package service

import (
	"errors"
	"strings"

	"wx_service/internal/marketing/model"
	"wx_service/internal/marketing/repository"
)

var (
	ErrTemplateTitleRequired    = errors.New("模板名称不能为空")
	ErrTemplateTitleTooLong     = errors.New("模板名称不能超过100个字符")
	ErrTemplateImageRequired    = errors.New("模板图片不能为空")
	ErrTemplateCategoryRequired = errors.New("请选择所属分类")
)

type TemplateService struct {
	repo *repository.TemplateRepository
}

func NewTemplateService(repo *repository.TemplateRepository) *TemplateService {
	return &TemplateService{repo: repo}
}

type TemplateRequest struct {
	CategoryID   uint   `json:"category_id"`
	Title        string `json:"title"`
	ImageURL     string `json:"image_url"`
	ThumbnailURL string `json:"thumbnail_url"`
	Width        int    `json:"width"`
	Height       int    `json:"height"`
	SortOrder    int    `json:"sort_order"`
	Status       *int   `json:"status"`
}

type TemplateListResponse struct {
	Templates []model.MarketingTemplate `json:"templates"`
	Total     int64                     `json:"total"`
	Page      int                       `json:"page"`
	PageSize  int                       `json:"page_size"`
}

func (s *TemplateService) Create(req TemplateRequest) (*model.MarketingTemplate, error) {
	if err := validateTemplateRequest(req); err != nil {
		return nil, err
	}

	status := 1
	if req.Status != nil {
		status = *req.Status
	}

	tpl := &model.MarketingTemplate{
		CategoryID:   req.CategoryID,
		Title:        strings.TrimSpace(req.Title),
		ImageURL:     strings.TrimSpace(req.ImageURL),
		ThumbnailURL: strings.TrimSpace(req.ThumbnailURL),
		Width:        req.Width,
		Height:       req.Height,
		SortOrder:    req.SortOrder,
		Status:       status,
	}

	if err := s.repo.Create(tpl); err != nil {
		return nil, err
	}
	return tpl, nil
}

func (s *TemplateService) Update(id uint, req TemplateRequest) (*model.MarketingTemplate, error) {
	if err := validateTemplateRequest(req); err != nil {
		return nil, err
	}

	tpl, err := s.repo.FindByID(id)
	if err != nil {
		return nil, err
	}

	tpl.CategoryID = req.CategoryID
	tpl.Title = strings.TrimSpace(req.Title)
	tpl.ImageURL = strings.TrimSpace(req.ImageURL)
	tpl.ThumbnailURL = strings.TrimSpace(req.ThumbnailURL)
	tpl.Width = req.Width
	tpl.Height = req.Height
	tpl.SortOrder = req.SortOrder
	if req.Status != nil {
		tpl.Status = *req.Status
	}

	if err := s.repo.Update(tpl); err != nil {
		return nil, err
	}
	return tpl, nil
}

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

func (s *TemplateService) GetByID(id uint) (*model.MarketingTemplate, error) {
	return s.repo.FindByID(id)
}

func (s *TemplateService) List(params repository.TemplateListParams) (*TemplateListResponse, error) {
	templates, total, err := s.repo.FindList(params)
	if err != nil {
		return nil, err
	}
	return &TemplateListResponse{
		Templates: templates,
		Total:     total,
		Page:      params.Page,
		PageSize:  params.PageSize,
	}, nil
}

func validateTemplateRequest(req TemplateRequest) error {
	title := strings.TrimSpace(req.Title)
	if title == "" {
		return ErrTemplateTitleRequired
	}
	if len(title) > 100 {
		return ErrTemplateTitleTooLong
	}
	if strings.TrimSpace(req.ImageURL) == "" {
		return ErrTemplateImageRequired
	}
	if req.CategoryID == 0 {
		return ErrTemplateCategoryRequired
	}
	return nil
}