/* eslint-disable @next/next/no-img-element -- External or generated image URLs; next/image migration is out of scope. */
import { useState, useEffect } from 'react';
import { useRouter } from 'next/router';
import Link from 'next/link';
import Layout from '../../components/Layout';
import { ManaCost, ColorIdentity } from '../../components/ManaSymbols';
import { Button } from '../../components/ui';
import { useAuth } from '../../lib/use-auth';
import { getColorIdentity } from '../../lib/mana-symbols';

/* 2026-06-04 design-sweep pass: this page used the broken Tailwind
   token classes (bg-bg-*, text-text-*, bg-accent-ember,
   hover:bg-accent-ember-dark, border-accent-ember) that don't
   resolve in tailwind.config.js. Sweep replaces them with inline
   CSS variables + Button primitive + glass-panel surface + the
   nav-item-active / nav-item-hover utilities so the page renders
   with the Liquid Glass design system. */

export default function DeckDetail() {
  const { user } = useAuth();
  const router = useRouter();
  const { id: deckId } = router.query;
  
  const [deck, setDeck] = useState(null);
  const [loading, setLoading] = useState(true);
  const [groupBy, setGroupBy] = useState('type');

  const fetchDeck = async () => {
    try {
      const token = localStorage.getItem('auth_token');
      const headers = token ? { 'Authorization': `Bearer ${token}` } : {};
      
      const response = await fetch(`/api/decks/${deckId}`, { headers });

      if (response.ok) {
        const data = await response.json();
        setDeck(data);
      } else {
        console.error('Failed to fetch deck');
        router.push('/decks');
      }
    } catch (error) {
      console.error('Error fetching deck:', error);
      router.push('/decks');
    } finally {
      setLoading(false);
    }
  }

  useEffect(() => {
    if (deckId) {
      // eslint-disable-next-line react-hooks/set-state-in-effect -- load deck when route id changes
      fetchDeck();
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps -- refetch when route deck id changes
  }, [deckId]);

;

  const getDeckStats = () => {
    if (!deck?.cards) return { totalCards: 0, avgCmc: 0, colorCounts: {}, typeCounts: {} };
    
    const totalCards = deck.cards.reduce((sum, card) => sum + card.quantity, 0);
    const avgCmc = deck.cards.length > 0 
      ? (deck.cards.reduce((sum, card) => sum + (card.cmc || 0) * card.quantity, 0) / totalCards).toFixed(1)
      : 0;
    
    const colorCounts = deck.cards.reduce((counts, card) => {
      if (card.colors) {
        try {
          const colors = JSON.parse(card.colors);
          colors.forEach(color => {
            counts[color] = (counts[color] || 0) + card.quantity;
          });
        } catch (e) {
          // Handle non-JSON color format
        }
      }
      return counts;
    }, {});

    const typeCounts = deck.cards.reduce((counts, card) => {
      if (card.card_type) {
        const types = card.card_type.split(' — ')[0].split(' ');
        types.forEach(type => {
          counts[type] = (counts[type] || 0) + card.quantity;
        });
      }
      return counts;
    }, {});

    return { totalCards, avgCmc, colorCounts, typeCounts };
  };

  const getGroupedCards = () => {
    if (!deck?.cards) return {};
    
    return deck.cards.reduce((groups, card) => {
      let key;
      
      switch (groupBy) {
        case 'type':
          key = card.card_type ? card.card_type.split(' — ')[0] : 'Unknown';
          break;
        case 'cmc':
          key = `${card.cmc || 0} Mana`;
          break;
        case 'color':
          try {
            const colors = card.colors ? JSON.parse(card.colors) : [];
            key = colors.length === 0 ? 'Colorless' : colors.map(c => c).join('');
          } catch (e) {
            key = 'Colorless';
          }
          break;
        case 'rarity':
          key = card.rarity || 'Unknown';
          break;
        default:
          key = 'All Cards';
      }
      
      if (!groups[key]) groups[key] = [];
      groups[key].push(card);
      return groups;
    }, {});
  };

  const getFormatIcon = (format) => {
    switch (format) {
      case 'Commander':
        return '⚔️';
      case 'Standard':
        return '🏆';
      case 'Modern':
        return '🔥';
      case 'Legacy':
        return '💎';
      default:
        return '🃏';
    }
  };

  if (loading) {
    return (
      <Layout user={user}>
        <div className="flex items-center justify-center min-h-screen">
          <div
            className="animate-spin rounded-full h-32 w-32 border-b-2"
            style={{ borderColor: 'var(--accent-ember)' }}
          />
        </div>
      </Layout>
    );
  }

