import { useEffect, useState } from 'react';
import { useRouter } from 'next/router';
import Layout from '../components/Layout';
import CameraScanner from '../components/CameraScanner';
import ScannerDestinationPicker from '../components/ScannerDestinationPicker';
import ScannedCardItem, { CONDITION_OPTIONS } from '../components/ScannedCardItem';
import OCRSettings from '../components/OCRSettings';
import { useAuth } from '../lib/use-auth';
import { useFocusTrap } from '../lib/use-focus-trap.js';
import { VOCAB } from '../lib/collection-vocabulary.js';
import {
  DEFAULT_SCANNER_DESTINATION,
  loadSavedScannerSession,
  saveScannerSession,
} from '../lib/scanner-session.js';
import { useScannerQueue } from '../lib/use-scanner-queue.js';

export default function Scanner() {
  const { user, loading: authLoading } = useAuth();
  const router = useRouter();
  const [showOCRSettings, setShowOCRSettings] = useState(false);
  const [sessionDestination, setSessionDestination] = useState(
    () => loadSavedScannerSession().destination
  );
  const [gameFilter, setGameFilter] = useState(() => loadSavedScannerSession().gameFilter);
  const [scanDefaults, setScanDefaults] = useState(() => loadSavedScannerSession().scanDefaults);

  const queue = useScannerQueue({ user, sessionDestination, scanDefaults });
  const createCollectionDialogRef = useFocusTrap(queue.showCreateCollection);

  useEffect(() => {
    if (!authLoading && !user) {
      router.push('/login');
    }
  }, [authLoading, user, router]);

  useEffect(() => {
    saveScannerSession({ destination: sessionDestination, gameFilter, scanDefaults });
  }, [sessionDestination, gameFilter, scanDefaults]);

  const handleGameFilterChange = (nextFilter) => {
    setGameFilter(nextFilter);
    setSessionDestination((current) => {
      if (!current || current.type === 'owned') return current;
      return DEFAULT_SCANNER_DESTINATION;
    });
  };

  const handleError = (error) => {
    console.error('Scanner error:', error);
  };

  if (authLoading) {
    return (
      <Layout user={null}>
        <div className="flex items-center justify-center min-h-[50vh]">
          <div className="animate-spin rounded-full h-12 w-12 border-b-2" style={{ borderColor: 'var(--text-accent)' }} />
        </div>
      </Layout>
    );
  }

  if (!user) {
    return <div>Redirecting to login...</div>;
  }

  return (
    <Layout user={user}>
      <div className="h-full flex flex-col">
        <div className="px-6 pt-6 pb-4">
          <h1 className="text-3xl font-bold mb-2" style={{ color: 'var(--text-primary)' }}>
            🃏 Card Scanner
          </h1>
          <p className="text-lg" style={{ color: 'var(--text-secondary)' }}>
            Pick a destination once — every scan lands there until you change it
          </p>
        </div>

        <ScannerDestinationPicker
          gameFilter={gameFilter}
          onGameFilterChange={handleGameFilterChange}
          destination={sessionDestination}
          onDestinationChange={setSessionDestination}
          collections={queue.collections}
          decks={queue.decks}
          disabled={queue.isProcessing}
        />

        {queue.autoRouteError && (
          <div
            className="mx-6 mb-4 px-4 py-3 rounded-lg border text-sm"
            style={{
              backgroundColor: 'var(--bg-secondary)',
              borderColor: 'var(--accent-flame)',
              color: 'var(--text-primary)',
            }}
            role="alert"
          >
            {queue.autoRouteError}
          </div>
        )}

        <div
          className="mx-6 mb-4 rounded-xl border p-4 flex flex-wrap items-end gap-4"
          style={{ backgroundColor: 'var(--bg-secondary)', borderColor: 'var(--border)' }}
        >
          <div>
            <h2 className="text-sm font-semibold uppercase tracking-wide mb-1" style={{ color: 'var(--text-secondary)' }}>
              Defaults for new scans
            </h2>
            <p className="text-xs" style={{ color: 'var(--text-secondary)' }}>
              Applied to each card when it enters the queue
            </p>
          </div>
          <label className="flex flex-col gap-1 text-sm">
            <span style={{ color: 'var(--text-secondary)' }}>Condition</span>
            <select
              value={scanDefaults.condition}
              onChange={(e) => setScanDefaults((current) => ({ ...current, condition: e.target.value }))}
              className="px-3 py-2 rounded-lg border"
              style={{
                backgroundColor: 'var(--bg-tertiary)',
                borderColor: 'var(--border)',
                color: 'var(--text-primary)',
              }}
            >
              {CONDITION_OPTIONS.map((option) => (
                <option key={option} value={option}>
                  {option}
                </option>
              ))}
            </select>
          </label>
          <label className="flex items-center gap-2 text-sm pb-2 cursor-pointer" style={{ color: 'var(--text-primary)' }}>
            <input
              type="checkbox"
              checked={scanDefaults.isFoil}
              onChange={(e) => setScanDefaults((current) => ({ ...current, isFoil: e.target.checked }))}
              style={{ accentColor: 'var(--accent-ember)' }}
            />
            Foil
          </label>
        </div>

