import { Injectable } from '@nestjs/common'
import { ResponseMapper } from '../common/response/response-mapper'
import { PrismaService } from '../prisma/prisma.service'
import { CreateInventoryTransferItemDto } from './dto/create-inventory-transfer-item.dto'

@Injectable()
export class InventoryTransferItemsService {
  constructor(private prisma: PrismaService) {}

  async create(dto: CreateInventoryTransferItemDto) {
    const payload: any = { ...dto }
    if (Object.prototype.hasOwnProperty.call(payload, 'productId')) {
      payload.product = { connect: { id: Number(payload.productId) } }
      delete payload.productId
    }
    if (Object.prototype.hasOwnProperty.call(payload, 'transferId')) {
      payload.transfer = { connect: { id: Number(payload.transferId) } }
      delete payload.transferId
    }

    const item = await this.prisma.inventoryTransferItem.create({ data: payload })
    return ResponseMapper.create(item)
  }

  async findAll(transferId?: number) {
    const where = transferId ? { transferId: Number(transferId) } : undefined
    const items = await this.prisma.inventoryTransferItem.findMany({
      where,
      include: { product: true },
    })
    return ResponseMapper.list(items)
  }

  async findOne(id: number) {
    const item = await this.prisma.inventoryTransferItem.findUnique({
      where: { id },
      include: { product: true, transfer: true },
    })
    if (!item) return null
    return ResponseMapper.single(item)
  }

  // scoped helpers for nested routes
  async createForTransfer(transferId: number, dto: CreateInventoryTransferItemDto) {
    const payload: any = { ...dto, transferId }
    return this.create(payload)
  }

  async findAllForTransfer(transferId: number) {
    return this.findAll(transferId)
  }

  async findOneForTransfer(transferId: number, id: number) {
    const item = await this.prisma.inventoryTransferItem.findFirst({
      where: { id, transferId },
      include: { product: true, transfer: true },
    })
    if (!item) return null
    return ResponseMapper.single(item)
  }

  async update(id: number, data: any) {
    const payload: any = { ...data }
    if (Object.prototype.hasOwnProperty.call(payload, 'productId')) {
      payload.product = { connect: { id: Number(payload.productId) } }
      delete payload.productId
    }
    if (Object.prototype.hasOwnProperty.call(payload, 'transferId')) {
      payload.transfer = { connect: { id: Number(payload.transferId) } }
      delete payload.transferId
    }

    const item = await this.prisma.inventoryTransferItem.update({
      where: { id },
      data: payload,
    })
    return ResponseMapper.update(item)
  }

  async updateForTransfer(transferId: number, id: number, data: any) {
    // ensure the item belongs to the transfer
    const existing = await this.prisma.inventoryTransferItem.findFirst({
      where: { id, transferId },
    })
    if (!existing) return null
    return this.update(id, data)
  }

  async remove(id: number) {
    const item = await this.prisma.inventoryTransferItem.delete({ where: { id } })
    return ResponseMapper.single(item)
  }

  async removeForTransfer(transferId: number, id: number) {
    const existing = await this.prisma.inventoryTransferItem.findFirst({
      where: { id, transferId },
    })
    if (!existing) return null
    return this.remove(id)
  }
}