package handler

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

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

type TemplateHandler struct {
	svc *service.TemplateService
}

func NewTemplateHandler(svc *service.TemplateService) *TemplateHandler {
	return &TemplateHandler{svc: svc}
}

// ListEnabled returns enabled templates for mini-program users.
func (h *TemplateHandler) ListEnabled(c *gin.Context) {
	categoryID := parseUintQuery(c, "category_id", 0)
	page := parseIntQuery(c, "page", 1)
	pageSize := parseIntQuery(c, "page_size", 20)

	resp, err := h.svc.List(repository.TemplateListParams{
		CategoryID:  categoryID,
		OnlyEnabled: true,
		Page:        page,
		PageSize:    pageSize,
	})
	if err != nil {
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}
	c.JSON(http.StatusOK, model.Success(resp))
}

// GetDetail returns a single template by ID.
func (h *TemplateHandler) GetDetail(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}

	tpl, err := h.svc.GetByID(id)
	if err != nil {
		if service.IsNotFoundError(err) {
			c.JSON(http.StatusNotFound, model.Error(http.StatusNotFound, "模板不存在"))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}
	c.JSON(http.StatusOK, model.Success(tpl))
}

// AdminList returns all templates for admin.
func (h *TemplateHandler) AdminList(c *gin.Context) {
	categoryID := parseUintQuery(c, "category_id", 0)
	page := parseIntQuery(c, "page", 1)
	pageSize := parseIntQuery(c, "page_size", 20)

	resp, err := h.svc.List(repository.TemplateListParams{
		CategoryID:  categoryID,
		OnlyEnabled: false,
		Page:        page,
		PageSize:    pageSize,
	})
	if err != nil {
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}
	c.JSON(http.StatusOK, model.Success(resp))
}

func (h *TemplateHandler) AdminCreate(c *gin.Context) {
	var req service.TemplateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "请求参数错误"))
		return
	}

	tpl, err := h.svc.Create(req)
	if err != nil {
		if service.IsBadRequestError(err) {
			c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, err.Error()))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}

	c.JSON(http.StatusOK, model.Success(tpl))
}

func (h *TemplateHandler) AdminUpdate(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}

	var req service.TemplateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "请求参数错误"))
		return
	}

	tpl, err := h.svc.Update(id, req)
	if err != nil {
		if service.IsNotFoundError(err) {
			c.JSON(http.StatusNotFound, model.Error(http.StatusNotFound, "模板不存在"))
			return
		}
		if service.IsBadRequestError(err) {
			c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, err.Error()))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}

	c.JSON(http.StatusOK, model.Success(tpl))
}

func (h *TemplateHandler) AdminDelete(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}

	if err := h.svc.Delete(id); err != nil {
		if service.IsNotFoundError(err) {
			c.JSON(http.StatusNotFound, model.Error(http.StatusNotFound, "模板不存在"))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "服务器错误"))
		return
	}

	c.JSON(http.StatusOK, model.Success(nil))
}

func parseIntQuery(c *gin.Context, key string, defaultValue int) int {
	v := c.Query(key)
	if v == "" {
		return defaultValue
	}
	parsed, err := strconv.Atoi(v)
	if err != nil {
		return defaultValue
	}
	return parsed
}

func parseUintQuery(c *gin.Context, key string, defaultValue uint) uint {
	v := c.Query(key)
	if v == "" {
		return defaultValue
	}
	parsed, err := strconv.ParseUint(v, 10, 64)
	if err != nil {
		return defaultValue
	}
	return uint(parsed)
}