// lib/procurement/items/service.ts
"use server"

import { revalidateTag, unstable_noStore } from "next/cache"
import db from "@/db/db"

import { filterColumns } from "@/lib/filter-columns"
import { unstable_cache } from "@/lib/unstable-cache"
import { getErrorMessage } from "@/lib/handle-error"

import { asc, desc, ilike, and, or, eq } from "drizzle-orm"
import { GetProcurementItemsSchema, UpdateProcurementItemSchema, createProcurementItemSchema } from "./validations"
import { ProcurementItem, procurementItems } from "@/db/schema/items"
import {
  countProcurementItems,
  deleteProcurementItemById,
  deleteProcurementItemsByIds,
  findAllProcurementItems,
  insertProcurementItem,
  selectProcurementItems,
  updateProcurementItem
} from "./repository"

/* -----------------------------------------------------
   1) 조회 관련
----------------------------------------------------- */

/**
 * 복잡한 조건으로 품목 목록을 조회 (+ pagination) 하고,
 * 총 개수에 따라 pageCount를 계산해서 리턴.
 * Next.js의 unstable_cache를 사용해 일정 시간 캐시.
 */
export async function getProcurementItems(input: GetProcurementItemsSchema) {
  const safePerPage = Math.min(input.perPage, 1000)

  return unstable_cache(
    async () => {
      try {
        const offset = (input.page - 1) * safePerPage

        const advancedWhere = filterColumns({
          table: procurementItems,
          filters: input.filters,
          joinOperator: input.joinOperator,
        })

        let globalWhere
        if (input.search) {
          const s = `%${input.search}%`
          globalWhere = or(
            ilike(procurementItems.itemCode, s),
            ilike(procurementItems.itemName, s),
            ilike(procurementItems.material, s),
            ilike(procurementItems.specification, s),
            ilike(procurementItems.unit, s),
          )
        }

        const finalWhere = and(advancedWhere, globalWhere)

        const orderBy = input.sort.length > 0
          ? input.sort.map((item) =>
              item.desc ? desc(procurementItems[item.id]) : asc(procurementItems[item.id])
            )
          : [asc(procurementItems.createdAt)]

        const { data, total } = await db.transaction(async (tx) => {
          const data = await selectProcurementItems(tx, {
            where: finalWhere,
            orderBy,
            offset,
            limit: safePerPage,
          })

          const total = await countProcurementItems(tx, finalWhere)
          return { data, total }
        })

        const pageCount = Math.ceil(total / safePerPage)
        return { data, pageCount }
      } catch (err) {
        console.error(err)
        return { data: [], pageCount: 0 }
      }
    },
    [JSON.stringify({...input, perPage: safePerPage})],
    {
      revalidate: 3600,
      tags: ["procurement-items"],
    }
  )()
}

/* -----------------------------------------------------
   2) 생성(Create)
----------------------------------------------------- */

export interface ProcurementItemCreateData {
  itemCode: string
  itemName: string
  material?: string | null
  specification?: string | null
  unit?: string | null
  isActive?: string | null
  createdBy?: string | null
}

/**
 * 품목 생성
 */
export async function createProcurementItem(input: ProcurementItemCreateData) {
  unstable_noStore()

  try {
    if (!input.itemCode || !input.itemName) {
      return {
        success: false,
        message: "품목코드와 품목명은 필수입니다",
        data: null,
        error: "필수 필드 누락"
      }
    }

    let result: any[] = []

    result = await db.transaction(async (tx) => {
      // 기존 품목 확인 (itemCode는 unique)
      const existingItem = await tx.query.procurementItems.findFirst({
        where: eq(procurementItems.itemCode, input.itemCode),
      })

      let txResult
      if (existingItem) {
        // 기존 품목 업데이트
        txResult = await updateProcurementItem(tx, existingItem.id, {
          itemName: input.itemName,
          material: input.material,
          specification: input.specification,
          unit: input.unit,
          isActive: input.isActive,
          createdBy: input.createdBy,
        })
      } else {
        // 새 품목 생성
        txResult = await insertProcurementItem(tx, {
          itemCode: input.itemCode,
          itemName: input.itemName,
          material: input.material,
          specification: input.specification,
          unit: input.unit,
          isActive: input.isActive || 'Y',
          createdBy: input.createdBy,
        })
      }

      return txResult
    })

    // 캐시 무효화
    revalidateTag("procurement-items")

    return {
      success: true,
      data: result[0] || null,
      error: null
    }
  } catch (err) {
    console.error("품목 생성/업데이트 오류:", err)

    // 중복 키 오류 처리
    if (err instanceof Error && err.message.includes("unique constraint")) {
      return {
        success: false,
        message: "이미 존재하는 품목코드입니다",
        data: null,
        error: "중복 키 오류"
      }
    }

    return {
      success: false,
      message: getErrorMessage(err),
      data: null,
      error: getErrorMessage(err)
    }
  }
}

/* -----------------------------------------------------
   3) 업데이트
----------------------------------------------------- */

