import { describe, it, expect } from 'vitest';

import { computeSalesKpiComparison } from '@/lib/services/reports/sales-comparison';
import type { SalesKpis } from '@/lib/services/reports/sales.service';

function makeKpis(overrides: Partial<SalesKpis>): SalesKpis {
  return {
    activeInterests: 0,
    wonInWindow: 0,
    lostInWindow: 0,
    lossBreakdown: [],
    winRate: null,
    pipelineValue: 0,
    pipelineValueCurrency: 'EUR',
    pipelineValueExcludedCount: 0,
    pipelineValueTotalActiveCount: 0,
    medianTimeToCloseDays: null,
    timeToCloseSampleSize: 0,
    newLeadsInWindow: 0,
    newLeadsBySource: [],
    ...overrides,
  };
}

describe('computeSalesKpiComparison', () => {
  it('diffs the window-derived count fields (current - prior)', () => {
    const current = makeKpis({ wonInWindow: 10, lostInWindow: 4, newLeadsInWindow: 20 });
    const prior = makeKpis({ wonInWindow: 6, lostInWindow: 5, newLeadsInWindow: 12 });

    const deltas = computeSalesKpiComparison(current, prior);

    expect(deltas.wonInWindow).toBe(4);
    expect(deltas.lostInWindow).toBe(-1);
    expect(deltas.newLeadsInWindow).toBe(8);
  });

  it('diffs winRate as a fraction when both periods have a rate', () => {
    const current = makeKpis({ winRate: 0.5 });
    const prior = makeKpis({ winRate: 0.4 });
    const deltas = computeSalesKpiComparison(current, prior);
    expect(deltas.winRate).toBeCloseTo(0.1, 10);
  });

  it('returns null winRate delta when either period has no rate', () => {
    expect(
      computeSalesKpiComparison(makeKpis({ winRate: 0.5 }), makeKpis({ winRate: null })).winRate,
    ).toBeNull();
    expect(
      computeSalesKpiComparison(makeKpis({ winRate: null }), makeKpis({ winRate: 0.5 })).winRate,
    ).toBeNull();
  });

  it('diffs medianTimeToCloseDays only when both periods have a median', () => {
    expect(
      computeSalesKpiComparison(
        makeKpis({ medianTimeToCloseDays: 30 }),
        makeKpis({ medianTimeToCloseDays: 45 }),
      ).medianTimeToCloseDays,
    ).toBe(-15);
    expect(
      computeSalesKpiComparison(
        makeKpis({ medianTimeToCloseDays: null }),
        makeKpis({ medianTimeToCloseDays: 45 }),
      ).medianTimeToCloseDays,
    ).toBeNull();
  });
});