feat(search): gator fields in oo_docs_text + field filters (#86)

- TextDoc carries gator keyword fields (doc_sha, number, seller, total, typ,
  issued_at, created_at, status, url); content is now omitempty so a partial
  doc can be written.
- oo_docs_text mapping extended with the keyword fields.
- ESTextIndex.UpsertFields: bulk update + doc_as_upsert, merging gator fields
  into an existing text doc without clobbering title/content.
- SearchQuery gains Seller/Number/Status term filters; SearchHit.Fields exposes
  the gator values. Pure builders unit-tested.

filestore_es_text.go

@@ -44,13 +44,24 @@ func ESTextConfigFromEnv() ESTextConfig {
 }
 
 // TextDoc is one document in the own full-text index. It is keyed by the
-// OnlyOffice file id so hits map straight back to Documents entries.
+// OnlyOffice file id so hits map straight back to Documents entries. The gator
+// fields (Option D) are keyword values filled from the gator corpus; they stay
+// empty for documents gator does not know.
 type TextDoc struct {
-	ID       string `json:"id"`
-	Title    string `json:"title"`
-	FolderID string `json:"folder,omitempty"`
-	Ext      string `json:"ext,omitempty"`
-	Content  string `json:"content"`
+	ID        string `json:"id"`
+	Title     string `json:"title"`
+	FolderID  string `json:"folder,omitempty"`
+	Ext       string `json:"ext,omitempty"`
+	Content   string `json:"content,omitempty"`
+	DocSHA    string `json:"doc_sha,omitempty"`
+	Number    string `json:"number,omitempty"`
+	Seller    string `json:"seller,omitempty"`
+	Total     string `json:"total,omitempty"`
+	Typ       string `json:"typ,omitempty"`
+	IssuedAt  string `json:"issued_at,omitempty"`
+	CreatedAt string `json:"created_at,omitempty"`
+	Status    string `json:"status,omitempty"`
+	URL       string `json:"url,omitempty"`
 }
 
 // TextIndex is the storage/search surface for locally extracted document text.
@@ -99,11 +110,20 @@ func (x *ESTextIndex) Index() string { return x.cfg.Index }
 const esTextMapping = `{
   "mappings": {
     "properties": {
-      "id":      {"type": "keyword"},
-      "title":   {"type": "text", "fields": {"keyword": {"type": "keyword", "ignore_above": 512}}},
-      "folder":  {"type": "keyword"},
-      "ext":     {"type": "keyword"},
-      "content": {"type": "text"}
+      "id":         {"type": "keyword"},
+      "title":      {"type": "text", "fields": {"keyword": {"type": "keyword", "ignore_above": 512}}},
+      "folder":     {"type": "keyword"},
+      "ext":        {"type": "keyword"},
+      "content":    {"type": "text"},
+      "doc_sha":    {"type": "keyword"},
+      "number":     {"type": "keyword"},
+      "seller":     {"type": "keyword"},
+      "total":      {"type": "keyword"},
+      "typ":        {"type": "keyword"},
+      "issued_at":  {"type": "keyword"},
+      "created_at": {"type": "keyword"},
+      "status":     {"type": "keyword"},
+      "url":        {"type": "keyword"}
     }
   }
 }`
@@ -147,6 +167,31 @@ func (x *ESTextIndex) Put(ctx context.Context, docs []TextDoc) error {
 	return fmt.Errorf("onlyoffice: bulk index %s: %s", x.cfg.Index, res.firstError())
 }
 
