import { describe, expect, it } from 'vitest';
import {
  defaultShanghaiRange,
  eachShanghaiBuckets,
  periodMomRatio,
  previousShanghaiRangeByGrain,
  shanghaiBucketKey,
  shanghaiQuarterIndex,
  shanghaiQuarterRange,
} from './dashboard-period';
import { shanghaiYmd } from './shanghai-date';

describe('shanghaiBucketKey', () => {
  it('周跨年落到周一 2025-12-29', () => {
    expect(shanghaiBucketKey(new Date('2026-01-02T04:00:00+08:00'), 'week')).toBe('2025-12-29');
  });

  it('Q4 → Q1 分属两年', () => {
    expect(shanghaiBucketKey(new Date('2025-12-15T00:00:00+08:00'), 'quarter')).toBe('2025-Q4');
    expect(shanghaiBucketKey(new Date('2026-01-02T00:00:00+08:00'), 'quarter')).toBe('2026-Q1');
  });
});

describe('eachShanghaiBuckets', () => {
  it('周跨年包含 2025-12-29 与 2026-01-05', () => {
    const keys = eachShanghaiBuckets(
      new Date('2025-12-31T00:00:00+08:00'),
      new Date('2026-01-06T00:00:00+08:00'),
      'week',
    ).map((b) => b.key);
    expect(keys).toEqual(['2025-12-29', '2026-01-05']);
  });

  it('季从 Q4 跨到 Q1', () => {
    const keys = eachShanghaiBuckets(
      new Date('2025-11-01T00:00:00+08:00'),
      new Date('2026-02-01T00:00:00+08:00'),
      'quarter',
    ).map((b) => b.key);
    expect(keys).toEqual(['2025-Q4', '2026-Q1']);
  });
});

describe('previousShanghaiRangeByGrain', () => {
  it('日：昨天~今天 的环比是 前天~昨天', () => {
    const prev = previousShanghaiRangeByGrain(
      new Date('2026-09-01T00:00:00+08:00'),
      new Date('2026-09-02T00:00:00+08:00'),
      'day',
    );
    expect(shanghaiYmd(prev.from)).toBe('2026-08-31');
    expect(shanghaiYmd(prev.to)).toBe('2026-09-01');
  });

  it('周：整段回退 7 天', () => {
    const prev = previousShanghaiRangeByGrain(
      new Date('2026-08-24T00:00:00+08:00'),
      new Date('2026-09-02T00:00:00+08:00'),
      'week',
    );
    expect(shanghaiYmd(prev.from)).toBe('2026-08-17');
    expect(shanghaiYmd(prev.to)).toBe('2026-08-26');
  });

  it('月：整段回退 1 个月', () => {
    const prev = previousShanghaiRangeByGrain(
      new Date('2026-08-01T00:00:00+08:00'),
      new Date('2026-09-02T00:00:00+08:00'),
      'month',
    );
    expect(shanghaiYmd(prev.from)).toBe('2026-07-01');
    expect(shanghaiYmd(prev.to)).toBe('2026-08-02');
  });
});

describe('periodMomRatio', () => {
  it('上期为 0：本期 0 为 null，本期 > 0 为 1', () => {
    expect(periodMomRatio(0, 0)).toBeNull();
    expect(periodMomRatio(8, 0)).toBe(1);
  });

  it('常规环比', () => {
    expect(periodMomRatio(12, 10)).toBeCloseTo(0.2);
    expect(periodMomRatio(8, 10)).toBeCloseTo(-0.2);
  });
});

describe('shanghaiQuarterRange', () => {
  it('Q1 为 1/1～4/1（不含）', () => {
    const { start, endExclusive } = shanghaiQuarterRange(2026, 1);
    expect(shanghaiYmd(start)).toBe('2026-01-01');
    expect(shanghaiYmd(endExclusive)).toBe('2026-04-01');
    expect(shanghaiQuarterIndex(start)).toEqual({ year: 2026, quarter: 1 });
  });
});

describe('defaultShanghaiRange', () => {
  it('日：昨天～今天', () => {
    const r = defaultShanghaiRange('day', new Date('2026-09-02T12:00:00+08:00'));
    expect(shanghaiYmd(r.from)).toBe('2026-09-01');
    expect(shanghaiYmd(r.to)).toBe('2026-09-02');
  });

  it('周：上周一～今天', () => {
    const r = defaultShanghaiRange('week', new Date('2026-09-02T12:00:00+08:00'));
    expect(shanghaiYmd(r.from)).toBe('2026-08-24');
    expect(shanghaiYmd(r.to)).toBe('2026-09-02');
  });

  it('月：上月1日～今天', () => {
    const r = defaultShanghaiRange('month', new Date('2026-09-02T12:00:00+08:00'));
    expect(shanghaiYmd(r.from)).toBe('2026-08-01');
    expect(shanghaiYmd(r.to)).toBe('2026-09-02');
  });

  it('季：上季首日～今天', () => {
    const r = defaultShanghaiRange('quarter', new Date('2026-09-02T12:00:00+08:00'));
    expect(shanghaiYmd(r.from)).toBe('2026-04-01');
    expect(shanghaiYmd(r.to)).toBe('2026-09-02');
  });

  it('年：去年1月1日～今天', () => {
    const r = defaultShanghaiRange('year', new Date('2026-09-02T12:00:00+08:00'));
    expect(shanghaiYmd(r.from)).toBe('2025-01-01');
    expect(shanghaiYmd(r.to)).toBe('2026-09-02');
  });
});