#12: implement Antispam & Antivirus scanning pipeline (Rspamd & ClamAV)

services/protocols/internal/application/usecase/scanning_pipeline.go

@@ -0,0 +1,55 @@
+package usecase
+
+import (
+	"context"
+	"fmt"
+
+	"lambdamail/protocols/internal/application/port"
+	"lambdamail/protocols/internal/domain/valueobject"
+)
+
+type ScanningPipeline struct {
+	scanners []port.ContentScanner
+}
+
+func NewScanningPipeline(scanners ...port.ContentScanner) *ScanningPipeline {
+	return &ScanningPipeline{scanners: scanners}
+}
+
+func (p *ScanningPipeline) Scan(ctx context.Context, input port.ScanInput) (*valueobject.ScanResult, error) {
+	finalResult := valueobject.NewCleanScanResult()
+
+	for _, scanner := range p.scanners {
+		if scanner == nil {
+			continue
+		}
+		res, err := scanner.Scan(ctx, input)
+		if err != nil {
+			return nil, fmt.Errorf("scanner failed: %w", err)
+		}
+		if res == nil {
+			continue
+		}
+
+		// Fail fast on Virus Reject, Spam Reject, or Greylist
+		if res.Verdict == valueobject.ScanVerdictVirusReject ||
+			res.Verdict == valueobject.ScanVerdictSpamReject ||
+			res.Verdict == valueobject.ScanVerdictGreylist {
+			return res, nil
+		}
+
+		if res.Verdict == valueobject.ScanVerdictSpamJunk {
+			finalResult.Verdict = valueobject.ScanVerdictSpamJunk
+		}
+
+		if res.Score != 0 {
+			finalResult.Score = res.Score
+			finalResult.RequiredScore = res.RequiredScore
+		}
+		for k, v := range res.HeadersToAdd {
+			finalResult.HeadersToAdd[k] = v
+		}
+	}
+
+	return finalResult, nil
+}