import { useState, useCallback } from 'react'
import { motion, AnimatePresence } from 'framer-motion'
import {
  Sparkles, Zap, Loader2, Settings, Image as ImageIcon, FileText,
  Layers, ChevronLeft, CheckCircle2, Database,
} from 'lucide-react'
import ImageUpload from './components/ImageUpload'
import ModeSelector from './components/ModeSelector'
import ResultPanel from './components/ResultPanel'
import AdvancedSettings from './components/AdvancedSettings'
import PDFProcessor from './components/PDFProcessor'
import MetadataForm from './components/MetadataForm'
import JobsPanel from './components/JobsPanel'
import axios from 'axios'

const API_BASE = import.meta.env.VITE_API_URL || '/api'

const INPUT_CLASS =
  'w-full bg-white/5 border border-white/10 rounded-lg px-3 py-2 text-sm text-gray-200 ' +
  'placeholder-gray-600 focus:outline-none focus:border-purple-500/50 transition-colors'

function App() {
  const [view, setView] = useState('new_job')

  // OCR state
  const [mode, setMode] = useState('plain_ocr')
  const [fileType, setFileType] = useState('image')
  const [image, setImage] = useState(null)
  const [imagePreview, setImagePreview] = useState(null)
  const [result, setResult] = useState(null)
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState(null)
  const [showAdvanced, setShowAdvanced] = useState(false)
  const [includeCaption, setIncludeCaption] = useState(false)

  const [prompt, setPrompt] = useState('')
  const [findTerm, setFindTerm] = useState('')
  const [advancedSettings, setAdvancedSettings] = useState({
    base_size: 1024, image_size: 640, crop_mode: true, test_compress: false,
  })

  const [metadata, setMetadata] = useState({ author: '', book: '', chapter: '', page: '' })
  const [editedOcrText, setEditedOcrText] = useState('')
  const [commitLoading, setCommitLoading] = useState(false)
  const [commitResult, setCommitResult] = useState(null)

  // Whether to show the full-screen result view
  const showResultView = view === 'new_job' && mode === 'plain_ocr' && !!result

  const handleFileTypeChange = useCallback((newType) => {
    setImage(null)
    if (imagePreview) URL.revokeObjectURL(imagePreview)
    setImagePreview(null)
    setError(null)
    setResult(null)
    setFileType(newType)
  }, [imagePreview])

  const handleImageSelect = useCallback((file) => {
    if (file === null) {
      setImage(null)
      if (imagePreview && fileType === 'image') URL.revokeObjectURL(imagePreview)
      setImagePreview(null)
      setError(null)
      setResult(null)
      setEditedOcrText('')
      setCommitResult(null)
    } else {
      setImage(file)
      setImagePreview(fileType === 'image' ? URL.createObjectURL(file) : file)
      setError(null)
      setResult(null)
      setEditedOcrText('')
      setCommitResult(null)
    }
  }, [imagePreview, fileType])

  const handleSubmit = async () => {
    if (!image) { setError('Please upload an image first'); return }
    setLoading(true)
    setError(null)
    setCommitResult(null)
    try {
      const formData = new FormData()
      formData.append('image', image)
      formData.append('mode', mode)
      formData.append('prompt', prompt)
      formData.append('grounding', mode === 'find_ref')
      formData.append('include_caption', includeCaption)
      formData.append('find_term', findTerm)
      formData.append('schema', '')
      formData.append('base_size', advancedSettings.base_size)
      formData.append('image_size', advancedSettings.image_size)
      formData.append('crop_mode', advancedSettings.crop_mode)
      formData.append('test_compress', advancedSettings.test_compress)

      const response = await axios.post(`${API_BASE}/ocr`, formData, {
        headers: { 'Content-Type': 'multipart/form-data' },
      })
      setResult(response.data)
      setEditedOcrText(response.data.text || '')
      setCommitResult(null)
    } catch (err) {
      setError(err.response?.data?.detail || err.message || 'An error occurred')
    } finally {
      setLoading(false)
    }
  }

  const handleNewAnalysis = () => {
    setResult(null)
    setEditedOcrText('')
    setCommitResult(null)
  }

