import { useMemo, useState } from 'react';
import { motion } from 'motion/react';
import { Badge } from '@/components/ui/badge';
import { CodingQuestion, codingQuestions } from '@/data/codingQuestions';
import {
  DIFFICULTY_TOTALS,
  TOTAL_CODING_QUESTIONS,
  getQuestionCaseCount,
  getQuestionReward,
  getSolvedDifficultyCounts,
} from '@/lib/codingProgress';
import { cn } from '@/lib/utils';
import {
  BookOpen,
  CheckCircle2,
  Code2,
  Coins,
  Search,
  Target,
  Trophy,
} from 'lucide-react';

interface CodingSheetProps {
  onSelectQuestion: (question: CodingQuestion, mode: 'code' | 'solution') => void;
  solvedQuestionIds: string[];
}

const categories = Array.from(new Set(codingQuestions.map((question) => question.category)));

export default function CodingSheet({
  onSelectQuestion,
  solvedQuestionIds,
}: CodingSheetProps) {
  const [searchQuery, setSearchQuery] = useState('');
  const [selectedCategory, setSelectedCategory] = useState<string | null>(null);

  const solvedSet = useMemo(() => new Set(solvedQuestionIds), [solvedQuestionIds]);
  const difficultySolved = useMemo(
    () => getSolvedDifficultyCounts(solvedQuestionIds),
    [solvedQuestionIds],
  );

  const filteredQuestions = useMemo(() => {
    return codingQuestions.filter((question) => {
      const matchesSearch =
        question.title.toLowerCase().includes(searchQuery.toLowerCase()) ||
        question.category.toLowerCase().includes(searchQuery.toLowerCase());
      const matchesCategory = selectedCategory ? question.category === selectedCategory : true;
      return matchesSearch && matchesCategory;
    });
  }, [searchQuery, selectedCategory]);

  const solvedCount = solvedSet.size;
  const progressPercent = Math.min(
    100,
    Math.round((solvedCount / TOTAL_CODING_QUESTIONS) * 100),
  );

  return (
    <div className="mx-auto max-w-5xl space-y-8 pb-12">
      <div className="flex flex-col gap-4 md:flex-row md:items-start md:justify-between">
        <div>
          <div className="flex items-center gap-2 text-xs font-black uppercase tracking-[0.28em] text-emerald-400/80">
            <Target size={16} />
            Problem Set
          </div>
          <h2 className="mt-3 text-4xl font-black tracking-tight text-white">Coding Question Bank</h2>
          <p className="mt-2 max-w-2xl text-sm leading-6 text-slate-400">
            Track real progress across all {TOTAL_CODING_QUESTIONS} coding questions with shared solved state, live rewards, and category-by-category completion.
          </p>
        </div>
      </div>

      <div className="grid grid-cols-2 gap-4 md:grid-cols-5">
        <div className="relative col-span-2 overflow-hidden rounded-[28px] border border-emerald-500/20 bg-emerald-500/5 p-6 backdrop-blur-sm">
          <div className="absolute -right-10 -top-10 h-40 w-40 rounded-full bg-emerald-500/10 blur-[60px]" />
          <div className="relative z-10">
            <div className="flex items-center justify-between">
              <span className="text-[11px] font-black uppercase tracking-[0.26em] text-emerald-300/70">Your Progress</span>
              <Trophy size={16} className="text-emerald-400" />
            </div>
            <div className="mt-2 flex items-end gap-2">
              <span className="text-4xl font-black text-white">{solvedCount}</span>
              <span className="mb-1 text-lg font-bold text-emerald-400/60">/ {TOTAL_CODING_QUESTIONS}</span>
            </div>
            <div className="mt-4 h-2 w-full overflow-hidden rounded-full bg-white/5">
              <motion.div
                className="h-full rounded-full bg-gradient-to-r from-emerald-500 to-emerald-400 shadow-[0_0_12px_rgba(16,185,129,0.5)]"
                initial={{ width: 0 }}
                animate={{ width: `${progressPercent}%` }}
                transition={{ duration: 1, ease: 'easeOut' }}
              />
            </div>
            <div className="mt-1.5 text-right text-xs font-bold text-emerald-400">{progressPercent}% Complete</div>
          </div>
        </div>

