package handler

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

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

// ===== 用户管理（RequireAdmin 兜底，前端不做权限判定） =====

// AdminListUsers 用户分页列表（搜索/角色/状态筛选 + 全站汇总）
func (h *Handlers) AdminListUsers(c *gin.Context) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))

	res, err := h.AdminUser.List(service.AdminUserListQuery{
		Page:    page,
		Size:    size,
		Keyword: strings.TrimSpace(c.Query("q")),
		Role:    c.Query("role"),
		Status:  c.Query("status"),
	})
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取用户列表失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"users":   res.Users,
		"total":   res.Total,
		"page":    res.Page,
		"size":    res.Size,
		"summary": res.Summary,
	})
}

// adminUserActionBody 角色/封禁变更的通用请求体
type adminUserRoleBody struct {
	Role string `json:"role"`
}

type adminUserBanBody struct {
	Banned bool `json:"banned"`
}

// AdminUpdateUserRole 设置用户角色（user / admin）
func (h *Handlers) AdminUpdateUserRole(c *gin.Context) {
	id, ok := parseAdminUserID(c)
	if !ok {
		return
	}
	var body adminUserRoleBody
	if err := c.ShouldBindJSON(&body); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	user, err := h.AdminUser.SetRole(middleware.CurrentUser(c).ID, id, body.Role)
	if err != nil {
		respondAdminUserError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"user": user})
}

// AdminSetUserBan 封禁 / 解封用户
func (h *Handlers) AdminSetUserBan(c *gin.Context) {
	id, ok := parseAdminUserID(c)
	if !ok {
		return
	}
	var body adminUserBanBody
	if err := c.ShouldBindJSON(&body); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	user, err := h.AdminUser.SetBanned(middleware.CurrentUser(c).ID, id, body.Banned)
	if err != nil {
		respondAdminUserError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"user": user})
}

// parseAdminUserID 解析路径中的用户 ID，失败时直接写出 400
func parseAdminUserID(c *gin.Context) (uint, bool) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil || id == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的用户 ID"})
		return 0, false
	}
	return uint(id), true
}

// respondAdminUserError 统一映射用户管理业务错误到 HTTP 状态码
func respondAdminUserError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, gorm.ErrRecordNotFound):
		c.JSON(http.StatusNotFound, gin.H{"error": "用户不存在"})
	case errors.Is(err, service.ErrAdminSelfAction),
		errors.Is(err, service.ErrLastAdmin),
		errors.Is(err, service.ErrInvalidUserRole):
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
	default:
		c.JSON(http.StatusInternalServerError, gin.H{"error": "操作失败"})
	}
}