feat(discover): drill into show episode previews without subscribing

src/pages/Discover/DiscoverPage.tsx

@@ -5,18 +5,28 @@
  *                       placeholder (1/5 slot kept).
  *   depth 1 (current) — podcast results for the drilled category. Parent
  *                       pane = the categories list.
- *   preview            — detail of the hovered item (category summary, or
- *                       podcast detail + subscribe action).
+ *   depth 2 (current) — episodes of the drilled show, fetched on demand
+ *                       WITHOUT subscribing. Parent pane = the results list.
+ *   preview            — detail of the hovered item (category summary,
+ *                       podcast detail, or episode detail).
  *
  * Renders entirely through `<PaneRow>`; no bespoke 3-column flexbox JSX
- * remains. `l`/Enter drills in (category → results) or subscribes (on a
- * podcast); `h` pops a depth (noop at 0). j/k move only within the current
- * column. Moving through categories at depth 0 updates the store's selected
- * category so the preview follows.
+ * remains. `l`/Enter drills in (category → results → episodes); `a`
+ * subscribes the focused show (enter/l never subscribe — they open the
+ * episode list); `h` pops a depth (noop at 0). j/k move only within the
+ * current column. Moving through categories at depth 0 updates the store's
+ * selected category so the preview follows.
  */
 
 import { createMemo, For, Show, onMount, onCleanup } from "solid-js";
 import { useDiscoverStore, DISCOVER_CATEGORIES } from "@/stores/discover";
+import { useFeedStore } from "@/stores/feed";
+import { useDownloadStore } from "@/stores/download";
+import { useAudio } from "@/hooks/useAudio";
+import { useAudioNavStore, AudioSource } from "@/stores/audio-nav";
+import { DownloadStatus } from "@/types/episode";
+import type { Episode } from "@/types/episode";
+import type { Podcast } from "@/types/podcast";
 import { format } from "date-fns";
 import { useTheme } from "@/context/ThemeContext";
 import {
@@ -32,6 +42,7 @@ import type { KeybindActionName } from "@/context/KeybindContext";
 import { PaneRow } from "@/components/PaneRow";
 import { TabListPane } from "@/components/TabPanel";
 import { LoadingIndicator } from "@/components/LoadingIndicator";
+import { EpisodeRow, EpisodePreview } from "@/components/EpisodeList";
 import { useScrollIntoView } from "@/hooks/useScrollIntoView";
 import { useSelectionMarker } from "@/hooks/useSelectionMarker";
 
@@ -41,11 +52,16 @@ function DiscoverPage() {
 	// Static: detection never changes mid-session.
 	const nerd = supportsNerdFonts();
 	const discoverStore = useDiscoverStore();
+	const feedStore = useFeedStore();
+	const downloadStore = useDownloadStore();
+	const audio = useAudio();
+	const audioNav = useAudioNavStore();
 	const { theme } = useTheme();
 	const muted = () => theme.muted || theme.text;
 	const nav = useNavigation();
 	const marker = useSelectionMarker();
 
+	const stack = nav.depthStack;
 	const depth = nav.currentDepth;
 	const focus = (d: number = depth()) => nav.depthFocus(d);
 
@@ -60,14 +76,37 @@ function DiscoverPage() {
 		podcasts().length === 0 ? 0 : Math.min(focus(1), podcasts().length - 1);
 	const focusedPodcast = createMemo(() => podcasts()[focusedPodIdx()]);
 
+	// depth-2 frame ctx = the drilled podcast id (episode preview, no
+	// subscription). Episodes come from the discover store's session cache.
+	const drilledPodcastId = (): string => stack()[2]?.ctx ?? "";
+	const drilledPodcast = (): Podcast | undefined =>
+		podcasts().find((p) => p.id === drilledPodcastId());
+	const episodes = createMemo<Episode[]>(() => {
+		if (depth() < 2) return [];
+		return discoverStore.episodesForPodcast(drilledPodcastId());
+	});
+	const episodesLoading = () =>
+		depth() >= 2 && discoverStore.isLoadingEpisodesFor(drilledPodcastId());
+	const episodesError = () =>
+		depth() >= 2 ? discoverStore.previewError(drilledPodcastId()) : undefined;
+	const focusedEpIdx = () =>
+		episodes().length === 0 ? 0 : Math.min(focus(2), episodes().length - 1);
+	const focusedEpisode = () => episodes()[focusedEpIdx()];
+
 	const curLen = () =>
-		depth() === 0 ? categories().length : podcasts().length;
+		depth() === 0
+			? categories().length
+			: depth() === 1
+				? podcasts().length
+				: episodes().length;
 
 	const ensureFocus = () => {
 		if (categories().length > 0 && focus(0) >= categories().length)
 			nav.setDepthFocus(categories().length - 1, 0);
 		if (podcasts().length > 0 && focus(1) >= podcasts().length)
 			nav.setDepthFocus(podcasts().length - 1, 1);
+		if (episodes().length > 0 && focus(2) >= episodes().length)
+			nav.setDepthFocus(episodes().length - 1, 2);
 	};
 	onMount(ensureFocus);
 