        {[
          {
            label: 'Easy',
            solved: difficultySolved.Easy,
            total: DIFFICULTY_TOTALS.Easy,
            color: 'text-emerald-400',
            glow: 'bg-emerald-500/5',
          },
          {
            label: 'Medium',
            solved: difficultySolved.Medium,
            total: DIFFICULTY_TOTALS.Medium,
            color: 'text-amber-400',
            glow: 'bg-amber-500/5',
          },
          {
            label: 'Hard',
            solved: difficultySolved.Hard,
            total: DIFFICULTY_TOTALS.Hard,
            color: 'text-rose-400',
            glow: 'bg-rose-500/5',
          },
        ].map((card) => (
          <div
            key={card.label}
            className="relative overflow-hidden rounded-[28px] border border-zinc-800/80 bg-zinc-950/50 p-6 backdrop-blur-sm"
          >
            <div className={cn('absolute -right-6 -top-6 h-24 w-24 rounded-full blur-[40px]', card.glow)} />
            <div className="relative z-10 space-y-1">
              <span className="text-[10px] font-black uppercase tracking-widest text-zinc-500">
                {card.label}
              </span>
              <div className={cn('text-3xl font-black', card.color)}>{card.solved}</div>
              <div className="text-xs font-medium text-zinc-500">{card.solved} / {card.total} solved</div>
            </div>
          </div>
        ))}
      </div>

      <div className="flex flex-col gap-4">
        <div className="relative">
          <Search className="absolute left-4 top-1/2 -translate-y-1/2 text-zinc-500" size={18} />
          <input
            type="text"
            placeholder="Search problems by name or category..."
            value={searchQuery}
            onChange={(event) => setSearchQuery(event.target.value)}
            className="w-full rounded-2xl border border-zinc-800 bg-zinc-950/60 py-3.5 pl-12 pr-4 text-sm text-white outline-none transition-all placeholder:text-zinc-600 focus:border-emerald-500/50 focus:ring-1 focus:ring-emerald-500/30"
          />
        </div>

        <div className="flex flex-wrap gap-2">
          <button
            onClick={() => setSelectedCategory(null)}
            className={cn(
              'rounded-xl px-4 py-2 text-xs font-bold uppercase tracking-wider transition-all',
              !selectedCategory
                ? 'bg-emerald-500 text-white shadow-[0_0_12px_rgba(16,185,129,0.3)]'
                : 'border border-zinc-800 bg-zinc-900/80 text-zinc-400 hover:border-zinc-700 hover:text-zinc-200',
            )}
          >
            All
          </button>
          {categories.map((category) => (
            <button
              key={category}
              onClick={() => setSelectedCategory(category)}
              className={cn(
                'rounded-xl px-4 py-2 text-xs font-bold uppercase tracking-wider transition-all',
                selectedCategory === category
                  ? 'bg-emerald-500 text-white shadow-[0_0_12px_rgba(16,185,129,0.3)]'
                  : 'border border-zinc-800 bg-zinc-900/80 text-zinc-400 hover:border-zinc-700 hover:text-zinc-200',
              )}
            >
              {category}
            </button>
          ))}
        </div>
      </div>

      <div className="space-y-10">
        {categories.map((category) => {
          const categoryQuestions = filteredQuestions.filter((question) => question.category === category);
          if (categoryQuestions.length === 0) {
            return null;
          }

          const categorySolved = categoryQuestions.filter((question) => solvedSet.has(question.id)).length;
          const categoryPercent =
            categoryQuestions.length > 0
              ? Math.round((categorySolved / categoryQuestions.length) * 100)
              : 0;

          return (
            <section key={category} className="space-y-4">
              <div className="flex items-center justify-between">
                <div className="flex items-center gap-3">
                  <div className="h-5 w-1.5 rounded-full bg-gradient-to-b from-emerald-400 to-emerald-600" />
                  <h2 className="text-lg font-black tracking-tight text-white">{category}</h2>
                  <Badge className="rounded-full border border-zinc-700 bg-zinc-900 px-3 py-0.5 text-[10px] font-black uppercase tracking-widest text-zinc-400">
                    {categoryQuestions.length} problems
                  </Badge>
                </div>
                <div className="flex items-center gap-3">
                  <span className="text-xs font-semibold text-zinc-400">
                    {categorySolved}/{categoryQuestions.length} solved
                  </span>
                  <div className="flex items-center gap-1.5">
                    <div className="h-1.5 w-24 overflow-hidden rounded-full bg-zinc-800">
                      <div
                        className="h-full rounded-full bg-emerald-500 transition-all duration-700"
                        style={{ width: `${categoryPercent}%` }}
                      />
                    </div>
                    <span className="text-[10px] font-bold text-emerald-400">{categoryPercent}%</span>
                  </div>
                </div>
              </div>

