import { billingRows, toCsv, usageTrend } from '../src/reports';
import { Customer } from '../src/auth';
import { TierConfig } from '../src/pricing';
import { UsageEntry } from '../src/usage';

const tiers: TierConfig[] = [
  { id: 'free', name: 'Free', multiplier: 1, monthlyCreditCents: 100 },
  { id: 'pro', name: 'Pro', multiplier: 0.5, monthlyCreditCents: 1000 },
];

const customers: Customer[] = [
  { id: 'cust_1', name: 'Ada', tierId: 'free', apiKey: 'key-ada' },
  { id: 'cust_2', name: 'Grace', tierId: 'pro', apiKey: 'key-grace' },
  { id: 'cust_3', name: 'Linus', tierId: 'pro', apiKey: 'key-linus', billingType: 'purchase_order' },
];

const entry = (customerId: string, cents: number, iso: string): UsageEntry => ({
  customerId,
  endpointId: 'storage',
  cents,
  metadataBytes: 0,
  attachmentBytes: 0,
  timestamp: new Date(iso),
});

describe('billingRows', () => {
  const entries = [
    entry('cust_1', 150, '2026-07-05T10:00:00Z'),
    entry('cust_2', 1500, '2026-07-06T10:00:00Z'),
    entry('cust_2', 300, '2026-08-01T00:30:00Z'),
  ];

  it('aggregates per customer with tier credits', () => {
    const rows = billingRows({ entries, customers, tiers });
    const ada = rows.find((r) => r.customerId === 'cust_1')!;
    expect(ada).toMatchObject({ calls: 1, totalCents: 150, creditCents: 100, billableCents: 50 });
    const grace = rows.find((r) => r.customerId === 'cust_2')!;
    expect(grace).toMatchObject({ calls: 2, totalCents: 1800, creditCents: 1000, billableCents: 800 });
  });

  it('includes zero-usage customers and exposes billingType', () => {
    const rows = billingRows({ entries, customers, tiers });
    const linus = rows.find((r) => r.customerId === 'cust_3')!;
    expect(linus).toMatchObject({ calls: 0, totalCents: 0, billableCents: 0, billingType: 'purchase_order' });
  });

  it('filters by date range (inclusive from, exclusive to)', () => {
    const rows = billingRows({
      entries,
      customers,
      tiers,
      from: new Date('2026-07-01T00:00:00Z'),
      to: new Date('2026-08-01T00:00:00Z'),
    });
    const grace = rows.find((r) => r.customerId === 'cust_2')!;
    expect(grace.calls).toBe(1); // August entry excluded
    expect(grace.totalCents).toBe(1500);
  });

  it('filters by customerId and billingType', () => {
    expect(billingRows({ entries, customers, tiers, customerId: 'cust_1' })).toHaveLength(1);
    const po = billingRows({ entries, customers, tiers, billingType: 'purchase_order' });
    expect(po.map((r) => r.customerId)).toEqual(['cust_3']);
  });
});

describe('usageTrend', () => {
  it('buckets by day', () => {
    const trend = usageTrend(
      [entry('cust_1', 10, '2026-07-05T09:00:00Z'), entry('cust_2', 20, '2026-07-05T20:00:00Z'), entry('cust_1', 5, '2026-07-06T10:00:00Z')],
      'day',
    );
    expect(trend).toEqual([
      { bucket: '2026-07-05', calls: 2, cents: 30 },
      { bucket: '2026-07-06', calls: 1, cents: 5 },
    ]);
  });

  it('buckets by ISO week (Monday key) across a month boundary', () => {
    const trend = usageTrend(
      [entry('cust_1', 10, '2026-07-31T10:00:00Z'), entry('cust_1', 20, '2026-08-01T10:00:00Z')],
      'week',
    );
    expect(trend).toEqual([{ bucket: '2026-07-27', calls: 2, cents: 30 }]);
  });
});

describe('toCsv', () => {
  it('escapes commas, quotes, and newlines per RFC 4180', () => {
    const csv = toCsv(
      [{ name: 'Ada, "The Great"', note: 'line1\nline2', cents: 50 }],
      [
        { key: 'name', label: 'Name' },
        { key: 'note', label: 'Note' },
        { key: 'cents', label: 'Cents' },
      ],
    );
    expect(csv).toBe('Name,Note,Cents\n"Ada, ""The Great""","line1\nline2",50');
  });
});