@@ -80,13 +119,56 @@ function DiscoverPage() {
 	onMount(() => {
 		nav.registerResolver(`${nav.activeTab()}:${DEPTH_CENTER_PANE}`, (i) => {
 			if (depth() === 0) return categories()[i]?.id;
-			return podcasts()[i]?.id;
+			if (depth() === 1) return podcasts()[i]?.id;
+			return episodes()[i]?.id;
 		});
 	});
 
 	// ── helpers ────────────────────────────────────────────────────────────────
 	const formatDate = (d: Date) => format(d, "MMM d, yyyy");
 
+	/** The subscribed feed backing a podcast, if any (matched by directory id
+	 *  or feed URL — a Discover show may already be subscribed). */
+	const feedForPodcast = (p: Podcast) =>
+		feedStore.feeds().find(
+			(f) =>
+				f.podcast.id === p.id ||
+				(!!p.feedUrl && f.podcast.feedUrl === p.feedUrl),
+		);
+
+	const downloadLabel = (id: string) => {
+		switch (downloadStore.getDownloadStatus(id)) {
+			case DownloadStatus.QUEUED:
+				return "[Q]";
+			case DownloadStatus.DOWNLOADING:
+				return `[${downloadStore.getDownloadProgress(id)}%]`;
+			case DownloadStatus.COMPLETED:
+				return "[DL]";
+			case DownloadStatus.FAILED:
+				return "[ERR]";
+			default:
+				return "";
+		}
+	};
+	const downloadColor = (id: string) => {
+		switch (downloadStore.getDownloadStatus(id)) {
+			case DownloadStatus.QUEUED:
+				return theme.warning;
+			case DownloadStatus.DOWNLOADING:
+				return theme.primary;
+			case DownloadStatus.COMPLETED:
+				return theme.success;
+			case DownloadStatus.FAILED:
+				return theme.error;
+			default:
+				return muted();
+		}
+	};
+	const playEpisode = (ep: Episode) => {
+		audio.play(ep).catch(() => {});
+		audioNav.setSource(AudioSource.SEARCH, drilledPodcast()?.id);
+	};
+
 	// ── drill / open ───────────────────────────────────────────────────────────
 	function open() {
 		if (depth() === 0) {
@@ -97,9 +179,19 @@ function DiscoverPage() {
 			nav.setActivePane(DEPTH_CENTER_PANE);
 			return;
 		}
-		if (depth() >= 1) {
+		if (depth() === 1) {
 			const pod = focusedPodcast();
-			if (pod) discoverStore.toggleSubscription(pod.id);
+			if (!pod) return;
+			// Drill into the show's episode list WITHOUT subscribing — `l`,
+			// right, and Enter open the episodes; `a` is the subscribe key.
+			discoverStore.openEpisodes(pod).catch(() => {});
+			nav.pushDepth({ kind: "episodes", ctx: pod.id, focus: 0 } as DepthFrame);
+			nav.setActivePane(DEPTH_CENTER_PANE);
+			return;
+		}
+		if (depth() >= 2) {
+			const ep = focusedEpisode();
+			if (ep) playEpisode(ep);
 		}
 	}
 