              <div className="overflow-hidden rounded-[20px] border border-zinc-800/80 bg-zinc-950/50 shadow-xl backdrop-blur-sm">
                <div className="overflow-x-auto">
                  <table className="w-full whitespace-nowrap text-left text-sm">
                    <thead className="border-b border-zinc-800 bg-zinc-900/80 text-xs text-zinc-500">
                      <tr>
                        <th className="w-14 px-4 py-3 text-center font-semibold uppercase tracking-wider">Status</th>
                        <th className="px-4 py-3 font-semibold uppercase tracking-wider">Title</th>
                        <th className="w-28 px-4 py-3 text-center font-semibold uppercase tracking-wider">Test Cases</th>
                        <th className="w-24 px-4 py-3 font-semibold uppercase tracking-wider">Difficulty</th>
                        <th className="w-24 px-4 py-3 text-center font-semibold uppercase tracking-wider">Reward</th>
                        <th className="w-40 px-4 py-3 text-right font-semibold uppercase tracking-wider">Actions</th>
                      </tr>
                    </thead>
                    <tbody>
                      {categoryQuestions.map((question, index) => {
                        const isSolved = solvedSet.has(question.id);
                        const reward = getQuestionReward(question.difficulty);
                        const testCaseCount = getQuestionCaseCount(question);

                        return (
                          <motion.tr
                            key={question.id}
                            initial={{ opacity: 0, y: 8 }}
                            animate={{ opacity: 1, y: 0 }}
                            transition={{ delay: index * 0.025 }}
                            className={cn(
                              'group cursor-pointer border-b border-zinc-800/50 transition-colors hover:bg-zinc-800/60',
                              index % 2 === 0 ? 'bg-zinc-900/30' : 'bg-zinc-900/10',
                            )}
                          >
                            <td className="px-4 py-3.5 text-center align-middle">
                              <div className="flex justify-center">
                                {isSolved ? (
                                  <div className="flex h-6 w-6 items-center justify-center rounded-full bg-emerald-500/20 text-emerald-400">
                                    <CheckCircle2 size={14} strokeWidth={3} />
                                  </div>
                                ) : (
                                  <div className="flex h-6 w-6 items-center justify-center rounded-full border-2 border-zinc-600 text-zinc-400">
                                    <span className="text-[10px] font-bold">{index + 1}</span>
                                  </div>
                                )}
                              </div>
                            </td>
                            <td
                              className={cn(
                                'px-4 py-3.5 font-semibold transition-colors',
                                isSolved ? 'text-emerald-400' : 'text-white group-hover:text-white',
                              )}
                            >
                              {question.title}
                            </td>
                            <td className="px-4 py-3.5 text-center font-medium text-zinc-400">
                              {testCaseCount} checks
                            </td>
                            <td className="px-4 py-3.5">
                              <span
                                className={cn(
                                  'text-xs font-black tracking-wide',
                                  question.difficulty === 'Easy'
                                    ? 'text-emerald-400'
                                    : question.difficulty === 'Medium'
                                      ? 'text-amber-400'
                                      : 'text-rose-400',
                                )}
                              >
                                {question.difficulty}
                              </span>
                            </td>
                            <td className="px-4 py-3.5 text-center">
                              <div className="inline-flex items-center gap-1 rounded-lg border border-amber-500/20 bg-amber-500/10 px-2 py-1 text-amber-400">
                                <Coins size={11} />
                                <span className="text-xs font-black">{reward}</span>
                              </div>
                            </td>
                            <td className="px-4 py-3.5 text-right">
                              <div className="flex items-center justify-end gap-2">
                                <button
                                  onClick={() => onSelectQuestion(question, 'solution')}
                                  className="flex items-center gap-1.5 rounded-xl border border-zinc-700 bg-zinc-800/80 px-3 py-1.5 text-xs font-bold text-zinc-300 transition-all hover:border-zinc-600 hover:bg-zinc-700 hover:text-white"
                                >
                                  <BookOpen size={12} />
                                  Solution
                                </button>
                                <button
                                  onClick={() => onSelectQuestion(question, 'code')}
                                  className="flex items-center gap-1.5 rounded-xl bg-emerald-600 px-3 py-1.5 text-xs font-bold text-white shadow-lg shadow-emerald-900/30 transition-all hover:bg-emerald-500 hover:shadow-emerald-500/20"
                                >
                                  <Code2 size={12} />
                                  Solve
                                </button>
                              </div>
                            </td>
                          </motion.tr>
                        );
                      })}
                    </tbody>
                  </table>
                </div>
              </div>
            </section>
          );
        })}

        {filteredQuestions.length === 0 && (
          <div className="flex flex-col items-center justify-center gap-4 rounded-[28px] border border-zinc-800 bg-zinc-950/40 py-20 text-zinc-600">
            <Search size={32} className="opacity-40" />
            <p className="text-base font-semibold">No problems match your search</p>
          </div>
        )}
      </div>
    </div>
  );
}