import { useState } from 'react';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';

import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
import { Skeleton } from '@/components/ui/skeleton';
import { useFollowing, useFollowers, useFollowActions } from '@/hooks/useFollowing';
import { useAuthor } from '@/hooks/useAuthor';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { genUserName } from '@/lib/genUserName';
import { Users, UserPlus, UserMinus, Loader2 } from 'lucide-react';
import { useTranslation } from '@/contexts/language';


function FollowingUserCard({ pubkey, onUnfollow }: { pubkey: string; onUnfollow: (pubkey: string) => void }) {
  const author = useAuthor(pubkey);
  const metadata = author.data?.metadata;
  const displayName = metadata?.name ?? genUserName(pubkey);
  const [isUnfollowing, setIsUnfollowing] = useState(false);
  const { t } = useTranslation();

  const handleUnfollow = async () => {
    setIsUnfollowing(true);
    await onUnfollow(pubkey);
    setIsUnfollowing(false);
  };

  return (
    <div className="flex items-center justify-between p-3 bg-black/50 rounded-lg border border-gray-700 hover:border-[#ff0040]/50 transition-all">
      <div className="flex items-center gap-3 flex-1 min-w-0">
        <Avatar className="h-10 w-10 border-2 border-[#ff0040]/30">
          <AvatarImage src={metadata?.picture} alt={displayName} />
          <AvatarFallback className="bg-black text-[#ff0040] text-xs">
            {displayName.slice(0, 2).toUpperCase()}
          </AvatarFallback>
        </Avatar>
        <div className="flex-1 min-w-0">
          <div className="font-bold text-white truncate">{displayName}</div>
          {metadata?.nip05 && (
            <div className="flex items-center gap-1 text-xs">
              <div className="w-1.5 h-1.5 rounded-full bg-[#ccff00]" />
              <span className="text-[#ccff00] truncate">{metadata.nip05}</span>
            </div>
          )}
          {!metadata?.nip05 && (
            <div className="text-xs text-gray-500 truncate font-mono">
              {pubkey.slice(0, 8)}...{pubkey.slice(-8)}
            </div>
          )}
        </div>
      </div>
      <Button
        variant="outline"
        size="sm"
        onClick={handleUnfollow}
        disabled={isUnfollowing}
        className="gap-1 border-gray-600 hover:border-red-500 hover:text-red-500"
      >
        {isUnfollowing ? (
          <Loader2 className="h-3 w-3 animate-spin" />
        ) : (
          <UserMinus className="h-3 w-3" />
        )}
        {t('settingsUi.followList.unfollow')}
      </Button>
    </div>
  );
}

function FollowerUserCard({ pubkey }: { pubkey: string }) {
  const author = useAuthor(pubkey);
  const metadata = author.data?.metadata;
  const displayName = metadata?.name ?? genUserName(pubkey);

  return (
    <div className="flex items-center gap-3 p-3 bg-black/50 rounded-lg border border-gray-700">
      <Avatar className="h-10 w-10 border-2 border-[#ccff00]/30">
        <AvatarImage src={metadata?.picture} alt={displayName} />
        <AvatarFallback className="bg-black text-[#ccff00] text-xs">
          {displayName.slice(0, 2).toUpperCase()}
        </AvatarFallback>
      </Avatar>
      <div className="flex-1 min-w-0">
        <div className="font-bold text-white truncate">{displayName}</div>
        {metadata?.nip05 && (
          <div className="flex items-center gap-1 text-xs">
            <div className="w-1.5 h-1.5 rounded-full bg-[#ccff00]" />
            <span className="text-[#ccff00] truncate">{metadata.nip05}</span>
          </div>
        )}
        {!metadata?.nip05 && (
          <div className="text-xs text-gray-500 truncate font-mono">
            {pubkey.slice(0, 8)}...{pubkey.slice(-8)}
          </div>
        )}
      </div>
    </div>
  );
}

export function FollowListManager() {
  const { user } = useCurrentUser();
  const { t } = useTranslation();
  const { data: following = [], isLoading: followingLoading } = useFollowing();
  const { data: followers = [], isLoading: followersLoading } = useFollowers();
  const { unfollow, followByIdentifier, isFollowing } = useFollowActions();

  const [followInput, setFollowInput] = useState('');

  const handleFollow = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!followInput.trim()) return;

    await followByIdentifier(followInput.trim());
    setFollowInput('');
  };

  if (!user) {
    return null;
  }

  return (
    <Card className="bg-gradient-to-br from-purple-950/30 to-blue-950/30 border-2 border-purple-500/50">
      <CardHeader>
        <CardTitle className="flex items-center gap-2 text-purple-400">
          <Users className="h-5 w-5" />
          {t('settingsUi.followList.title')}
        </CardTitle>
        <CardDescription className="text-gray-300">
          {t('settingsUi.followList.desc')}
        </CardDescription>
      </CardHeader>
      <CardContent>
        <Tabs defaultValue="following" className="space-y-4">
          <TabsList className="grid w-full grid-cols-2">
            <TabsTrigger value="following" className="gap-2">
              <UserPlus className="h-4 w-4" />
              {t('settingsUi.followList.following', { count: following.length })}
            </TabsTrigger>
            <TabsTrigger value="followers" className="gap-2">
              <Users className="h-4 w-4" />
              {t('settingsUi.followList.followers', { count: followers.length })}
            </TabsTrigger>
          </TabsList>

