Chore: Restructure Repository for SvelteKit

_old/features/downloads/lib/autoRetry.ts

@@ -0,0 +1,39 @@
+import type { DownloadQueueItem } from "@types/index";
+
+const RETRY_DELAY_MS = 20_000;
+
+export interface AutoRetryHandle {
+  stop: () => void;
+}
+
+export function startAutoRetry(
+  getQueue:    () => DownloadQueueItem[],
+  isRunning:   () => boolean,
+  retryErrored: () => Promise<void>,
+): AutoRetryHandle {
+  let stopped = false;
+  let timer:   ReturnType<typeof setTimeout> | null = null;
+
+  async function tick() {
+    if (stopped) return;
+
+    const queue   = getQueue();
+    const errored = queue.filter(i => i.state === "ERROR");
+    const active  = queue.filter(i => i.state !== "ERROR");
+
+    if (errored.length > 0 && active.length === 0 && !isRunning()) {
+      await retryErrored().catch(() => {});
+    }
+
+    if (!stopped) timer = setTimeout(tick, RETRY_DELAY_MS);
+  }
+
+  timer = setTimeout(tick, RETRY_DELAY_MS);
+
+  return {
+    stop() {
+      stopped = true;
+      if (timer !== null) { clearTimeout(timer); timer = null; }
+    },
+  };
+}

_old/features/downloads/lib/downloadQueue.ts

@@ -0,0 +1,84 @@
+import type { DownloadQueueItem, ActiveDownload } from "@types/index";
+
+export function toActiveDownloads(queue: DownloadQueueItem[]): ActiveDownload[] {
+  return queue.map((item) => ({
+    chapterId: item.chapter.id,
+    mangaId:   item.chapter.mangaId,
+    progress:  item.progress,
+  }));
+}
+
+export function optimisticRemove(queue: DownloadQueueItem[], chapterId: number): DownloadQueueItem[] {
+  return queue.filter((i) => i.chapter.id !== chapterId);
+}
+
+export function optimisticRemoveMany(queue: DownloadQueueItem[], chapterIds: Set<number>): DownloadQueueItem[] {
+  return queue.filter((i) => !chapterIds.has(i.chapter.id));
+}
+
+export function isRunning(state: string | undefined): boolean {
+  return state === "STARTED";
+}
+
+export function getErrored(queue: DownloadQueueItem[]): DownloadQueueItem[] {
+  return queue.filter((i) => i.state === "ERROR");
+}
+
+export function pageProgress(progress: number, pageCount: number): { done: number; total: number } {
+  return { done: Math.round(progress * pageCount), total: pageCount };
+}
+
+export interface SpeedSample {
+  ts:       number;
+  progress: number;
+  pages:    number;
+}
+
+export function calcSpeed(prev: SpeedSample | null, current: SpeedSample): number | null {
+  if (!prev) return null;
+  const dt = (current.ts - prev.ts) / 1000;
+  if (dt <= 0) return null;
+  const prevDone = Math.round(prev.progress * prev.pages);
+  const curDone  = Math.round(current.progress * current.pages);
+  const delta    = curDone - prevDone;
+  if (delta <= 0) return null;
+  return delta / dt;
+}
+
+export function estimateEta(pagesPerSec: number, queue: DownloadQueueItem[]): number | null {
+  if (pagesPerSec <= 0 || queue.length === 0) return null;
+  let remaining = 0;
+  for (const item of queue) {
+    const pages = item.chapter.pageCount ?? 0;
+    remaining += pages - Math.round(item.progress * pages);
+  }
+  return remaining / pagesPerSec;
+}
+
+export function reorderSelectedToEdge(
+  queue: DownloadQueueItem[],
+  selected: Set<number>,
+  edge: "top" | "bottom",
+): DownloadQueueItem[] {
+  const pinned   = queue.filter((i) => selected.has(i.chapter.id));
+  const rest     = queue.filter((i) => !selected.has(i.chapter.id));
+  return edge === "top" ? [...pinned, ...rest] : [...rest, ...pinned];
+}
+
+const AVG_BYTES_PER_PAGE = 1_500_000;
+
+export function estimateQueueBytes(queue: DownloadQueueItem[]): number {
+  let total = 0;
+  for (const item of queue) {
+    const pages     = item.chapter.pageCount ?? 0;
+    const remaining = pages - Math.round(item.progress * pages);
+    total += remaining * AVG_BYTES_PER_PAGE;
+  }
+  return total;
+}
+
+export function formatEta(seconds: number): string {
+  if (seconds < 60)  return `~${Math.ceil(seconds)}s`;
+  if (seconds < 3600) return `~${Math.ceil(seconds / 60)}m`;
+  return `~${(seconds / 3600).toFixed(1)}h`;
+}