import { getPagePath } from '@nanostores/router'
import { clsx } from 'clsx'
import { For, Show, createEffect, createSignal, on, onCleanup, onMount } from 'solid-js'

import { useLocalize } from '../../../context/localize'
import { apiClient } from '../../../graphql/client/core'
import { LoadShoutsFilters, LoadShoutsOptions, Shout } from '../../../graphql/schema/core.gen'
import { LayoutType } from '../../../pages/types'
import { router } from '../../../stores/router'
import { getUnixtime } from '../../../utils/getServerDate'
import { restoreScrollPosition, saveScrollPosition } from '../../../utils/scroll'
import { ArticleCard } from '../../Feed/ArticleCard'
import { Button } from '../../_shared/Button'
import { ConditionalWrapper } from '../../_shared/ConditionalWrapper'
import { Loading } from '../../_shared/Loading'
import { ArticleCardSwiper } from '../../_shared/SolidSwiper/ArticleCardSwiper'

import styles from './Expo.module.scss'

type Props = {
  shouts: Shout[]
  layout: LayoutType
}

export const PRERENDERED_ARTICLES_COUNT = 36
const LOAD_MORE_PAGE_SIZE = 12

export const Expo = (props: Props) => {
  const { t } = useLocalize()
  const [isLoadMoreButtonVisible, setIsLoadMoreButtonVisible] = createSignal(false)
  const [favoriteTopArticles, setFavoriteTopArticles] = createSignal<Shout[]>([])
  const [reactedTopMonthArticles, setReactedTopMonthArticles] = createSignal<Shout[]>([])
  const [articlesEndPage, setArticlesEndPage] = createSignal<number>(PRERENDERED_ARTICLES_COUNT)
  const [expoShouts, setExpoShouts] = createSignal<Shout[]>([])
  const getLoadShoutsFilters = (additionalFilters: LoadShoutsFilters = {}): LoadShoutsFilters => {
    const filters = { ...additionalFilters }

    if (!filters.layouts) filters.layouts = []
    if (props.layout) {
      filters.layouts.push(props.layout)
    } else {
      filters.layouts.push('audio', 'video', 'image', 'literature')
    }

    return filters
  }

  const loadMore = async (count: number) => {
    const options: LoadShoutsOptions = {
      filters: getLoadShoutsFilters(),
      limit: count,
      offset: expoShouts().length,
    }

    options.filters = props.layout
      ? { layouts: [props.layout] }
      : { layouts: ['audio', 'video', 'image', 'literature'] }

    const newShouts = await apiClient.getShouts(options)
    const hasMore = newShouts?.length !== options.limit + 1 && newShouts?.length !== 0
    setIsLoadMoreButtonVisible(hasMore)

    setExpoShouts((prev) => [...prev, ...newShouts])
  }

  const loadMoreWithoutScrolling = async (count: number) => {
    saveScrollPosition()
    await loadMore(count)
    restoreScrollPosition()
  }

  const loadRandomTopArticles = async () => {
    const options: LoadShoutsOptions = {
      filters: { ...getLoadShoutsFilters(), featured: true },
      limit: 10,
      random_limit: 100,
    }
    const result = await apiClient.getRandomTopShouts({ options })
    setFavoriteTopArticles(result)
  }

  const loadRandomTopMonthArticles = async () => {
    const now = new Date()
    const after = getUnixtime(new Date(now.setMonth(now.getMonth() - 1)))

    const options: LoadShoutsOptions = {
      filters: { ...getLoadShoutsFilters({ after }), reacted: true },
      limit: 10,
      random_limit: 10,
    }

    const result = await apiClient.getRandomTopShouts({ options })
    setReactedTopMonthArticles(result)
  }

  onMount(() => {
    loadMore(PRERENDERED_ARTICLES_COUNT + LOAD_MORE_PAGE_SIZE)
    loadRandomTopArticles()
    loadRandomTopMonthArticles()
  })

  createEffect(
    on(
      () => props.layout,
      () => {
        setExpoShouts([])
        setIsLoadMoreButtonVisible(false)
        setFavoriteTopArticles([])
        setReactedTopMonthArticles([])
        setArticlesEndPage(PRERENDERED_ARTICLES_COUNT)
        loadMore(PRERENDERED_ARTICLES_COUNT + LOAD_MORE_PAGE_SIZE)
        loadRandomTopArticles()
        loadRandomTopMonthArticles()
      },
    ),
  )

  onCleanup(() => {
    setExpoShouts([])
  })

