import { LedgerCurrency, LedgerDirection, OrderStatus, Prisma } from '@prisma/client';
import { LedgerService } from './ledger.service';

/**
 * ACC-03 / MON-04 — an order's debt follows its status, exactly as legacy's
 * recomputed `Σ orders.input WHERE sts > 4`: owed once while delivered (to the
 * expert or the customer), nothing otherwise, never twice.
 */
describe('LedgerService.syncOrderDebt', () => {
  type Entry = { orderId: string; currency: LedgerCurrency; direction: LedgerDirection; amount: Prisma.Decimal; confirmed: boolean };

  function build(order: { status: OrderStatus; totalGoldWeightGrams: string; flatRialCharge: string }) {
    const entries: Entry[] = [];
    const balance = { gold: new Prisma.Decimal(0), rial: new Prisma.Decimal(0) };
    const row = { id: 'o1', customerId: 'c1', ...order };
    const tx = {
      order: { findUnique: jest.fn(async () => row) },
      ledgerEntry: {
        create: jest.fn(async ({ data }: { data: Entry }) => {
          entries.push(data);
          return data;
        }),
        groupBy: jest.fn(async ({ where }: { where: { orderId: string; currency: LedgerCurrency } }) => {
          const out: { direction: LedgerDirection; _sum: { amount: Prisma.Decimal } }[] = [];
          for (const d of [LedgerDirection.DEBIT, LedgerDirection.CREDIT]) {
            const hit = entries.filter((e) => e.orderId === where.orderId && e.currency === where.currency && e.direction === d && e.confirmed);
            if (hit.length) out.push({ direction: d, _sum: { amount: hit.reduce((s, e) => s.add(e.amount), new Prisma.Decimal(0)) } });
          }
          return out;
        }),
      },
      customer: {
        update: jest.fn(async ({ data }: { data: { goldDebtGrams?: { increment: Prisma.Decimal }; fiatDebtRial?: { increment: Prisma.Decimal } } }) => {
          if (data.goldDebtGrams) balance.gold = balance.gold.add(data.goldDebtGrams.increment);
          if (data.fiatDebtRial) balance.rial = balance.rial.add(data.fiatDebtRial.increment);
        }),
      },
    };
    const service = new LedgerService(tx as never);
    const move = async (status: OrderStatus) => {
      row.status = status;
      await service.syncOrderDebt('o1', tx as never);
    };
    return { move, entries, balance };
  }

  it('posts the gold and rial debt once on delivery to the expert', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '10.5', flatRialCharge: '2000' });
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    expect(t.balance.gold.toString()).toBe('10.5');
    expect(t.balance.rial.toString()).toBe('2000');
    expect(t.entries).toHaveLength(2);
  });

  it('never posts twice when the order reaches delivered again (the ACC-03 bug)', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '10.5', flatRialCharge: '0' });
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    await t.move(OrderStatus.DELIVERED_TO_CUSTOMER);
    expect(t.balance.gold.toString()).toBe('10.5');
    expect(t.entries).toHaveLength(1);
  });

  it('takes the debt off when the order goes back, and puts it back once', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '10.5', flatRialCharge: '0' });
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    await t.move(OrderStatus.PREPARING);
    expect(t.balance.gold.toString()).toBe('0');
    expect(t.entries[1].direction).toBe(LedgerDirection.CREDIT);
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    expect(t.balance.gold.toString()).toBe('10.5');
  });

  it('posts the debt when an order goes straight to delivered-to-customer', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '3', flatRialCharge: '0' });
    await t.move(OrderStatus.DELIVERED_TO_CUSTOMER);
    expect(t.balance.gold.toString()).toBe('3');
  });

  it('a cancelled delivered order owes nothing', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '3', flatRialCharge: '500' });
    await t.move(OrderStatus.DELIVERED_TO_AGENT);
    await t.move(OrderStatus.CANCELLED);
    expect(t.balance.gold.toString()).toBe('0');
    expect(t.balance.rial.toString()).toBe('0');
  });

  it('posts nothing for an order that was never delivered', async () => {
    const t = build({ status: OrderStatus.PLACED, totalGoldWeightGrams: '3', flatRialCharge: '500' });
    await t.move(OrderStatus.ADMIN_APPROVED);
    await t.move(OrderStatus.PREPARING);
    expect(t.entries).toHaveLength(0);
  });
});