  const handleCommitJob = useCallback(async () => {
    if (!image) return
    setCommitLoading(true)
    setCommitResult(null)
    try {
      const formData = new FormData()
      formData.append('image', image)
      formData.append('author', metadata.author)
      formData.append('book', metadata.book)
      formData.append('chapter', metadata.chapter)
      formData.append('page', metadata.page)
      formData.append('ocr_text', editedOcrText)
      formData.append('mode', mode)

      const response = await axios.post(`${API_BASE}/jobs`, formData, {
        headers: { 'Content-Type': 'multipart/form-data' },
      })
      setCommitResult({ success: true, job: response.data })
    } catch (err) {
      setCommitResult({ success: false, error: err.response?.data?.detail || err.message })
    } finally {
      setCommitLoading(false)
    }
  }, [image, editedOcrText, metadata, mode])

  const handleCopy = useCallback(() => {
    const text = editedOcrText || result?.text
    if (text) navigator.clipboard.writeText(text)
  }, [editedOcrText, result])

  const handleDownload = useCallback(() => {
    const text = editedOcrText || result?.text
    if (!text) return
    const ext = { plain_ocr: 'txt', describe: 'txt', find_ref: 'txt', freeform: 'txt' }[mode] || 'txt'
    const blob = new Blob([text], { type: 'text/plain' })
    const url = URL.createObjectURL(blob)
    const a = document.createElement('a')
    a.href = url
    a.download = `deepseek-ocr-result.${ext}`
    a.click()
    URL.revokeObjectURL(url)
  }, [editedOcrText, result, mode])

  const metaField = (key) => (e) => setMetadata(m => ({ ...m, [key]: e.target.value }))

  return (
    <div className="min-h-screen relative overflow-hidden">
      {/* Animated background */}
      <div className="fixed inset-0 -z-10">
        <div className="absolute inset-0 bg-gradient-to-br from-purple-900/20 via-pink-900/20 to-cyan-900/20" />
        <div className="absolute inset-0 bg-[url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iNjAiIGhlaWdodD0iNjAiIHZpZXdCb3g9IjAgMCA2MCA2MCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48ZyBmaWxsPSJub25lIiBmaWxsLXJ1bGU9ImV2ZW5vZGQiPjxwYXRoIGQ9Ik0zNiAxOGMzLjMxIDAgNiAyLjY5IDYgNnMtMi42OSA2LTYgNi02LTIuNjktNi02IDIuNjktNiA2LTZ6TTI0IDZjMy4zMSAwIDYgMi42OSA2IDZzLTIuNjkgNi02IDYtNi0yLjY5LTYtNiAyLjY5LTYgNi02ek00OCAzNmMzLjMxIDAgNiAyLjY5IDYgNnMtMi42OSA2LTYgNi02LTIuNjktNi02IDIuNjktNiA2LTZ6IiBzdHJva2U9InJnYmEoMTQ3LCA1MSwgMjM0LCAwLjEpIiBzdHJva2Utd2lkdGg9IjIiLz48L2c+PC9zdmc+')] opacity-30" />
        <motion.div
          className="absolute top-20 left-20 w-96 h-96 bg-purple-500/10 rounded-full blur-3xl"
          animate={{ scale: [1, 1.2, 1], opacity: [0.3, 0.5, 0.3] }}
          transition={{ duration: 8, repeat: Infinity, ease: 'easeInOut' }}
        />
        <motion.div
          className="absolute bottom-20 right-20 w-96 h-96 bg-cyan-500/10 rounded-full blur-3xl"
          animate={{ scale: [1.2, 1, 1.2], opacity: [0.5, 0.3, 0.5] }}
          transition={{ duration: 8, repeat: Infinity, ease: 'easeInOut' }}
        />
      </div>

      {/* Header */}
      <header className="sticky top-0 z-50 glass border-b border-white/10">
        <div className="max-w-7xl mx-auto px-6 py-4">
          <div className="flex items-center justify-between">
            <motion.div className="flex items-center gap-3" initial={{ opacity: 0, x: -20 }} animate={{ opacity: 1, x: 0 }}>
              <div className="relative">
                <div className="absolute inset-0 bg-gradient-to-r from-purple-500 to-cyan-500 rounded-xl blur-lg opacity-75" />
                <div className="relative bg-gradient-to-br from-purple-600 to-cyan-500 p-2 rounded-xl">
                  <Sparkles className="w-6 h-6" />
                </div>
              </div>
              <div>
                <h1 className="text-2xl font-bold gradient-text">DeepSeek OCR</h1>
                <p className="text-xs text-gray-400">Next-Gen Vision AI</p>
              </div>
            </motion.div>

