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

import { createInitialBillingStatements } from "@/modules/billing/lib/presentation-data";
import {
  addBillingCharge,
  addBillingPayment,
  calculateBillingSummary,
  getBillingStatus,
  getStatementOutstandingCents,
  getStatementTotalCents,
} from "@/modules/billing/types";

const referenceDate = new Date("2026-07-09T12:00:00.000Z");

describe("billing calculations", () => {
  it("derives paid, partial, pending, and overdue states from ledger activity", () => {
    const statements = createInitialBillingStatements(referenceDate);

    expect(statements.map((statement) => getBillingStatus(statement, referenceDate))).toEqual([
      "paid",
      "partial",
      "pending",
      "overdue",
      "overdue",
      "paid",
    ]);
  });

  it("calculates statement and workspace totals from charges and payments", () => {
    const statements = createInitialBillingStatements(referenceDate);
    const summary = calculateBillingSummary(statements, referenceDate);
    const firstStatement = statements[0];
    expect(firstStatement).toBeDefined();
    if (!firstStatement) {
      return;
    }

    expect(getStatementTotalCents(firstStatement)).toBe(960000);
    expect(summary.receivableCents).toBe(5995000);
    expect(summary.collectedCents).toBe(2810000);
    expect(summary.outstandingCents).toBe(3185000);
    expect(summary.overdueCount).toBe(2);
  });

  it("updates outstanding amounts when payments and charges are appended", () => {
    const statement = createInitialBillingStatements(referenceDate)[2];
    expect(statement).toBeDefined();
    if (!statement) {
      return;
    }

    const paidStatement = addBillingPayment(statement, {
      id: "payment-new",
      amountCents: 200000,
      method: "wechat",
      paidAt: referenceDate.toISOString(),
      reference: "WX-NEW",
      operator: "收费员",
      note: "",
    });
    expect(getStatementOutstandingCents(paidStatement)).toBe(640000);
    expect(getBillingStatus(paidStatement, referenceDate)).toBe("partial");

    const chargedStatement = addBillingCharge(paidStatement, {
      id: "charge-new",
      category: "生活用品",
      description: "护理耗材",
      quantity: 2,
      serviceDate: referenceDate.toISOString(),
      unitPriceCents: 5000,
    });
    expect(getStatementOutstandingCents(chargedStatement)).toBe(650000);
    expect(chargedStatement.invoiceStatus).toBe("not_requested");
  });
});