import { prisma } from "@/lib/prisma";
import type {
  BusinessCustomerDto,
  BusinessCustomerStatus,
} from "@/modules/customer/types";
import { ValidationError } from "@/modules/quote/types";

function serializeBusinessCustomer(row: {
  customerId: string;
  businessCustomerId: string;
  name: string;
  externalCode: string | null;
  status: string;
  remark: string | null;
  createdAt: Date;
  updatedAt: Date;
}): BusinessCustomerDto {
  return {
    customer_id: row.customerId,
    business_customer_id: row.businessCustomerId,
    name: row.name,
    external_code: row.externalCode,
    status: row.status as BusinessCustomerStatus,
    remark: row.remark,
    created_at: row.createdAt.toISOString(),
    updated_at: row.updatedAt.toISOString(),
  };
}

export async function listBusinessCustomers(customerId: string): Promise<BusinessCustomerDto[]> {
  const rows = await prisma.businessCustomer.findMany({
    where: { customerId, isDeleted: false },
    orderBy: { createdAt: "desc" },
    include: {
      _count: {
        select: {
          users: {
            where: { isDeleted: false, status: "active" },
          },
        },
      },
    },
  });
  return rows.map((row) => ({
    ...serializeBusinessCustomer(row),
    user_count: row._count.users,
  }));
}

export async function createBusinessCustomer(input: {
  customerId: string;
  businessCustomerId: string;
  name: string;
  externalCode?: string | null;
  remark?: string | null;
}): Promise<BusinessCustomerDto> {
  const customerId = input.customerId.trim();
  const businessCustomerId = input.businessCustomerId.trim();
  const name = input.name.trim();
  if (!customerId) {
    throw new Error("租户标识不能为空");
  }
  if (!businessCustomerId) {
    throw new Error("客户标识不能为空");
  }
  if (!name) {
    throw new Error("客户名称不能为空");
  }
  const created = await prisma.businessCustomer.create({
    data: {
      customerId,
      businessCustomerId,
      name,
      externalCode: input.externalCode?.trim() || null,
      remark: input.remark?.trim() || null,
      status: "active",
    },
  });
  return serializeBusinessCustomer(created);
}

export async function updateBusinessCustomer(
  customerId: string,
  businessCustomerId: string,
  input: {
    name?: string;
    externalCode?: string | null;
    status?: BusinessCustomerStatus;
    remark?: string | null;
  },
): Promise<BusinessCustomerDto> {
  const existing = await prisma.businessCustomer.findFirst({
    where: { customerId, businessCustomerId, isDeleted: false },
  });
  if (!existing) {
    throw new Error("客户不存在");
  }
  const data: {
    name?: string;
    externalCode?: string | null;
    status?: BusinessCustomerStatus;
    remark?: string | null;
  } = {};
  if (input.name !== undefined) {
    const name = input.name.trim();
    if (!name) {
      throw new Error("客户名称不能为空");
    }
    data.name = name;
  }
  if (input.externalCode !== undefined) {
    data.externalCode = input.externalCode?.trim() || null;
  }
  if (input.status !== undefined) {
    data.status = input.status;
  }
  if (input.remark !== undefined) {
    data.remark = input.remark?.trim() || null;
  }
  const updated = await prisma.businessCustomer.update({
    where: {
      customerId_businessCustomerId: {
        customerId,
        businessCustomerId,
      },
    },
    data,
  });
  return serializeBusinessCustomer(updated);
}

export async function getBusinessCustomer(
  customerId: string,
  businessCustomerId: string,
): Promise<BusinessCustomerDto | null> {
  const row = await prisma.businessCustomer.findFirst({
    where: { customerId, businessCustomerId, isDeleted: false },
  });
  return row ? serializeBusinessCustomer(row) : null;
}

export async function assertBusinessCustomerBelongsToTenant(
  customerId: string,
  businessCustomerId?: string | null,
): Promise<void> {
  if (!businessCustomerId) {
    return;
  }
  const exists = await prisma.businessCustomer.count({
    where: {
      customerId,
      businessCustomerId,
      isDeleted: false,
      status: "active",
    },
  });
  if (!exists) {
    throw new ValidationError("客户不存在或已停用");
  }
}