package middleware

import (
    "encoding/json"
    "fmt"
    "net/http"
    "strconv"
    "strings"

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

// AuthMiddleware creates a middleware for JWT authentication
func AuthMiddleware(jwtSecret string) gin.HandlerFunc {
    return func(c *gin.Context) {
        authHeader := c.GetHeader("Authorization")
        if authHeader == "" {
            c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization header is required"})
            c.Abort()
            return
        }

        parts := strings.Split(authHeader, " ")
        if len(parts) != 2 || parts[0] != "Bearer" {
            c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization header format must be Bearer {token}"})
            c.Abort()
            return
        }

        token, err := jwt.Parse(parts[1], func(token *jwt.Token) (interface{}, error) {
            if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
                return nil, jwt.ErrSignatureInvalid
            }
            return []byte(jwtSecret), nil
        })

        if err != nil {
            log.Error().Err(err).Msg("Failed to parse token")
            c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token"})
            c.Abort()
            return
        }

        if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
            // 添加调试信息
            log.Debug().Interface("claims", claims).Msg("Token claims")
            
            // 获取用户ID
            sub, exists := claims["sub"]
            if !exists {
                log.Error().Msg("Token does not contain sub claim")
                c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token format"})
                c.Abort()
                return
            }

            // 打印类型信息
            log.Debug().
                Str("type", fmt.Sprintf("%T", sub)).
                Interface("value", sub).
                Msg("User ID from token")

            var userID int
            switch v := sub.(type) {
            case string:
                var err error
                userID, err = strconv.Atoi(v)
                if err != nil {
                    log.Error().Err(err).Str("sub", v).Msg("Failed to convert string user ID to int")
                    c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid user ID format"})
                    c.Abort()
                    return
                }
            case float64:
                userID = int(v)
            case json.Number:
                var err error
                userID, err = strconv.Atoi(v.String())
                if err != nil {
                    log.Error().Err(err).Str("sub", v.String()).Msg("Failed to convert json.Number user ID to int")
                    c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid user ID format"})
                    c.Abort()
                    return
                }
            default:
                log.Error().
                    Str("type", fmt.Sprintf("%T", sub)).
                    Interface("value", sub).
                    Msg("Unexpected user ID type")
                c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid user ID type"})
                c.Abort()
                return
            }

            // 将 userID 转换为 int64 以确保类型一致性
            c.Set("user_id", int64(userID))
            if roles, ok := claims["roles"].([]interface{}); ok {
                c.Set("user_roles", roles)
            }
            c.Next()
        } else {
            c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token"})
            c.Abort()
            return
        }
    }
}

// RoleMiddleware creates a middleware for role-based authorization
func RoleMiddleware(roles ...string) gin.HandlerFunc {
    return func(c *gin.Context) {
        userRole, exists := c.Get("user_role")
        if !exists {
            c.JSON(http.StatusUnauthorized, gin.H{"error": "User role not found"})
            c.Abort()
            return
        }

        roleStr, ok := userRole.(string)
        if !ok {
            c.JSON(http.StatusInternalServerError, gin.H{"error": "Invalid user role type"})
            c.Abort()
            return
        }

        for _, role := range roles {
            if role == roleStr {
                c.Next()
                return
            }
        }

        c.JSON(http.StatusForbidden, gin.H{"error": "Insufficient permissions"})
        c.Abort()
    }
}