import { alertHistoryRange, mergeAlertHistory } from './alert-history';

describe('historical alert observation cycles', () => {
  it('uses seven Shanghai calendar days and rejects invalid or excessive dates', () => {
    expect(alertHistoryRange(undefined, undefined, new Date('2026-09-09T16:30:00Z'))).toMatchObject({
      startDate: '2026-09-04',
      endDate: '2026-09-10',
    });
    for (const [from, to] of [
      ['2026-02-30', '2026-03-01'],
      ['2026-09-09', '2026-09-08'],
      ['2026-07-01', '2026-09-09'],
    ]) {
      expect(() => alertHistoryRange(from, to)).toThrow();
    }
  });
  it('retains distinct cycles, merges daily boundaries and excludes stale/nonpositive samples', () => {
    const result = new Map();
    const metric = { __name__: 'ALERTS_FOR_STATE', alertname: 'CPUHigh', instance: 'host', severity: 'warning' };
    mergeAlertHistory(
      result,
      [
        {
          metric,
          values: [
            [110, '100'],
            [120, '100'],
            [130, '0'],
            [140, 'NaN'],
            [150, '145'],
            [200, '145'],
          ],
        },
      ],
      110,
      200,
    );
    mergeAlertHistory(result, [{ metric, values: [[160, '145']] }], 110, 200);
    expect(result.size).toBe(2);
    expect([...result.values()].map((item) => item.lastObservedAt)).toEqual([
      new Date(120000).toISOString(),
      new Date(160000).toISOString(),
    ]);
  });
});