import { useCallback, useEffect, useState } from 'react'
import { useParams } from 'react-router-dom'
import { PostsService } from '../posts/postsService.ts'
import SingleColumnLayout from '../../../layouts/SingleColumnLayout.tsx'
import NavBar from '../../../components/NavBar.tsx'
import AuthNavButtons from '../../auth/components/AuthNavButtons.tsx'
import PostItem from '../components/PostItem.tsx'
import NavButton from '../../../components/buttons/NavButton.tsx'
import { useTranslations } from '../../i18n/translations.ts'
import { usePostViewModel } from '../posts/usePostViewModel.ts'
import { Temporal } from '@js-temporal/polyfill'
import { useUserStore } from '../../user/user.ts'
import { PostTimeline } from '../components/PostTimeline.tsx'
import NewCommentWidget from '../components/NewCommentWidget.tsx'

interface PostPageProps {
  postsService: PostsService
}

export default function PostPage({ postsService }: PostPageProps) {
  const { postId } = useParams<{ postId: string }>()
  const { posts, setPosts, addReaction, reactions: _reactions, removeReaction } = usePostViewModel()
  const { t } = useTranslations()
  const username = useUserStore((state) => state.user?.username)
  const post = posts.at(0)
  const reactions = (post?.postId ? _reactions[post.postId] : []) ?? []

  const loadPost = useCallback(() => {
    if (!postId) return
    postsService.load(postId).then((post) => setPosts(post ? [post] : []))
  }, [postId, postsService, setPosts])

  useEffect(() => {
    loadPost()
  }, [loadPost])

  const onAddReaction = async (emoji: string) => {
    if (!username) return
    if (!post) return

    await postsService.addReaction(post.postId, emoji)

    addReaction(post.postId, emoji, username, Temporal.Now.instant())
  }

  const onClearReaction = async (emoji: string) => {
    if (!username) return
    if (!post) return

    await postsService.removeReaction(post.postId, emoji)
    removeReaction(post.postId, emoji, username)
  }

  async function onSubmitComment(content: string) {
    if (!postId) return
    if (!content.trim()) return

    try {
      setIsSubmittingComment(true)
      await postsService.addComment(postId, content)
    } finally {
      setIsSubmittingComment(false)
    }

    loadPost()
  }

  const [isSubmittingComment, setIsSubmittingComment] = useState(false)

  return (
    <SingleColumnLayout
      navbar={
        <NavBar>
          <NavButton to={{ pathname: '/' }}>{t('nav.home')}</NavButton>
          <AuthNavButtons />
        </NavBar>
      }
    >
      <main className="w-full max-w-3xl mx-auto">
        {post && (
          <div className="w-full">
            <PostItem
              post={post}
              reactions={reactions}
              addReaction={onAddReaction}
              clearReaction={onClearReaction}
              hideViewButton={true}
            />
            <PostTimeline reactions={reactions} comments={post.comments} />
            <NewCommentWidget onSubmit={onSubmitComment} isSubmitting={isSubmittingComment} />
          </div>
        )}
      </main>
    </SingleColumnLayout>
  )
}