// Filename: internal/middleware/auth.go
package middleware

import (
	"gemini-balancer/internal/service"
	"net/http"
	"strings"

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

// === API Admin 认证管道 (/admin/* API路由) ===

func APIAdminAuthMiddleware(securityService *service.SecurityService) gin.HandlerFunc {
	return func(c *gin.Context) {
		tokenValue := extractBearerToken(c)
		if tokenValue == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "Authorization token is missing"})
			return
		}
		authToken, err := securityService.AuthenticateToken(tokenValue)
		if err != nil || !authToken.IsAdmin {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "Invalid or non-admin token"})
			return
		}
		c.Set("adminUser", authToken)
		c.Next()
	}
}

// === /v1 Proxy 认证 ===

func ProxyAuthMiddleware(securityService *service.SecurityService) gin.HandlerFunc {
	return func(c *gin.Context) {
		tokenValue := extractProxyToken(c)
		if tokenValue == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "API key is missing from request"})
			return
		}
		authToken, err := securityService.AuthenticateToken(tokenValue)
		if err != nil {
			// 通用信息，避免泄露过多信息
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "Invalid or inactive token provided"})
			return
		}
		c.Set("authToken", authToken)
		c.Next()
	}
}

func extractProxyToken(c *gin.Context) string {
	if key := c.Query("key"); key != "" {
		return key
	}
	authHeader := c.GetHeader("Authorization")
	if authHeader != "" {
		if strings.HasPrefix(authHeader, "Bearer ") {
			return strings.TrimPrefix(authHeader, "Bearer ")
		}
	}
	if key := c.GetHeader("X-Api-Key"); key != "" {
		return key
	}
	if key := c.GetHeader("X-Goog-Api-Key"); key != "" {
		return key
	}
	return ""
}

// === 辅助函数 ===

func extractBearerToken(c *gin.Context) string {
	authHeader := c.GetHeader("Authorization")
	if authHeader == "" {
		return ""
	}
	parts := strings.Split(authHeader, " ")
	if len(parts) == 2 && parts[0] == "Bearer" {
		return parts[1]
	}
	return ""
}