feat(downloads): estimate a transcode's size so the progress bar moves

A transcode is produced as it is sent — chunked, with no Content-Length — and the worker reported progress 0.0 for its whole duration: an empty bar reading "0%" while the byte count climbed for an hour. That is the case every film whose audio must be re-encoded lands in. The backend already fetches the item to decide the audio policy, and that item carries what a prediction needs: the source's size (an `original` download copies the picture, so the output is the source give or take the audio track) and its runtime (a preset re-encodes at fixed rates, so the size is rate × runtime — from a preset table the URL builder now shares, so the two cannot drift). The prediction is made where the URL is resolved and persisted as the row's file_size. The worker uses it only when the response has no length; the server's figure always wins; an estimated bar is capped at 99% so a low prediction never shows a finished download still running; and the Completed event now carries the bytes actually written so the frontend stops persisting the row's file_size as the final size. The row renders three honest states: exact "42%", estimated "~42%" with "X / ~Y", or — with no total at all — an indeterminate band and the bytes so far, never "0%". The single-video button joins the series/season buttons on the enqueue path so all three resolve, and predict, in one place. DR-290, UT-252, UT-253, UT-254. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 11:18:29 +02:00
parent e271874b1d
commit b3228cb4f4
15 changed files with 716 additions and 105 deletions
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+import { describe, it, expect } from "vitest";
+import { describeProgress } from "./downloadProgress";
+
+const base = {
+  status: "downloading" as const,
+  progress: 0,
+  bytesDownloaded: 0,
+  fileSize: undefined as number | undefined,
+  fileSizeEstimated: false,
+};
+
+// TRACES: UR-071 | DR-290 | UT-254
+describe("describeProgress", () => {
+  it("shows an indeterminate bar, not 0%, when the size is unknown", () => {
+    // A transcode has no Content-Length and (before the estimate) no total:
+    // 200 MB in, the bar read "0%". That is not progress information.
+    const view = describeProgress({ ...base, bytesDownloaded: 200 * 1024 * 1024 });
+    expect(view.kind).toBe("indeterminate");
+    expect(view.percent).toBeNull();
+    expect(view.label).toBe("200.0 MB");
+  });
+
+  it("marks an estimated total as approximate", () => {
+    const view = describeProgress({
+      ...base,
+      progress: 0.42,
+      bytesDownloaded: 420,
+      fileSize: 1000,
+      fileSizeEstimated: true,
+    });
+    expect(view.kind).toBe("estimated");
+    expect(view.percent).toBe(42);
+    expect(view.percentLabel).toBe("~42%");
+    expect(view.label).toBe("420 B / ~1000 B");
+  });
+
+  it("reports an exact total plainly", () => {
+    const view = describeProgress({
+      ...base,
+      progress: 0.5,
+      bytesDownloaded: 512,
+      fileSize: 1024,
+    });
+    expect(view.kind).toBe("exact");
+    expect(view.percent).toBe(50);
+    expect(view.percentLabel).toBe("50%");
+    expect(view.label).toBe("512 B / 1.0 KB");
+  });
+
+  it("keeps a paused download's bar where it stopped", () => {
+    const view = describeProgress({
+      ...base,
+      status: "paused",
+      progress: 0.25,
+      bytesDownloaded: 256,
+      fileSize: 1024,
+    });
+    expect(view.kind).toBe("exact");
+    expect(view.percent).toBe(25);
+  });
+});