nextjs-app/src/components/SentimentAnalyzer.tsx

'use client';

import { useState } from 'react';
import { MessageSquare, TrendingUp, TrendingDown, Minus, Sparkles } from 'lucide-react';

import { fetchJson } from '@/lib/http';

interface SentimentResult {
  label: 'POSITIVE' | 'NEGATIVE' | 'NEUTRAL';
  score: number;
}

interface SentimentData {
  text: string;
  sentiment: SentimentResult;
  timestamp: string;
}

export default function SentimentAnalyzer({ market = 'bist' }: { market?: 'bist' | 'us' }) {
  const isUS = market === 'us';
  const [text, setText] = useState('');
  const [result, setResult] = useState<SentimentData | null>(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const analyzeSentiment = async () => {
    if (!text.trim()) return;

    setLoading(true);
    setError(null);

    try {
      const data = await fetchJson<Record<string, unknown>>(
        `/api/sentiment`,
        { method: 'POST' },
        { timeoutMs: 20000, retries: 0, jsonBody: { text } }
      );

      if (data?.ok === false) {
        const message = [data.error, data.hint].filter((value) => typeof value === 'string' && value).join(' ');
        throw new Error(message || 'Invalid sentiment payload');
      }

      // No-toy: if backend returns no sentiment, we show no label.
      if (!data || (typeof data !== 'object')) {
        throw new Error('Invalid sentiment payload');
      }

      if (!('sentiment' in data)) {
        throw new Error('Invalid sentiment payload');
      }

      setResult(data as unknown as SentimentData);
    } catch (err) {
      console.error('Sentiment analysis failed:', err);
      setResult(null);
      setError(isUS ? 'Sentiment analysis service unreachable or model not ready. No result produced.' : 'Duygu analizi servisine ulaşılamadı veya model hazır değil. Bu durumda sonuç üretilmez.');
    } finally {
      setLoading(false);
    }
  };

  const getSentimentColor = (label: string) => {
    switch (label) {
      case 'POSITIVE':
        return 'text-green-600 bg-green-50 border-green-200';
      case 'NEGATIVE':
        return 'text-red-600 bg-red-50 border-red-200';
      default:
        return 'text-gray-600 bg-gray-50 border-gray-200';
    }
  };

  const getSentimentIcon = (label: string) => {
    switch (label) {
      case 'POSITIVE':
        return <TrendingUp className="w-5 h-5" />;
      case 'NEGATIVE':
        return <TrendingDown className="w-5 h-5" />;
      default:
        return <Minus className="w-5 h-5" />;
    }
  };

  const getSentimentLabel = (label: string) => {
    switch (label) {
      case 'POSITIVE':
        return isUS ? 'Positive' : 'Pozitif';
      case 'NEGATIVE':
        return isUS ? 'Negative' : 'Negatif';
      default:
        return isUS ? 'Neutral' : 'Nötr';
    }
  };

  return (
    <div className="bg-white rounded-lg shadow p-6">
      <div className="flex items-center gap-2 mb-6">
        <Sparkles className="w-5 h-5 text-indigo-600" />
        <h2 className="text-lg font-semibold">{isUS ? 'News Sentiment Analysis' : 'Haber Duygu Analizi'}</h2>
      </div>

      <div className="space-y-4">
        <div>
          <label htmlFor="sentiment-text" className="block text-sm font-medium text-gray-700 mb-2">
            {isUS ? 'News Text (English)' : 'Haber Metni (Türkçe)'}
          </label>
          <textarea
            id="sentiment-text"
            value={text}
            onChange={(e) => setText(e.target.value)}
            placeholder={isUS ? 'Example: AAPL shares surged 5% today and hit a new all-time high...' : 'Örnek: THYAO hisseleri bugün %5 yükseliş gösterdi ve yeni rekor kırdı...'}
            className="w-full px-4 py-3 border border-gray-300 rounded-lg focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 resize-none"
            rows={4}
          />
        </div>

        <button
          onClick={analyzeSentiment}
          disabled={loading || !text.trim()}
          className="w-full bg-indigo-600 text-white py-3 rounded-lg hover:bg-indigo-700 disabled:bg-gray-300 disabled:cursor-not-allowed flex items-center justify-center gap-2"
        >
          <MessageSquare className="w-5 h-5" />
          {loading ? (isUS ? 'Analyzing...' : 'Analiz Ediliyor...') : (isUS ? 'Analyze Sentiment' : 'Duygu Analizi Yap')}
        </button>

        {result && (
          <div className={`mt-6 p-4 border-2 rounded-lg ${getSentimentColor(result.sentiment.label)}`}>
            <div className="flex items-center justify-between mb-4">
              <div className="flex items-center gap-2">
                {getSentimentIcon(result.sentiment.label)}
                <span className="text-xl font-bold">
                  {getSentimentLabel(result.sentiment.label)}
                </span>
              </div>
              <div className="text-right">
                <div className="text-sm opacity-75">{isUS ? 'Confidence' : 'Güven'}</div>
                <div className="text-2xl font-bold">
                  {Math.round(result.sentiment.score * 100)}%
                </div>
              </div>
            </div>

            <div className="mt-4 pt-4 border-t border-current border-opacity-20">
              <div className="text-sm opacity-75">{isUS ? 'Analyzed Text:' : 'Analiz Edilen Metin:'}</div>
              <div className="mt-2 text-sm italic">&quot;{result.text}&quot;</div>
            </div>
          </div>
        )}

        {result && !result.sentiment ? (
          <div className="mt-6 p-4 bg-amber-50 border border-amber-200 rounded-lg text-sm text-amber-900">
            {isUS ? 'No sentiment result could be produced for this text.' : 'Bu metin için sentiment sonucu üretilemedi.'}
          </div>
        ) : null}

        {error && (
          <div className="mt-6 p-4 bg-amber-50 border border-amber-200 rounded-lg text-sm text-amber-900">
            {error}
          </div>
        )}

        <div className="mt-6 p-4 bg-blue-50 border border-blue-200 rounded-lg">
          <div className="flex items-start gap-2 text-sm text-blue-800">
            <MessageSquare className="w-4 h-4 flex-shrink-0 mt-0.5" />
            <div>
              <p className="font-semibold mb-1">{isUS ? 'Sentiment Analysis' : 'Duygu Analizi'}</p>
              <p className="text-xs text-blue-700">
                {isUS
                  ? 'This feature works best-effort with a real model. If the service is unreachable or the model cannot load, no result is returned.'
                  : 'Bu özellik gerçek bir model ile best-effort çalışır. Servis erişilemezse veya model yüklenemezse sonuç dönmez (toy sonuç üretilmez).'}
              </p>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}