'use client';

import { useState, useMemo } from 'react';
import { useCombatStore } from '@/lib/game/stores';
import {
  ACHIEVEMENTS,
  ACHIEVEMENT_CATEGORY_COLORS,
  getAchievementsByCategory,
  isAchievementRevealed,
} from '@/lib/game/data/achievements';
import type { AchievementDef } from '@/lib/game/types';
import { Card, CardContent } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Progress } from '@/components/ui/progress';
import { ScrollArea } from '@/components/ui/scroll-area';
import { SectionHeader } from '@/components/ui/section-header';
import { DebugName } from '@/components/game/debug/debug-context';
import { fmt } from '@/lib/game/stores';

// ─── Helpers ─────────────────────────────────────────────────────────────────

const CATEGORY_LABELS: Record<string, string> = {
  combat: '⚔️ Combat',
  progression: '📈 Progression',
  crafting: '🔨 Crafting',
  magic: '✨ Magic',
  special: '🌟 Special',
};

function getProgressForAchievement(
  achievement: AchievementDef,
  progress: Record<string, number>,
): number {
  return progress[achievement.id] ?? 0;
}

function getProgressPercent(achievement: AchievementDef, current: number): number {
  if (achievement.requirement.value <= 0) return 100;
  return Math.min(100, Math.round((current / achievement.requirement.value) * 100));
}

function formatReward(reward: AchievementDef['reward']): string {
  const parts: string[] = [];
  if (reward.insight) parts.push(`${reward.insight} insight`);
  if (reward.manaBonus) parts.push(`+${reward.manaBonus} mana`);
  if (reward.damageBonus) parts.push(`+${(reward.damageBonus * 100).toFixed(0)}% dmg`);
  if (reward.regenBonus) parts.push(`+${reward.regenBonus} regen`);
  if (reward.title) parts.push(`title: "${reward.title}"`);
  if (reward.unlockEffect) parts.push(`unlock: ${reward.unlockEffect}`);
  return parts.join(', ');
}

// ─── Category Section ────────────────────────────────────────────────────────

interface CategorySectionProps {
  category: string;
  achievements: AchievementDef[];
  unlocked: string[];
  progress: Record<string, number>;
  collapsed: boolean;
  onToggleCollapse: () => void;
}

function CategorySection({
  category,
  achievements,
  unlocked,
  progress,
  collapsed,
  onToggleCollapse,
}: CategorySectionProps) {
  const color = ACHIEVEMENT_CATEGORY_COLORS[category] ?? '#9CA3AF';
  const label = CATEGORY_LABELS[category] ?? category;
  const unlockedCount = achievements.filter((a) => unlocked.includes(a.id)).length;

  return (
    <Card className="bg-gray-900/60 border-gray-700">
      <SectionHeader
        title={`${label} (${unlockedCount}/${achievements.length})`}
        action={
          <button
            onClick={onToggleCollapse}
            className="text-xs text-gray-400 hover:text-gray-200 transition-colors"
          >
            {collapsed ? 'Expand ▼' : 'Collapse ▲'}
          </button>
        }
      />
      {!collapsed && (
        <CardContent className="space-y-3">
          {achievements.map((achievement) => {
            const isUnlocked = unlocked.includes(achievement.id);
            const currentProgress = getProgressForAchievement(achievement, progress);
            const percent = getProgressPercent(achievement, currentProgress);
            const revealed = isAchievementRevealed(achievement, currentProgress);

            if (!revealed) {
              return (
                <div
                  key={achievement.id}
                  className="p-3 rounded border border-gray-700/50 bg-gray-800/30"
                >
                  <div className="flex items-center gap-2">
                    <span className="text-gray-500">???</span>
                    <span className="text-xs text-gray-600 italic">
                      Hidden achievement — keep progressing to reveal
                    </span>
                  </div>
                  <div className="mt-2">
                    <Progress value={percent} className="h-1.5" />
                  </div>
                </div>
              );
            }

            return (
              <div
                key={achievement.id}
                className={`p-3 rounded border ${
                  isUnlocked
                    ? 'border-green-700/50 bg-green-900/20'
                    : 'border-gray-700/50 bg-gray-800/30'
                }`}
              >
                <div className="flex items-center justify-between mb-1">
                  <div className="flex items-center gap-2">
                    <span className="font-medium text-sm" style={{ color }}>
                      {achievement.name}
                    </span>
                    {isUnlocked && (
                      <Badge className="bg-green-900/50 text-green-300 text-xs">
                        ✓ Unlocked
                      </Badge>
                    )}
                  </div>
                  <span className="text-xs text-gray-500">
                    {fmt(currentProgress)} / {fmt(achievement.requirement.value)}
                  </span>
                </div>

                <p className="text-xs text-gray-400 mb-2">{achievement.desc}</p>

                <div className="flex items-center gap-2 mb-2">
                  <Progress value={percent} className="h-1.5 flex-1" />
                  <span className="text-xs text-gray-500 w-10 text-right">
                    {percent}%
                  </span>
                </div>

                <div className="text-xs text-gray-500">
                  <span className="text-gray-400">Reward:</span>{' '}
                  {formatReward(achievement.reward)}
                </div>
              </div>
            );
          })}
        </CardContent>
      )}
    </Card>
  );
}

// ─── Main Component ──────────────────────────────────────────────────────────

export function AchievementsTab() {
  const achievements = useCombatStore((s) => s.achievements);
  const [collapsedCategories, setCollapsedCategories] = useState<Record<string, boolean>>({});

  const byCategory = useMemo(() => getAchievementsByCategory(), []);
  const categories = useMemo(
    () => Object.keys(byCategory).sort(),
    [byCategory],
  );

  const totalAchievements = Object.keys(ACHIEVEMENTS).length;
  const unlockedCount = achievements.unlocked.length;

  const toggleCollapse = (category: string) => {
    setCollapsedCategories((prev) => ({
      ...prev,
      [category]: !prev[category],
    }));
  };

  return (
    <DebugName name="AchievementsTab">
      <div className="space-y-4">
        {/* Summary header */}
        <Card className="bg-gray-900/60 border-gray-700">
          <CardContent className="py-4">
            <div className="flex items-center justify-between">
              <div>
                <h2 className="text-lg font-semibold text-gray-100">
                  Achievements
                </h2>
                <p className="text-sm text-gray-400">
                  Track your progress and unlock rewards
                </p>
              </div>
              <div className="text-right">
                <div className="text-2xl font-bold text-amber-400">
                  {unlockedCount}
                  <span className="text-sm text-gray-500 font-normal">
                    /{totalAchievements}
                  </span>
                </div>
                <Progress
                  value={Math.round((unlockedCount / totalAchievements) * 100)}
                  className="h-2 w-32 mt-1"
                />
              </div>
            </div>
          </CardContent>
        </Card>

        {/* Category sections */}
        <ScrollArea className="h-[600px] pr-2">
          <div className="space-y-4">
            {categories.map((category) => (
              <CategorySection
                key={category}
                category={category}
                achievements={byCategory[category]}
                unlocked={achievements.unlocked}
                progress={achievements.progress}
                collapsed={collapsedCategories[category] ?? false}
                onToggleCollapse={() => toggleCollapse(category)}
              />
            ))}
          </div>
        </ScrollArea>
      </div>
    </DebugName>
  );
}

AchievementsTab.displayName = 'AchievementsTab';