const { deviceFromUA, cleanSource, sessionsFrom, rollupRows, funnelReport } = require('../src/utils/analytics');

const ev = (sessionId, stage, day, extra = {}) => ({ sessionId, stage, createdAt: `${day}T10:00:00Z`, ...extra });

describe('deviceFromUA', () => {
  test('mobile, tablet, desktop and bots', () => {
    expect(deviceFromUA('Mozilla/5.0 (iPhone; CPU iPhone OS 17_0) Mobile/15E148')).toBe('mobile');
    expect(deviceFromUA('Mozilla/5.0 (Linux; Android 14; SM-X200) Safari')).toBe('tablet');
    expect(deviceFromUA('Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/120')).toBe('desktop');
    expect(deviceFromUA('Googlebot/2.1')).toBeNull();
    expect(deviceFromUA('')).toBeNull();
  });
});

describe('cleanSource', () => {
  test('tidies, defaulting to direct', () => {
    expect(cleanSource(' Facebook ')).toBe('facebook');
    expect(cleanSource('camp-2025<script>')).toBe('camp-2025script');
    expect(cleanSource('')).toBe('direct');
  });
});

describe('sessionsFrom', () => {
  test('a session counts as having reached every earlier stage', () => {
    const [s] = sessionsFrom([ev('a', 'start', '2026-01-02')]);
    expect(s.reach).toBe(1);
    expect(s.days.view).toBe('2026-01-02');
  });

  test('paid only counts for sessions that submitted', () => {
    const out = sessionsFrom([ev('a', 'view', '2026-01-01', { source: 'fb', device: 'mobile' }), ev('a', 'submit', '2026-01-03'), ev('b', 'view', '2026-01-01')], new Set(['a', 'b']));
    const a = out.find(s => s.sessionId === 'a');
    expect(a.reach).toBe(3);
    expect(a.days.paid).toBe('2026-01-03');
    expect(a.source).toBe('fb');
    expect(out.find(s => s.sessionId === 'b').reach).toBe(0);
  });
});

describe('funnelReport', () => {
  const sessions = sessionsFrom([
    ev('a', 'view', '2026-01-01', { source: 'fb', device: 'mobile' }), ev('a', 'start', '2026-01-01'), ev('a', 'submit', '2026-01-01'),
    ev('b', 'view', '2026-01-01', { source: 'fb', device: 'desktop' }), ev('b', 'start', '2026-01-02'),
    ev('c', 'view', '2026-01-02', { device: 'mobile' }),
    ev('d', 'view', '2026-01-02', { device: 'mobile' }),
  ], new Set(['a']));

  test('counts and conversion per stage', () => {
    const r = funnelReport(sessions);
    expect(r.totals).toEqual({ view: 4, start: 2, submit: 1, paid: 1 });
    expect(r.conversion.start).toBe(50);
    expect(r.conversion.paid).toBe(25);
    expect(r.conversion.startToSubmit).toBe(50);
  });

  test('daily trend and breakdowns', () => {
    const r = funnelReport(sessions);
    expect(r.trend).toEqual([{ day: '2026-01-01', view: 2, start: 1, submit: 1, paid: 1 }, { day: '2026-01-02', view: 2, start: 1, submit: 0, paid: 0 }]);
    expect(r.bySource.find(s => s.key === 'fb')).toMatchObject({ view: 2, paid: 1, conversion: 50 });
    expect(r.bySource.find(s => s.key === 'direct').view).toBe(2);
    expect(r.byDevice.find(s => s.key === 'mobile').view).toBe(3);
  });

  test('rolled-up rows add to the raw counts', () => {
    const daily = rollupRows(sessionsFrom([ev('x', 'view', '2025-10-01'), ev('x', 'submit', '2025-10-01')], new Set(['x'])));
    expect(daily.find(r => r.stage === 'paid').sessions).toBe(1);
    const r = funnelReport(sessions, daily);
    expect(r.totals).toEqual({ view: 5, start: 3, submit: 2, paid: 2 });
  });
});