            <nav className="flex gap-2">
              {showResultView && (
                <motion.button
                  onClick={handleNewAnalysis}
                  className="flex items-center gap-2 px-4 py-2 rounded-xl text-sm font-medium glass text-gray-400 hover:bg-white/5 transition-all"
                  whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}
                >
                  <ChevronLeft className="w-4 h-4" />
                  New Analysis
                </motion.button>
              )}
              <motion.button
                onClick={() => setView('new_job')}
                className={`flex items-center gap-2 px-4 py-2 rounded-xl text-sm font-medium transition-all ${view === 'new_job' ? 'bg-gradient-to-r from-purple-600 to-cyan-600 text-white' : 'glass text-gray-400 hover:bg-white/5'}`}
                whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}
              >
                <Zap className="w-4 h-4" />
                New Job
              </motion.button>
              <motion.button
                onClick={() => setView('jobs')}
                className={`flex items-center gap-2 px-4 py-2 rounded-xl text-sm font-medium transition-all ${view === 'jobs' ? 'bg-gradient-to-r from-purple-600 to-cyan-600 text-white' : 'glass text-gray-400 hover:bg-white/5'}`}
                whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}
              >
                <Layers className="w-4 h-4" />
                Browse Jobs
              </motion.button>
            </nav>
          </div>
        </div>
      </header>

      {/* Main Content */}
      <main className="max-w-7xl mx-auto px-6 py-6">
        <AnimatePresence mode="wait">

          {/* ── Full-screen OCR result view (plain_ocr + result) ── */}
          {showResultView ? (
            <motion.div
              key="ocr_result"
              initial={{ opacity: 0, y: 20 }}
              animate={{ opacity: 1, y: 0 }}
              exit={{ opacity: 0, y: -20 }}
              className="flex flex-col gap-4"
              style={{ height: 'calc(100vh - 9.5rem)' }}
            >
              {/* Image + Text */}
              <div className="grid gap-6 flex-1 min-h-0" style={{ gridTemplateColumns: '3fr 2fr' }}>
                {imagePreview && typeof imagePreview === 'string' ? (
                  <div className="glass rounded-2xl overflow-hidden flex items-center justify-center bg-black/20 min-h-0">
                    <img
                      src={imagePreview}
                      alt="Source"
                      className="w-full h-full object-contain"
                    />
                  </div>
                ) : (
                  <div className="glass rounded-2xl flex items-center justify-center">
                    <p className="text-gray-500 text-sm">No preview</p>
                  </div>
                )}
                <div className="glass rounded-2xl p-4 flex flex-col min-h-0">
                  <p className="text-xs text-gray-400 mb-2 flex-shrink-0">
                    OCR Text <span className="text-purple-400">(edit before committing)</span>
                  </p>
                  <textarea
                    value={editedOcrText}
                    onChange={e => setEditedOcrText(e.target.value)}
                    className="flex-1 w-full bg-transparent text-sm text-gray-200 font-mono resize-none focus:outline-none min-h-0"
                    placeholder="OCR text appears here..."
                  />
                </div>
              </div>

              {/* Metadata row */}
              <div className="glass p-4 rounded-2xl flex-shrink-0">
                <div className="grid grid-cols-4 gap-4">
                  {[
                    { key: 'author', label: 'Author', placeholder: 'Author name' },
                    { key: 'book',   label: 'Book',   placeholder: 'Book title' },
                    { key: 'chapter', label: 'Chapter', placeholder: 'Chapter' },
                    { key: 'page',   label: 'Page',   placeholder: 'Page number' },
                  ].map(({ key, label, placeholder }) => (
                    <div key={key}>
                      <label className="text-xs text-gray-400 mb-1 block">{label}</label>
                      <input
                        type="text"
                        value={metadata[key]}
                        onChange={metaField(key)}
                        placeholder={placeholder}
                        className={INPUT_CLASS}
                      />
                    </div>
                  ))}
                </div>
              </div>

