From 770cfc9ff7a96b103ab7d1b141046fb4bf1eec76 Mon Sep 17 00:00:00 2001
From: Lucas Winther <lucwin@ece.au.dk>
Date: Fri, 17 Jul 2026 14:14:43 +0200
Subject: [PATCH] Allow txt export with timestampts

---
 src/components/TranscriptView.tsx | 23 ++++++++++-
 src/lib/export.ts                 | 31 +++++++++++++-
 tests/export.test.ts              | 69 +++++++++++++++++++++++++++++++
 3 files changed, 121 insertions(+), 2 deletions(-)

diff --git a/src/components/TranscriptView.tsx b/src/components/TranscriptView.tsx
index 5ba0439..d0cb010 100644
--- a/src/components/TranscriptView.tsx
+++ b/src/components/TranscriptView.tsx
@@ -1,5 +1,10 @@
 import { useEffect, useState } from "react";
-import { exportFilename, transcriptToSrt, transcriptToTxt } from "../lib/export";
+import {
+  exportFilename,
+  transcriptToSrt,
+  transcriptToTimestampedTxt,
+  transcriptToTxt,
+} from "../lib/export";
 import type { TranscriptChunk } from "../worker/protocol";
 
 interface TranscriptViewProps {
@@ -121,6 +126,22 @@ export function TranscriptView({
               .srt
             </button>
           )}
+          {result && result.chunks.length > 0 && (
+            <button
+              type="button"
+              className="copy-button"
+              title="Text with timestamps"
+              onClick={() =>
+                download(
+                  transcriptToTimestampedTxt(result.chunks),
+                  exportFilename(exportName, "timestamps.txt"),
+                  "text/plain",
+                )
+              }
+            >
+              .txt+ts
+            </button>
+          )}
           <button
             type="button"
             className="copy-button"
diff --git a/src/lib/export.ts b/src/lib/export.ts
index fe31014..23e0d4d 100644
--- a/src/lib/export.ts
+++ b/src/lib/export.ts
@@ -59,10 +59,39 @@ export function transcriptToSrt(chunks: TranscriptChunk[]): string {
   return cues.length === 0 ? "" : `${cues.join("\n\n")}\n`;
 }
 
+/** Seconds → compact clock timestamp, e.g. 3.21 → "00:03.2" (mm:ss.s). */
+export function formatClockTimestamp(seconds: number): string {
+  const totalTenths = Math.max(0, Math.round(seconds * 10));
+  const tenths = totalTenths % 600;
+  const m = (totalTenths - tenths) / 600;
+  return `${String(m).padStart(2, "0")}:${(tenths / 10).toFixed(1).padStart(4, "0")}`;
+}
+
+/**
+ * Timestamped chunks → plain text, one line per chunk:
+ * "[00:03.2 – 00:07.9] text". A null end time — Whisper sometimes never
+ * closes the last segment — omits the range end: "[00:03.2] text".
+ * Empty-text chunks are skipped, mirroring transcriptToSrt.
+ */
+export function transcriptToTimestampedTxt(chunks: TranscriptChunk[]): string {
+  const lines = chunks
+    .filter((chunk) => chunk.text.trim() !== "")
+    .map((chunk) => {
+      const [start, end] = chunk.timestamp;
+      const range =
+        end === null
+          ? formatClockTimestamp(start)
+          : `${formatClockTimestamp(start)} – ${formatClockTimestamp(end)}`;
+      return `[${range}] ${chunk.text.trim()}`;
+    });
+  return lines.length === 0 ? "" : `${lines.join("\n")}\n`;
+}
+
 /**
  * Download filename for an export: the source file's base name with the
  * extension swapped ("talk.m4a" → "talk.srt"), or "transcript.<ext>" when no
- * usable source name is known.
+ * usable source name is known. `ext` may be compound ("timestamps.txt") so
+ * sibling exports of the same format get distinct names.
  */
 export function exportFilename(sourceName: string | null | undefined, ext: string): string {
   const trimmed = sourceName?.trim() ?? "";
diff --git a/tests/export.test.ts b/tests/export.test.ts
index 7af743e..437ff13 100644
--- a/tests/export.test.ts
+++ b/tests/export.test.ts
@@ -1,8 +1,10 @@
 import { describe, expect, test } from "bun:test";
 import {
   exportFilename,
+  formatClockTimestamp,
   formatSrtTimestamp,
   transcriptToSrt,
+  transcriptToTimestampedTxt,
   transcriptToTxt,
 } from "../src/lib/export";
 import type { TranscriptChunk } from "../src/worker/protocol";
@@ -100,6 +102,64 @@ describe("transcriptToSrt", () => {
   });
 });
 
+describe("formatClockTimestamp", () => {
+  test("zero", () => {
+    expect(formatClockTimestamp(0)).toBe("00:00.0");
+  });
+
+  test("pads minutes and seconds", () => {
+    expect(formatClockTimestamp(3.21)).toBe("00:03.2");
+    expect(formatClockTimestamp(65.4)).toBe("01:05.4");
+  });
+
+  test("rounding to tenths carries into the minutes", () => {
+    expect(formatClockTimestamp(59.96)).toBe("01:00.0");
+  });
+
+  test("minutes keep growing past an hour", () => {
+    expect(formatClockTimestamp(3661.5)).toBe("61:01.5");
+  });
+
+  test("clamps negatives to zero", () => {
+    expect(formatClockTimestamp(-1)).toBe("00:00.0");
+  });
+});
+
+describe("transcriptToTimestampedTxt", () => {
+  const chunk = (
+    text: string,
+    start: number,
+    end: number | null,
+  ): TranscriptChunk => ({ text, timestamp: [start, end] });
+
+  test("one bracketed range per line, trailing newline", () => {
+    const txt = transcriptToTimestampedTxt([
+      chunk(" Hello.", 3.21, 7.9),
+      chunk(" World.", 7.9, 12),
+    ]);
+    expect(txt).toBe("[00:03.2 – 00:07.9] Hello.\n[00:07.9 – 00:12.0] World.\n");
+  });
+
+  test("null end omits the range end", () => {
+    expect(transcriptToTimestampedTxt([chunk("Tail", 10, null)])).toBe(
+      "[00:10.0] Tail\n",
+    );
+  });
+
+  test("skips empty and whitespace-only chunks", () => {
+    const txt = transcriptToTimestampedTxt([
+      chunk("  ", 0, 1),
+      chunk("Kept", 1, 2),
+    ]);
+    expect(txt).toBe("[00:01.0 – 00:02.0] Kept\n");
+  });
+
+  test("no captioned chunks yields an empty string", () => {
+    expect(transcriptToTimestampedTxt([])).toBe("");
+    expect(transcriptToTimestampedTxt([chunk(" ", 0, 1)])).toBe("");
+  });
+});
+
 describe("exportFilename", () => {
   test("swaps the extension", () => {
     expect(exportFilename("talk.m4a", "srt")).toBe("talk.srt");
@@ -120,6 +180,15 @@ describe("exportFilename", () => {
     expect(exportFilename(".bashrc", "txt")).toBe(".bashrc.txt");
   });
 
+  test("compound extension keeps timestamped exports distinct", () => {
+    expect(exportFilename("talk.m4a", "timestamps.txt")).toBe(
+      "talk.timestamps.txt",
+    );
+    expect(exportFilename(null, "timestamps.txt")).toBe(
+      "transcript.timestamps.txt",
+    );
+  });
+
   test("null, undefined, and blank fall back to transcript.*", () => {
     expect(exportFilename(null, "srt")).toBe("transcript.srt");
     expect(exportFilename(undefined, "txt")).toBe("transcript.txt");