          <TabsContent value="following" className="space-y-4">
            {/* Add Follow Input */}
            <form onSubmit={handleFollow} className="space-y-2">
              <div className="flex gap-2">
                <Input
                  placeholder="npub1... or user@domain.com"
                  value={followInput}
                  onChange={(e) => setFollowInput(e.target.value)}
                  className="flex-1"
                  disabled={isFollowing}
                />
                <Button
                  type="submit"
                  disabled={!followInput.trim() || isFollowing}
                  className="gap-2 bg-[#ff0040] hover:bg-[#ff0040]/90"
                >
                  {isFollowing ? (
                    <Loader2 className="h-4 w-4 animate-spin" />
                  ) : (
                    <UserPlus className="h-4 w-4" />
                  )}
                  {t('settingsUi.followList.follow')}
                </Button>
              </div>
              <p className="text-xs text-gray-500">
                {t('settingsUi.followList.followHint')}
              </p>
            </form>

            {/* Following List */}
            {followingLoading ? (
              <div className="space-y-2">
                {Array.from({ length: 3 }).map((_, i) => (
                  <div key={i} className="p-3 bg-black/50 rounded-lg border border-gray-700">
                    <div className="flex items-center gap-3">
                      <Skeleton className="h-10 w-10 rounded-full" />
                      <div className="space-y-1 flex-1">
                        <Skeleton className="h-4 w-32" />
                        <Skeleton className="h-3 w-24" />
                      </div>
                    </div>
                  </div>
                ))}
              </div>
            ) : following.length > 0 ? (
              <div className="space-y-2 max-h-96 overflow-y-auto">
                {following.map((pubkey) => (
                  <FollowingUserCard
                    key={pubkey}
                    pubkey={pubkey}
                    onUnfollow={unfollow}
                  />
                ))}
              </div>
            ) : (
              <div className="text-center py-8 border-2 border-dashed border-gray-700 rounded-lg">
                <Users className="h-12 w-12 mx-auto mb-3 text-gray-600" />
                <p className="text-gray-400 mb-2">{t('settingsUi.followList.notFollowing')}</p>
                <p className="text-sm text-gray-500">
                  {t('settingsUi.followList.notFollowingHint')}
                </p>
              </div>
            )}

            {/* Trust Info */}
            {following.length > 0 && (
              <div className="p-4 rounded-lg bg-green-950/30 border border-green-500/30 text-sm">
                <p className="text-green-400">
                  <strong>{t('settingsUi.followList.trustActiveStrong')}</strong> {t('settingsUi.followList.trustActive')}
                </p>
              </div>
            )}
          </TabsContent>

          <TabsContent value="followers" className="space-y-4">
            {followersLoading ? (
              <div className="space-y-2">
                {Array.from({ length: 3 }).map((_, i) => (
                  <div key={i} className="p-3 bg-black/50 rounded-lg border border-gray-700">
                    <div className="flex items-center gap-3">
                      <Skeleton className="h-10 w-10 rounded-full" />
                      <div className="space-y-1 flex-1">
                        <Skeleton className="h-4 w-32" />
                        <Skeleton className="h-3 w-24" />
                      </div>
                    </div>
                  </div>
                ))}
              </div>
            ) : followers.length > 0 ? (
              <div className="space-y-2 max-h-96 overflow-y-auto">
                {followers.map((pubkey) => (
                  <FollowerUserCard key={pubkey} pubkey={pubkey} />
                ))}
              </div>
            ) : (
              <div className="text-center py-8 border-2 border-dashed border-gray-700 rounded-lg">
                <Users className="h-12 w-12 mx-auto mb-3 text-gray-600" />
                <p className="text-gray-400 mb-2">{t('settingsUi.followList.noFollowers')}</p>
                <p className="text-sm text-gray-500">
                  {t('settingsUi.followList.noFollowersHint')}
                </p>
              </div>
            )}
          </TabsContent>
        </Tabs>

        {/* Info Card */}
        <Card className="bg-blue-950/30 border-2 border-blue-500/50 mt-6">
          <CardHeader>
            <CardTitle className="text-sm text-blue-400">{t('settingsUi.followList.howTitle')}</CardTitle>
          </CardHeader>
          <CardContent className="space-y-2 text-sm text-gray-300">
            <p>
              <strong className="text-white">{t('settingsUi.followList.verifiedStrong')}</strong> {t('settingsUi.followList.verifiedDesc')}
            </p>
            <p>
              <strong className="text-white">{t('settingsUi.followList.trustedStrong')}</strong> {t('settingsUi.followList.trustedDesc')}
            </p>
            <p>
              <strong className="text-white">{t('settingsUi.followList.unverifiedStrong')}</strong> {t('settingsUi.followList.unverifiedDesc')}
            </p>
            <p className="text-xs text-blue-400 mt-4">
              {t('settingsUi.followList.tip')}
            </p>
          </CardContent>
        </Card>
      </CardContent>
    </Card>
  );
}