package middleware

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

	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
)

var jwtSecret []byte

func InitJWT(secret string) {
	jwtSecret = []byte(secret)
}

type Claims struct {
	UserID   uint   `json:"user_id"`
	TenantID uint   `json:"tenant_id"`
	Role     string `json:"role"`
	jwt.RegisteredClaims
}

func GenerateToken(userID, tenantID uint, role string) (string, error) {
	claims := Claims{
		UserID:   userID,
		TenantID: tenantID,
		Role:     role,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString(jwtSecret)
}

func AuthRequired() gin.HandlerFunc {
	return func(c *gin.Context) {
		auth := c.GetHeader("Authorization")
		if auth == "" || !strings.HasPrefix(auth, "Bearer ") {
			c.JSON(http.StatusUnauthorized, gin.H{"code": 401, "message": "未授权"})
			c.Abort()
			return
		}

		tokenStr := strings.TrimPrefix(auth, "Bearer ")
		token, err := jwt.ParseWithClaims(tokenStr, &Claims{}, func(t *jwt.Token) (interface{}, error) {
			return jwtSecret, nil
		})
		if err != nil || !token.Valid {
			c.JSON(http.StatusUnauthorized, gin.H{"code": 401, "message": "token无效"})
			c.Abort()
			return
		}

		claims := token.Claims.(*Claims)
		c.Set("user_id", claims.UserID)
		c.Set("tenant_id", claims.TenantID)
		c.Set("role", claims.Role)
		c.Next()
	}
}

func AdminRequired() gin.HandlerFunc {
	return func(c *gin.Context) {
		role, _ := c.Get("role")
		if role != "admin" && role != "platform_admin" {
			c.JSON(http.StatusForbidden, gin.H{"code": 403, "message": "无权限"})
			c.Abort()
			return
		}
		c.Next()
	}
}

func PlatformRequired() gin.HandlerFunc {
	return func(c *gin.Context) {
		role, _ := c.Get("role")
		if role != "platform_admin" {
			c.JSON(http.StatusForbidden, gin.H{"code": 403, "message": "仅平台管理员可操作"})
			c.Abort()
			return
		}
		c.Next()
	}
}

func GetTenantID(c *gin.Context) uint {
	id, _ := c.Get("tenant_id")
	return id.(uint)
}

func GetUserID(c *gin.Context) uint {
	id, _ := c.Get("user_id")
	return id.(uint)
}

func GetPageParams(c *gin.Context) (page, pageSize int) {
	page, _ = strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ = strconv.Atoi(c.DefaultQuery("pageSize", "10"))
	if page < 1 {
		page = 1
	}
	if pageSize < 1 || pageSize > 100 {
		pageSize = 10
	}
	return
}

func JSON(c *gin.Context, data interface{}) {
	c.JSON(http.StatusOK, gin.H{"code": 0, "message": "ok", "data": data})
}

func JSONList(c *gin.Context, list interface{}, total int64, page, pageSize int) {
	c.JSON(http.StatusOK, gin.H{
		"code":     0,
		"message":  "ok",
		"list":     list,
		"total":    total,
		"page":     page,
		"pageSize": pageSize,
	})
}