import { useEffect, useState } from 'react'
import { Button, Badge, Card, Col, Container, Form, Modal, Row } from 'react-bootstrap'
import { Link, useParams } from 'react-router-dom'
import { createThread, getForum, listForumsByParent, listThreadsByForum } from '../api/client'
import { useAuth } from '../context/AuthContext'
import { useTranslation } from 'react-i18next'

export default function ForumView() {
  const { id } = useParams()
  const { token } = useAuth()
  const [forum, setForum] = useState(null)
  const [children, setChildren] = useState([])
  const [threads, setThreads] = useState([])
  const [error, setError] = useState('')
  const [loading, setLoading] = useState(true)
  const [showModal, setShowModal] = useState(false)
  const [title, setTitle] = useState('')
  const [body, setBody] = useState('')
  const [saving, setSaving] = useState(false)
  const { t } = useTranslation()

  const renderChildRows = (nodes) =>
    nodes.map((node) => (
      <div className="bb-board-row" key={node.id}>
        <div className="bb-board-cell bb-board-cell--title">
          <div className="bb-board-title">
            <span className="bb-board-icon" aria-hidden="true">
              <i className={`bi ${node.type === 'category' ? 'bi-folder2' : 'bi-chat-left-text'}`} />
            </span>
            <div>
              <Link to={`/forum/${node.id}`} className="bb-board-link">
                {node.name}
              </Link>
              <div className="bb-board-desc">{node.description || t('forum.no_description')}</div>
            </div>
          </div>
        </div>
        <div className="bb-board-cell bb-board-cell--topics">—</div>
        <div className="bb-board-cell bb-board-cell--posts">—</div>
        <div className="bb-board-cell bb-board-cell--last">
          <span className="bb-muted">{t('thread.no_replies')}</span>
        </div>
      </div>
    ))

  useEffect(() => {
    let active = true

    const loadData = async () => {
      setLoading(true)
      setError('')
      try {
        const forumData = await getForum(id)
        if (!active) return
        setForum(forumData)
        const childData = await listForumsByParent(id)
        if (!active) return
        setChildren(childData)
        if (forumData.type === 'forum') {
          const threadData = await listThreadsByForum(id)
          if (!active) return
          setThreads(threadData)
        } else {
          setThreads([])
        }
      } catch (err) {
        if (active) setError(err.message)
      } finally {
        if (active) setLoading(false)
      }
    }

    loadData()

    return () => {
      active = false
    }
  }, [id])

  const handleSubmit = async (event) => {
    event.preventDefault()
    setSaving(true)
    setError('')
    try {
      await createThread({ title, body, forumId: id })
      setTitle('')
      setBody('')
      const updated = await listThreadsByForum(id)
      setThreads(updated)
      setShowModal(false)
    } catch (err) {
      setError(err.message)
    } finally {
      setSaving(false)
    }
  }

