import Ionicons from "@expo/vector-icons/Ionicons";
import {
  BottomSheetBackdrop,
  type BottomSheetBackdropProps,
  BottomSheetModal,
  BottomSheetView,
} from "@gorhom/bottom-sheet";
import type {
  BaseItemDto,
  MediaSourceInfo,
} from "@jellyfin/sdk/lib/generated-client/models";
import { type Href, router, useFocusEffect } from "expo-router";
import { t } from "i18next";
import { useAtom } from "jotai";
import type React from "react";
import { useCallback, useMemo, useRef, useState } from "react";
import { Alert, Platform, Switch, View, type ViewProps } from "react-native";
import { toast } from "sonner-native";
import { useDownload } from "@/providers/DownloadProvider";
import { apiAtom, userAtom } from "@/providers/JellyfinProvider";
import { queueAtom } from "@/utils/atoms/queue";
import { useSettings } from "@/utils/atoms/settings";
import { getDefaultPlaySettings } from "@/utils/jellyfin/getDefaultPlaySettings";
import { getDownloadUrl } from "@/utils/jellyfin/media/getDownloadUrl";
import { AudioTrackSelector } from "./AudioTrackSelector";
import { type Bitrate, BitrateSelector } from "./BitrateSelector";
import { Button } from "./Button";
import { Text } from "./common/Text";
import { Loader } from "./Loader";
import { MediaSourceSelector } from "./MediaSourceSelector";
import ProgressCircle from "./ProgressCircle";
import { RoundButton } from "./RoundButton";
import { SubtitleTrackSelector } from "./SubtitleTrackSelector";

interface DownloadProps extends ViewProps {
  items: BaseItemDto[];
  MissingDownloadIconComponent: () => React.ReactElement;
  DownloadedIconComponent: () => React.ReactElement;
  title?: string;
  subtitle?: string;
  size?: "default" | "large";
}

export const DownloadItems: React.FC<DownloadProps> = ({
  items,
  MissingDownloadIconComponent,
  DownloadedIconComponent,
  title = "Download",
  subtitle = "",
  size = "default",
  ...props
}) => {
  const [api] = useAtom(apiAtom);
  const [user] = useAtom(userAtom);
  const [queue, _setQueue] = useAtom(queueAtom);
  const [settings] = useSettings();
  const [downloadUnwatchedOnly, setDownloadUnwatchedOnly] = useState(false);

  const { processes, startBackgroundDownload, getDownloadedItems } =
    useDownload();
  const downloadedFiles = getDownloadedItems();

  const [selectedMediaSource, setSelectedMediaSource] = useState<
    MediaSourceInfo | undefined | null
  >(undefined);
  const [selectedAudioStream, setSelectedAudioStream] = useState<number>(-1);
  const [selectedSubtitleStream, setSelectedSubtitleStream] =
    useState<number>(0);
  const [maxBitrate, setMaxBitrate] = useState<Bitrate>(
    settings?.defaultBitrate ?? {
      key: "Max",
      value: undefined,
    },
  );

  const userCanDownload = useMemo(
    () => user?.Policy?.EnableContentDownloading,
    [user],
  );

  const bottomSheetModalRef = useRef<BottomSheetModal>(null);

  const handlePresentModalPress = useCallback(() => {
    bottomSheetModalRef.current?.present();
  }, []);

  const handleSheetChanges = useCallback((_index: number) => {}, []);

  const closeModal = useCallback(() => {
    bottomSheetModalRef.current?.dismiss();
  }, []);

  const itemIds = useMemo(() => items.map((i) => i.Id), [items]);

  const itemsNotDownloaded = useMemo(
    () =>
      items.filter((i) => !downloadedFiles?.some((f) => f.item.Id === i.Id)),
    [items, downloadedFiles],
  );

  const itemsToDownload = useMemo(() => {
    if (downloadUnwatchedOnly) {
      return itemsNotDownloaded.filter((item) => !item.UserData?.Played);
    }
    return itemsNotDownloaded;
  }, [itemsNotDownloaded, downloadUnwatchedOnly]);

  const allItemsDownloaded = useMemo(() => {
    if (items.length === 0) return false;
    return itemsNotDownloaded.length === 0;
  }, [items, itemsNotDownloaded]);
  const itemsProcesses = useMemo(
    () => processes?.filter((p) => itemIds.includes(p.item.Id)),
    [processes, itemIds],
  );