@@ -115,12 +207,59 @@ function DiscoverPage() {
 		"goto-bottom": () => nav.gotoIndex(curLen() - 1, curLen()),
 		open: () => open(),
 		"toggle-select": () => {
-			if (depth() >= 1) {
+			if (depth() === 1) {
 				const pod = focusedPodcast();
 				if (pod) nav.toggleSelected(pod.id);
 			}
+			if (depth() >= 2) {
+				const ep = focusedEpisode();
+				if (ep) nav.toggleSelected(ep.id);
+			}
+		},
+		download: () => {
+			if (depth() !== 2) return;
+			const pod = drilledPodcast();
+			const ep = focusedEpisode();
+			if (!pod || !ep) return;
+			// Under its subscribed feed when already subscribed, otherwise as
+			// an "unsubscribed show" download (mirrors Search).
+			const feed = feedForPodcast(pod);
+			if (feed) downloadStore.startDownload(ep, feed.id);
+			else downloadStore.startUnsubscribedDownload(ep, pod);
+		},
+		"delete-download": () => {
+			if (depth() !== 2) return;
+			const ep = focusedEpisode();
+			if (!ep) return;
+			const id = ep.id;
+			if (downloadStore.getDownloadStatus(id) === DownloadStatus.NONE) return;
+			downloadStore.cancelDownload(id);
+			downloadStore.removeDownload(id).catch(() => {});
+		},
+		// `a`/`x` — the dedicated subscribe/unsubscribe keys (enter/l now open
+		// the episode list, so subscribing moved off open).
+		subscribe: () => {
+			if (depth() === 1) {
+				const pod = focusedPodcast();
+				if (pod && !pod.isSubscribed) discoverStore.subscribe(pod.id);
+				return;
+			}
+			if (depth() >= 2) {
+				const pod = drilledPodcast();
+				if (pod && !pod.isSubscribed) discoverStore.subscribe(pod.id);
+			}
+		},
+		unsubscribe: () => {
+			if (depth() !== 1) return;
+			const pod = focusedPodcast();
+			if (pod?.isSubscribed) discoverStore.unsubscribe(pod.id);
 		},
 		refresh: () => {
+			if (depth() >= 2) {
+				const pod = drilledPodcast();
+				if (pod) discoverStore.refreshEpisodes(pod).catch(() => {});
+				return;
+			}
 			discoverStore.refresh().catch(() => {});
 		},
 	};
@@ -161,7 +300,9 @@ function DiscoverPage() {
 	const currentLabel = () =>
 		depth() === 0
 			? "Categories"
-			: `${focusedCategory()?.name ?? "Discover"} · ${podcasts().length}`;
+			: depth() === 1
+				? `${focusedCategory()?.name ?? "Discover"} · ${podcasts().length}`
+				: `${drilledPodcast()?.title ?? "Episodes"} · ${episodes().length}`;
 
 	// ── parent pane: previous-depth list (muted/blank at depth 0) ─────────────
 	// Sibling <Show> blocks per depth (the known-good opentui disposal
@@ -174,7 +315,7 @@ function DiscoverPage() {
 			<Show when={depth() === 0}>
 				<TabListPane muted />
 			</Show>
-			<Show when={depth() >= 1}>
+			<Show when={depth() === 1}>
 				<For each={categories()}>
 					{(cat, index) => {
 						const lf = () => nav.depthFocus(0);
@@ -203,6 +344,33 @@ function DiscoverPage() {
 					}}
 				</For>
 			</Show>
+			<Show when={depth() >= 2}>
+				<For each={podcasts()}>
+					{(podcast, index) => {
+						const lf = () => nav.depthFocus(1);
+						const ref = useScrollIntoView(() => index() === lf());
+						return (
+							<box
+								ref={ref}
+								flexDirection="row"
+								gap={1}
+								paddingRight={1}
+								backgroundColor={focusBg(index(), lf(), false)}
+							>
+								<text fg={focusFg(index(), lf(), false)}>
+									{index() === lf() ? marker() : " "}
+								</text>
+								<text wrapMode="none" truncate fg={focusFg(index(), lf(), false)}>
+									{podcast.title}
+								</text>
+								<Show when={podcast.isSubscribed}>
+									<text flexShrink={0} fg={muted()}>[+]</text>
+								</Show>
+							</box>
+						);
+					}}
+				</For>
+			</Show>
 		</>
 	);
 