  return (
    <Container className="py-5">
      {loading && <p className="bb-muted">{t('forum.loading')}</p>}
      {error && <p className="text-danger">{error}</p>}
      {forum && (
        <>
          <Row className="g-4">
            <Col lg={12}>
              {forum.type !== 'forum' && (
                <div className="bb-board-index">
                  <section className="bb-board-section">
                    <header className="bb-board-section__header">
                      <span className="bb-board-section__title">{forum.name}</span>
                      <div className="bb-board-section__cols">
                        <span>{t('portal.topic')}</span>
                        <span>{t('thread.views')}</span>
                        <span>{t('thread.last_post')}</span>
                      </div>
                    </header>
                    <div className="bb-board-section__body">
                      {children.length > 0 ? (
                        renderChildRows(children)
                      ) : (
                        <div className="bb-board-empty">{t('forum.empty_children')}</div>
                      )}
                    </div>
                  </section>
                </div>
              )}
              {forum.type === 'forum' && (
                <>
                  <div className="bb-topic-toolbar mt-4 mb-2">
                    <div className="bb-topic-toolbar__left">
                      <Button
                        variant="dark"
                        className="bb-topic-action bb-accent-button"
                        onClick={() => setShowModal(true)}
                        disabled={!token || saving}
                      >
                        <i className="bi bi-pencil me-2" aria-hidden="true" />
                        {t('forum.start_thread')}
                      </Button>
                    </div>
                    <div className="bb-topic-toolbar__right">
                      <span className="bb-topic-count">
                        {threads.length} {t('forum.threads').toLowerCase()}
                      </span>
                      <div className="bb-topic-pagination">
                        <Button size="sm" variant="outline-secondary" disabled>
                          ‹
                        </Button>
                        <Button size="sm" variant="outline-secondary" className="is-active" disabled>
                          1
                        </Button>
                        <Button size="sm" variant="outline-secondary" disabled>
                          ›
                        </Button>
                      </div>
                    </div>
                  </div>
                  {!token && <p className="bb-muted mb-3">{t('forum.login_hint')}</p>}
                  <div className="bb-topic-table">
                    <div className="bb-topic-header">
                      <div className="bb-topic-cell bb-topic-cell--title">{t('forum.threads')}</div>
                      <div className="bb-topic-cell bb-topic-cell--replies">{t('thread.replies')}</div>
                      <div className="bb-topic-cell bb-topic-cell--views">{t('thread.views')}</div>
                      <div className="bb-topic-cell bb-topic-cell--last">{t('thread.last_post')}</div>
                    </div>
                    {threads.length === 0 && (
                      <div className="bb-topic-empty">{t('forum.empty_threads')}</div>
                    )}
                    {threads.map((thread) => (
                      <div className="bb-topic-row" key={thread.id}>
                        <div className="bb-topic-cell bb-topic-cell--title">
                          <div className="bb-topic-title">
                            <span className="bb-topic-icon" aria-hidden="true">
                              <i className="bi bi-chat-left" />
                            </span>
                            <div className="bb-topic-text">
                              <Link to={`/thread/${thread.id}`}>{thread.title}</Link>
                              <div className="bb-topic-meta">
                                <i className="bi bi-paperclip" aria-hidden="true" />
                                <span>{t('thread.by')}</span>
                                <span className="bb-topic-author">
                                  {thread.user_name || t('thread.anonymous')}
                                </span>
                                {thread.created_at && (
                                  <span className="bb-topic-date">
                                    {thread.created_at.slice(0, 10)}
                                  </span>
                                )}
                              </div>
                            </div>
                          </div>
                        </div>
                        <div className="bb-topic-cell bb-topic-cell--replies">0</div>
                        <div className="bb-topic-cell bb-topic-cell--views">—</div>
                        <div className="bb-topic-cell bb-topic-cell--last">
                          <div className="bb-topic-last">
                            <span className="bb-topic-last-by">
                              {t('thread.by')}{' '}
                              <span className="bb-topic-author">
                                {thread.user_name || t('thread.anonymous')}
                              </span>
                            </span>
                            {thread.created_at && (
                              <span className="bb-topic-date">{thread.created_at.slice(0, 10)}</span>
                            )}
                          </div>
                        </div>
                      </div>
                    ))}
                  </div>
                </>
              )}
            </Col>
          </Row>
        </>
      )}
      {forum?.type === 'forum' && (
        <Modal show={showModal} onHide={() => setShowModal(false)} centered size="lg">
          <Modal.Header closeButton>
            <Modal.Title>{t('forum.start_thread')}</Modal.Title>
          </Modal.Header>
          <Modal.Body>
            {!token && <p className="bb-muted mb-3">{t('forum.login_hint')}</p>}
            <Form onSubmit={handleSubmit}>
              <Form.Group className="mb-3">
                <Form.Label>{t('form.title')}</Form.Label>
                <Form.Control
                  type="text"
                  placeholder={t('form.thread_title_placeholder')}
                  value={title}
                  onChange={(event) => setTitle(event.target.value)}
                  disabled={!token || saving}
                  required
                />
              </Form.Group>
              <Form.Group className="mb-3">
                <Form.Label>{t('form.body')}</Form.Label>
                <Form.Control
                  as="textarea"
                  rows={6}
                  placeholder={t('form.thread_body_placeholder')}
                  value={body}
                  onChange={(event) => setBody(event.target.value)}
                  disabled={!token || saving}
                  required
                />
              </Form.Group>
              <div className="d-flex gap-2 justify-content-between">
                <Button type="button" variant="outline-secondary" onClick={() => setShowModal(false)}>
                  {t('acp.cancel')}
                </Button>
                <Button type="submit" className="bb-accent-button" disabled={!token || saving}>
                  {saving ? t('form.posting') : t('form.create_thread')}
                </Button>
              </div>
            </Form>
          </Modal.Body>
        </Modal>
      )}
    </Container>
  )
}