周末尾', () => {
    // 2026-09-06 是周日
    const sunday = new Date(2026, 8, 6);
    expect(sunday.getDay()).toBe(0);
    // 它所在周的周一应是 08-31，不是 09-07
    expect(dayKey(startOfWeek(sunday))).toBe('2026-08-31');
    expect(dayKey(endOfWeek(sunday))).toBe('2026-09-06');
  });

  it('周一自己就是周首', () => {
    const monday = new Date(2026, 8, 7);
    expect(monday.getDay()).toBe(1);
    expect(dayKey(startOfWeek(monday))).toBe('2026-09-07');
  });
});

describe('日期运算', () => {
  it('addDays 不修改入参', () => {
    const d = new Date(2026, 8, 3);
    const r = addDays(d, 5);
    expect(dayKey(r)).toBe('2026-09-08');
    expect(dayKey(d)).toBe('2026-09-03');
  });

  it('addDays 跨月', () => {
    expect(dayKey(addDays(new Date(2026, 8, 29), 5))).toBe('2026-10-04');
  });

  it('addMonths 从月末加一个月不会溢出', () => {
    // setMonth 在 1 月 31 日上加一个月会给 3 月 2/3 日
    const jan31 = new Date(2026, 0, 31);
    expect(dayKey(addMonths(jan31, 1))).toBe('2026-02-01');
  });

  it('isSameDay 只比年月日', () => {
    expect(isSameDay(new Date(2026, 8, 3, 0, 0), new Date(2026, 8, 3, 23, 59))).toBe(true);
    expect(isSameDay(new Date(2026, 8, 3), new Date(2026, 8, 4))).toBe(false);
    expect(isSameDay(new Date(2026, 8, 3), new Date(2025, 8, 3))).toBe(false);
  });
});

describe('monthGrid', () => {
  it('固定 42 格（6 行 × 7 列）', () => {
    // 行数变化会让网格高度跳动，翻月时页面内容上下弹
    expect(monthGrid(new Date(2026, 8, 15))).toHaveLength(42);
    expect(monthGrid(new Date(2026, 1, 15))).toHaveLength(42);
  });

  it('首格是月首所在周的周一', () => {
    // 2026-09-01 是周二 → 首格应是 08-31（周一）
    const cells = monthGrid(new Date(2026, 8, 15));
    expect(dayKey(cells[0])).toBe('2026-08-31');
  });

  it('格子连续无空洞', () => {
    const cells = monthGrid(new Date(2026, 8, 15));
    for (let i = 1; i < cells.length; i++) {
      const diff = cells[i].getTime() - cells[i - 1].getTime();
      // 允许夏令时造成的 ±1 小时偏差
      expect(diff).toBeGreaterThanOrEqual(23 * 3600_000);
      expect(diff).toBeLessThanOrEqual(25 * 3600_000);
    }
  });

  it('包含整个当月', () => {
    const anchor = new Date(2026, 8, 15);
    const keys = monthGrid(anchor).map(dayKey);
    expect(keys).toContain('2026-09-01');
    expect(keys).toContain('2026-09-30');
  });
});

describe('weekDays', () => {
  it('给 7 天，周一起头', () => {
    const days = weekDays(new Date(2026, 8, 3)); // 周四
    expect(days).toHaveLength(7);
    expect(dayKey(days[0])).toBe('2026-08-31');
    expect(dayKey(days[6])).toBe('2026-09-06');
  });
});

describe('remindAt', () => {
  it('提前 30 分钟', () => {
    const e = ev({ event_time: '2026-09-03T14:30:00+08:00', remind_before: 30 });
    expect(remindAt(e).toISOString()).toBe('2026-09-03T06:00:00.000Z');
  });

  it('remind_before 为 0 时就是事件时间', () => {
    const e = ev({ event_time: '2026-09-03T14:30:00+08:00', remind_before: 0 });
    expect(remindAt(e).toISOString()).toBe('2026-09-03T06:30:00.000Z');
  });

  it('提前一整天', () => {
    const e = ev({ event_time: '2026-09-03T14:30:00+08:00', remind_before: 1440 });
    expect(remindAt(e).toISOString()).toBe('2026-09-02T06:30:00.000Z');
  });
});

describe('bucketByDay', () => {
  it('按本地日期分桶，不用 UTC 前缀', () => {
    // 东八区 22:00 → UTC 是前一天 14:00。用 toISOString().slice(0,10) 会归错天
    const e = ev({ event_time: '2026-09-03T22:00:00+08:00' });
    const m = bucketByDay([e]);
    expect([...m.keys()]).toEqual(['2026-09-03']);
  });

  it('同一天内按时间正序', () => {
    const late = ev({ event_time: '2026-09-03T18:00:00+08:00', title: '晚' });
    const early = ev({ event_time: '2026-09-03T09:00:00+08:00', title: '早' });
    const m = bucketByDay([late, early]);
    expect(m.get('2026-09-03')!.map(x => x.title)).toEqual(['早', '晚']);
  });

