feat: 添加 Redis 客户端和 Token 黑名单模块

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/pkg/database/redis.go

@@ -0,0 +1,137 @@
+package database
+
+import (
+    "context"
+    "crypto/sha256"
+    "encoding/json"
+    "fmt"
+    "time"
+
+    "github.com/redis/go-redis/v9"
+)
+
+const (
+    BlacklistKeyPrefix = "blacklist:token:"
+)
+
+// RedisClient Redis 客户端单例
+var RedisClient *redis.Client
+
+// Config Redis 配置
+type RedisConfig struct {
+    Host     string
+    Port     int
+    Password string
+    DB       int
+}
+
+// InitRedis 初始化 Redis 连接
+func InitRedis(cfg RedisConfig) error {
+    RedisClient = redis.NewClient(&redis.Options{
+        Addr:     fmt.Sprintf("%s:%d", cfg.Host, cfg.Port),
+        Password: cfg.Password,
+        DB:       cfg.DB,
+    })
+
+    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+    defer cancel()
+
+    if err := RedisClient.Ping(ctx).Err(); err != nil {
+        return fmt.Errorf("failed to connect to redis: %w", err)
+    }
+
+    return nil
+}
+
+// CloseRedis 关闭 Redis 连接
+func CloseRedis() error {
+    if RedisClient != nil {
+        return RedisClient.Close()
+    }
+    return nil
+}
+
+// GetRedis 获取 Redis 客户端实例
+func GetRedis() *redis.Client {
+    return RedisClient
+}
+
+// RedisHealthCheck 健康检查
+func RedisHealthCheck() error {
+    if RedisClient == nil {
+        return fmt.Errorf("redis client is not initialized")
+    }
+    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+    defer cancel()
+    return RedisClient.Ping(ctx).Err()
+}
+
+// BlacklistEntry 黑名单条目
+type BlacklistEntry struct {
+    UserID int64  `json:"user_id"`
+    Reason string `json:"reason"`
+}
+
+// tokenToHash 将 Token 转换为 SHA256 哈希作为 Key
+func tokenToHash(token string) string {
+    hash := sha256.Sum256([]byte(token))
+    return fmt.Sprintf("%x", hash)
+}
+
+// AddToBlacklist 添加 Token 到黑名单
+func AddToBlacklist(ctx context.Context, token string, userID int64, banReason string, ttl time.Duration) error {
+    if token == "" {
+        return fmt.Errorf("token is empty")
+    }
+    if RedisClient == nil {
+        return fmt.Errorf("redis client is not initialized")
+    }
+
+    key := BlacklistKeyPrefix + tokenToHash(token)
+    entry := BlacklistEntry{UserID: userID, Reason: banReason}
+    value, err := json.Marshal(entry)
+    if err != nil {
+        return fmt.Errorf("failed to marshal blacklist entry: %w", err)
+    }
+
+    return RedisClient.Set(ctx, key, value, ttl).Err()
+}
+
+// IsBlacklisted 检查 Token 是否在黑名单
+func IsBlacklisted(ctx context.Context, token string) (bool, int64, string, error) {
+    if token == "" {
+        return false, 0, "", nil
+    }
+    if RedisClient == nil {
+        return false, 0, "", fmt.Errorf("redis client is not initialized")
+    }
+
+    key := BlacklistKeyPrefix + tokenToHash(token)
+    value, err := RedisClient.Get(ctx, key).Result()
+    if err == redis.Nil {
+        return false, 0, "", nil
+    }
+    if err != nil {
+        return false, 0, "", err
+    }
+
+    var entry BlacklistEntry
+    if err := json.Unmarshal([]byte(value), &entry); err != nil {
+        return false, 0, "", fmt.Errorf("failed to unmarshal blacklist entry: %w", err)
+    }
+
+    return true, entry.UserID, entry.Reason, nil
+}
+
+// RemoveFromBlacklist 从黑名单移除 Token（用于解封）
+func RemoveFromBlacklist(ctx context.Context, token string) error {
+    if token == "" {
+        return nil
+    }
+    if RedisClient == nil {
+        return fmt.Errorf("redis client is not initialized")
+    }
+
+    key := BlacklistKeyPrefix + tokenToHash(token)
+    return RedisClient.Del(ctx, key).Err()
+}