import type { Prisma } from "@/generated/prisma/client"
import { paginate } from "@/lib/paginate"
import prisma from "@/lib/prisma"
import type {
  Item,
  ItemSummary,
  ItemWithAssetAndMovementCount,
  ItemWithAssetCount,
} from "@/types"

export const ItemService = {
  findAllItemsCount: async (): Promise<number> => {
    return prisma.item.count({ where: { deletedAt: { equals: null } } })
  },

  findAllWithAssetCount: async ({
    page,
    pageSize,
    search,
  }: {
    page?: number
    pageSize?: number
    search?: string
  }) => {
    return paginate<ItemWithAssetCount>({
      model: prisma.item,
      page,
      pageSize,
      where: {
        deletedAt: null,
        ...(search
          ? {
              name: { contains: search, mode: "insensitive" },
            }
          : {}),
      },
      orderBy: { name: "asc" },
      select: {
        id: true,
        name: true,
        stock: true,
        category: { select: { id: true, name: true } },
        _count: { select: { assets: true } },
      },
    })
  },

  findAll: async (opts?: {
    includeCategory?: boolean
    includeAssets?: boolean
    includeMovements?: boolean
  }): Promise<Item[]> => {
    return prisma.item.findMany({
      include: {
        category: !!opts?.includeCategory,
        assets: opts?.includeAssets
          ? { select: { id: true, serialNumber: true, status: true } }
          : false,
        stockMovementLines: opts?.includeMovements
          ? {
              select: {
                id: true,
                stockDelta: true,
                movement: { select: { type: true } },
              },
            }
          : false,
      },
    })
  },

  findAllAssignable: async (): Promise<Item[]> => {
    return prisma.item.findMany({
      where: {
        deletedAt: null,
        OR: [
          {
            stock: { gt: 0 },
            assets: { some: {} },
          },
          {
            stock: 0,
            assets: { some: {} },
          },
          {
            stock: 0,
            assets: { none: {} },
          },
        ],
      },
      orderBy: { name: "asc" },
    }) as Promise<Item[]>
  },

  findByIdWithCategory: async (
    id: string,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<ItemSummary | null> => {
    return db.item.findUnique({
      where: { id },
      include: {
        category: { select: { id: true, name: true } },
      },
    })
  },

  findByIdWithAssetCount: async (
    id: string,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<ItemWithAssetCount | null> => {
    return db.item.findUnique({
      where: { id },
      include: {
        category: { select: { id: true, name: true } },
        _count: { select: { assets: true } },
      },
    })
  },

  findByIdWithAssetAndMovementCount: async (
    id: string,
  ): Promise<ItemWithAssetAndMovementCount | null> => {
    const item = await prisma.item.findUnique({
      where: { id },
      include: {
        category: { select: { id: true, name: true } },
        _count: { select: { assets: true, stockMovementLines: true } },
      },
    })

    return item
      ? {
          ...item,
          _count: {
            assets: item._count.assets,
            movements: item._count.stockMovementLines,
          },
        }
      : null
  },

  findByName: async (
    name: string,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item | null> => {
    return db.item.findFirst({
      where: { name },
      include: { category: true, assets: true, stockMovementLines: true },
    }) as Promise<Item | null>
  },

  findById: async (
    id: string,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item | null> => {
    return db.item.findUnique({
      where: { id },
      include: { category: true, assets: true, stockMovementLines: true },
    }) as Promise<Item | null>
  },

  findAllWithStock: async (): Promise<Item[]> => {
    return prisma.item.findMany({
      orderBy: { name: "asc" },
      where: {
        stock: { gt: 0 },
        deletedAt: { equals: null },
      },
      include: {
        category: true,
        assets: { select: { id: true, serialNumber: true, status: true } },
        stockMovementLines: {
          select: {
            id: true,
            stockDelta: true,
            movement: { select: { type: true } },
          },
        },
      },
    }) as Promise<Item[]>
  },

  create: async (
    data: Prisma.ItemCreateInput,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item> => {
    return db.item.create({ data })
  },

  update: async (
    id: string,
    data: Prisma.ItemUpdateInput,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item> => {
    return db.item.update({ where: { id }, data })
  },

  updateStock: async (
    id: string,
    quantity: number,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item> => {
    return db.item.update({
      where: { id },
      data: { stock: { increment: quantity } },
    })
  },

  decrementStockIfAvailable: async (
    id: string,
    quantity: number,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<boolean> => {
    const result = await db.item.updateMany({
      where: {
        id,
        stock: { gte: quantity },
      },
      data: { stock: { decrement: quantity } },
    })

    return result.count === 1
  },

  delete: async (
    id: string,
    db: Prisma.TransactionClient | typeof prisma = prisma,
  ): Promise<Item> => {
    return db.item.update({
      where: { id },
      data: { deletedAt: new Date() },
    })
  },
}