package listing

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

	"hfb_sys/backend/internal/middleware"
	filemodule "hfb_sys/backend/internal/modules/file"
	"hfb_sys/backend/pkg/response"

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

type Handler struct {
	service *Service
	storage *filemodule.Storage
}

func NewHandler(service *Service, storage *filemodule.Storage) *Handler {
	return &Handler{service: service, storage: storage}
}

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

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

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

func (h *Handler) AdminOffline(c *gin.Context) {
	h.adminAction(c, h.service.AdminOffline)
}

func (h *Handler) AdminMarkAbnormal(c *gin.Context) {
	h.adminAction(c, h.service.AdminMarkAbnormal)
}

func (h *Handler) adminAction(c *gin.Context, fn func(uint64, uint64, AdminActionRequest, AuditMeta) (*ListingDTO, error)) {
	adminID, ok := currentAdminID(c)
	if !ok {
		response.Unauthorized(c, "缺少管理员上下文")
		return
	}
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req AdminActionRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "操作原因不能为空")
		return
	}
	item, err := fn(adminID, id, req, AuditMeta{IP: c.ClientIP(), UserAgent: c.GetHeader("User-Agent")})
	if err != nil {
		writeListingError(c, err)
		return
	}
	response.OK(c, item)
}

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

func (h *Handler) Reject(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req ReviewRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "审核拒绝原因不能为空")
		return
	}
	item, err := h.service.Reject(id, req)
	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) Cover(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	key, err := h.service.FindPublicCoverKey(id)
	if err != nil {
		writeListingError(c, err)
		return
	}
	h.writePublicObject(c, key)
}

func (h *Handler) Screenshot(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	index, err := strconv.Atoi(c.Param("index"))
	if err != nil || index < 0 {
		response.BadRequest(c, "截图序号不正确")
		return
	}
	key, err := h.service.FindPublicScreenshotKey(id, index)
	if err != nil {
		writeListingError(c, err)
		return
	}
	h.writePublicObject(c, key)
}

func (h *Handler) writePublicObject(c *gin.Context, key string) {
	if h.storage == nil {
		response.ServiceUnavailable(c, "文件存储未连接")
		return
	}
	object, err := h.storage.Get(c.Request.Context(), key)
	if err != nil {
		response.Error(c, http.StatusNotFound, "not_found", "图片不存在或暂不可访问")
		return
	}
	defer func() {
		_ = object.Reader.Close()
	}()
	contentType := object.ContentType
	if contentType == "" {
		contentType = "application/octet-stream"
	}
	c.Header("Content-Type", contentType)
	c.Header("Cache-Control", "public, max-age=300")
	c.DataFromReader(http.StatusOK, object.Size, contentType, object.Reader, nil)
}

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 currentAdminID(c *gin.Context) (uint64, bool) {
	value, ok := c.Get(middleware.ContextAdminID)
	if !ok {
		return 0, false
	}
	adminID, ok := value.(uint64)
	return adminID, 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 parseAdminListQuery(c *gin.Context) (AdminListQuery, bool) {
	var query AdminListQuery
	if raw := c.Query("owner_id"); raw != "" {
		value, err := strconv.ParseUint(raw, 10, 64)
		if err != nil || value == 0 {
			response.BadRequest(c, "号主 ID 不正确")
			return query, false
		}
		query.OwnerID = value
	}
	if raw := c.Query("limit"); raw != "" {
		value, err := strconv.Atoi(raw)
		if err != nil || value <= 0 {
			response.BadRequest(c, "查询条数不正确")
			return query, false
		}
		query.Limit = value
	}
	query.Status = c.Query("status")
	query.ReviewStatus = c.Query("review_status")
	return query, 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, ErrMissingTitle):
		response.BadRequest(c, "发布标题不能为空")
	case errors.Is(err, ErrMissingServerRegion):
		response.BadRequest(c, "请选择区服")
	case errors.Is(err, ErrInvalidPrice):
		response.BadRequest(c, "发布价格不正确")
	case errors.Is(err, ErrInvalidDeposit):
		response.BadRequest(c, "押金不能小于 0")
	case errors.Is(err, ErrDepositTooLow):
		response.BadRequest(c, "押金必须大于额外消耗品总价值")
	case errors.Is(err, ErrInvalidHafCoin):
		response.BadRequest(c, "哈夫币数量不正确")
	case errors.Is(err, ErrMissingScreenshot):
		response.BadRequest(c, "请至少上传一张账号截图")
	case isFireLevelTooLow(err):
		var levelErr FireLevelTooLowError
		errors.As(err, &levelErr)
		response.BadRequest(c, "烽火等级低于"+strconv.Itoa(levelErr.Min)+"级的号无法发布")
	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")
	}
}

func isFireLevelTooLow(err error) bool {
	var levelErr FireLevelTooLowError
	return errors.As(err, &levelErr)
}