import { Suspense } from 'react'
import lazyPage from '../utils/lazyPage'
import { Link } from 'react-router-dom'
import RichText from './RichText'
import QuestionReadingLinks from './QuestionReadingLinks'
import { uploadUrl } from '../utils/uploads'

const TeachChat = lazyPage(() => import('./TeachChat'))

/**
 * One question, shown whole, without leaving the page you found it on.
 *
 * It is a preview, not practice: the correct option, the per-option reasoning,
 * the explanation and the key points are all shown at once. Making someone
 * answer first is the right shape for a quiz and the wrong one for a list of
 * questions being inspected.
 *
 * Favourites and personal folders are optional and off by default — those
 * belong to studying a question, not to looking through the bank.
 */
/* No "Add to library" here any more. It was three faults in one twelve-line
   block: it said library and meant collection; its dropdown was always empty,
   because the only page that renders this preview passes no collections; and
   the "New library…" input called setCollections, which does not exist in this
   component — so typing a name and pressing Enter created the collection,
   added the question, and then threw a ReferenceError. Putting a question
   aside belongs to the reading and session flows, where the collections are
   actually loaded; this is a moderator's editing preview. */
export default function QuestionPreview({ question, onClose, isFavorited, onToggleFavorite }) {
  return (
    <>
      <div style={{ position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.55)', zIndex: 1000, display: 'flex', alignItems: 'center', justifyContent: 'center', padding: 16 }}
        onClick={e => e.target === e.currentTarget && onClose()}>
        <div style={{ background: 'var(--card-bg)', borderRadius: 'var(--card-radius)', padding: 24, maxWidth: 600, width: '100%', maxHeight: '90vh', overflowY: 'auto', boxShadow: '0 20px 60px rgba(0,0,0,0.3)' }}>
          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 12 }}>
            <span style={{ fontSize: '0.75rem', fontWeight: 600, color: 'var(--text-muted)', textTransform: 'uppercase' }}>
              {question.quiz_title}{question.question_category_name ? ` · ${question.question_category_name}` : ''}
            </span>
            <div style={{ display: 'flex', gap: 8, alignItems: 'center' }}>
              {onToggleFavorite && (
                <button onClick={() => onToggleFavorite(question.id)}
                  title={isFavorited ? 'Remove from favorites' : 'Add to favorites'}
                  style={{ background: 'none', border: 'none', cursor: 'pointer', fontSize: '1.4rem', padding: 2, lineHeight: 1 }}>
                  {isFavorited ? '⭐' : '☆'}
                </button>
              )}
              <button onClick={onClose} style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-muted)', fontSize: '1.2rem' }}>✕</button>
            </div>
          </div>
          {/* Markdown, not injected HTML: a stem is educator prose, and the
              same renderer the quiz player uses keeps a lab table a table. */}
          <div style={{ fontWeight: 600, fontSize: '0.95rem', marginBottom: 16 }}>
            <RichText value={question.question_text} />
          </div>
          {question.image_path && (
            <div style={{ margin: '0 0 14px' }}>
              <img src={`/uploads/${question.image_path}`} alt="Question illustration"
                style={{ maxWidth: '100%', maxHeight: 280, borderRadius: 8, border: '1px solid var(--border)' }}
                onError={e => e.target.style.display = 'none'} />
            </div>
          )}
          {question.options && (
            <div style={{ display: 'flex', flexDirection: 'column', gap: 8, marginBottom: 16 }}>
              {question.options.map((opt, i) => {
                const isCorrectOpt = opt === question.correct_answer
                return (
                  <div key={i}
                    className={`option ${isCorrectOpt ? 'correct' : ''}`}>
                    <span className="option-letter">{String.fromCharCode(65 + i)}</span>
                    <span style={{ flex: 1 }}>{opt}</span>
                    {isCorrectOpt && <span style={{ marginLeft: 'auto', fontSize: '0.8rem', fontWeight: 700, color: 'var(--correct-fg)' }}>✓ Correct</span>}
                    {question.option_explanations?.[opt] && (
                      <span style={{ flexBasis: '100%', fontSize: '0.8rem', color: 'var(--text-muted)' }}>
                        <RichText value={question.option_explanations[opt]} />
                      </span>
                    )}
                  </div>
                )
              })}
            </div>
          )}
          {(question.explanation || question.explanation_image_path) && (
            <div className="explanation">
              <strong>Explanation:</strong>
              {question.explanation && <div style={{ marginTop: 8 }}><RichText value={question.explanation} /></div>}
              {question.explanation_image_path && (
                <div style={{ marginTop: 12 }}>
                  <img src={`/uploads/${question.explanation_image_path}`} alt="Explanation illustration"
                    style={{ maxWidth: '100%', maxHeight: 280, borderRadius: 8, border: '1px solid var(--border)' }}
                    onError={e => e.currentTarget.style.display = 'none'} />
                </div>
              )}
            </div>
          )}
          {(question.key_points || []).length > 0 && (
            <div className="explanation" style={{ marginTop: 12 }}>
              <strong>Key points</strong>
              <ul style={{ margin: '6px 0 0', paddingLeft: 18, fontSize: '0.85rem' }}>
                {question.key_points.map((point, i) => (
                  <li key={i}>
                    {point.text}
                    {point.article_id && (
                      <Link to={`/articles/${point.article_id}${point.article_section_id ? `?section=${point.article_section_id}` : ''}`}
                        style={{ marginLeft: 8, color: 'var(--primary)', textDecoration: 'none', fontWeight: 600, fontSize: '0.8rem' }}>📖 Read more</Link>
                    )}
                  </li>
                ))}
              </ul>
            </div>
          )}
          <QuestionReadingLinks questionId={question.id} />
          <div style={{ marginTop: 14, display: 'flex', gap: 8 }}>
            <button className="btn btn-secondary btn-sm" onClick={onClose}>Close</button>
          </div>
        </div>
      </div>
      {/* AI Tutor — z-index above the modal */}
      <Suspense fallback={null}>
        <TeachChat question={question} elevated />
      </Suspense>
    </>
  )
}