/** 단건 업데이트 */
export async function modifyProcurementItem(input: UpdateProcurementItemSchema & { id: number }) {
  unstable_noStore()
  try {
    await db.transaction(async (tx) => {
      await updateProcurementItem(tx, input.id, {
        itemCode: input.itemCode,
        itemName: input.itemName,
        material: input.material,
        specification: input.specification,
        unit: input.unit,
        isActive: input.isActive,
      })
    })

    revalidateTag("procurement-items")
    return { data: null, error: null }
  } catch (err) {
    return { data: null, error: getErrorMessage(err) }
  }
}

/** 단건 삭제 */
export async function removeProcurementItem(input: { id: number }) {
  unstable_noStore()
  try {
    await db.transaction(async (tx) => {
      await deleteProcurementItemById(tx, input.id)
    })

    revalidateTag("procurement-items")
    return { data: null, error: null }
  } catch (err) {
    return { data: null, error: getErrorMessage(err) }
  }
}

/** 복수 삭제 */
export async function removeProcurementItems(input: { ids: number[] }) {
  unstable_noStore()
  try {
    await db.transaction(async (tx) => {
      await deleteProcurementItemsByIds(tx, input.ids)
    })

    revalidateTag("procurement-items")
    return { data: null, error: null }
  } catch (err) {
    return { data: null, error: getErrorMessage(err) }
  }
}

export async function getAllProcurementItems(): Promise<ProcurementItem[]> {
  try {
    return await findAllProcurementItems()
  } catch (err) {
    throw new Error("Failed to get procurement items")
  }
}

// 품목 검색 함수
export async function searchProcurementItems(query: string): Promise<{ itemCode: string; itemName: string }[]> {
  unstable_noStore()

  try {
    // 검색어가 없으면 상위 50개 반환
    if (!query || query.trim().length < 1) {
      const results = await db
        .select({
          itemCode: procurementItems.itemCode,
          itemName: procurementItems.itemName,
        })
        .from(procurementItems)
        .where(eq(procurementItems.isActive, 'Y'))
        .limit(50)
        .orderBy(asc(procurementItems.itemCode))
      
      return results
    }

    const searchQuery = `%${query.trim()}%`

    const results = await db
      .select({
        itemCode: procurementItems.itemCode,
        itemName: procurementItems.itemName,
      })
      .from(procurementItems)
      .where(
        and(
          or(
            ilike(procurementItems.itemCode, searchQuery),
            ilike(procurementItems.itemName, searchQuery)
          ),
          // 활성화된 품목만
          eq(procurementItems.isActive, 'Y')
        )
      )
      .limit(50)
      .orderBy(asc(procurementItems.itemCode))

    return results
  } catch (err) {
    console.error("품목 검색 오류:", err)
    return []
  }
}

/* -----------------------------------------------------
   4) Excel Import
----------------------------------------------------- */

export interface ImportResult {
  success: boolean
  importedCount: number
  errorCount: number
  errors: string[]
  message: string
}

/**
 * Excel 파일에서 품목 데이터 대량 가져오기
 */
export async function importProcurementItemsFromExcel(excelData: any[]): Promise<ImportResult> {
  unstable_noStore()

  try {
    if (!Array.isArray(excelData)) {
      return {
        success: false,
        importedCount: 0,
        errorCount: 0,
        errors: ["데이터 배열이 필요합니다."],
        message: "데이터 배열이 필요합니다."
      }
    }

    let importedCount = 0
    let errorCount = 0
    const errors: string[] = []

    // 배치 처리 (한 번에 너무 많은 데이터를 처리하지 않도록)
    const batchSize = 50
    for (let i = 0; i < excelData.length; i += batchSize) {
      const batch = excelData.slice(i, i + batchSize)

      for (const itemData of batch) {
        try {
          // 데이터 검증
          const cleanedData = {
            itemCode: itemData.itemCode?.toString().trim() || "",
            itemName: itemData.itemName?.toString().trim() || "",
            material: itemData.material?.toString().trim() || "",
            specification: itemData.specification?.toString().trim() || "",
            unit: itemData.unit?.toString().trim() || "",
            isActive: itemData.isActive?.toString().trim() || 'Y',
          }
          const validatedData = createProcurementItemSchema.parse(cleanedData)

          // 품목 생성 또는 업데이트
          const result = await createProcurementItem({
            itemCode: validatedData.itemCode,
            itemName: validatedData.itemName,
            material: validatedData.material || "",
            specification: validatedData.specification || "",
            unit: validatedData.unit || "",
            isActive: validatedData.isActive || 'Y',
          })

          if (result.success) {
            importedCount++
          } else {
            errorCount++
            errors.push(`${validatedData.itemCode}: ${result.error}`)
          }
        } catch (validationError) {
          errorCount++
          errors.push(`${itemData.itemCode || '알 수 없음'}: 검증 오류`)
        }
      }
    }

    return {
      success: true,
      importedCount,
      errorCount,
      errors: errors.slice(0, 10), // 너무 많은 오류 메시지를 보내지 않도록 제한
      message: `${importedCount}개 품목이 성공적으로 가져오기를 완료했습니다.${errorCount > 0 ? ` ${errorCount}개 오류 발생.` : ''}`
    }

  } catch (error) {
    console.error("품목 가져오기 오류:", error)
    return {
      success: false,
      importedCount: 0,
      errorCount: 0,
      errors: ["서버 내부 오류가 발생했습니다."],
      message: "서버 내부 오류가 발생했습니다."
    }
  }
}