import type { BillingCharge, BillingPayment, BillingStatement, PaymentMethod } from "@/modules/billing/types";

type StatementSeed = {
  id: string;
  elderId: string;
  elderName: string;
  roomLabel: string;
  contactName: string;
  contactPhone: string;
  dueOffsetDays: number;
  charges: Array<Omit<BillingCharge, "id" | "serviceDate">>;
  payments: Array<{
    amountCents: number;
    method: PaymentMethod;
    paidOffsetDays: number;
    reference: string;
    operator: string;
    note: string;
  }>;
  invoiceStatus?: BillingStatement["invoiceStatus"];
  invoiceNumber?: string;
  receiptCount?: number;
};

const STATEMENT_SEEDS: StatementSeed[] = [
  {
    id: "bill-wgl",
    elderId: "elder-wgl",
    elderName: "王桂兰",
    roomLabel: "A101-1",
    contactName: "张敏",
    contactPhone: "13800000001",
    dueOffsetDays: 6,
    charges: [
      { category: "床位服务", description: "标准护理房床位费", quantity: 1, unitPriceCents: 360000 },
      { category: "护理服务", description: "重点照护服务包", quantity: 1, unitPriceCents: 390000 },
      { category: "膳食服务", description: "低盐营养膳食", quantity: 1, unitPriceCents: 180000 },
      { category: "健康管理", description: "血压跟踪与健康复核", quantity: 1, unitPriceCents: 30000 },
    ],
    payments: [
      {
        amountCents: 960000,
        method: "wechat",
        paidOffsetDays: -2,
        reference: "WX202607090018",
        operator: "前台收费组",
        note: "家属线上支付",
      },
    ],
    invoiceStatus: "issued",
    invoiceNumber: "FP20260709001",
    receiptCount: 1,
  },
  {
    id: "bill-ljg",
    elderId: "elder-ljg",
    elderName: "李建国",
    roomLabel: "A102-1",
    contactName: "李明",
    contactPhone: "13800000002",
    dueOffsetDays: 8,
    charges: [
      { category: "床位服务", description: "半护理房床位费", quantity: 1, unitPriceCents: 320000 },
      { category: "护理服务", description: "半护理服务包", quantity: 1, unitPriceCents: 250000 },
      { category: "膳食服务", description: "日常营养膳食", quantity: 1, unitPriceCents: 170000 },
      { category: "活动服务", description: "康体活动与陪同", quantity: 1, unitPriceCents: 40000 },
    ],
    payments: [
      {
        amountCents: 400000,
        method: "bank_transfer",
        paidOffsetDays: -1,
        reference: "BANK20260708032",
        operator: "财务值班",
        note: "首笔转账已确认",
      },
    ],
    invoiceStatus: "pending",
  },
  {
    id: "bill-zyz",
    elderId: "elder-zyz",
    elderName: "周玉珍",
    roomLabel: "A201-1",
    contactName: "周强",
    contactPhone: "13800000003",
    dueOffsetDays: 10,
    charges: [
      { category: "床位服务", description: "记忆照护专区床位费", quantity: 1, unitPriceCents: 370000 },
      { category: "护理服务", description: "协助护理服务包", quantity: 1, unitPriceCents: 285000 },
      { category: "膳食服务", description: "糖尿病营养膳食", quantity: 1, unitPriceCents: 185000 },
    ],
    payments: [],
  },
  {
    id: "bill-zgh",
    elderId: "elder-zgh",
    elderName: "赵国华",
    roomLabel: "A202-1",
    contactName: "赵琳",
    contactPhone: "13800000004",
    dueOffsetDays: -3,
    charges: [
      { category: "床位服务", description: "重点护理房床位费", quantity: 1, unitPriceCents: 380000 },
      { category: "护理服务", description: "失能照护服务包", quantity: 1, unitPriceCents: 420000 },
      { category: "膳食服务", description: "软食营养膳食", quantity: 1, unitPriceCents: 185000 },
      { category: "生活用品", description: "护理耗材包", quantity: 1, unitPriceCents: 60000 },
    ],
    payments: [
      {
        amountCents: 200000,
        method: "cash",
        paidOffsetDays: -6,
        reference: "CASH20260703009",
        operator: "前台收费组",
        note: "现金预缴",
      },
    ],
  },
  {
    id: "bill-msf",
    elderId: "elder-msf",
    elderName: "马淑芬",
    roomLabel: "A301-1",
    contactName: "马晨",
    contactPhone: "13800000011",
    dueOffsetDays: -5,
    charges: [
      { category: "床位服务", description: "失能照护区床位费", quantity: 1, unitPriceCents: 390000 },
      { category: "护理服务", description: "全护理服务包", quantity: 1, unitPriceCents: 460000 },
      { category: "膳食服务", description: "吞咽困难软食套餐", quantity: 1, unitPriceCents: 205000 },
      { category: "营养服务", description: "营养师评估与加餐", quantity: 1, unitPriceCents: 65000 },
    ],
    payments: [],
  },
  {
    id: "bill-qsb",
    elderId: "elder-qsb",
    elderName: "钱松柏",
    roomLabel: "S101-1",
    contactName: "钱宁",
    contactPhone: "13800000014",
    dueOffsetDays: 4,
    charges: [
      { category: "床位服务", description: "医养观察房床位费", quantity: 1, unitPriceCents: 430000 },
      { category: "护理服务", description: "医养重点照护服务包", quantity: 1, unitPriceCents: 480000 },
      { category: "膳食服务", description: "呼吸慢病营养膳食", quantity: 1, unitPriceCents: 190000 },
      { category: "设备服务", description: "制氧与血氧监测服务", quantity: 1, unitPriceCents: 150000 },
    ],
    payments: [
      {
        amountCents: 1250000,
        method: "card",
        paidOffsetDays: -1,
        reference: "POS20260708017",
        operator: "医养前台",
        note: "银行卡支付",
      },
    ],
    receiptCount: 1,
  },
];