              {/* Commit row */}
              <div className="flex items-center gap-4 flex-shrink-0">
                <AnimatePresence>
                  {commitResult?.success && (
                    <motion.div
                      initial={{ opacity: 0, x: -10 }} animate={{ opacity: 1, x: 0 }} exit={{ opacity: 0 }}
                      className="flex-1 glass p-3 rounded-xl bg-green-500/10 border border-green-500/20"
                    >
                      <p className="text-xs text-green-400">
                        Job saved &mdash; ID: <span className="font-mono">{commitResult.job?.id}</span>
                      </p>
                    </motion.div>
                  )}
                  {commitResult && !commitResult.success && (
                    <motion.div
                      initial={{ opacity: 0, x: -10 }} animate={{ opacity: 1, x: 0 }} exit={{ opacity: 0 }}
                      className="flex-1 glass p-3 rounded-xl bg-red-500/10 border border-red-500/20"
                    >
                      <p className="text-xs text-red-400">{commitResult.error}</p>
                    </motion.div>
                  )}
                </AnimatePresence>
                <motion.button
                  onClick={handleCommitJob}
                  disabled={commitLoading || commitResult?.success}
                  className={`flex items-center gap-2 px-6 py-3 rounded-xl font-medium text-sm transition-all flex-shrink-0 ${
                    commitLoading || commitResult?.success
                      ? 'opacity-50 cursor-not-allowed bg-white/5'
                      : 'bg-gradient-to-r from-blue-600 to-indigo-600 hover:from-blue-500 hover:to-indigo-500'
                  }`}
                  whileHover={!commitLoading && !commitResult?.success ? { scale: 1.02 } : {}}
                  whileTap={!commitLoading && !commitResult?.success ? { scale: 0.98 } : {}}
                >
                  {commitLoading ? (
                    <><Loader2 className="w-4 h-4 animate-spin" /> Committing...</>
                  ) : commitResult?.success ? (
                    <><CheckCircle2 className="w-4 h-4" /> Committed</>
                  ) : (
                    <><Database className="w-4 h-4" /> Commit Job</>
                  )}
                </motion.button>
              </div>
            </motion.div>

          ) : view === 'jobs' ? (
            <motion.div
              key="jobs"
              initial={{ opacity: 0, y: 20 }}
              animate={{ opacity: 1, y: 0 }}
              exit={{ opacity: 0, y: -20 }}
            >
              <JobsPanel />
            </motion.div>

          ) : (
            /* ── Upload / Controls layout ── */
            <motion.div
              key="new_job"
              initial={{ opacity: 0, y: 20 }}
              animate={{ opacity: 1, y: 0 }}
              exit={{ opacity: 0, y: -20 }}
            >
              <div className="grid lg:grid-cols-2 gap-6">
                {/* Left Panel */}
                <motion.div
                  initial={{ opacity: 0, y: 20 }}
                  animate={{ opacity: 1, y: 0 }}
                  transition={{ delay: 0.1 }}
                  className="space-y-6"
                >
                  {/* File Type Toggle */}
                  <div className="glass p-4 rounded-2xl">
                    <div className="grid grid-cols-2 gap-2">
                      <motion.button
                        onClick={() => handleFileTypeChange('image')}
                        className={`p-3 rounded-xl text-sm font-medium transition-all flex items-center justify-center gap-2 ${fileType === 'image' ? 'bg-gradient-to-r from-purple-600 to-cyan-600 text-white' : 'glass text-gray-400 hover:bg-white/5'}`}
                        whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}
                      >
                        <ImageIcon className="w-4 h-4" /> Image OCR
                      </motion.button>
                      <motion.button
                        onClick={() => handleFileTypeChange('pdf')}
                        className={`p-3 rounded-xl text-sm font-medium transition-all flex items-center justify-center gap-2 ${fileType === 'pdf' ? 'bg-gradient-to-r from-purple-600 to-cyan-600 text-white' : 'glass text-gray-400 hover:bg-white/5'}`}
                        whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}
                      >
                        <FileText className="w-4 h-4" /> PDF Processing
                      </motion.button>
                    </div>
                  </div>

