import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import { PreOrderStatus, Prisma } from '@prisma/client';
import { PrismaService } from '../../prisma/prisma.service';
import { TableService } from '../admin-table/table.service';
import type { TableQueryDto } from '../admin-table/table-query.dto';

/**
 * Custom / made-to-order requests — legacy "سفارش های ساختنی".
 *
 * Legacy served these from CustomOrderController (`POST get-custom-orders`,
 * `PUT custom-order/{id}`, `DELETE custom-order/{id}`). The redesigned schema
 * models them as PreOrder: a design request that an admin prices and later
 * converts into a real, debt-bearing Order.
 */
const PREORDER_STATUS_LABELS: Record<PreOrderStatus, string> = {
  PLACED: 'ثبت شده',
  ADMIN_APPROVED: 'تایید مدیر',
  WORKSHOP_APPROVED: 'تایید کارگاه',
  READY_TO_SHIP: 'آماده ارسال',
  DELIVERED: 'تحویل شده',
  CANCELLED: 'لغو شده',
};

@Injectable()
export class AdminPreOrdersService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly table: TableService,
  ) {}

  private static readonly ALLOWED = [
    'id',
    'status',
    'createdAt',
    'updatedAt',
    'colorName',
    'sizeSpec',
    'stoneColor',
    'minaColor',
    'estimatedWeightGrams',
    'estimatedPriceRial',
    'customer.fullName',
    'customer.mobile',
  ];

  /** Legacy `POST get-custom-orders`. */
  async list(query: TableQueryDto) {
    this.table.assertNotExport(query);

    const { where, orderBy, skip, take, page, limit } = this.table.build(query, {
      searchable: ['customer.fullName', 'customer.mobile'],
      allowed: AdminPreOrdersService.ALLOWED,
      defaultOrderBy: { createdAt: 'desc' },
    });

    const [rows, total] = await Promise.all([
      this.prisma.preOrder.findMany({
        where: where as Prisma.PreOrderWhereInput,
        orderBy: orderBy as Prisma.PreOrderOrderByWithRelationInput,
        skip,
        take,
        include: { customer: true, city: true, workshop: true },
      }),
      this.prisma.preOrder.count({ where: where as Prisma.PreOrderWhereInput }),
    ]);

    return this.table.respond(rows.map((r) => this.toRow(r)), total, query, page, limit);
  }

  /** Legacy field names (color, size, color_mina, color_stone, ...) preserved. */
  private toRow(
    p: Prisma.PreOrderGetPayload<{ include: { customer: true; city: true; workshop: true } }>,
  ) {
    return {
      id: p.id,
      status: p.status,
      sts_str_fa: PREORDER_STATUS_LABELS[p.status],
      color: p.colorName,
      size: p.sizeSpec,
      color_mina: p.minaColor,
      color_stone: p.stoneColor,
      // legacy 'sum' (quantity); a PreOrder models a single design request
      sum: 1,
      description: p.description,
      designImageUrl: p.designImageUrl,
      estimatedWeightGrams: p.estimatedWeightGrams,
      estimatedPriceRial: p.estimatedPriceRial,
      time_creat_fa: p.createdAt,
      time_update_fa: p.updatedAt,
      convertedOrderId: p.convertedOrderId,
      city: p.city ? { id: p.city.id, title: p.city.name } : null,
      workshop: p.workshop ? { id: p.workshop.id, name: p.workshop.name } : null,
      customer: {
        id: p.customer.id,
        // D0 — real name parts
        fname: p.customer.firstName ?? p.customer.fullName,
        lname: p.customer.lastName ?? '',
        name: p.customer.fullName,
        fullName: p.customer.fullName,
        mobile: p.customer.mobile,
      },
    };
  }

  async findOne(id: string) {
    const p = await this.prisma.preOrder.findUnique({
      where: { id },
      include: { customer: true, city: true, workshop: true },
    });
    if (!p) throw new NotFoundException('سفارش ساختنی یافت نشد');
    return this.toRow(p);
  }

  /** Legacy `PUT custom-order/{id}`. */
  async update(id: string, data: Record<string, unknown>) {
    const existing = await this.prisma.preOrder.findUnique({ where: { id } });
    if (!existing) throw new NotFoundException('سفارش ساختنی یافت نشد');

    const patch: Prisma.PreOrderUpdateInput = {};
    if (data.status !== undefined) patch.status = data.status as PreOrderStatus;
    if (data.color !== undefined) patch.colorName = data.color as string;
    if (data.size !== undefined) patch.sizeSpec = data.size as string;
    if (data.color_mina !== undefined) patch.minaColor = data.color_mina as string;
    if (data.color_stone !== undefined) patch.stoneColor = data.color_stone as string;
    if (data.description !== undefined) patch.description = data.description as string;
    if (data.estimatedWeightGrams !== undefined) {
      patch.estimatedWeightGrams = new Prisma.Decimal(data.estimatedWeightGrams as string);
    }
    if (data.estimatedPriceRial !== undefined) {
      patch.estimatedPriceRial = new Prisma.Decimal(data.estimatedPriceRial as string);
    }

    return this.prisma.preOrder.update({ where: { id }, data: patch });
  }

  /** Legacy `DELETE custom-order/{id}`. */
  async remove(id: string) {
    const p = await this.prisma.preOrder.findUnique({ where: { id } });
    if (!p) throw new NotFoundException('سفارش ساختنی یافت نشد');

    // Once converted into a real Order the design request is part of an
    // accounting trail; deleting it would orphan that link. Legacy had no guard.
    if (p.convertedOrderId) {
      throw new BadRequestException(
        'حذف ممکن نیست: این سفارش ساختنی قبلاً به سفارش قطعی تبدیل شده است.',
      );
    }

    await this.prisma.$transaction([
      this.prisma.preOrderStatusEvent.deleteMany({ where: { preOrderId: id } }),
      this.prisma.preOrder.delete({ where: { id } }),
    ]);
    return { success: true };
  }

  statusOptions() {
    return Object.entries(PREORDER_STATUS_LABELS).map(([value, title]) => ({ value, title }));
  }
}