'use client'

import React, { useState, useEffect, useCallback } from 'react'
import { useParams, useRouter } from 'next/navigation'
import { useTheme } from '@/lib/ThemeContext'
import { AudioButton } from '@/components/learn/AudioButton'
import { MicrophoneInput } from '@/components/learn/MicrophoneInput'
import { SyllableBow, simpleSyllableSplit } from '@/components/learn/SyllableBow'
import { StarRating, accuracyToStars } from '@/components/gamification/StarRating'

interface QAItem {
  id: string; question: string; answer: string
  syllables_en?: string[]; syllables_de?: string[]
  ipa_en?: string; ipa_de?: string
}

function getApiBase() { return '' }

export default function PronouncePage() {
  const { unitId } = useParams<{ unitId: string }>()
  const router = useRouter()
  const { isDark } = useTheme()

  const [items, setItems] = useState<QAItem[]>([])
  const [currentIndex, setCurrentIndex] = useState(0)
  const [isLoading, setIsLoading] = useState(true)
  const [stats, setStats] = useState({ correct: 0, incorrect: 0 })
  const [isComplete, setIsComplete] = useState(false)
  const [lang, setLang] = useState<'en' | 'de'>('en')

  const glassCard = isDark
    ? 'bg-white/10 backdrop-blur-xl border border-white/10'
    : 'bg-white/80 backdrop-blur-xl border border-black/5'

  useEffect(() => {
    (async () => {
      try {
        const resp = await fetch(`${getApiBase()}/api/learning-units/${unitId}/qa`)
        if (resp.ok) { const d = await resp.json(); setItems(d.qa_items || []) }
      } catch {} finally { setIsLoading(false) }
    })()
  }, [unitId])

  const currentItem = items[currentIndex]
  const currentWord = currentItem ? (lang === 'en' ? currentItem.question : currentItem.answer) : ''
  const syllables = currentItem
    ? (lang === 'en' ? currentItem.syllables_en : currentItem.syllables_de) || simpleSyllableSplit(currentWord)
    : []
  const ipa = currentItem ? (lang === 'en' ? currentItem.ipa_en : currentItem.ipa_de) : ''

  const handleResult = useCallback((transcript: string, correct: boolean) => {
    setStats(prev => ({
      correct: prev.correct + (correct ? 1 : 0),
      incorrect: prev.incorrect + (correct ? 0 : 1),
    }))

    setTimeout(() => {
      if (currentIndex + 1 >= items.length) { setIsComplete(true) }
      else { setCurrentIndex(i => i + 1) }
    }, correct ? 1000 : 2500)
  }, [currentIndex, items.length])

  if (isLoading) {
    return <div className={`min-h-screen flex items-center justify-center ${isDark ? 'bg-gradient-to-br from-indigo-900 via-purple-900 to-pink-800' : 'bg-gradient-to-br from-slate-100 via-rose-50 to-red-100'}`}>
      <div className="w-8 h-8 border-4 border-rose-400 border-t-transparent rounded-full animate-spin" />
    </div>
  }

  return (
    <div className={`min-h-screen flex flex-col ${isDark ? 'bg-gradient-to-br from-indigo-900 via-purple-900 to-pink-800' : 'bg-gradient-to-br from-slate-100 via-rose-50 to-red-100'}`}>
      {/* Header */}
      <div className={`${glassCard} border-0 border-b`}>
        <div className="max-w-2xl mx-auto px-6 py-4 flex items-center justify-between">
          <button onClick={() => router.push('/learn')} className={`flex items-center gap-2 text-sm ${isDark ? 'text-white/60 hover:text-white' : 'text-slate-500 hover:text-slate-900'}`}>
            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 19l-7-7 7-7" /></svg>
            Zurueck
          </button>
          <h1 className={`text-lg font-bold ${isDark ? 'text-white' : 'text-slate-900'}`}>Nachsprechen</h1>
          <button onClick={() => setLang(l => l === 'en' ? 'de' : 'en')} className={`text-xs px-3 py-1.5 rounded-lg ${isDark ? 'bg-white/10 text-white/70' : 'bg-slate-100 text-slate-600'}`}>
            {lang === 'en' ? 'EN' : 'DE'}
          </button>
        </div>
      </div>

      {/* Progress */}
      <div className="w-full h-1 bg-white/10">
        <div className="h-full bg-gradient-to-r from-rose-500 to-red-500 transition-all" style={{ width: `${(currentIndex / Math.max(items.length, 1)) * 100}%` }} />
      </div>

      <div className="flex-1 flex items-center justify-center px-6 py-8">
        {isComplete ? (
          <div className={`${glassCard} rounded-3xl p-10 text-center max-w-md w-full`}>
            <StarRating stars={accuracyToStars(stats.correct, stats.correct + stats.incorrect)} size="lg" animated />
            <h2 className={`text-2xl font-bold mt-4 mb-2 ${isDark ? 'text-white' : 'text-slate-900'}`}>Super gemacht!</h2>
            <p className={`mb-6 ${isDark ? 'text-white/60' : 'text-slate-500'}`}>{stats.correct}/{stats.correct + stats.incorrect} richtig ausgesprochen</p>
            <div className="flex gap-3">
              <button onClick={() => { setCurrentIndex(0); setStats({ correct: 0, incorrect: 0 }); setIsComplete(false) }} className="flex-1 py-3 rounded-xl bg-gradient-to-r from-rose-500 to-red-500 text-white font-medium">Nochmal</button>
              <button onClick={() => router.push('/learn')} className={`flex-1 py-3 rounded-xl border font-medium ${isDark ? 'border-white/20 text-white/80' : 'border-slate-300 text-slate-700'}`}>Zurueck</button>
            </div>
          </div>
        ) : currentItem ? (
          <div className="w-full max-w-lg space-y-8">
            {/* Word + Syllables */}
            <div className={`${glassCard} rounded-3xl p-8 text-center`}>
              <div className="flex justify-center mb-4">
                <SyllableBow word={currentWord} syllables={syllables} isDark={isDark} size="lg" />
              </div>
              {ipa && <p className={`text-lg ${isDark ? 'text-white/40' : 'text-slate-400'}`}>{ipa}</p>}
              <div className="flex justify-center gap-3 mt-4">
                <AudioButton text={currentWord} lang={lang} isDark={isDark} size="lg" />
              </div>
              <p className={`text-sm mt-3 ${isDark ? 'text-white/30' : 'text-slate-400'}`}>
                Hoere zu, dann sprich nach
              </p>
            </div>

            {/* Microphone */}
            <MicrophoneInput
              expectedText={currentWord}
              lang={lang}
              onResult={handleResult}
              isDark={isDark}
            />

            <p className={`text-center text-sm ${isDark ? 'text-white/40' : 'text-slate-400'}`}>
              {currentIndex + 1} / {items.length}
            </p>
          </div>
        ) : null}
      </div>
    </div>
  )
}