function addDays(reference: Date, days: number): string {
  const result = new Date(reference);
  result.setDate(result.getDate() + days);
  return result.toISOString();
}

function getPeriod(reference: Date): string {
  const year = reference.getFullYear();
  const month = String(reference.getMonth() + 1).padStart(2, "0");
  return `${year}-${month}`;
}

function createCharges(seed: StatementSeed, reference: Date): BillingCharge[] {
  return seed.charges.map((charge, index) => ({
    ...charge,
    id: `${seed.id}-charge-${index + 1}`,
    serviceDate: addDays(reference, -Math.max(1, 12 - index * 2)),
  }));
}

function createPayments(seed: StatementSeed, reference: Date): BillingPayment[] {
  return seed.payments.map((payment, index) => ({
    id: `${seed.id}-payment-${index + 1}`,
    amountCents: payment.amountCents,
    method: payment.method,
    paidAt: addDays(reference, payment.paidOffsetDays),
    reference: payment.reference,
    operator: payment.operator,
    note: payment.note,
  }));
}

export function createInitialBillingStatements(referenceDate = new Date()): BillingStatement[] {
  return STATEMENT_SEEDS.map((seed) => ({
    id: seed.id,
    elderId: seed.elderId,
    elderName: seed.elderName,
    roomLabel: seed.roomLabel,
    contactName: seed.contactName,
    contactPhone: seed.contactPhone,
    period: getPeriod(referenceDate),
    dueAt: addDays(referenceDate, seed.dueOffsetDays),
    charges: createCharges(seed, referenceDate),
    payments: createPayments(seed, referenceDate),
    invoiceStatus: seed.invoiceStatus ?? "not_requested",
    invoiceNumber: seed.invoiceNumber,
    receiptCount: seed.receiptCount ?? 0,
  }));
}