improved kv metacore

internal/api/snapshot.go

@@ -0,0 +1,167 @@
+package api
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/metazla/meta-core/internal/snapshot"
+)
+
+// Bound the upload size so a malicious client can't OOM the server.
+// 2 GiB is well above any realistic export.
+const maxImportBytes = 2 << 30
+
+// pluginOutputDir is where plugin-produced artifacts live on disk
+// (subtitles, posters, etc). Mounted from the host into the meta-core
+// container at $FILES_PATH/plugin.
+func (s *Server) pluginOutputDir() string {
+	return filepath.Join(s.config.FilesPath, "plugin")
+}
+
+// handleSnapshotExport streams a ZIP snapshot of all metadata.
+// GET /api/snapshot/export?include=hash-index,plugin-output
+func (s *Server) handleSnapshotExport(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	// The server has a 30s WriteTimeout (server.go:222). Long exports
+	// blow past that, leaving a truncated ZIP without a central directory.
+	// Clear the deadline for this handler so the export can run as long as
+	// needed. ResponseController is the standard way to do this.
+	rc := http.NewResponseController(w)
+	_ = rc.SetWriteDeadline(time.Time{})
+
+	include := splitCSVParam(r.URL.Query().Get("include"))
+	opts := snapshot.ExportOptions{
+		IncludePluginOutput: include["plugin-output"],
+		PluginOutputDir:     s.pluginOutputDir(),
+	}
+
+	filename := fmt.Sprintf("metamesh-snapshot-%s.zip", time.Now().UTC().Format("20060102-150405"))
+	w.Header().Set("Content-Type", "application/zip")
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, filename))
+	// We stream — no Content-Length.
+
+	exporter := snapshot.NewExporter(s.storage)
+	if _, err := exporter.Export(w, opts); err != nil {
+		// Headers may already be sent; log and bail.
+		// Client will see a truncated zip, which is the best signal we can give.
+		fmt.Printf("[Snapshot] export failed: %v\n", err)
+		return
+	}
+}
+
+// handleSnapshotImport applies an uploaded ZIP snapshot.
+// POST /api/snapshot/import?mode=replace|merge&conflict=mine|source&dry_run=true
+// Body: application/zip (raw) OR multipart/form-data with field "snapshot"
+func (s *Server) handleSnapshotImport(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	// Long imports can blow past the server's 30s ReadTimeout/WriteTimeout
+	// when the snapshot is large. Clear both for this handler.
+	rc := http.NewResponseController(w)
+	_ = rc.SetReadDeadline(time.Time{})
+	_ = rc.SetWriteDeadline(time.Time{})
+
+	q := r.URL.Query()
+	opts := snapshot.ImportOptions{
+		Mode:            snapshot.Mode(q.Get("mode")),
+		Conflict:        snapshot.Conflict(q.Get("conflict")),
+		DryRun:          strings.EqualFold(q.Get("dry_run"), "true"),
+		PluginOutputDir: s.pluginOutputDir(),
+	}
+	if opts.Mode == "" {
+		opts.Mode = snapshot.ModeMerge
+	}
+	if opts.Mode == snapshot.ModeMerge && opts.Conflict == "" {
+		opts.Conflict = snapshot.ConflictSource
+	}
+
+	body, err := readImportBody(r)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	importer := snapshot.NewImporter(s.storage)
+	result, err := importer.Import(bytes.NewReader(body), int64(len(body)), opts)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, result)
+}
+
+// handleSnapshotWipe clears Redis metadata.
+// POST /api/snapshot/wipe?scope=metadata
+func (s *Server) handleSnapshotWipe(w http.ResponseWriter, r *http.Request) {
+	if !s.storage.IsConnected() {
+		writeError(w, http.StatusServiceUnavailable, "storage not connected")
+		return
+	}
+
+	scopes := splitCSVParam(r.URL.Query().Get("scope"))
+	if len(scopes) == 0 {
+		writeError(w, http.StatusBadRequest, "scope query param is required (e.g. scope=metadata)")
+		return
+	}
+	scope := snapshot.WipeScope{
+		Metadata: scopes["metadata"],
+	}
+	if !scope.Metadata {
+		writeError(w, http.StatusBadRequest, "no supported scope requested; scope=metadata is the only accepted value")
+		return
+	}
+
+	wiper := snapshot.NewWiper(s.storage)
+	res, err := wiper.Wipe(scope)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, res)
+}
+
+// readImportBody accepts either a raw application/zip body or a multipart
+// upload with a field named "snapshot". Buffers up to maxImportBytes.
+func readImportBody(r *http.Request) ([]byte, error) {
+	r.Body = http.MaxBytesReader(nil, r.Body, maxImportBytes)
+
+	ct := r.Header.Get("Content-Type")
+	if strings.HasPrefix(ct, "multipart/form-data") {
+		if err := r.ParseMultipartForm(32 << 20); err != nil {
+			return nil, fmt.Errorf("parse multipart: %w", err)
+		}
+		f, _, err := r.FormFile("snapshot")
+		if err != nil {
+			return nil, fmt.Errorf("missing 'snapshot' file field: %w", err)
+		}
+		defer f.Close()
+		return io.ReadAll(f)
+	}
+
+	return io.ReadAll(r.Body)
+}
+
+// splitCSVParam parses "a,b,c" into a set. Empty values yield an empty set.
+func splitCSVParam(v string) map[string]bool {
+	out := map[string]bool{}
+	for _, part := range strings.Split(v, ",") {
+		p := strings.TrimSpace(part)
+		if p != "" {
+			out[p] = true
+		}
+	}
+	return out
+}