import { describe, it, expect } from 'vitest';
import {
  calculateCascadeWarnings,
  getNextWarning,
  checkWarnings,
  getCascadeIntervals,
  formatMinutesBefore,
  CASCADE_PRESETS,
} from './cascade';

describe('cascade', () => {
  const ONE_MIN = 60 * 1000;
  const ONE_HOUR = 60 * ONE_MIN;

  describe('CASCADE_PRESETS', () => {
    it('aggressive has 9 intervals', () => {
      expect(CASCADE_PRESETS.aggressive).toHaveLength(9);
    });

    it('standard has 5 intervals', () => {
      expect(CASCADE_PRESETS.standard).toHaveLength(5);
    });

    it('none has 0 intervals', () => {
      expect(CASCADE_PRESETS.none).toHaveLength(0);
    });
  });

  describe('calculateCascadeWarnings', () => {
    it('creates warnings for all intervals', () => {
      const targetTime = Date.now() + 3 * ONE_HOUR;
      const warnings = calculateCascadeWarnings(targetTime, [120, 60, 30, 15, 5]);
      expect(warnings).toHaveLength(5);
    });

    it('marks past warnings as fired', () => {
      const now = Date.now();
      const targetTime = now + 10 * ONE_MIN; // 10 min from now
      const warnings = calculateCascadeWarnings(targetTime, [30, 15, 5], now);
      // 30m and 15m warnings are in the past (target is only 10m away)
      const firedCount = warnings.filter((w) => w.fired).length;
      expect(firedCount).toBe(2);
    });

    it('returns empty array for empty intervals', () => {
      const warnings = calculateCascadeWarnings(Date.now() + ONE_HOUR, []);
      expect(warnings).toHaveLength(0);
    });

    it('sorts warnings by minutesBefore descending (earliest first)', () => {
      const targetTime = Date.now() + 5 * ONE_HOUR;
      const warnings = calculateCascadeWarnings(targetTime, [5, 60, 15, 120]);
      expect(warnings[0].minutesBefore).toBe(120);
      expect(warnings[3].minutesBefore).toBe(5);
    });

    it('all warnings are in the future when target is far away', () => {
      const targetTime = Date.now() + 24 * ONE_HOUR;
      const warnings = calculateCascadeWarnings(targetTime, [120, 60, 30]);
      expect(warnings.every((w) => !w.fired)).toBe(true);
    });
  });

  describe('getNextWarning', () => {
    it('returns first unfired warning', () => {
      const targetTime = Date.now() + 2 * ONE_HOUR;
      const warnings = calculateCascadeWarnings(targetTime, [120, 60, 30, 15, 5]);
      const next = getNextWarning(warnings);
      expect(next).not.toBeNull();
      expect(next!.fired).toBe(false);
    });

    it('returns null when all warnings are fired', () => {
      const targetTime = Date.now() - ONE_MIN; // in the past
      const warnings = calculateCascadeWarnings(targetTime, [5, 1]);
      const next = getNextWarning(warnings);
      expect(next).toBeNull();
    });
  });

  describe('checkWarnings', () => {
    it('fires warnings whose time has come', () => {
      const now = Date.now();
      const targetTime = now + 20 * ONE_MIN;
      const warnings = calculateCascadeWarnings(targetTime, [30, 15, 5], now);
      // At now, 30m warning is past (target - 30m < now)
      // Advance time to 10m before target (5m warning should fire)
      const laterNow = targetTime - 10 * ONE_MIN;
      const fired = checkWarnings(warnings, laterNow);
      expect(fired.length).toBeGreaterThan(0);
    });

    it('does not re-fire already fired warnings', () => {
      const now = Date.now();
      const targetTime = now + 2 * ONE_MIN;
      const warnings = calculateCascadeWarnings(targetTime, [5], now);
      // 5m warning is already past since target is 2m away
      const fired1 = checkWarnings(warnings, now);
      const fired2 = checkWarnings(warnings, now + 1000);
      // Second check should not re-fire
      expect(fired2).toHaveLength(0);
      expect(fired1.length).toBeGreaterThanOrEqual(0);
    });
  });

  describe('getCascadeIntervals', () => {
    it('returns preset intervals for standard', () => {
      const intervals = getCascadeIntervals({ preset: 'standard', intervals: [] });
      expect(intervals).toEqual(CASCADE_PRESETS.standard);
    });

    it('returns custom intervals sorted descending', () => {
      const intervals = getCascadeIntervals({ preset: 'custom', intervals: [5, 30, 10] });
      expect(intervals).toEqual([30, 10, 5]);
    });
  });

  describe('formatMinutesBefore', () => {
    it('formats minutes under 60', () => {
      expect(formatMinutesBefore(5)).toBe('5m');
      expect(formatMinutesBefore(15)).toBe('15m');
    });

    it('formats exact hours', () => {
      expect(formatMinutesBefore(60)).toBe('1h');
      expect(formatMinutesBefore(120)).toBe('2h');
    });

    it('formats hours and minutes', () => {
      expect(formatMinutesBefore(90)).toBe('1h 30m');
      expect(formatMinutesBefore(150)).toBe('2h 30m');
    });
  });
});