import { A, useLocation } from '@solidjs/router'
import { clsx } from 'clsx'
import { For, Match, Show, Switch, createEffect, createMemo, createSignal, on } from 'solid-js'
import { Loading } from '~/components/_shared/Loading'
import { useAuthors } from '~/context/authors'
import { useFollowing } from '~/context/following'
import { useGraphQL } from '~/context/graphql'
import { useLocalize } from '~/context/localize'
import { useSession } from '~/context/session'
import getAuthorFollowersQuery from '~/graphql/query/core/author-followers'
import getAuthorFollowsQuery from '~/graphql/query/core/author-follows'
import type { Author, Reaction, Shout, Topic } from '~/graphql/schema/core.gen'
import { byCreated } from '~/lib/sort'
import { paginate } from '~/utils/paginate'
import stylesArticle from '../../Article/Article.module.scss'
import { Comment } from '../../Article/Comment'
import { AuthorCard } from '../../Author/AuthorCard'
import { AuthorShoutsRating } from '../../Author/AuthorShoutsRating'
import { Placeholder } from '../../Feed/Placeholder'
import { Row1 } from '../../Feed/Row1'
import { Row2 } from '../../Feed/Row2'
import { Row3 } from '../../Feed/Row3'
import styles from './Author.module.scss'

type AuthorViewProps = {
  authorSlug: string
  selectedTab: string
  shouts?: Shout[]
  author?: Author
}

export const PRERENDERED_ARTICLES_COUNT = 12
const LOAD_MORE_PAGE_SIZE = 9

export const AuthorView = (props: AuthorViewProps) => {
  // contexts
  const { t } = useLocalize()
  const loc = useLocation()
  const { session } = useSession()
  const { query } = useGraphQL()
  const { loadAuthor, authorsEntities } = useAuthors()
  const { followers: myFollowers, follows: myFollows } = useFollowing()

  // signals
  const [isBioExpanded, setIsBioExpanded] = createSignal(false)
  const [author, setAuthor] = createSignal<Author>()
  const [followers, setFollowers] = createSignal<Author[]>([] as Author[])
  const [following, changeFollowing] = createSignal<Array<Author | Topic>>([] as Array<Author | Topic>) // flat AuthorFollowsResult
  const [showExpandBioControl, setShowExpandBioControl] = createSignal(false)
  const [commented, setCommented] = createSignal<Reaction[]>([])

  // derivatives
  const me = createMemo<Author>(() => session()?.user?.app_data?.profile as Author)
  const pages = createMemo<Shout[][]>(() =>
    paginate((props.shouts || []).slice(1), PRERENDERED_ARTICLES_COUNT, LOAD_MORE_PAGE_SIZE)
  )

  // 1 // проверяет не собственный ли это профиль, иначе - загружает
  const [isFetching, setIsFetching] = createSignal(false)
  createEffect(
    on(
      [() => session()?.user?.app_data?.profile, () => props.authorSlug || ''],
      async ([me, slug]) => {
        console.debug('[AuthorView] checking if my profile')
        const my = slug && me?.slug === slug
        if (my) {
          console.debug('[Author] my profile precached')
          if (me) {
            setAuthor(me)
            if (myFollowers()) setFollowers((myFollowers() || []) as Author[])
            changeFollowing([...(myFollows?.topics || []), ...(myFollows?.authors || [])])
          }
        } else if (slug && !isFetching()) {
          setIsFetching(true)
          await loadAuthor({ slug })
          setIsFetching(false) // Сброс состояния загрузки после завершения
        }
      },
      { defer: true }
    )
  )

  // 2 // догружает подписки автора
  createEffect(
    on(
      () => authorsEntities()[props.author?.slug || props.authorSlug || ''],
      async (found) => {
        if (!found) return
        console.debug('[AuthorView] ')
        console.info(`[Author] profile for @${found.slug} fetched`)
        const followsResp = await query(getAuthorFollowsQuery, { slug: found.slug }).toPromise()
        const follows = followsResp?.data?.get_author_followers || {}
        changeFollowing([...(follows?.authors || []), ...(follows?.topics || [])])
        console.info(`[Author] follows for @${found.slug} fetched`)
        const followersResp = await query(getAuthorFollowersQuery, { slug: found.slug }).toPromise()
        setFollowers(followersResp?.data?.get_author_followers || [])
        console.info(`[Author] followers for @${found.slug} fetched`)
        setIsFetching(false)
        setTimeout(() => setAuthor(found), 1)
      },
      { defer: true }
    )
  )

  // event handlers
  let bioContainerRef: HTMLDivElement
  let bioWrapperRef: HTMLDivElement
  const checkBioHeight = (bio = bioWrapperRef) => {
    if (!bio) return
    const showExpand = bioContainerRef.offsetHeight > bio.offsetHeight
    setShowExpandBioControl(showExpand)
    console.debug('[AuthorView] mounted, show expand bio container:', showExpand)
  }

  const handleDeleteComment = (id: number) => {
    setCommented((prev) => (prev || []).filter((comment) => comment.id !== id))
  }