  const progress = useMemo(() => {
    if (itemIds.length === 1)
      return itemsProcesses.reduce((acc, p) => acc + p.progress, 0);
    return (
      ((itemIds.length -
        queue.filter((q) => itemIds.includes(q.item.Id)).length) /
        itemIds.length) *
      100
    );
  }, [queue, itemsProcesses, itemIds]);

  const itemsQueued = useMemo(() => {
    return (
      itemsNotDownloaded.length > 0 &&
      itemsNotDownloaded.every((p) => queue.some((q) => p.Id === q.item.Id))
    );
  }, [queue, itemsNotDownloaded]);
  const navigateToDownloads = () => router.push("/downloads");

  const onDownloadedPress = () => {
    const firstItem = items?.[0];
    router.push(
      firstItem.Type !== "Episode"
        ? "/downloads"
        : ({
            pathname: `/downloads/${firstItem.SeriesId}`,
            params: {
              episodeSeasonIndex: firstItem.ParentIndexNumber,
            },
          } as Href),
    );
  };

  const initiateDownload = useCallback(
    async (...items: BaseItemDto[]) => {
      if (
        !api ||
        !user?.Id ||
        items.some((p) => !p.Id) ||
        (itemsNotDownloaded.length === 1 && !selectedMediaSource?.Id)
      ) {
        throw new Error(
          "DownloadItem ~ initiateDownload: No api or user or item",
        );
      }
      const downloadDetailsPromises = items.map(async (item) => {
        const { mediaSource, audioIndex, subtitleIndex } =
          itemsNotDownloaded.length > 1
            ? getDefaultPlaySettings(item, settings!)
            : {
                mediaSource: selectedMediaSource,
                audioIndex: selectedAudioStream,
                subtitleIndex: selectedSubtitleStream,
              };

        const downloadDetails = await getDownloadUrl({
          api,
          item,
          userId: user.Id!,
          mediaSource: mediaSource!,
          audioStreamIndex: audioIndex ?? -1,
          subtitleStreamIndex: subtitleIndex ?? -1,
          maxBitrate,
          deviceId: api.deviceInfo.id,
        });

        return {
          url: downloadDetails?.url,
          item,
          mediaSource: downloadDetails?.mediaSource,
        };
      });

      const downloadDetails = await Promise.all(downloadDetailsPromises);
      for (const { url, item, mediaSource } of downloadDetails) {
        if (!url) {
          Alert.alert(
            t("home.downloads.something_went_wrong"),
            t("home.downloads.could_not_get_stream_url_from_jellyfin"),
          );
          continue;
        }
        if (!mediaSource) {
          console.error(`Could not get download URL for ${item.Name}`);
          toast.error(
            t("Could not get download URL for {{itemName}}", {
              itemName: item.Name,
            }),
          );
          continue;
        }
        await startBackgroundDownload(url, item, mediaSource, maxBitrate);
      }
    },
    [
      api,
      user?.Id,
      itemsNotDownloaded,
      selectedMediaSource,
      selectedAudioStream,
      selectedSubtitleStream,
      settings,
      maxBitrate,
      startBackgroundDownload,
    ],
  );

  const acceptDownloadOptions = useCallback(() => {
    if (userCanDownload === true) {
      if (itemsToDownload.some((i) => !i.Id)) {
        throw new Error("No item id");
      }
      closeModal();

      initiateDownload(...itemsToDownload);
    } else {
      toast.error(
        t("home.downloads.toasts.you_are_not_allowed_to_download_files"),
      );
    }
  }, [closeModal, initiateDownload, itemsToDownload, userCanDownload]);

  const renderBackdrop = useCallback(
    (props: BottomSheetBackdropProps) => (
      <BottomSheetBackdrop
        {...props}
        disappearsOnIndex={-1}
        appearsOnIndex={0}
      />
    ),
    [],
  );
  useFocusEffect(
    useCallback(() => {
      if (!settings) return;
      if (itemsNotDownloaded.length !== 1) return;
      const { bitrate, mediaSource, audioIndex, subtitleIndex } =
        getDefaultPlaySettings(items[0], settings);
      setSelectedMediaSource(mediaSource ?? undefined);
      setSelectedAudioStream(audioIndex ?? 0);
      setSelectedSubtitleStream(subtitleIndex ?? -1);
      setMaxBitrate(bitrate);
    }, [items, itemsNotDownloaded, settings]),
  );

