package listing

import (
	"errors"
	"net/http"
	"strconv"

	"hfb_sys/backend/internal/middleware"
	"hfb_sys/backend/pkg/response"

	"github.com/gin-gonic/gin"
)

type Handler struct {
	service *Service
}

func NewHandler(service *Service) *Handler {
	return &Handler{service: service}
}

func (h *Handler) Create(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	var req CreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "发布信息不完整")
		return
	}
	item, err := h.service.Create(ownerID, req)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.Created(c, item)
}

func (h *Handler) Update(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req UpdateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "发布信息不完整")
		return
	}
	item, err := h.service.Update(ownerID, id, req)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) SubmitReview(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	id, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.SubmitReview(ownerID, id)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) Offline(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	id, ok := parseID(c)
	if !ok {
		return
	}
	if err := h.service.Offline(ownerID, id); err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, gin.H{"offline": true})
}

func (h *Handler) ListPublic(c *gin.Context) {
	items, err := h.service.ListPublic()
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, gin.H{"items": items})
}

func (h *Handler) FindPublic(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.FindPublic(id)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) ListMine(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	items, err := h.service.ListMine(ownerID)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, gin.H{"items": items})
}

func (h *Handler) FindMine(c *gin.Context) {
	ownerID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	id, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.FindMine(ownerID, id)
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, item)
}

func currentUserID(c *gin.Context) (uint64, bool) {
	value, ok := c.Get(middleware.ContextUserID)
	if !ok {
		return 0, false
	}
	userID, ok := value.(uint64)
	return userID, ok
}

func parseID(c *gin.Context) (uint64, bool) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil || id == 0 {
		response.BadRequest(c, "ID 不正确")
		return 0, false
	}
	return id, true
}

func writeListingError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, ErrDependencyUnavailable):
		response.ServiceUnavailable(c, "数据库未连接")
	case errors.Is(err, ErrInvalidInput):
		response.BadRequest(c, "发布信息不符合规则")
	case errors.Is(err, ErrListingLocked):
		response.Error(c, http.StatusConflict, "listing_locked", "当前发布不可修改")
	case IsNotFound(err):
		response.Error(c, http.StatusNotFound, "not_found", "发布不存在")
	default:
		response.Error(c, http.StatusInternalServerError, "internal_error", "发布服务暂时不可用")
	}
}