                  <MetadataForm metadata={metadata} onChange={setMetadata} />

                  <ModeSelector
                    mode={mode} onModeChange={setMode}
                    prompt={prompt} onPromptChange={setPrompt}
                    findTerm={findTerm} onFindTermChange={setFindTerm}
                  />

                  <ImageUpload onImageSelect={handleImageSelect} preview={imagePreview} fileType={fileType} />

                  <motion.button
                    onClick={() => setShowAdvanced(!showAdvanced)}
                    className="w-full glass px-4 py-3 rounded-2xl flex items-center justify-between hover:bg-white/5 transition-colors"
                    whileHover={{ scale: 1.01 }} whileTap={{ scale: 0.99 }}
                  >
                    <div className="flex items-center gap-2">
                      <Settings className="w-4 h-4 text-purple-400" />
                      <span className="text-sm font-medium text-gray-300">Advanced Settings</span>
                    </div>
                    <motion.div animate={{ rotate: showAdvanced ? 180 : 0 }} transition={{ duration: 0.3 }}>
                      <svg className="w-4 h-4 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
                      </svg>
                    </motion.div>
                  </motion.button>

                  <AnimatePresence>
                    {showAdvanced && (
                      <AdvancedSettings
                        settings={advancedSettings} onSettingsChange={setAdvancedSettings}
                        includeCaption={includeCaption} onIncludeCaptionChange={setIncludeCaption}
                      />
                    )}
                  </AnimatePresence>

                  {fileType === 'pdf' ? (
                    <PDFProcessor
                      pdfFile={image} mode={mode} prompt={prompt}
                      advancedSettings={advancedSettings} includeCaption={includeCaption}
                    />
                  ) : (
                    <>
                      <motion.button
                        onClick={handleSubmit}
                        disabled={!image || loading}
                        className={`w-full relative overflow-hidden rounded-2xl p-[2px] ${!image || loading ? 'opacity-50 cursor-not-allowed' : ''}`}
                        whileHover={!loading && image ? { scale: 1.02 } : {}}
                        whileTap={!loading && image ? { scale: 0.98 } : {}}
                      >
                        <div className="absolute inset-0 bg-gradient-to-r from-purple-600 via-pink-600 to-cyan-600 animate-gradient" />
                        <div className="relative bg-dark-100 px-8 py-4 rounded-2xl flex items-center justify-center gap-3">
                          {loading ? (
                            <><Loader2 className="w-5 h-5 animate-spin" /><span className="font-semibold">Processing Magic...</span></>
                          ) : (
                            <><Zap className="w-5 h-5" /><span className="font-semibold">Analyze Image</span></>
                          )}
                        </div>
                      </motion.button>

                      {error && (
                        <motion.div
                          initial={{ opacity: 0, y: -10 }} animate={{ opacity: 1, y: 0 }}
                          className="glass p-4 rounded-2xl border-red-500/50 bg-red-500/10"
                        >
                          <p className="text-sm text-red-400">{error}</p>
                        </motion.div>
                      )}
                    </>
                  )}
                </motion.div>

                {/* Right Panel - Results (non-plain_ocr modes or loading) */}
                <motion.div
                  initial={{ opacity: 0, y: 20 }}
                  animate={{ opacity: 1, y: 0 }}
                  transition={{ delay: 0.2 }}
                >
                  <ResultPanel
                    result={result}
                    loading={loading}
                    imagePreview={imagePreview}
                    onCopy={handleCopy}
                    onDownload={handleDownload}
                  />
                </motion.div>
              </div>
            </motion.div>
          )}
        </AnimatePresence>
      </main>

      {/* Footer */}
      <footer className="mt-20 border-t border-white/10 glass">
        <div className="max-w-7xl mx-auto px-6 py-8 text-center space-y-2">
          <p className="text-sm text-gray-400">
            Powered by <span className="gradient-text font-semibold">DeepSeek-OCR</span> &bull;
            Built with <span className="text-pink-400">♥</span> using React + FastAPI
          </p>
          <p className="text-xs text-gray-500">
            Thanks to <a href="https://github.com/p-xiexin" target="_blank" rel="noopener noreferrer" className="text-purple-400 hover:text-purple-300 transition-colors">@p-xiexin</a> for the clipboard paste idea!
          </p>
        </div>
      </footer>
    </div>
  )
}

export default App