  if (!deck) {
    return (
      <Layout user={user}>
        <div className="flex items-center justify-center min-h-screen">
          <div className="text-center">
            <h1
              className="text-2xl font-bold mb-4"
              style={{ color: 'var(--text-primary)' }}
            >
              Deck not found
            </h1>
            <Link
              href="/decks"
              className="hover:underline"
              style={{ color: 'var(--accent-ember)' }}
            >
              Back to Decks
            </Link>
          </div>
        </div>
      </Layout>
    );
  }

  const stats = getDeckStats();
  const groupedCards = getGroupedCards();
  const isOwner = user && deck.user_id === user.userId;

  return (
    <Layout user={user}>
      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
        {/* Header */}
        <div className="flex justify-between items-start mb-8">
          <div>
            <div className="flex items-center space-x-3 mb-2">
              <Link
                href="/decks"
                className="hover:underline"
                style={{ color: 'var(--accent-ember)' }}
              >
                ← Back to Decks
              </Link>
            </div>
            <div className="flex items-center space-x-3 mb-2">
              <span className="text-3xl">{getFormatIcon(deck.format)}</span>
              <h1
                className="text-3xl font-bold"
                style={{ color: 'var(--text-primary)' }}
              >
                {deck.name}
              </h1>
              {deck.is_public && (
                <span
                  className="px-2 py-1 rounded-full text-xs font-medium"
                  style={{
                    backgroundColor: 'var(--bg-tertiary)',
                    color: 'var(--accent-ember)',
                  }}
                >
                  Public
                </span>
              )}
            </div>
            <p className="mb-2" style={{ color: 'var(--text-secondary)' }}>
              by {deck.creator_username} • {deck.format} • {stats.totalCards} cards
            </p>
            {deck.description && (
              <p
                className="max-w-2xl"
                style={{ color: 'var(--text-secondary)' }}
              >
                {deck.description}
              </p>
            )}
          </div>

          {isOwner && (
            <div className="flex space-x-3">
              <Link href={`/deck-builder?deck=${deck.id}`}>
                <Button variant="primary">Edit Deck</Button>
              </Link>
            </div>
          )}
        </div>

        <div className="grid grid-cols-1 lg:grid-cols-4 gap-6">
          {/* Stats Sidebar */}
          <div className="lg:col-span-1">
            <div className="glass-panel rounded-2xl p-6 mb-6">
              <h3
                className="text-lg font-semibold mb-4"
                style={{ color: 'var(--text-primary)' }}
              >
                Statistics
              </h3>

              <div className="space-y-3">
                <div className="flex justify-between">
                  <span style={{ color: 'var(--text-secondary)' }}>Total Cards:</span>
                  <span className="font-medium" style={{ color: 'var(--text-primary)' }}>
                    {stats.totalCards}
                  </span>
                </div>
                <div className="flex justify-between">
                  <span style={{ color: 'var(--text-secondary)' }}>Avg. CMC:</span>
                  <span className="font-medium" style={{ color: 'var(--text-primary)' }}>
                    {stats.avgCmc}
                  </span>
                </div>
                <div className="flex justify-between">
                  <span style={{ color: 'var(--text-secondary)' }}>Format:</span>
                  <span className="font-medium" style={{ color: 'var(--text-primary)' }}>
                    {deck.format}
                  </span>
                </div>
              </div>

              {/* Color Distribution */}
              {Object.keys(stats.colorCounts).length > 0 && (
                <div className="mt-6">
                  <h4
                    className="text-sm font-medium mb-3"
                    style={{ color: 'var(--text-secondary)' }}
                  >
                    Color Distribution
                  </h4>
                  <div className="space-y-2">
                    {Object.entries(stats.colorCounts)
                      .sort(([, a], [, b]) => b - a)
                      .map(([color, count]) => (
                        <div key={color} className="flex justify-between items-center">
                          <div className="flex items-center space-x-2">
                            <span className="text-lg">{color}</span>
                            <span
                              className="text-sm"
                              style={{ color: 'var(--text-secondary)' }}
                            >
                              {color}
                            </span>
                          </div>
                          <span
                            className="font-medium"
                            style={{ color: 'var(--text-primary)' }}
                          >
                            {count}
                          </span>
                        </div>
                      ))}
                  </div>
                </div>
              )}

