package middleware

import (
	"strconv"
	"strings"

	"gofaster/internal/shared/jwt"
	"gofaster/internal/shared/response"

	"github.com/gin-gonic/gin"
)

// JWTConfig JWT中间件配置
type JWTConfig struct {
	SecretKey string
	Issuer    string
}

// JWTAuth JWT认证中间件
func JWTAuth(config JWTConfig) gin.HandlerFunc {
	return func(c *gin.Context) {
		// 获取Authorization头部
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			response.Unauthorized(c, "未提供认证令牌", "Authorization头部缺失")
			c.Abort()
			return
		}

		// 检查Bearer前缀
		if !strings.HasPrefix(authHeader, "Bearer ") {
			response.Unauthorized(c, "认证令牌格式错误", "令牌必须以Bearer开头")
			c.Abort()
			return
		}

		// 提取令牌
		tokenString := strings.TrimPrefix(authHeader, "Bearer ")

		// 创建JWT管理器
		jwtManager := jwt.NewJWTManager(config.SecretKey, config.Issuer)

		// 验证令牌
		claims, err := jwtManager.ValidateToken(tokenString)
		if err != nil {
			response.Unauthorized(c, "认证令牌无效", err.Error())
			c.Abort()
			return
		}

		// 将用户信息存储到上下文中
		if userID, exists := claims["user_id"]; exists {
			c.Set("user_id", userID)
		}
		if username, exists := claims["username"]; exists {
			c.Set("username", username)
		}
		if email, exists := claims["email"]; exists {
			c.Set("email", email)
		}

		// 继续处理请求
		c.Next()
	}
}

// OptionalJWTAuth 可选的JWT认证中间件（不强制要求认证）
func OptionalJWTAuth(config JWTConfig) gin.HandlerFunc {
	return func(c *gin.Context) {
		// 获取Authorization头部
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			// 没有令牌，继续处理请求
			c.Next()
			return
		}

		// 检查Bearer前缀
		if !strings.HasPrefix(authHeader, "Bearer ") {
			// 令牌格式错误，继续处理请求（不强制要求）
			c.Next()
			return
		}

		// 提取令牌
		tokenString := strings.TrimPrefix(authHeader, "Bearer ")

		// 创建JWT管理器
		jwtManager := jwt.NewJWTManager(config.SecretKey, config.Issuer)

		// 验证令牌
		claims, err := jwtManager.ValidateToken(tokenString)
		if err != nil {
			// 令牌无效，继续处理请求（不强制要求）
			c.Next()
			return
		}

		// 将用户信息存储到上下文中
		if userID, exists := claims["user_id"]; exists {
			c.Set("user_id", userID)
		}
		if username, exists := claims["username"]; exists {
			c.Set("username", username)
		}
		if email, exists := claims["email"]; exists {
			c.Set("email", email)
		}

		// 继续处理请求
		c.Next()
	}
}

// GetUserID 从上下文中获取用户ID
func GetUserID(c *gin.Context) (uint, bool) {
	userID, exists := c.Get("user_id")
	if !exists {
		return 0, false
	}

	switch v := userID.(type) {
	case float64:
		return uint(v), true
	case int:
		return uint(v), true
	case string:
		if parsed, err := strconv.ParseUint(v, 10, 32); err == nil {
			return uint(parsed), true
		}
	}
	return 0, false
}

// GetUsername 从上下文中获取用户名
func GetUsername(c *gin.Context) (string, bool) {
	username, exists := c.Get("username")
	if !exists {
		return "", false
	}
	if str, ok := username.(string); ok {
		return str, true
	}
	return "", false
}

// GetEmail 从上下文中获取邮箱
func GetEmail(c *gin.Context) (string, bool) {
	email, exists := c.Get("email")
	if !exists {
		return "", false
	}
	if str, ok := email.(string); ok {
		return str, true
	}
	return "", false
}