package service

import (
	"fmt"
	"io"
	"mime/multipart"
	"os"
	"path/filepath"
	"strconv"
	"time"

	"github.com/rovina/zsp-backend/internal/model"
	"github.com/rovina/zsp-backend/internal/repository"
)

type ContractService interface {
	CreateContract(contract *model.Contract, files []model.ContractFile) error
	SaveFiles(files []model.ContractFile) error
	BatchSaveFiles(
		basePath string,
		files []*multipart.FileHeader,
	) (int, error)
	List(contractType string) ([]model.Contract, error)
	GetByID(id uint) (*model.Contract, error)
	Update(contract *model.Contract) error
	UpdateWithFiles(id uint, keepFileIDs []uint, newFileModels []model.ContractFile, form map[string]string) error
	Delete(id uint) error
}

type contractService struct {
	repo repository.ContractRepository
}

func NewContractService(repo repository.ContractRepository) (ContractService, error) {
	return &contractService{repo: repo}, nil
}

func (s *contractService) CreateContract(contract *model.Contract, files []model.ContractFile) error {
	return s.repo.CreateWithFiles(contract, files)
}

func (s *contractService) SaveFiles(files []model.ContractFile) error {
	return s.repo.CreateFiles(files)
}

func (s *contractService) BatchSaveFiles(
	basePath string,
	files []*multipart.FileHeader,
) (int, error) {

	// 相对路径根目录
	root := filepath.Join("./data/contract/batch", basePath)

	if err := os.MkdirAll(root, os.ModePerm); err != nil {
		return 0, err
	}

	count := 0

	for _, file := range files {
		filename := fmt.Sprintf("%d_%s", time.Now().UnixNano(), file.Filename)
		savePath := filepath.Join(root, filename)

		if err := saveUploadedFile(file, savePath); err != nil {
			return count, err
		}

		count++
	}

	return count, nil
}

func (s *contractService) List(contractType string) ([]model.Contract, error) {
	return s.repo.List(contractType)
}

func (s *contractService) GetByID(id uint) (*model.Contract, error) {
	return s.repo.GetByID(id)
}

func (s *contractService) Update(contract *model.Contract) error {
	return s.repo.Update(contract)
}

func (s *contractService) UpdateWithFiles(id uint, keepFileIDs []uint, newFileModels []model.ContractFile, form map[string]string) error {
	contract, err := s.repo.GetByID(id)
	if err != nil {
		return err
	}
	// 更新合同元信息
	get := func(k string) string { return form[k] }
	if v := get("name"); v != "" {
		contract.Name = v
	}
	if v := get("contractType"); v != "" {
		contract.ContractType = v
	}
	if v := get("contractCode"); v != "" {
		contract.ContractCode = v
	}
	if v := get("buyParty"); v != "" {
		contract.BuyParty = v
	}
	if v := get("sellParty"); v != "" {
		contract.SellParty = v
	}
	if v := get("commodity"); v != "" {
		contract.Commodity = v
	}
	if v := get("count"); v != "" {
		if n, e := strconv.ParseFloat(v, 64); e == nil {
			contract.Count = n
		}
	}
	if v := get("unitPrice"); v != "" {
		if n, e := strconv.ParseFloat(v, 64); e == nil {
			contract.UnitPrice = n
		}
	}
	if v := get("blNumber"); v != "" {
		contract.BLNumber = v
	}
	contract.DeliveryTime = get("deliveryTime")
	contract.PickUpTime = get("pickUpTime")
	contract.Packaging = get("packaging")
	contract.Remarks = get("remarks")
	contract.UpdateTime = time.Now()

	return s.repo.UpdateWithFiles(contract, keepFileIDs, newFileModels)
}

func (s *contractService) Delete(id uint) error {
	return s.repo.Delete(id)
}

func saveUploadedFile(file *multipart.FileHeader, dst string) error {
	src, err := file.Open()
	if err != nil {
		return err
	}
	defer src.Close()

	out, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer out.Close()

	_, err = io.Copy(out, src)
	return err
}