/**
 * MyShowsPage - Two-panel file-explorer style view
 * Left panel: list of subscribed shows
 * Right panel: episodes for the selected show
 */

import { createSignal, For, Show, createMemo, createEffect } from "solid-js";
import { useKeyboard } from "@opentui/solid";
import { useFeedStore } from "@/stores/feed";
import { useDownloadStore } from "@/stores/download";
import { DownloadStatus } from "@/types/episode";
import { format } from "date-fns";
import type { Episode } from "@/types/episode";
import type { Feed } from "@/types/feed";
import { PageProps } from "@/App";

enum MyShowsPaneType {
  SHOWS,
  EPISODES,
}

export const MyShowsPaneCount = 2

export function MyShowsPage(props: PageProps) {
  const feedStore = useFeedStore();
  const downloadStore = useDownloadStore();
  const [focusPane, setFocusPane] = createSignal<>("shows");
  const [showIndex, setShowIndex] = createSignal(0);
  const [episodeIndex, setEpisodeIndex] = createSignal(0);
  const [isRefreshing, setIsRefreshing] = createSignal(false);

  /** Threshold: load more when within this many items of the end */
  const LOAD_MORE_THRESHOLD = 5;

  const shows = () => feedStore.getFilteredFeeds();

  const selectedShow = createMemo(() => {
    const s = shows();
    const idx = showIndex();
    return idx < s.length ? s[idx] : undefined;
  });

  const episodes = createMemo(() => {
    const show = selectedShow();
    if (!show) return [];
    return [...show.episodes].sort(
      (a, b) => b.pubDate.getTime() - a.pubDate.getTime(),
    );
  });

  // Detect when user navigates near the bottom and load more episodes
  createEffect(() => {
    const idx = episodeIndex();
    const eps = episodes();
    const show = selectedShow();
    if (!show || eps.length === 0) return;

    const nearBottom = idx >= eps.length - LOAD_MORE_THRESHOLD;
    if (
      nearBottom &&
      feedStore.hasMoreEpisodes(show.id) &&
      !feedStore.isLoadingMore()
    ) {
      feedStore.loadMoreEpisodes(show.id);
    }
  });

  const formatDate = (date: Date): string => {
    return format(date, "MMM d, yyyy");
  };

  const formatDuration = (seconds: number): string => {
    const mins = Math.floor(seconds / 60);
    const hrs = Math.floor(mins / 60);
    if (hrs > 0) return `${hrs}h ${mins % 60}m`;
    return `${mins}m`;
  };

  /** Get download status label for an episode */
  const downloadLabel = (episodeId: string): string => {
    const status = downloadStore.getDownloadStatus(episodeId);
    switch (status) {
      case DownloadStatus.QUEUED:
        return "[Q]";
      case DownloadStatus.DOWNLOADING: {
        const pct = downloadStore.getDownloadProgress(episodeId);
        return `[${pct}%]`;
      }
      case DownloadStatus.COMPLETED:
        return "[DL]";
      case DownloadStatus.FAILED:
        return "[ERR]";
      default:
        return "";
    }
  };

  /** Get download status color */
  const downloadColor = (episodeId: string): string => {
    const status = downloadStore.getDownloadStatus(episodeId);
    switch (status) {
      case DownloadStatus.QUEUED:
        return "yellow";
      case DownloadStatus.DOWNLOADING:
        return "cyan";
      case DownloadStatus.COMPLETED:
        return "green";
      case DownloadStatus.FAILED:
        return "red";
      default:
        return "gray";
    }
  };

  const handleRefresh = async () => {
    const show = selectedShow();
    if (!show) return;
    setIsRefreshing(true);
    await feedStore.refreshFeed(show.id);
    setIsRefreshing(false);
  };

  const handleUnsubscribe = () => {
    const show = selectedShow();
    if (!show) return;
    feedStore.removeFeed(show.id);
    setShowIndex((i) => Math.max(0, i - 1));
    setEpisodeIndex(0);
  };

  return {
    showsPanel: () => (
      <box flexDirection="column" height="100%">
        <Show when={isRefreshing()}>
          <text fg="yellow">Refreshing...</text>
        </Show>
        <Show
          when={shows().length > 0}
          fallback={
            <box padding={1}>
              <text fg="gray">
                No shows yet. Subscribe from Discover or Search.
              </text>
            </box>
          }
        >
          <scrollbox height="100%" focused={props.depth}>
            <For each={shows()}>
              {(feed, index) => (
                <box
                  flexDirection="row"
                  gap={1}
                  paddingLeft={1}
                  paddingRight={1}
                  backgroundColor={index() === showIndex() ? "#333" : undefined}
                  onMouseDown={() => {
                    setShowIndex(index());
                    setEpisodeIndex(0);
                  }}
                >
                  <text fg={index() === showIndex() ? "cyan" : "gray"}>
                    {index() === showIndex() ? ">" : " "}
                  </text>
                  <text fg={index() === showIndex() ? "white" : undefined}>
                    {feed.customName || feed.podcast.title}
                  </text>
                  <text fg="gray">({feed.episodes.length})</text>
                </box>
              )}
            </For>
          </scrollbox>
        </Show>
      </box>
    ),

    episodesPanel: () => (
      <box flexDirection="column" height="100%">
        <Show
          when={selectedShow()}
          fallback={
            <box padding={1}>
              <text fg="gray">Select a show</text>
            </box>
          }
        >
          <Show
            when={episodes().length > 0}
            fallback={
              <box padding={1}>
                <text fg="gray">No episodes. Press [r] to refresh.</text>
              </box>
            }
          >
            <scrollbox
              height="100%"
              focused={props.focused && focusPane() === "episodes"}
            >
              <For each={episodes()}>
                {(episode, index) => (
                  <box
                    flexDirection="column"
                    gap={0}
                    paddingLeft={1}
                    paddingRight={1}
                    backgroundColor={
                      index() === episodeIndex() ? "#333" : undefined
                    }
                    onMouseDown={() => setEpisodeIndex(index())}
                  >
                    <box flexDirection="row" gap={1}>
                      <text fg={index() === episodeIndex() ? "cyan" : "gray"}>
                        {index() === episodeIndex() ? ">" : " "}
                      </text>
                      <text
                        fg={index() === episodeIndex() ? "white" : undefined}
                      >
                        {episode.episodeNumber
                          ? `#${episode.episodeNumber} `
                          : ""}
                        {episode.title}
                      </text>
                    </box>
                    <box flexDirection="row" gap={2} paddingLeft={2}>
                      <text fg="gray">{formatDate(episode.pubDate)}</text>
                      <text fg="gray">{formatDuration(episode.duration)}</text>
                      <Show when={downloadLabel(episode.id)}>
                        <text fg={downloadColor(episode.id)}>
                          {downloadLabel(episode.id)}
                        </text>
                      </Show>
                    </box>
                  </box>
                )}
              </For>
              <Show when={feedStore.isLoadingMore()}>
                <box paddingLeft={2} paddingTop={1}>
                  <text fg="yellow">Loading more episodes...</text>
                </box>
              </Show>
              <Show
                when={
                  !feedStore.isLoadingMore() &&
                  selectedShow() &&
                  feedStore.hasMoreEpisodes(selectedShow()!.id)
                }
              >
                <box paddingLeft={2} paddingTop={1}>
                  <text fg="gray">Scroll down for more episodes</text>
                </box>
              </Show>
            </scrollbox>
          </Show>
        </Show>
      </box>
    ),

    focusPane,
    selectedShow,
  };
}