feat: activity log backend foundation

internal/infrastructure/useCases/ExportActivity.go

@@ -0,0 +1,88 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/audit"
+	"encoding/csv"
+	"io"
+	"strings"
+	"time"
+)
+
+const exportBatchSize = 500
+
+const formulaGuard = "'"
+const formulaStarts = "=+-@"
+
+var exportHeader = []string{"when", "actor", "action", "target", "outcome", "source", "ip"}
+
+type ExportActivityUseCase struct {
+	events audit.Repository
+	now    func() time.Time
+}
+
+type ActivityExport struct {
+	events audit.Repository
+	filter audit.Filter
+}
+
+func NewExportActivityUseCase(events audit.Repository, now func() time.Time) *ExportActivityUseCase {
+	return &ExportActivityUseCase{events, now}
+}
+
+func (e *ExportActivityUseCase) Prepare(query ActivityQuery) (*ActivityExport, error) {
+	filter, err := buildActivityFilter(query, e.now())
+	if err != nil {
+		return nil, err
+	}
+	return &ActivityExport{events: e.events, filter: filter}, nil
+}
+
+func (a *ActivityExport) WriteCSV(w io.Writer) error {
+	writer := csv.NewWriter(w)
+	if err := writer.Write(exportHeader); err != nil {
+		return err
+	}
+	for page := 1; ; page++ {
+		filter := a.filter
+		filter.Page, filter.Size = page, exportBatchSize
+		found, err := a.events.List(filter)
+		if err != nil {
+			return err
+		}
+		for _, event := range found.Items {
+			if err := writer.Write(exportRow(event)); err != nil {
+				return err
+			}
+		}
+		writer.Flush()
+		if err := writer.Error(); err != nil {
+			return err
+		}
+		if len(found.Items) < exportBatchSize || page*exportBatchSize >= found.Total {
+			return nil
+		}
+	}
+}
+
+func exportRow(event audit.Event) []string {
+	ip := ""
+	if event.IP != nil {
+		ip = *event.IP
+	}
+	return []string{
+		event.CreatedAt.UTC().Format(time.RFC3339),
+		guardCell(event.Actor.Name),
+		guardCell(event.Action),
+		guardCell(event.Target.Name),
+		string(event.Outcome),
+		string(event.Source),
+		guardCell(ip),
+	}
+}
+
+func guardCell(value string) string {
+	if value != "" && strings.ContainsRune(formulaStarts, rune(value[0])) {
+		return formulaGuard + value
+	}
+	return value
+}