        <div className="flex-1 grid grid-cols-1 lg:grid-cols-5 gap-6 px-6 pb-6">
          <div className="lg:col-span-3 flex flex-col">
            <div className="flex-1 rounded-xl p-6 flex flex-col" style={{ backgroundColor: 'var(--bg-secondary)', border: '1px solid var(--border)' }}>
              <div className="flex justify-between items-center mb-4">
                <h2 className="text-xl font-semibold" style={{ color: 'var(--text-primary)' }}>
                  Camera Scanner
                </h2>
                <button
                  onClick={() => setShowOCRSettings(true)}
                  className="px-4 py-2 rounded-xl font-medium border transition-all duration-200 hover:opacity-80"
                  style={{
                    borderColor: 'var(--border)',
                    color: 'var(--text-primary)',
                  }}
                >
                  ⚙️ OCR Settings
                </button>
              </div>

              <div className="flex-1">
                <CameraScanner onCardScanned={queue.handleCardScanned} onError={handleError} />
              </div>
            </div>
          </div>

          <div className="lg:col-span-2 flex flex-col">
            <div className="flex-1 rounded-xl p-6 flex flex-col" style={{ backgroundColor: 'var(--bg-secondary)', border: '1px solid var(--border)' }}>
              <div className="flex justify-between items-center mb-4">
                <h2 className="text-xl font-semibold" style={{ color: 'var(--text-primary)' }}>
                  Scanned Cards
                </h2>
                <div className="flex items-center gap-2">
                  <div
                    className="text-sm"
                    style={{ color: 'var(--text-secondary)' }}
                    aria-live="polite"
                    aria-atomic="true"
                  >
                    {queue.scannedCards.length} cards
                  </div>
                  {queue.scannedCards.length > 0 && (
                    <button
                      onClick={queue.clearScannedCards}
                      className="px-3 py-1 rounded-lg text-sm border hover:opacity-80"
                      style={{
                        borderColor: 'var(--border)',
                        color: 'var(--text-secondary)',
                      }}
                      aria-label="Clear all scanned cards from queue"
                    >
                      Clear All
                    </button>
                  )}
                </div>
              </div>

              <div className="flex-1 overflow-y-auto">
                {queue.scannedCards.length === 0 ? (
                  <div className="text-center py-8" style={{ color: 'var(--text-secondary)' }}>
                    <div className="text-4xl mb-2" aria-hidden="true">📱</div>
                    <div className="font-medium">No cards scanned yet</div>
                    <div className="text-sm">Start scanning to see cards here</div>
                  </div>
                ) : (
                  <ul className="space-y-3 list-none p-0 m-0" aria-label="Scanned cards queue">
                    {queue.scannedCards.map((card) => (
                      <li key={card.id}>
                        <ScannedCardItem
                          card={card}
                          collections={queue.collections}
                          decks={queue.decks}
                          selected={queue.selectedCards.has(card.id)}
                          onToggleSelect={() => queue.toggleCardSelection(card.id)}
                          onIncrement={() => queue.incrementCardQuantity(card.id)}
                          onDecrement={() => queue.decrementCardQuantity(card.id)}
                          onUpdateMetadata={(patch) => queue.updateCardMetadata(card.id, patch)}
                          onMarkOwned={() => queue.addSingleCardToOwned(card)}
                          onAddToCollection={(collectionId) => queue.addSingleCardToCollection(card, collectionId)}
                          onAddToDeck={(deckId) => queue.addSingleCardToDeck(card, deckId)}
                          onRemove={() => queue.removeScannedCard(card.id)}
                          isAdding={queue.addingCardIds.has(card.id)}
                        />
                      </li>
                    ))}
                  </ul>
                )}
              </div>
            </div>
          </div>
        </div>

        {queue.selectedCards.size > 0 && (
          <div className="fixed bottom-6 left-1/2 transform -translate-x-1/2 z-50">
            <div
              className="rounded-2xl shadow-2xl border px-6 py-4 flex items-center gap-4 max-w-4xl"
              role="toolbar"
              aria-label="Bulk actions for selected scanned cards"
              style={{
                backgroundColor: 'var(--bg-secondary)',
                borderColor: 'var(--border)',
                backdropFilter: 'blur(10px)',
              }}
            >
              <div className="flex items-center gap-2" aria-live="polite" aria-atomic="true">
                <div
                  className="w-8 h-8 rounded-full flex items-center justify-center text-sm font-bold text-white"
                  style={{ backgroundColor: 'var(--accent-ember)' }}
                >
                  {queue.selectedCards.size}
                </div>
                <span className="font-medium" style={{ color: 'var(--text-primary)' }}>
                  {queue.selectedCards.size === 1 ? 'card selected' : 'cards selected'}
                </span>
              </div>