  const renderButtonContent = () => {
    if (processes.length > 0 && itemsProcesses.length > 0) {
      return progress === 0 ? (
        <Loader />
      ) : (
        <View className='-rotate-45'>
          <ProgressCircle
            size={24}
            fill={progress}
            width={4}
            tintColor='#9334E9'
            backgroundColor='#bdc3c7'
          />
        </View>
      );
    }

    if (itemsQueued) {
      return <Ionicons name='hourglass' size={24} color='white' />;
    }

    if (allItemsDownloaded) {
      return <DownloadedIconComponent />;
    }

    return <MissingDownloadIconComponent />;
  };

  const onButtonPress = () => {
    if (processes && itemsProcesses.length > 0) {
      navigateToDownloads();
    } else if (itemsQueued) {
      navigateToDownloads();
    } else if (allItemsDownloaded) {
      onDownloadedPress();
    } else {
      handlePresentModalPress();
    }
  };

  return (
    <View {...props}>
      <RoundButton size={size} onPress={onButtonPress}>
        {renderButtonContent()}
      </RoundButton>
      <BottomSheetModal
        ref={bottomSheetModalRef}
        enableDynamicSizing
        handleIndicatorStyle={{
          backgroundColor: "white",
        }}
        backgroundStyle={{
          backgroundColor: "#171717",
        }}
        onChange={handleSheetChanges}
        backdropComponent={renderBackdrop}
      >
        <BottomSheetView>
          <View className='flex flex-col space-y-4 px-4 pb-8 pt-2'>
            <View>
              <Text className='font-bold text-2xl text-neutral-100'>
                {title}
              </Text>
              <Text className='text-neutral-300'>
                {subtitle ||
                  t("item_card.download.download_x_item", {
                    item_count: itemsToDownload.length,
                  })}
              </Text>
            </View>
            <View className='flex flex-col space-y-2 w-full items-start'>
              <BitrateSelector
                inverted
                onChange={setMaxBitrate}
                selected={maxBitrate}
              />
              {itemsNotDownloaded.length > 1 && (
                <View className='flex flex-row items-center justify-between w-full py-2'>
                  <Text>{t("item_card.download.download_unwatched_only")}</Text>
                  <Switch
                    onValueChange={setDownloadUnwatchedOnly}
                    value={downloadUnwatchedOnly}
                  />
                </View>
              )}
              {itemsNotDownloaded.length === 1 && (
                <>
                  <MediaSourceSelector
                    item={items[0]}
                    onChange={setSelectedMediaSource}
                    selected={selectedMediaSource}
                  />
                  {selectedMediaSource && (
                    <View className='flex flex-col space-y-2'>
                      <AudioTrackSelector
                        source={selectedMediaSource}
                        onChange={setSelectedAudioStream}
                        selected={selectedAudioStream}
                      />
                      <SubtitleTrackSelector
                        source={selectedMediaSource}
                        onChange={setSelectedSubtitleStream}
                        selected={selectedSubtitleStream}
                      />
                    </View>
                  )}
                </>
              )}
            </View>

            <Button
              className='mt-auto'
              onPress={acceptDownloadOptions}
              color='purple'
            >
              {t("item_card.download.download_button")}
            </Button>
          </View>
        </BottomSheetView>
      </BottomSheetModal>
    </View>
  );
};

export const DownloadSingleItem: React.FC<{
  size?: "default" | "large";
  item: BaseItemDto;
}> = ({ item, size = "default" }) => {
  if (Platform.isTV) return;

  return (
    <DownloadItems
      size={size}
      title={
        item.Type === "Episode"
          ? t("item_card.download.download_episode")
          : t("item_card.download.download_movie")
      }
      subtitle={item.Name!}
      items={[item]}
      MissingDownloadIconComponent={() => (
        <Ionicons name='cloud-download-outline' size={24} color='white' />
      )}
      DownloadedIconComponent={() => (
        <Ionicons name='cloud-download' size={26} color='#9333ea' />
      )}
    />
  );
};