  // on load
  createEffect(on(() => bioContainerRef, checkBioHeight))
  createEffect(
    on(
      () => props.selectedTab,
      (tab) => tab && console.log('[views.Author] profile tab switched')
    )
  )
  const AuthorFeed = () => (
    <Show when={Array.isArray(props.shouts) && props.shouts.length > 0 && props.shouts[0]}>
      <Row1 article={props.shouts?.[0] as Shout} noauthor={true} nodate={true} />

      <Show when={props.shouts?.length || 0}>
        <Show when={props.shouts?.length === 1}>
          <Row1 article={props.shouts?.[0] as Shout} noauthor={true} nodate={true} />
        </Show>
        <Show when={props.shouts?.length === 2}>
          <Row2 articles={props.shouts as Shout[]} isEqual={true} noauthor={true} nodate={true} />
        </Show>
        <Show when={props.shouts?.length === 3}>
          <Row3 articles={props.shouts as Shout[]} noauthor={true} nodate={true} />
        </Show>
        <Show when={props.shouts && props.shouts.length > 3}>
          <For each={pages()}>
            {(page) => (
              <>
                <Row1 article={page[0]} noauthor={true} nodate={true} />
                <Row2 articles={page.slice(1, 3)} isEqual={true} noauthor={true} />
                <Row1 article={page[3]} noauthor={true} nodate={true} />
                <Row2 articles={page.slice(4, 6)} isEqual={true} noauthor={true} />
                <Row1 article={page[6]} noauthor={true} nodate={true} />
                <Row2 articles={page.slice(7, 9)} isEqual={true} noauthor={true} />
              </>
            )}
          </For>
        </Show>
      </Show>
    </Show>
  )
  return (
    <div class={styles.authorPage}>
      <div class="wide-container">
        <Show when={author()} fallback={<Loading />}>
          <>
            <div class={styles.authorHeader}>
              <AuthorCard
                author={author() as Author}
                followers={followers() || []}
                flatFollows={following() || []}
              />
            </div>
            <div class={clsx(styles.groupControls, 'row')}>
              <div class="col-md-16">
                <ul class="view-switcher">
                  <li classList={{ 'view-switcher__item--selected': !props.selectedTab }}>
                    <A href={`/@${props.authorSlug}`}>{t('Publications')}</A>
                    <Show when={author()?.stat}>
                      <span class="view-switcher__counter">{author()?.stat?.shouts || 0}</span>
                    </Show>
                  </li>
                  <li classList={{ 'view-switcher__item--selected': props.selectedTab === 'comment' }}>
                    <A href={`/@${props.authorSlug}/comments`}>{t('Comments')}</A>
                    <Show when={author()?.stat}>
                      <span class="view-switcher__counter">{author()?.stat?.comments || 0}</span>
                    </Show>
                  </li>
                  <li classList={{ 'view-switcher__item--selected': props.selectedTab === 'about' }}>
                    <A onClick={() => checkBioHeight()} href={`/@${props.authorSlug}/about`}>
                      {t('About the author')}
                    </A>
                  </li>
                </ul>
              </div>
              <div class={clsx('col-md-8', styles.additionalControls)}>
                <Show when={author()?.stat?.rating || author()?.stat?.rating === 0}>
                  <div class={styles.ratingContainer}>
                    {t('All posts rating')}
                    <AuthorShoutsRating author={author() as Author} class={styles.ratingControl} />
                  </div>
                </Show>
              </div>
            </div>
          </>
        </Show>
      </div>

      <Switch>
        <Match when={props.selectedTab === 'about'}>
          <div class="wide-container">
            <div class="row">
              <div class="col-md-20 col-lg-18">
                <div
                  ref={(el) => (bioWrapperRef = el)}
                  class={styles.longBio}
                  classList={{ [styles.longBioExpanded]: isBioExpanded() }}
                >
                  <div ref={(el) => (bioContainerRef = el)} innerHTML={author()?.about || ''} />
                </div>

                <Show when={showExpandBioControl()}>
                  <button
                    class={clsx('button button--subscribe-topic', styles.longBioExpandedControl)}
                    onClick={() => setIsBioExpanded(!isBioExpanded())}
                  >
                    {t('Show more')}
                  </button>
                </Show>
              </div>
            </div>
          </div>
        </Match>
        <Match when={props.selectedTab === 'comments'}>
          <Show when={me()?.slug === props.authorSlug && !me().stat?.comments}>
            <div class="wide-container">
              <Placeholder type={loc?.pathname} mode="profile" />
            </div>
          </Show>

          <div class="wide-container">
            <div class="row">
              <div class="col-md-20 col-lg-18">
                <ul class={stylesArticle.comments}>
                  <For each={commented()?.sort(byCreated).reverse()}>
                    {(comment) => (
                      <Comment
                        comment={comment}
                        class={styles.comment}
                        showArticleLink={true}
                        onDelete={(id) => handleDeleteComment(id)}
                      />
                    )}
                  </For>
                </ul>
              </div>
            </div>
          </div>
        </Match>
        <Match when={!props.selectedTab}>
          <Show when={me()?.slug === props.authorSlug && !me().stat?.shouts}>
            <div class="wide-container">
              <Placeholder type={loc?.pathname} mode="profile" />
            </div>
          </Show>

          <AuthorFeed />
        </Match>
      </Switch>
    </div>
  )
}