  it('同刻事件用 event_id 兜底定序', () => {
    const ts = '2026-09-03T09:00:00+08:00';
    const a = ev({ event_id: 'aaa', event_time: ts });
    const z = ev({ event_id: 'zzz', event_time: ts });
    const m1 = bucketByDay([a, z]).get('2026-09-03')!.map(x => x.event_id);
    const m2 = bucketByDay([z, a]).get('2026-09-03')!.map(x => x.event_id);
    expect(m1).toEqual(m2);
    expect(m1).toEqual(['aaa', 'zzz']);
  });

  it('时间解析失败的脏数据被跳过而不是让整个视图空白', () => {
    const bad = ev({ event_time: '不是时间' });
    const good = ev({ event_time: '2026-09-03T09:00:00+08:00' });
    const m = bucketByDay([bad, good]);
    expect([...m.keys()]).toEqual(['2026-09-03']);
  });

  it('空输入给空 Map', () => {
    expect(bucketByDay([]).size).toBe(0);
  });
});

describe('renderReminder', () => {
  it('替换三个变量', () => {
    const out = renderReminder('【{title}】{time} — {description}', {
      title: '发布评审',
      description: '看 llmsproxy 的部署脚本',
      event_time: '2026-09-03T14:30:00+08:00'
    });
    expect(out).toBe('【发布评审】2026-09-03 14:30 — 看 llmsproxy 的部署脚本');
  });

  it('同一变量出现多次全部替换', () => {
    // replaceAll 而非 replace：后者只换第一个
    const out = renderReminder('{title} / {title}', {
      title: 'X',
      event_time: '2026-09-03T14:30:00+08:00'
    });
    expect(out).toBe('X / X');
  });

  it('description 缺失时替换成空串而不是 undefined', () => {
    const out = renderReminder('{description}|', {
      title: 'T',
      event_time: '2026-09-03T14:30:00+08:00'
    });
    expect(out).toBe('|');
  });

  it('没有变量的模板原样返回', () => {
    const out = renderReminder('纯文本提醒', {
      title: 'T',
      event_time: '2026-09-03T14:30:00+08:00'
    });
    expect(out).toBe('纯文本提醒');
  });

  it('时间解析失败时回退到原始串', () => {
    const out = renderReminder('{time}', { title: 'T', event_time: '坏时间' });
    expect(out).toBe('坏时间');
  });
});

describe('datetime-local 往返', () => {
  it('toLocalInput 给本地时区的 YYYY-MM-DDTHH:mm', () => {
    const d = new Date(2026, 8, 3, 14, 30);
    expect(toLocalInput(d)).toBe('2026-09-03T14:30');
  });

  it('补零', () => {
    const d = new Date(2026, 0, 5, 9, 5);
    expect(toLocalInput(d)).toBe('2026-01-05T09:05');
  });

  it('fromLocalInput 按本地时区解析（人写的就是本地时间）', () => {
    const iso = fromLocalInput('2026-09-03T14:30');
    // 结果应与本地构造的 Date 一致
    expect(iso).toBe(new Date(2026, 8, 3, 14, 30).toISOString());
  });

  it('往返不丢分钟', () => {
    const original = new Date(2026, 8, 3, 14, 30);
    expect(toLocalInput(new Date(fromLocalInput(toLocalInput(original))))).toBe('2026-09-03T14:30');
  });

  it('非法输入给空串', () => {
    expect(fromLocalInput('')).toBe('');
    expect(fromLocalInput('坏值')).toBe('');
  });
});

describe('人类可读描述', () => {
  it('重复规则', () => {
    expect(describeRecurrence(ev({ recurrence: 'none' }))).toBe('不重复');
    expect(describeRecurrence(ev({ recurrence: 'daily' }))).toBe('每天');
    expect(describeRecurrence(ev({ recurrence: 'weekly' }))).toBe('每周');
    expect(describeRecurrence(ev({ recurrence: 'monthly' }))).toBe('每月');
  });

  it('带终止时间', () => {
    const e = ev({ recurrence: 'daily', recurrence_end: '2026-12-31T00:00:00+08:00' });
    expect(describeRecurrence(e)).toBe('每天，至 2026-12-31');
  });

  it('none 时忽略 recurrence_end', () => {
    const e = ev({ recurrence: 'none', recurrence_end: '2026-12-31T00:00:00+08:00' });
    expect(describeRecurrence(e)).toBe('不重复');
  });

  it('提前提醒', () => {
    expect(describeRemindBefore(0)).toBe('到点提醒');
    expect(describeRemindBefore(15)).toBe('提前 15 分钟');
    expect(describeRemindBefore(60)).toBe('提前 1 小时');
    expect(describeRemindBefore(120)).toBe('提前 2 小时');
    expect(describeRemindBefore(90)).toBe('提前 1 小时 30 分钟');
    expect(describeRemindBefore(1440)).toBe('提前 24 小时');
  });
});