Scoreboard/server/internal/middleware/audit.go

package middleware

import (
	"context"
	"database/sql"
	"encoding/json"
	"log/slog"
	"net/http"

	"git.yeij.top/AskaEth/Scoreboard/server/internal/auth"
)

// AuditEntry 是一条待落库的审计记录；Before/After 为任意可 JSON 序列化的快照。
type AuditEntry struct {
	// Action 用点号分层，关键动作单独成段，如 result.publish / result.void / user.create。
	Action     string
	EntityType string
	EntityID   int64
	// ActorID 非 0 时优先作为审计主体，用于登录等「身份刚建立、请求 ctx 里仍是 guest」的动作。
	ActorID int64
	Before  any
	After   any
}

type auditCollector struct {
	entries []AuditEntry
}

// Record 由 handler 调用，登记一条审计；仅在请求成功（2xx）时落库。
func Record(ctx context.Context, e AuditEntry) {
	if c, ok := ctx.Value(ctxKeyAudit).(*auditCollector); ok {
		c.entries = append(c.entries, e)
	}
}

// Auditor 把成功写操作的审计记录写入赛事库 audit_logs（只追加、不修改）。
type Auditor struct {
	db  *sql.DB
	log *slog.Logger
}

// NewAuditor 创建审计中间件；db 为赛事库（event.db）。
func NewAuditor(db *sql.DB, logger *slog.Logger) *Auditor {
	if logger == nil {
		logger = slog.Default()
	}
	return &Auditor{db: db, log: logger}
}

// Middleware 收集 handler 登记的审计并在成功后落库。
func (a *Auditor) Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		sw := &statusWriter{ResponseWriter: w, status: http.StatusOK}
		c := &auditCollector{}
		ctx := context.WithValue(r.Context(), ctxKeyAudit, c)
		next.ServeHTTP(sw, r.WithContext(ctx))

		if sw.status >= http.StatusBadRequest || len(c.entries) == 0 {
			return
		}
		a.flush(ctx, r, c.entries)
	})
}

func (a *Auditor) flush(ctx context.Context, r *http.Request, entries []AuditEntry) {
	if a.db == nil {
		return
	}
	u := User(ctx)
	requestID := GetRequestID(ctx)
	ip := ClientIP(r)

	for _, e := range entries {
		var entityID any
		if e.EntityID != 0 {
			entityID = e.EntityID
		}
		// 登录等动作在请求 ctx 里还没有登录身份，改由条目自带的 ActorID 补上。
		actor := nullableID(u)
		if e.ActorID != 0 {
			actor = e.ActorID
		}
		_, err := a.db.ExecContext(ctx,
			`INSERT INTO audit_logs (user_id, action, entity_type, entity_id, before_json, after_json, ip, request_id)
			 VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
			actor, e.Action, e.EntityType, entityID,
			marshalOrNil(e.Before), marshalOrNil(e.After), ip, requestID)
		if err != nil {
			// 审计失败不能吞掉业务结果，但必须留下痕迹。
			a.log.Error("写入审计失败", "err", err, "action", e.Action, "requestId", requestID)
		}
	}
}

func nullableID(u *auth.User) any {
	if u == nil || u.Role == auth.RoleGuest || u.ID == 0 {
		return nil
	}
	return u.ID
}

func marshalOrNil(v any) any {
	if v == nil {
		return nil
	}
	raw, err := json.Marshal(v)
	if err != nil {
		return nil
	}
	return string(raw)
}