  const handleLoadMoreClick = () => {
    loadMoreWithoutScrolling(LOAD_MORE_PAGE_SIZE)
    setArticlesEndPage((prev) => prev + LOAD_MORE_PAGE_SIZE)
  }

  return (
    <div class={styles.Expo}>
      <div class="wide-container">
        <ul class={clsx('view-switcher')}>
          <li class={clsx({ 'view-switcher__item--selected': !props.layout })}>
            <ConditionalWrapper
              condition={Boolean(props.layout)}
              wrapper={(children) => <a href={getPagePath(router, 'expo', { layout: '' })}>{children}</a>}
            >
              <span class={clsx('linkReplacement')}>{t('All')}</span>
            </ConditionalWrapper>
          </li>
          <li class={clsx({ 'view-switcher__item--selected': props.layout === 'literature' })}>
            <ConditionalWrapper
              condition={props.layout !== 'literature'}
              wrapper={(children) => (
                <a href={getPagePath(router, 'expo', { layout: 'literature' })}>{children}</a>
              )}
            >
              <span class={clsx('linkReplacement')}>{t('Literature')}</span>
            </ConditionalWrapper>
          </li>
          <li class={clsx({ 'view-switcher__item--selected': props.layout === 'audio' })}>
            <ConditionalWrapper
              condition={props.layout !== 'audio'}
              wrapper={(children) => (
                <a href={getPagePath(router, 'expo', { layout: 'audio' })}>{children}</a>
              )}
            >
              <span class={clsx('linkReplacement')}>{t('Music')}</span>
            </ConditionalWrapper>
          </li>
          <li class={clsx({ 'view-switcher__item--selected': props.layout === 'image' })}>
            <ConditionalWrapper
              condition={props.layout !== 'image'}
              wrapper={(children) => (
                <a href={getPagePath(router, 'expo', { layout: 'image' })}>{children}</a>
              )}
            >
              <span class={clsx('linkReplacement')}>{t('Gallery')}</span>
            </ConditionalWrapper>
          </li>
          <li class={clsx({ 'view-switcher__item--selected': props.layout === 'video' })}>
            <ConditionalWrapper
              condition={props.layout !== 'video'}
              wrapper={(children) => (
                <a href={getPagePath(router, 'expo', { layout: 'video' })}>{children}</a>
              )}
            >
              <span class={clsx('cursorPointer linkReplacement')}>{t('Video')}</span>
            </ConditionalWrapper>
          </li>
        </ul>
      </div>

      <Show when={expoShouts().length > 0} fallback={<Loading />}>
        <div class="wide-container">
          <div class="row">
            <For each={expoShouts()?.slice(0, LOAD_MORE_PAGE_SIZE)}>
              {(shout) => (
                <div class="col-md-6 mt-md-5 col-sm-8 mt-sm-3">
                  <ArticleCard
                    article={shout}
                    settings={{ nodate: true, nosubtitle: true, noAuthorLink: true }}
                    desktopCoverSize="XS"
                    withAspectRatio={true}
                  />
                </div>
              )}
            </For>
            <Show when={reactedTopMonthArticles()?.length > 0} keyed={true}>
              <ArticleCardSwiper title={t('Top month')} slides={reactedTopMonthArticles()} />
            </Show>
            <For each={expoShouts().slice(LOAD_MORE_PAGE_SIZE, LOAD_MORE_PAGE_SIZE * 2)}>
              {(shout) => (
                <div class="col-md-6 mt-md-5 col-sm-8 mt-sm-3">
                  <ArticleCard
                    article={shout}
                    settings={{ nodate: true, nosubtitle: true, noAuthorLink: true }}
                    desktopCoverSize="XS"
                    withAspectRatio={true}
                  />
                </div>
              )}
            </For>
            <Show when={favoriteTopArticles()?.length > 0} keyed={true}>
              <ArticleCardSwiper title={t('Favorite')} slides={favoriteTopArticles()} />
            </Show>
            <For each={expoShouts().slice(LOAD_MORE_PAGE_SIZE * 2, articlesEndPage())}>
              {(shout) => (
                <div class="col-md-6 mt-md-5 col-sm-8 mt-sm-3">
                  <ArticleCard
                    article={shout}
                    settings={{ nodate: true, nosubtitle: true, noAuthorLink: true }}
                    desktopCoverSize="XS"
                    withAspectRatio={true}
                  />
                </div>
              )}
            </For>
          </div>
          <Show when={isLoadMoreButtonVisible()}>
            <div class={styles.showMore}>
              <Button size="L" onClick={handleLoadMoreClick} value={t('Load more')} />
            </div>
          </Show>
        </div>
      </Show>
    </div>
  )
}