[feature] Add from: search operator and account_id query param (#2943)

* Add from: search operator

* Fix whitespace in Swagger YAML comment

* Move query parsing into its own method

* Document search

* Clarify post search scope

internal/processing/search/get.go

@@ -62,14 +62,15 @@ func (p *Processor) Get(
 	req *apimodel.SearchRequest,
 ) (*apimodel.SearchResult, gtserror.WithCode) {
 	var (
-		maxID     = req.MaxID
-		minID     = req.MinID
-		limit     = req.Limit
-		offset    = req.Offset
-		query     = strings.TrimSpace(req.Query)                      // Trim trailing/leading whitespace.
-		queryType = strings.TrimSpace(strings.ToLower(req.QueryType)) // Trim trailing/leading whitespace; convert to lowercase.
-		resolve   = req.Resolve
-		following = req.Following
+		maxID         = req.MaxID
+		minID         = req.MinID
+		limit         = req.Limit
+		offset        = req.Offset
+		query         = strings.TrimSpace(req.Query)                      // Trim trailing/leading whitespace.
+		queryType     = strings.TrimSpace(strings.ToLower(req.QueryType)) // Trim trailing/leading whitespace; convert to lowercase.
+		resolve       = req.Resolve
+		following     = req.Following
+		fromAccountID = req.AccountID
 
 		// Include instance accounts in the first
 		// parts of this search. This will be
@@ -114,6 +115,7 @@ func (p *Processor) Get(
 			{"queryType", queryType},
 			{"resolve", resolve},
 			{"following", following},
+			{"fromAccountID", fromAccountID},
 		}...).
 		Debugf("beginning search")
 
@@ -309,6 +311,7 @@ func (p *Processor) Get(
 		query,
 		queryType,
 		following,
+		fromAccountID,
 		appendAccount,
 		appendStatus,
 	); err != nil && !errors.Is(err, db.ErrNoEntries) {
@@ -743,6 +746,7 @@ func (p *Processor) byText(
 	query string,
 	queryType string,
 	following bool,
+	fromAccountID string,
 	appendAccount func(*gtsmodel.Account),
 	appendStatus func(*gtsmodel.Status),
 ) error {
@@ -779,6 +783,7 @@ func (p *Processor) byText(
 			limit,
 			offset,
 			query,
+			fromAccountID,
 			appendStatus,
 		); err != nil {
 			return err
@@ -826,12 +831,30 @@ func (p *Processor) statusesByText(
 	limit int,
 	offset int,
 	query string,
+	fromAccountID string,
 	appendStatus func(*gtsmodel.Status),
 ) error {
+	parsed, err := p.parseQuery(ctx, query)
+	if err != nil {
+		return err
+	}
+	query = parsed.query
+	// If the owning account for statuses was not provided as the account_id query parameter,
+	// it may still have been provided as a search operator in the query string.
+	if fromAccountID == "" {
+		fromAccountID = parsed.fromAccountID
+	}
+
 	statuses, err := p.state.DB.SearchForStatuses(
 		ctx,
 		requestingAccountID,
-		query, maxID, minID, limit, offset)
+		query,
+		fromAccountID,
+		maxID,
+		minID,
+		limit,
+		offset,
+	)
 	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return gtserror.Newf("error checking database for statuses using text %s: %w", query, err)
 	}
@@ -842,3 +865,60 @@ func (p *Processor) statusesByText(
 
 	return nil
 }
+
+// parsedQuery represents the results of parsing the search operator terms within a query.
+type parsedQuery struct {
+	// query is the original search query text with operator terms removed.
+	query string
+	// fromAccountID is the account from a successfully resolved `from:` operator, if present.
+	fromAccountID string
+}
+
+// parseQuery parses query text and handles any search operator terms present.
+func (p *Processor) parseQuery(ctx context.Context, query string) (parsed parsedQuery, err error) {
+	queryPartSeparator := " "
+	queryParts := strings.Split(query, queryPartSeparator)
+	nonOperatorQueryParts := make([]string, 0, len(queryParts))
+	for _, queryPart := range queryParts {
+		if arg, hasPrefix := strings.CutPrefix(queryPart, "from:"); hasPrefix {
+			parsed.fromAccountID, err = p.parseFromOperatorArg(ctx, arg)
+			if err != nil {
+				return
+			}
+		} else {
+			nonOperatorQueryParts = append(nonOperatorQueryParts, queryPart)
+		}
+	}
+	parsed.query = strings.Join(nonOperatorQueryParts, queryPartSeparator)
+	return
+}
+
+// parseFromOperatorArg attempts to parse the from: operator's argument as an account name,
+// and returns the account ID if possible. Allows specifying an account name with or without a leading @.
+func (p *Processor) parseFromOperatorArg(ctx context.Context, namestring string) (string, error) {
+	if namestring == "" {
+		return "", gtserror.New(
+			"the 'from:' search operator requires an account name, but it wasn't provided",
+		)
+	}
+	if namestring[0] != '@' {
+		namestring = "@" + namestring
+	}
+
+	username, domain, err := util.ExtractNamestringParts(namestring)
+	if err != nil {
+		return "", gtserror.Newf(
+			"the 'from:' search operator couldn't parse its argument as an account name: %w",
+			err,
+		)
+	}
+	account, err := p.state.DB.GetAccountByUsernameDomain(gtscontext.SetBarebones(ctx), username, domain)
+	if err != nil {
+		return "", gtserror.Newf(
+			"the 'from:' search operator couldn't find the requested account name: %w",
+			err,
+		)
+	}
+
+	return account.ID, nil
+}