upd

internal/capture/images.go

@@ -0,0 +1,80 @@
+package capture
+
+import (
+	"fmt"
+	"mime"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"git.gulenok.ru/greenhaze/gaslight/internal/domain"
+)
+
+type ImageSaver struct {
+	outputDir string
+	counter   uint64
+}
+
+func NewImageSaver(outputDir string) *ImageSaver {
+	return &ImageSaver{outputDir: outputDir}
+}
+
+func (s *ImageSaver) Save(resp *http.Response, body []byte) error {
+	n := atomic.AddUint64(&s.counter, 1)
+	ts := time.Now().UTC().Format("20060102T150405.000000000Z")
+	host := sanitizeName(domain.HostWithoutPort(resp.Request.Host))
+	ext := imageExtension(resp.Header.Get("Content-Type"), resp.Request.URL.Path)
+	name := fmt.Sprintf("%s_%06d_%s%s", ts, n, host, ext)
+	return os.WriteFile(filepath.Join(s.outputDir, name), body, 0o644)
+}
+
+func IsImageResponse(contentType, path string) bool {
+	if strings.HasPrefix(strings.ToLower(contentType), "image/") {
+		return true
+	}
+	switch strings.ToLower(filepath.Ext(path)) {
+	case ".jpg", ".jpeg", ".png", ".gif", ".bmp", ".webp", ".svg", ".ico", ".avif":
+		return true
+	default:
+		return false
+	}
+}
+
+func imageExtension(contentType, requestPath string) string {
+	if ext := strings.ToLower(filepath.Ext(requestPath)); ext != "" && ext != "." {
+		return ext
+	}
+
+	base := strings.ToLower(strings.TrimSpace(strings.Split(contentType, ";")[0]))
+	if base != "" {
+		if exts, err := mime.ExtensionsByType(base); err == nil && len(exts) > 0 {
+			return exts[0]
+		}
+	}
+	return ".img"
+}
+
+func sanitizeName(s string) string {
+	s = strings.ToLower(strings.TrimSpace(s))
+	if s == "" {
+		return "unknown-host"
+	}
+
+	var b strings.Builder
+	for _, r := range s {
+		switch {
+		case r >= 'a' && r <= 'z':
+			b.WriteRune(r)
+		case r >= '0' && r <= '9':
+			b.WriteRune(r)
+		case r == '.', r == '-', r == '_':
+			b.WriteRune(r)
+		default:
+			b.WriteByte('_')
+		}
+	}
+	return b.String()
+}