package handler

import (
	"net/http"
	"strconv"

	"github.com/freefire/jiang13-bbs/service"
	"github.com/gin-gonic/gin"
)

// 榜单参数白名单
var (
	lbPeriods = map[string]bool{service.PeriodWeek: true, service.PeriodMonth: true, service.PeriodAll: true}
	lbMetrics = map[string]bool{service.MetricAll: true, service.MetricPost: true,
		service.MetricComment: true, service.MetricLike: true, service.MetricAnswer: true}
)

// lbParams 解析并校验 period/metric，非法值回退默认并标记 400
func lbParams(c *gin.Context) (period, metric string, bad bool) {
	period = c.DefaultQuery("period", service.PeriodAll)
	metric = c.DefaultQuery("metric", service.MetricAll)
	if !lbPeriods[period] || !lbMetrics[metric] {
		return "", "", true
	}
	return period, metric, false
}

// Leaderboard 用户贡献榜：period=week|month|all × metric=all|post|comment|like|answer（公开接口）
func (h *Handlers) Leaderboard(c *gin.Context) {
	period, metric, bad := lbParams(c)
	if bad {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的榜单参数"})
		return
	}
	limit := 50
	if v := c.Query("limit"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n > 0 {
			limit = n
		}
	}
	if limit > 100 {
		limit = 100
	}
	res, err := h.LeaderboardSvc.Board(period, metric, limit)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取排行榜失败"})
		return
	}
	c.JSON(http.StatusOK, res)
}

// LeaderboardMe 当前用户在指定榜单的排名（可选登录；游客返回 me:null）
func (h *Handlers) LeaderboardMe(c *gin.Context) {
	period, metric, bad := lbParams(c)
	if bad {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的榜单参数"})
		return
	}
	if v, ok := c.Get("user"); ok {
		if claims, ok := v.(*service.UserClaims); ok && claims.ID > 0 {
			res, err := h.LeaderboardSvc.MyRank(period, metric, claims.ID)
			if err != nil {
				c.JSON(http.StatusInternalServerError, gin.H{"error": "获取排名失败"})
				return
			}
			c.JSON(http.StatusOK, gin.H{"me": res})
			return
		}
	}
	c.JSON(http.StatusOK, gin.H{"me": nil})
}