+// UpsertFields writes only the gator keyword fields for each document via the
+// bulk update API with doc_as_upsert: an existing document keeps its
+// title/content while gaining the gator fields; an unknown id is created with
+// just these fields. Refreshes so results are immediately searchable.
+func (x *ESTextIndex) UpsertFields(ctx context.Context, docs []TextDoc) error {
+	if len(docs) == 0 {
+		return nil
+	}
+	status, raw, err := x.do(ctx, http.MethodPost, "/"+x.cfg.Index+"/_bulk?refresh=true", esUpdateBulkBody(docs), "application/x-ndjson")
+	if err != nil {
+		return err
+	}
+	if status >= 400 {
+		return fmt.Errorf("onlyoffice: bulk update %s: %d %s", x.cfg.Index, status, truncate(string(raw), 400))
+	}
+	var res esBulkResponse
+	if err := json.Unmarshal(raw, &res); err != nil {
+		return fmt.Errorf("onlyoffice: decode bulk response: %w", err)
+	}
+	if !res.Errors {
+		return nil
+	}
+	return fmt.Errorf("onlyoffice: bulk update %s: %s", x.cfg.Index, res.firstError())
+}
+
 // Delete removes documents by OnlyOffice file id. A missing index means there
 // is nothing to delete.
 func (x *ESTextIndex) Delete(ctx context.Context, ids []string) error {
@@ -233,6 +278,20 @@ func esTextBulkBody(docs []TextDoc) []byte {
 	return b.Bytes()
 }
 
+// esUpdateBulkBody renders bulk update actions with doc_as_upsert, so a partial
+// TextDoc (gator fields only) merges into an existing document instead of
+// replacing it. Pure, so it is unit-tested.
+func esUpdateBulkBody(docs []TextDoc) []byte {
+	var b bytes.Buffer
+	enc := json.NewEncoder(&b)
+	enc.SetEscapeHTML(false)
+	for _, d := range docs {
+		_ = enc.Encode(map[string]any{"update": map[string]any{"_id": d.ID}})
+		_ = enc.Encode(map[string]any{"doc": d, "doc_as_upsert": true})
+	}
+	return b.Bytes()
+}
+
 // esTextSearchRequest builds the own-index query. Pure, so it is unit-tested.
 func esTextSearchRequest(q SearchQuery) esRequest {
 	limit := q.Limit
@@ -252,10 +311,19 @@ func esTextSearchRequest(q SearchQuery) esRequest {
 	if exts := normalizeExtensions(q.Extensions); len(exts) > 0 {
 		filter = append(filter, esClause{Terms: map[string]any{"ext": exts}})
 	}
+	if v := strings.TrimSpace(q.Seller); v != "" {
+		filter = append(filter, esClause{Term: map[string]any{"seller": v}})
+	}
+	if v := strings.TrimSpace(q.Number); v != "" {
+		filter = append(filter, esClause{Term: map[string]any{"number": v}})
+	}
+	if v := strings.TrimSpace(q.Status); v != "" {
+		filter = append(filter, esClause{Term: map[string]any{"status": v}})
+	}
 
 	return esRequest{
 		Size:      limit,
-		Source:    []string{"id", "title", "folder", "ext"},
+		Source:    []string{"id", "title", "folder", "ext", "doc_sha", "number", "seller", "total", "typ", "issued_at", "created_at", "status", "url"},
 		Query:     esQuery{Bool: esBool{Must: must, Filter: filter}},
 		Highlight: esHighlight{PreTags: []string{"<em>"}, PostTags: []string{"</em>"}, Fields: map[string]struct{}{"title": {}, "content": {}}},
 	}
@@ -330,7 +398,26 @@ func parseESTextResponse(raw []byte) ([]SearchHit, error) {
 			Score:     h.Score,
 			Highlight: esHighlightText(h.HL),
 			Path:      path,
+			Fields:    gatorFields(h.Source),
 		})
 	}
 	return hits, nil
 }
+
+// gatorFields extracts the non-empty gator keyword fields from a stored doc.
+func gatorFields(d TextDoc) map[string]string {
+	out := map[string]string{}
+	for k, v := range map[string]string{
+		"doc_sha": d.DocSHA, "number": d.Number, "seller": d.Seller, "total": d.Total,
+		"typ": d.Typ, "issued_at": d.IssuedAt, "created_at": d.CreatedAt,
+		"status": d.Status, "url": d.URL,
+	} {
+		if v != "" {
+			out[k] = v
+		}
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}