import gradio as gr
from youtube_transcript_api import YouTubeTranscriptApi
from transformers import pipeline
import re

# Model yükleme (ilk çalıştırmada indirir)
summarizer = pipeline("summarization", model="facebook/bart-large-cnn")
sentiment_analyzer = pipeline(
    "sentiment-analysis",
    model="cardiffnlp/twitter-roberta-base-sentiment-latest"
)

LABEL_MAP = {
    "positive": "Olumlu",
    "negative": "Olumsuz",
    "neutral": "Nötr"
}

def extract_video_id(url: str) -> str:
    patterns = [
        r"v=([a-zA-Z0-9_-]{11})",
        r"youtu\.be/([a-zA-Z0-9_-]{11})",
        r"embed/([a-zA-Z0-9_-]{11})",
    ]
    for pattern in patterns:
        match = re.search(pattern, url)
        if match:
            return match.group(1)
    raise ValueError("Geçersiz YouTube URL'si")

def get_transcript(video_id: str) -> str:
    try:
        transcript = YouTubeTranscriptApi.get_transcript(video_id, languages=["tr", "en"])
        return " ".join([t["text"] for t in transcript])
    except Exception:
        try:
            transcript = YouTubeTranscriptApi.get_transcript(video_id)
            return " ".join([t["text"] for t in transcript])
        except Exception as e:
            raise ValueError(f"Transkript alınamadı: {str(e)}")

def chunk_text(text: str, max_tokens: int = 1000) -> list[str]:
    words = text.split()
    chunks = []
    current = []
    for word in words:
        current.append(word)
        if len(current) >= max_tokens:
            chunks.append(" ".join(current))
            current = []
    if current:
        chunks.append(" ".join(current))
    return chunks

def summarize_text(text: str) -> str:
    if len(text.split()) < 50:
        return "Transkript çok kısa, özet oluşturulamadı."
    chunks = chunk_text(text, max_tokens=900)
    summaries = []
    for chunk in chunks[:4]:  # max 4 chunk
        result = summarizer(chunk, max_length=150, min_length=40, do_sample=False)
        summaries.append(result[0]["summary_text"])
    return " ".join(summaries)

def analyze_sentiment(text: str) -> dict:
    chunks = chunk_text(text, max_tokens=200)
    scores = {"positive": 0, "negative": 0, "neutral": 0}
    for chunk in chunks[:10]:  # max 10 chunk
        result = sentiment_analyzer(chunk[:512])[0]
        label = result["label"].lower()
        if label in scores:
            scores[label] += result["score"]
    total = sum(scores.values())
    if total == 0:
        return scores
    return {k: round(v / total * 100, 1) for k, v in scores.items()}

def extract_keywords(text: str) -> str:
    words = re.findall(r'\b[a-zA-ZğüşöçıİĞÜŞÖÇ]{4,}\b', text.lower())
    freq = {}
    stopwords = {"this", "that", "with", "have", "from", "they", "will", "been",
                 "were", "your", "what", "when", "here", "there", "more", "also",
                 "just", "like", "some", "than", "then", "into", "over", "after"}
    for w in words:
        if w not in stopwords:
            freq[w] = freq.get(w, 0) + 1
    top = sorted(freq.items(), key=lambda x: x[1], reverse=True)[:10]
    return ", ".join([w for w, _ in top])

def analyze_youtube(url: str):
    if not url.strip():
        return "URL girin.", "", "", ""
    try:
        video_id = extract_video_id(url)
        transcript = get_transcript(video_id)

        summary = summarize_text(transcript)
        sentiment = analyze_sentiment(transcript)
        keywords = extract_keywords(transcript)

        sentiment_text = (
            f"Olumlu: %{sentiment['positive']}\n"
            f"Olumsuz: %{sentiment['negative']}\n"
            f"Nötr: %{sentiment['neutral']}"
        )

        dominant = max(sentiment, key=sentiment.get)
        dominant_tr = LABEL_MAP.get(dominant, dominant)

        return (
            summary,
            sentiment_text,
            f"Genel Ton: {dominant_tr}",
            keywords
        )
    except ValueError as e:
        return str(e), "", "", ""
    except Exception as e:
        return f"Hata: {str(e)}", "", "", ""

with gr.Blocks(title="YouTube Video Analizci", theme=gr.themes.Soft()) as demo:
    gr.Markdown("# YouTube Video Analizci")
    gr.Markdown("YouTube video URL'si girin — transkript özetini, duygu analizini ve anahtar kelimeleri çıkarır.")

    with gr.Row():
        url_input = gr.Textbox(
            label="YouTube URL",
            placeholder="https://www.youtube.com/watch?v=...",
            scale=4
        )
        analyze_btn = gr.Button("Analiz Et", variant="primary", scale=1)

    with gr.Row():
        summary_out = gr.Textbox(label="Video Özeti", lines=6, scale=3)
        with gr.Column(scale=1):
            sentiment_out = gr.Textbox(label="Duygu Analizi", lines=3)
            tone_out = gr.Textbox(label="Genel Ton", lines=1)

    keywords_out = gr.Textbox(label="Anahtar Kelimeler", lines=2)

    analyze_btn.click(
        fn=analyze_youtube,
        inputs=[url_input],
        outputs=[summary_out, sentiment_out, tone_out, keywords_out]
    )

    gr.Examples(
        examples=[["https://www.youtube.com/watch?v=dQw4w9WgXcQ"]],
        inputs=[url_input]
    )

if __name__ == "__main__":
    demo.launch()