@@ -243,7 +411,7 @@ function DiscoverPage() {
 				</For>
 			</Show>
 			{/* depth ≥1: results */}
-			<Show when={depth() >= 1}>
+			<Show when={depth() === 1}>
 				<Show
 					when={podcasts().length > 0}
 					fallback={
@@ -304,11 +472,59 @@ function DiscoverPage() {
 					</For>
 					<Show when={discoverStore.isLoading()}>
 						<box paddingLeft={2} paddingTop={1}>
-							<LoadingIndicator label="Refreshing…" />
+							<LoadingIndicator />
 						</box>
 					</Show>
 				</Show>
 			</Show>
+			{/* depth ≥2: episodes of the drilled show (preview, no subscription) */}
+			<Show when={depth() >= 2}>
+				<Show when={episodesLoading()}>
+					<box padding={1}>
+						<LoadingIndicator label="Loading episodes…" />
+					</box>
+				</Show>
+				<Show when={episodesError() && !episodesLoading()}>
+					<box padding={1}>
+						<text fg={theme.error}>{episodesError()}</text>
+						<box height={1} />
+						<text fg={muted()}>r: retry · h: back</text>
+					</box>
+				</Show>
+				<Show
+					when={
+						!episodesLoading() && !episodesError() && episodes().length === 0
+					}
+				>
+					<box padding={1}>
+						<text fg={muted()}>No episodes found. :refresh</text>
+					</box>
+				</Show>
+				<Show
+					when={
+						!episodesLoading() && !episodesError() && episodes().length > 0
+					}
+				>
+					<For each={episodes()}>
+						{(ep, index) => (
+							<EpisodeRow
+								episode={ep}
+								index={index}
+								focused={focusedEpIdx}
+								active={isActive}
+								selected={() => nav.isSelected(ep.id)}
+								downloadLabel={() => downloadLabel(ep.id)}
+								downloadColor={() => downloadColor(ep.id)}
+								marker={marker}
+								onMouseDown={() => {
+									nav.setActivePane(DEPTH_CENTER_PANE);
+									nav.setDepthFocus(index(), 2);
+								}}
+							/>
+						)}
+					</For>
+				</Show>
+			</Show>
 		</>
 	);
 
@@ -357,8 +573,8 @@ function DiscoverPage() {
 					</box>
 				)}
 			</Show>
-		) : (
-			// depth ≥1 preview: hovered podcast + subscribe
+		) : depth() === 1 ? (
+			// depth 1 preview: hovered podcast + episode-list hint
 			<Show
 				when={focusedPodcast()}
 				fallback={
@@ -376,10 +592,10 @@ function DiscoverPage() {
 							<text fg={muted()}>by {pod().author}</text>
 						</Show>
 						<Show when={pod().isSubscribed}>
-							<text fg={theme.success}>✓ Subscribed</text>
+							<text fg={theme.success}>✓ Subscribed · x: unsubscribe</text>
 						</Show>
 						<Show when={!pod().isSubscribed}>
-							<text fg={theme.primary}>[+] Subscribe (enter)</text>
+							<text fg={theme.primary}>a: subscribe</text>
 						</Show>
 						<box height={1} />
 						<text fg={theme.textSecondary}>
@@ -398,10 +614,67 @@ function DiscoverPage() {
 						</Show>
 						<text fg={muted()}>Updated: {formatDate(pod().lastUpdated)}</text>
 						<box height={1} />
-						<text fg={muted()}>enter: subscribe · h: back · r: refresh</text>
+						<text fg={muted()}>enter/l: episodes · h: back · r: refresh</text>
 					</box>
 				)}
 			</Show>
+		) : (
+			// depth ≥2 preview: hovered episode (or loading/error/empty)
+			<>
+				<Show when={episodesLoading()}>
+					<box padding={1}>
+						<LoadingIndicator label="Loading episodes…" />
+					</box>
+				</Show>
+				<Show when={episodesError() && !episodesLoading()}>
+					<box padding={1}>
+						<text fg={theme.error}>{episodesError()}</text>
+						<box height={1} />
+						<text fg={muted()}>r: retry · h: back</text>
+					</box>
+				</Show>
+				<Show
+					when={
+						!episodesLoading() && !episodesError() && episodes().length === 0
+					}
+				>
+					<box padding={1}>
+						<text fg={muted()}>No episodes found.</text>
+					</box>
+				</Show>
+				<Show
+					when={
+						!episodesLoading() &&
+						!episodesError() &&
+						episodes().length > 0 &&
+						focusedEpisode()
+					}
+					fallback={
+						<box padding={1}>
+							<text fg={muted()}>No episode focused</text>
+						</box>
+					}
+				>
+					{(ep) => (
+						<EpisodePreview
+							episode={() => ep()}
+							author={() => drilledPodcast()?.author}
+							downloadLabel={() => downloadLabel(ep().id)}
+							downloadColor={() => downloadColor(ep().id)}
+							hint={() =>
+								`enter: play · d: download${
+									downloadStore.getDownloadStatus(ep().id) !==
+									DownloadStatus.NONE
+										? " · D: delete"
+										: ""
+								}${
+									drilledPodcast()?.isSubscribed ? "" : " · a: subscribe"
+								} · h: back`
+							}
+						/>
+					)}
+				</Show>
+			</>
 		);
 
 	return (