refactor: split modules and harden scraping workflows

internal/service/strm_proxy.go

@@ -0,0 +1,89 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+)
+
+// ProxySTRM proxies a STRM target and preserves Range requests for players.
+func (s *STRMService) ProxySTRM(ctx context.Context, id string, req *http.Request, w http.ResponseWriter) error {
+	record, err := s.repo.STRM.FindByID(ctx, id)
+	if err != nil {
+		return err
+	}
+	if record == nil {
+		return ErrSTRMNotFound
+	}
+	if !model.IsAllowedProtocol(record.Protocol) {
+		return ErrSTRMProtocolInvalid
+	}
+
+	targetURL, err := validateSTRMProxyURL(record.URL)
+	if err != nil {
+		return err
+	}
+	proxyReq, err := http.NewRequestWithContext(ctx, req.Method, targetURL.String(), nil)
+	if err != nil {
+		return fmt.Errorf("create proxy request: %w", err)
+	}
+	copySTRMRequestHeaders(req, proxyReq)
+
+	client := &http.Client{Timeout: 60 * time.Second}
+	resp, err := client.Do(proxyReq) // #nosec G107,G704 -- STRM proxy target is validated by validateSTRMProxyURL before request creation.
+	if err != nil {
+		return fmt.Errorf("proxy request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	copySTRMResponseHeaders(resp, w)
+	w.WriteHeader(resp.StatusCode)
+	_, err = io.Copy(w, resp.Body)
+	return err
+}
+
+func validateSTRMProxyURL(raw string) (*url.URL, error) {
+	u, err := url.Parse(strings.TrimSpace(raw))
+	if err != nil || u.Scheme == "" || u.Host == "" {
+		return nil, ErrSTRMURLInvalid
+	}
+	switch strings.ToLower(u.Scheme) {
+	case "http", "https":
+	default:
+		return nil, ErrSTRMProtocolInvalid
+	}
+	if isPrivateHost(u.Hostname()) {
+		return nil, ErrSTRMURLInvalid
+	}
+	return u, nil
+}
+
+func copySTRMRequestHeaders(src *http.Request, dst *http.Request) {
+	for _, header := range []string{
+		"Range", "If-Range", "If-Match", "If-None-Match",
+		"If-Modified-Since", "If-Unmodified-Since",
+		"Accept", "Accept-Encoding", "Accept-Language",
+	} {
+		if v := src.Header.Get(header); v != "" {
+			dst.Header.Set(header, v)
+		}
+	}
+}
+
+func copySTRMResponseHeaders(src *http.Response, dst http.ResponseWriter) {
+	for _, header := range []string{
+		"Content-Type", "Content-Length", "Content-Range",
+		"Accept-Ranges", "Last-Modified", "ETag",
+		"Cache-Control", "Content-Disposition",
+	} {
+		if v := src.Header.Get(header); v != "" {
+			dst.Header().Set(header, v)
+		}
+	}
+}