feat: add transcription diagnostics for empty result bug

src/app.ts

@@ -41,9 +41,22 @@ export interface ModelWithStatus {
 	localPath?: string | null;
 }
 
+export interface TranscriptionAttempt {
+	stage: string;
+	audioPath: string;
+	audioSizeBytes: number;
+	sidecar: string;
+	model: string;
+	exitCode: number | null;
+	stdoutTail: string;
+	stderrTail: string;
+	error: string | null;
+}
+
 export interface TranscriptDraft {
 	text: string;
 	lastMessage: string | null;
+	lastAttempt?: TranscriptionAttempt;
 }
 
 export interface AppSnapshot {
@@ -121,8 +134,25 @@ function element<K extends keyof HTMLElementTagNameMap>(
 }
 
 function formatBytes(bytes: number): string {
-	const mib = bytes / 1024 / 1024;
-	return `${mib.toFixed(0)} MiB`;
+	if (bytes < 1024) return `${bytes} B`;
+	if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
+	return `${(bytes / 1024 / 1024).toFixed(2)} MB`;
+}
+
+function formatAttempt(attempt: TranscriptionAttempt): string {
+	const lines = [
+		`stage: ${attempt.stage}`,
+		`audio: ${attempt.audioPath} (${formatBytes(attempt.audioSizeBytes)})`,
+		`sidecar: ${attempt.sidecar}`,
+		`model: ${attempt.model}`,
+		`exitCode: ${attempt.exitCode ?? "n/a"}`,
+		`error: ${attempt.error ?? "—"}`,
+		`stdout:`,
+		attempt.stdoutTail || "(vazio)",
+		`stderr:`,
+		attempt.stderrTail || "(vazio)",
+	];
+	return lines.join("\n");
 }
 
 function modelStatusLabel(status: ModelWithStatus["status"]): string {
@@ -221,7 +251,17 @@ export function createTranscriptionApp(
 	) as HTMLButtonElement;
 	modelPanel.append(modelTitle, modelDetails, modelStatus, downloadModelButton);
 
-	shell.append(topbar, editorLabel, editor, message, actions, modelPanel);
+	const diagnostics = element("details", "diagnostics");
+	const diagnosticsSummary = element(
+		"summary",
+		"diagnostics-summary",
+		"Detalhes técnicos",
+	);
+	const diagnosticsBody = element("pre", "diagnostics-body");
+	diagnostics.append(diagnosticsSummary, diagnosticsBody);
+	diagnostics.open = false;
+
+	shell.append(topbar, editorLabel, editor, message, actions, modelPanel, diagnostics);
 	mount.append(shell);
 
 	const render = (next: AppSnapshot): void => {
@@ -248,6 +288,14 @@ export function createTranscriptionApp(
 		downloadModelButton.disabled = firstModelStatus?.status === "ready";
 		downloadModelButton.textContent =
 			firstModelStatus?.status === "ready" ? "Modelo pronto" : "Baixar modelo";
+
+		const attempt = snapshot.transcript.lastAttempt;
+		if (attempt) {
+			diagnostics.open = true;
+			diagnosticsBody.textContent = formatAttempt(attempt);
+		} else {
+			diagnosticsBody.textContent = "Nenhuma tentativa registrada ainda.";
+		}
 	};
 
 	const refresh = async (): Promise<void> => {
@@ -255,7 +303,8 @@ export function createTranscriptionApp(
 	};
 
 	const showError = (error: unknown): void => {
-		message.textContent = error instanceof Error ? error.message : String(error);
+		message.textContent =
+			error instanceof Error ? error.message : String(error);
 	};
 
 	const toggleRecording = async (): Promise<void> => {