实现七月迭代公共技术基础

internal/infrastructure/systemconfig/reader.go

@@ -0,0 +1,149 @@
+package systemconfig
+
+import (
+	"context"
+	stderrors "errors"
+	"sort"
+
+	"github.com/redis/go-redis/v9"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/break/junhong_cmp_fiber/internal/model"
+	"github.com/break/junhong_cmp_fiber/pkg/constants"
+)
+
+// AlertSink 接收配置读取和缓存故障的中文安全告警。
+type AlertSink interface {
+	Warn(ctx context.Context, code, component, safeID, summary string)
+}
+
+// LogAlertSink 使用应用日志承接安全告警。
+type LogAlertSink struct {
+	logger *zap.Logger
+}
+
+// NewLogAlertSink 创建系统配置日志告警 Adapter。
+func NewLogAlertSink(logger *zap.Logger) *LogAlertSink {
+	if logger == nil {
+		logger = zap.NewNop()
+	}
+	return &LogAlertSink{logger: logger}
+}
+
+// Warn 记录不包含配置值的中文安全告警。
+func (s *LogAlertSink) Warn(_ context.Context, code, component, safeID, summary string) {
+	s.logger.Warn(summary, zap.String("error_code", code), zap.String("component", component), zap.String("safe_id", safeID))
+}
+
+// Reader 提供以 PostgreSQL 为唯一事实来源的缓存读取能力。
+type Reader struct {
+	db       *gorm.DB
+	registry *Registry
+	cache    Cache
+	alerts   AlertSink
+}
+
+func (r *Reader) warn(ctx context.Context, code, key, summary string) {
+	if r.alerts != nil {
+		r.alerts.Warn(ctx, code, "system_config", key, summary)
+	}
+}
+
+// NewReader 创建系统配置读取器。
+func NewReader(db *gorm.DB, registry *Registry, cache Cache, alerts AlertSink) *Reader {
+	return &Reader{db: db, registry: registry, cache: cache, alerts: alerts}
+}
+
+// Get 读取单个已注册配置；Redis 故障时回退 PostgreSQL。
+func (r *Reader) Get(ctx context.Context, key string) (string, error) {
+	definition, registered := r.registry.Get(key)
+	if !registered {
+		return "", stderrors.New("系统配置 Key 未注册")
+	}
+	cacheKey := constants.RedisSystemConfigKey(key)
+	if r.cache != nil {
+		if value, err := r.cache.Get(ctx, cacheKey); err == nil {
+			if ValidateValue(definition, value) == nil {
+				r.registry.Remember(key, value)
+				return value, nil
+			}
+			r.warn(ctx, "SYSTEM_CONFIG_CACHE_INVALID", key, "系统配置缓存值非法，已回退 PostgreSQL")
+		} else if err != redis.Nil {
+			r.warn(ctx, "SYSTEM_CONFIG_CACHE_READ_FAILED", key, "系统配置缓存读取失败，已回退 PostgreSQL")
+		}
+	}
+	var record model.SystemConfig
+	err := r.db.WithContext(ctx).Where("config_key = ?", key).First(&record).Error
+	if err == gorm.ErrRecordNotFound {
+		return definition.DefaultValue, nil
+	}
+	if err != nil {
+		return "", err
+	}
+	value := record.ConfigValue
+	if ValidateValue(definition, value) != nil {
+		value = r.registry.LastValidatedOrDefault(definition)
+		r.warn(ctx, "SYSTEM_CONFIG_DATABASE_VALUE_INVALID", key, "数据库配置值非法，已使用最近验证值或安全默认值")
+	} else {
+		r.registry.Remember(key, value)
+	}
+	if r.cache != nil {
+		if err := r.cache.Set(ctx, cacheKey, value, constants.SystemConfigCacheTTL); err != nil {
+			r.warn(ctx, "SYSTEM_CONFIG_CACHE_WRITE_FAILED", key, "系统配置缓存回填失败")
+		}
+	}
+	return value, nil
+}
+
+// ListItem 是查询层组装 DTO 所需的稳定投影。
+type ListItem struct {
+	Definition Definition
+	Record     *model.SystemConfig
+	Value      string
+	Registered bool
+}
+
+// List 合并代码注册表和数据库遗留记录；未注册记录强制只读。
+func (r *Reader) List(ctx context.Context, module string) ([]ListItem, error) {
+	var records []model.SystemConfig
+	query := r.db.WithContext(ctx).Order("config_key ASC")
+	if module != "" {
+		query = query.Where("module = ?", module)
+	}
+	if err := query.Find(&records).Error; err != nil {
+		return nil, err
+	}
+	byKey := make(map[string]*model.SystemConfig, len(records))
+	for index := range records {
+		byKey[records[index].ConfigKey] = &records[index]
+	}
+	items := make([]ListItem, 0, len(records)+len(r.registry.List()))
+	for _, definition := range r.registry.List() {
+		if module != "" && definition.Module != module {
+			continue
+		}
+		record := byKey[definition.Key]
+		value := definition.DefaultValue
+		if record != nil {
+			value = record.ConfigValue
+			if ValidateValue(definition, value) != nil {
+				value = r.registry.LastValidatedOrDefault(definition)
+				r.warn(ctx, "SYSTEM_CONFIG_DATABASE_VALUE_INVALID", definition.Key, "数据库配置值非法，列表已使用安全值")
+			} else {
+				r.registry.Remember(definition.Key, value)
+			}
+			delete(byKey, definition.Key)
+		}
+		items = append(items, ListItem{Definition: definition, Record: record, Value: value, Registered: true})
+	}
+	for _, record := range byKey {
+		definition := Definition{
+			Key: record.ConfigKey, Module: record.Module, ValueType: record.ValueType,
+			Description: record.Description, Readonly: true, Sensitive: record.IsSensitive, Control: "readonly",
+		}
+		items = append(items, ListItem{Definition: definition, Record: record, Value: record.ConfigValue, Registered: false})
+	}
+	sort.Slice(items, func(i, j int) bool { return items[i].Definition.Key < items[j].Definition.Key })
+	return items, nil
+}