              <div className="w-px h-8" style={{ backgroundColor: 'var(--border)' }}></div>

              <div className="flex items-center gap-3">
                <button
                  onClick={() => queue.handleBulkAction('owned')}
                  disabled={queue.isProcessing}
                  className="px-4 py-2 rounded-lg font-medium hover:opacity-80 disabled:opacity-50 flex items-center gap-2"
                  style={{ backgroundColor: 'var(--accent-gold)', color: 'white' }}
                >
                  <span aria-hidden="true">💎 </span>
                  {VOCAB.ADD_TO_MY_COLLECTION}
                </button>

                {queue.collections.length > 0 && (
                  <select
                    onChange={(e) => {
                      const collectionId = e.target.value;
                      e.target.value = '';
                      if (collectionId) {
                        queue.handleBulkAction('collection', collectionId);
                      }
                    }}
                    disabled={queue.isProcessing}
                    className="px-4 py-2 rounded-lg font-medium"
                    style={{ backgroundColor: 'var(--accent-ember)', color: 'white', border: 'none' }}
                    aria-label="Add selected cards to list"
                  >
                    <option value="">{`📚 ${VOCAB.ADD_TO_LIST}`}</option>
                    {queue.collections.map((collection) => (
                      <option key={collection.id} value={collection.id}>
                        {collection.name}
                      </option>
                    ))}
                  </select>
                )}

                {queue.decks.length > 0 && (
                  <select
                    onChange={(e) => {
                      const deckId = e.target.value;
                      e.target.value = '';
                      if (deckId) {
                        queue.handleBulkAction('deck', deckId);
                      }
                    }}
                    disabled={queue.isProcessing}
                    className="px-4 py-2 rounded-lg font-medium"
                    style={{ backgroundColor: 'var(--accent-flame)', color: 'white', border: 'none' }}
                    aria-label="Add selected cards to deck"
                  >
                    <option value="">🃏 Add to Deck</option>
                    {queue.decks.map((deck) => (
                      <option key={deck.id} value={deck.id}>
                        {deck.name} ({deck.game})
                      </option>
                    ))}
                  </select>
                )}
              </div>

              <div className="w-px h-8" style={{ backgroundColor: 'var(--border)' }}></div>

              <button
                onClick={queue.clearSelection}
                className="px-3 py-2 rounded-lg hover:opacity-80"
                style={{ color: 'var(--text-secondary)' }}
                aria-label="Clear selection"
              >
                <span aria-hidden="true">✕</span>
              </button>
            </div>
          </div>
        )}

        {queue.showCreateCollection && (
          <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
            <div
              ref={createCollectionDialogRef}
              className="rounded-xl p-6 max-w-md w-full mx-4"
              style={{ backgroundColor: 'var(--bg-secondary)' }}
              role="dialog"
              aria-modal="true"
              aria-labelledby="create-collection-title"
            >
              <h3 id="create-collection-title" className="text-lg font-semibold mb-4" style={{ color: 'var(--text-primary)' }}>
                Create New List
              </h3>
              <label htmlFor="create-collection-name" className="sr-only">
                List name
              </label>
              <input
                id="create-collection-name"
                type="text"
                placeholder="List name..."
                value={queue.newCollectionName}
                onChange={(e) => queue.setNewCollectionName(e.target.value)}
                className="w-full px-4 py-2 rounded-lg border mb-4"
                style={{
                  backgroundColor: 'var(--bg-tertiary)',
                  borderColor: 'var(--border)',
                  color: 'var(--text-primary)',
                }}
                onKeyPress={(e) => {
                  if (e.key === 'Enter') {
                    queue.createCollection();
                  }
                }}
              />
              <div className="flex gap-3">
                <button
                  onClick={queue.createCollection}
                  disabled={!queue.newCollectionName.trim()}
                  className="flex-1 px-4 py-2 rounded-lg font-medium disabled:opacity-50"
                  style={{ backgroundColor: 'var(--accent-ember)', color: 'white' }}
                >
                  Create
                </button>
                <button
                  onClick={() => queue.setShowCreateCollection(false)}
                  className="flex-1 px-4 py-2 rounded-lg border font-medium"
                  style={{ borderColor: 'var(--border)', color: 'var(--text-primary)' }}
                >
                  Cancel
                </button>
              </div>
            </div>
          </div>
        )}

        {showOCRSettings && <OCRSettings onClose={() => setShowOCRSettings(false)} />}
      </div>
    </Layout>
  );
}