"use client";

import { useEffect, useMemo, useRef, useState } from "react";
import {
  Avatar,
  Combobox,
  Group,
  Loader,
  PillsInput,
  ScrollArea,
  Stack,
  Text,
  ThemeIcon,
  useCombobox,
} from "@mantine/core";
import { IconCheck, IconLink, IconPlus } from "@tabler/icons-react";

import type { RouterOutputs } from "@homarr/api";
import { clientApi } from "@homarr/api/client";
import { useI18n } from "@homarr/translation/client";

import type { SortableItemListInput } from "../options";
import { createDirectBookmark, getBookmarkFaviconUrl, splitBookmarkUrls } from "./bookmark-item";
import type { BookmarkItem } from "./bookmark-item";

type SelectableApp = RouterOutputs["app"]["selectable"][number];
export type BookmarkSelectionItem = SelectableApp | BookmarkItem;

const createOptionValue = "$create-url";

export const BookmarkAddButton: SortableItemListInput<BookmarkSelectionItem, string>["AddButton"] = ({
  addItem,
  migrateItems,
  values,
  initialOptions,
}) => {
  const t = useI18n("widget.bookmarks.option.items.apps");
  const tCommon = useI18n("common");
  const tSelect = useI18n("app.action.select");
  const { data: apps = [], isPending, error } = clientApi.app.selectable.useQuery();
  const [search, setSearch] = useState("");
  const combobox = useCombobox({
    onDropdownClose: () => combobox.resetSelectedOption(),
    onDropdownOpen: () => combobox.updateSelectedOptionIndex("active"),
  });
  const selectedValues = useMemo(() => new Set(values), [values]);
  const migrationStartedRef = useRef(false);
  const legacyUrls = useMemo(() => {
    if (!Array.isArray(initialOptions.customUrls)) return [];
    return initialOptions.customUrls.filter((value): value is string => typeof value === "string");
  }, [initialOptions.customUrls]);

  useEffect(() => {
    if (migrationStartedRef.current || legacyUrls.length === 0) return;

    migrationStartedRef.current = true;
    const legacyItems = legacyUrls.flatMap((url) => createDirectBookmark(url) ?? []);
    migrateItems(legacyItems, { customUrls: [] });
  }, [legacyUrls, migrateItems]);

  const normalizedSearch = search.trim().toLowerCase();
  const filteredApps = apps.filter((app) => {
    if (selectedValues.has(app.id)) return false;
    if (normalizedSearch.length === 0) return true;

    return app.name.toLowerCase().includes(normalizedSearch) || app.href?.toLowerCase().includes(normalizedSearch);
  });
  const pendingUrl = createDirectBookmark(search);

  const addUrls = (input: string) => {
    const nextValues = new Set(values);
    for (const value of splitBookmarkUrls(input)) {
      const item = createDirectBookmark(value);
      if (!item || nextValues.has(item.id)) continue;
      addItem(item);
      nextValues.add(item.id);
    }
    setSearch("");
    combobox.closeDropdown();
  };

  const handleOptionSubmit = (value: string) => {
    if (value === createOptionValue) {
      addUrls(search);
      return;
    }

    const app = apps.find((candidate) => candidate.id === value);
    if (app) addItem(app);
    setSearch("");
  };

  const options = filteredApps.map((app) => (
    <Combobox.Option value={app.id} key={app.id}>
      <Group gap="sm" wrap="nowrap">
        <Avatar src={app.iconUrl} name={app.name} color="gray" size={28} radius="sm">
          <IconLink size={16} />
        </Avatar>
        <Stack gap={0} miw={0} flex={1}>
          <Text size="sm" fw={600} truncate>
            {app.name}
          </Text>
          <Text size="xs" c="dimmed" truncate>
            {app.href}
          </Text>
        </Stack>
        <IconPlus size={16} aria-hidden />
      </Group>
    </Combobox.Option>
  ));

  return (
    <Combobox
      store={combobox}
      onOptionSubmit={handleOptionSubmit}
      position="bottom-start"
      middlewares={{ flip: true, shift: true }}
      styles={{
        dropdown: { overflow: "hidden" },
        option: { borderRadius: "var(--mantine-radius-sm)" },
      }}
    >
      <Combobox.DropdownTarget>
        <PillsInput
          label={t("label")}
          description={t("description")}
          error={error ? tCommon("error") : undefined}
          onClick={() => combobox.openDropdown()}
          leftSection={
            <ThemeIcon variant="light" size="sm" radius="xl">
              <IconLink size={14} />
            </ThemeIcon>
          }
          rightSection={isPending ? <Loader size="xs" /> : undefined}
          styles={{ input: { minHeight: 44 } }}
        >
          <Combobox.EventsTarget>
            <PillsInput.Field
              value={search}
              placeholder={t("placeholder")}
              onFocus={() => combobox.openDropdown()}
              onBlur={() => combobox.closeDropdown()}
              onChange={(event) => {
                setSearch(event.currentTarget.value);
                combobox.openDropdown();
                combobox.updateSelectedOptionIndex();
              }}
              onPaste={(event) => {
                const pastedValue = event.clipboardData.getData("text");
                if (splitBookmarkUrls(pastedValue).length < 2) return;
                event.preventDefault();
                addUrls(pastedValue);
              }}
              onKeyDown={(event) => {
                if (event.key !== "Enter") return;
                if (!pendingUrl) return;
                event.preventDefault();
                addUrls(search);
              }}
            />
          </Combobox.EventsTarget>
        </PillsInput>
      </Combobox.DropdownTarget>

      <Combobox.Dropdown>
        <ScrollArea.Autosize mah={280}>
          <Combobox.Options>
            {pendingUrl && !selectedValues.has(pendingUrl.id) ? (
              <Combobox.Option value={createOptionValue}>
                <Group gap="sm" wrap="nowrap">
                  <Avatar src={getBookmarkFaviconUrl(pendingUrl.href)} size={28} radius="sm" color="gray">
                    <IconLink size={16} />
                  </Avatar>
                  <Stack gap={0} miw={0} flex={1}>
                    <Text size="sm" fw={600} truncate>
                      {t("addUrl")}
                    </Text>
                    <Text size="xs" c="dimmed" truncate>
                      {pendingUrl.href}
                    </Text>
                  </Stack>
                  <IconCheck size={16} aria-hidden />
                </Group>
              </Combobox.Option>
            ) : null}
            {options}
            {!pendingUrl && options.length === 0 ? <Combobox.Empty>{tSelect("notFound")}</Combobox.Empty> : null}
          </Combobox.Options>
        </ScrollArea.Autosize>
        <Combobox.Footer>
          <Text size="xs" c="dimmed">
            {t("hint")}
          </Text>
        </Combobox.Footer>
      </Combobox.Dropdown>
    </Combobox>
  );
};