package handlers

import (
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"go_blog/models"

	"gorm.io/gorm"
)

// adminCommentPageSize 限制后台每页显示的评论数量。
const adminCommentPageSize = 30

// commentListView 是 Comment 加上后台列表所需的派生展示字段。
type commentListView struct {
	models.Comment
	GravatarURL  string
	Initial      string
	AvatarColor  string
	MaskedEmail  string
	StatusLabel  string
	StatusBadge  string
	ArticleTitle string
	ArticleSlug  string
}

// CommentListPage 渲染后台评论审核列表，可通过
// ?status=pending|approved|rejected|all 按状态筛选。
func CommentListPage(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		tr := getTr(c)
		status := strings.TrimSpace(c.Query("status"))
		if status == "" {
			status = "pending"
		}

		q := db.Model(&models.Comment{}).Order("created_at DESC")
		switch status {
		case "approved":
			q = q.Where("status = ?", models.CommentApproved)
		case "rejected":
			q = q.Where("status = ?", models.CommentRejected)
		case "all":
			// 不过滤
		default: // pending
			status = "pending"
			q = q.Where("status = ?", models.CommentPending)
		}

		var comments []models.Comment
		q.Limit(adminCommentPageSize).Find(&comments)

		// 用一次查询拉取引用的文章，避免 N+1。
		ids := make(map[uint]struct{})
		for _, cm := range comments {
			ids[cm.ArticleID] = struct{}{}
		}
		articleMap := make(map[uint]models.Article)
		if len(ids) > 0 {
			idList := make([]uint, 0, len(ids))
			for id := range ids {
				idList = append(idList, id)
			}
			var articles []models.Article
			db.Unscoped().Where("id IN ?", idList).Find(&articles)
			for _, a := range articles {
				articleMap[a.ID] = a
			}
		}

		views := make([]commentListView, 0, len(comments))
		// SECURITY_TODO #15：后台列表遵循平台开关——关闭时不发起 Gravatar
		// 请求（改为使用前端占位头像）。
		useGravatar := models.GetCommentConfig().UseGravatar
		for _, cm := range comments {
			gravURL := ""
			if useGravatar {
				gravURL = cm.GravatarURL(40)
			}
			v := commentListView{
				Comment:     cm,
				GravatarURL: gravURL,
				MaskedEmail: cm.MaskedEmail(),
				Initial:     cm.AuthorInitial(),
				AvatarColor: avatarColorFor(cm.ID),
			}
			if a, ok := articleMap[cm.ArticleID]; ok {
				v.ArticleTitle = a.Title
				v.ArticleSlug = a.Slug
			}
			switch cm.Status {
			case models.CommentPending:
				v.StatusLabel = tr["comment_status_pending"]
				v.StatusBadge = "bg-yellow-100 text-yellow-700"
			case models.CommentApproved:
				v.StatusLabel = tr["comment_status_approved"]
				v.StatusBadge = "bg-green-100 text-green-700"
			case models.CommentRejected:
				v.StatusLabel = tr["comment_status_rejected"]
				v.StatusBadge = "bg-red-100 text-red-700"
			}
			views = append(views, v)
		}

		// 标签徽章使用的待审数量。
		var pendingCount int64
		db.Model(&models.Comment{}).Where("status = ?", models.CommentPending).Count(&pendingCount)

		data := DefaultData(c)
		data["Title"] = tr["admin_comments_title"]
		data["Comments"] = views
		data["Status"] = status
		data["PendingCount"] = pendingCount
		if msg := c.Query("saved"); msg == "1" {
			switch c.Query("msg") {
			case "approved":
				data["Success"] = tr["comment_approved"]
			case "rejected":
				data["Success"] = tr["comment_rejected"]
			case "deleted":
				data["Success"] = tr["comment_deleted"]
			default:
				data["Success"] = tr["settings_saved"]
			}
		}
		c.HTML(http.StatusOK, "comment_list", data)
	}
}

// CommentApprove 将评论标记为通过。
func CommentApprove(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		if id := parseUintParam(c, "id"); id == 0 {
			APIError(c, http.StatusBadRequest, "api_invalid_request")
			return
		} else {
			db.Model(&models.Comment{}).Where("id = ?", id).Update("status", models.CommentApproved)
		}
		APIOK(c, "/admin/comments?status=pending&saved=1&msg=approved", nil)
	}
}

// CommentReject 将评论标记为拒绝（前端隐藏，后台列表保留）。
func CommentReject(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		if id := parseUintParam(c, "id"); id == 0 {
			APIError(c, http.StatusBadRequest, "api_invalid_request")
			return
		} else {
			db.Model(&models.Comment{}).Where("id = ?", id).Update("status", models.CommentRejected)
		}
		APIOK(c, "/admin/comments?status=pending&saved=1&msg=rejected", nil)
	}
}

// CommentDelete 软删除一条评论。
func CommentDelete(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		if id := parseUintParam(c, "id"); id == 0 {
			APIError(c, http.StatusBadRequest, "api_invalid_request")
			return
		} else {
			db.Where("id = ?", id).Delete(&models.Comment{})
		}
		APIOK(c, "/admin/comments?status=all&saved=1&msg=deleted", nil)
	}
}