              {/* Type Distribution */}
              {Object.keys(stats.typeCounts).length > 0 && (
                <div className="mt-6">
                  <h4
                    className="text-sm font-medium mb-3"
                    style={{ color: 'var(--text-secondary)' }}
                  >
                    Card Types
                  </h4>
                  <div className="space-y-2">
                    {Object.entries(stats.typeCounts)
                      .sort(([, a], [, b]) => b - a)
                      .slice(0, 8)
                      .map(([type, count]) => (
                        <div key={type} className="flex justify-between">
                          <span
                            className="text-sm"
                            style={{ color: 'var(--text-secondary)' }}
                          >
                            {type}
                          </span>
                          <span
                            className="font-medium"
                            style={{ color: 'var(--text-primary)' }}
                          >
                            {count}
                          </span>
                        </div>
                      ))}
                  </div>
                </div>
              )}
            </div>

            {/* Group By Controls */}
            <div className="glass-panel rounded-2xl p-6">
              <h3
                className="text-lg font-semibold mb-4"
                style={{ color: 'var(--text-primary)' }}
              >
                Group Cards By
              </h3>
              <div className="space-y-2">
                {[
                  { value: 'type', label: 'Card Type' },
                  { value: 'cmc', label: 'Mana Cost' },
                  { value: 'color', label: 'Color' },
                  { value: 'rarity', label: 'Rarity' },
                ].map(option => (
                  <button
                    key={option.value}
                    onClick={() => setGroupBy(option.value)}
                    className={`nav-item w-full text-left px-3 py-2 ${
                      groupBy === option.value ? 'nav-item-active' : 'nav-item-hover'
                    }`}
                  >
                    {option.label}
                  </button>
                ))}
              </div>
            </div>
          </div>

          {/* Card List */}
          <div className="lg:col-span-3">
            <div className="glass-panel rounded-2xl p-6">
              {deck.cards && deck.cards.length === 0 ? (
                <div className="text-center py-12">
                  <div className="text-6xl mb-4">🃏</div>
                  <h3
                    className="text-xl font-semibold mb-2"
                    style={{ color: 'var(--text-primary)' }}
                  >
                    Empty Deck
                  </h3>
                  <p style={{ color: 'var(--text-secondary)' }}>
                    This deck doesn&apos;t have any cards yet
                  </p>
                </div>
              ) : (
                <div className="space-y-6">
                  {Object.entries(groupedCards)
                    .sort(([a], [b]) => a.localeCompare(b))
                    .map(([group, cards]) => (
                      <div key={group}>
                        <h3
                          className="text-lg font-semibold mb-3 border-b pb-2"
                          style={{
                            color: 'var(--text-primary)',
                            borderColor: 'var(--border)',
                          }}
                        >
                          {group} ({cards.reduce((sum, card) => sum + card.quantity, 0)})
                        </h3>
                        <div className="grid grid-cols-1 md:grid-cols-2 gap-3">
                          {cards
                            .sort((a, b) => a.name.localeCompare(b.name))
                            .map((card) => (
                              <div
                                key={`${card.card_id}-${card.id}`}
                                className="flex items-center space-x-3 p-3 rounded-xl transition-colors nav-item-hover"
                                style={{ backgroundColor: 'var(--bg-primary)' }}
                              >
                                {card.image_url && (
                                  <img
                                    src={card.image_url}
                                    alt={card.name}
                                    className="w-12 h-16 object-cover rounded"
                                  />
                                )}
                                <div className="flex-1 min-w-0">
                                  <div className="flex items-center justify-between">
                                    <h4
                                      className="font-medium truncate"
                                      style={{ color: 'var(--text-primary)' }}
                                    >
                                      {card.name}
                                    </h4>
                                    <span
                                      className="font-medium ml-2"
                                      style={{ color: 'var(--text-primary)' }}
                                    >
                                      {card.quantity}x
                                    </span>
                                  </div>
                                  <p
                                    className="text-sm"
                                    style={{ color: 'var(--text-secondary)' }}
                                  >
                                    {card.set_name}
                                  </p>
                                  <div
                                    className="flex items-center space-x-2 text-xs"
                                    style={{ color: 'var(--text-secondary)' }}
                                  >
                                    {card.mana_cost && (
                                      <ManaCost cost={card.mana_cost} size="xs" />
                                    )}
                                    {card.rarity && (
                                      <span className="capitalize">{card.rarity}</span>
                                    )}
                                  </div>
                                </div>
                              </div>
                            ))}
                        </div>
                      </div>
                    ))}
                </div>
              )}
            </div>
          </div>
        </div>
      </div>
    </Layout>
  );
}