import pandas as pd
import numpy as np
import warnings
import feedparser
from datetime import datetime
import gradio as gr

warnings.filterwarnings('ignore')
print("✅ Core imports done.")

from datasets import load_dataset

# ── Fallback generators (non-negotiable for reproducibility) ─────────────────
def generate_fallback_liar():
    """Synthetic LIAR-style dataset if HuggingFace load fails."""
    data = [
        ("The unemployment rate is at a 50-year low.", "half-true"),
        ("Vaccines contain microchips for government tracking.", "pants-fire"),
        ("Climate change is causing more frequent hurricanes.", "mostly-true"),
        ("The stock market had its best year ever last year.", "false"),
        ("Water covers about 71% of Earth's surface.", "true"),
        ("The moon landing was filmed in a Hollywood studio.", "pants-fire"),
        ("Eating carrots improves night vision significantly.", "barely-true"),
        ("5G towers spread the COVID-19 virus.", "pants-fire"),
        ("Exercise reduces the risk of type 2 diabetes.", "true"),
        ("The Eiffel Tower grows taller in summer.", "mostly-true"),
    ] * 50  # 500 samples
    df = pd.DataFrame(data, columns=['statement', 'label'])
    print("⚠️  Using synthetic LIAR fallback (500 samples).")
    return df

def generate_fallback_hallucination():
    """Synthetic hallucination dataset if HuggingFace load fails."""
    data = [
        ("The Eiffel Tower is located in Berlin.", True),
        ("Python was created by Guido van Rossum.", False),
        ("Shakespeare wrote 'War and Peace'.", True),
        ("The speed of light is approximately 3×10⁸ m/s.", False),
        ("The Great Wall of China is visible from space with the naked eye.", True),
    ] * 40
    df = pd.DataFrame(data, columns=['claim', 'is_hallucination'])
    print("⚠️  Using synthetic hallucination fallback (200 samples).")
    return df

# ── Load LIAR dataset ─────────────────────────────────────────────────────────
try:
    liar_raw = load_dataset("liar", trust_remote_code=True)
    liar_df = pd.DataFrame({
        'statement': liar_raw['train']['statement'],
        'label': liar_raw['train']['label']
    })
    label_names = ['pants-fire','false','barely-true','half-true','mostly-true','true']
    liar_df['label'] = liar_df['label'].apply(lambda x: label_names[x] if isinstance(x, int) else x)
    print(f"✅ LIAR dataset loaded: {len(liar_df)} samples")
except Exception as e:
    print(f"LIAR load failed ({e}), using fallback.")
    liar_df = generate_fallback_liar()

# ── Load TruthfulQA ───────────────────────────────────────────────────────────
try:
    tqa_raw = load_dataset("truthful_qa", "generation", trust_remote_code=True)
    tqa_df = pd.DataFrame({
        'question': tqa_raw['validation']['question'],
        'best_answer': tqa_raw['validation']['best_answer'],
    })
    print(f"✅ TruthfulQA loaded: {len(tqa_df)} samples")
except Exception as e:
    print(f"TruthfulQA load failed ({e}), using fallback.")
    tqa_df = generate_fallback_hallucination()

# ── Load HaluEval ─────────────────────────────────────────────────────────────
try:
    halu_raw = load_dataset("pminervini/HaluEval", "general_samples", trust_remote_code=True)
    halu_df = pd.DataFrame(halu_raw['data'])
    print(f"✅ HaluEval loaded: {len(halu_df)} samples")
except Exception as e:
    print(f"HaluEval load failed ({e}), using fallback.")
    halu_df = generate_fallback_hallucination()

print("\n📊 Dataset summary:")
print(f"  LIAR:       {len(liar_df)} rows, columns: {list(liar_df.columns)}")
print(f"  TruthfulQA: {len(tqa_df)} rows")
print(f"  HaluEval:   {len(halu_df)} rows")

# ── Live RSS News Feed ────────────────────────────────────────────────────────
RSS_FEEDS = {
    'BBC':     'http://feeds.bbci.co.uk/news/world/rss.xml',
    'Reuters': 'https://feeds.reuters.com/reuters/topNews',
    'AP':      'https://rsshub.app/apnews/topics/apf-topnews',
}

headlines = []
for source, url in RSS_FEEDS.items():
    try:
        feed = feedparser.parse(url)
        for entry in feed.entries[:10]:
            pub = entry.get('published', str(datetime.now()))
            headlines.append({
                'headline': entry.get('title', ''),
                'summary': entry.get('summary', ''),
                'source': source,
                'published_at': pub,
                'link': entry.get('link', '')
            })
    except Exception as e:
        print(f"  ⚠️  {source} RSS failed: {e}")

if not headlines:
    # Fallback static headlines for offline environments
    headlines = [
        {'headline': 'Global temperatures hit record highs in 2024', 'summary': '', 'source': 'synthetic', 'published_at': '2024-01-01', 'link': ''},
        {'headline': 'AI models show improved reasoning capabilities', 'summary': '', 'source': 'synthetic', 'published_at': '2024-01-02', 'link': ''},
        {'headline': 'New vaccine approved for respiratory illness', 'summary': '', 'source': 'synthetic', 'published_at': '2024-01-03', 'link': ''},
    ] * 5
    print("⚠️  Using synthetic headlines (no network access).")

news_df = pd.DataFrame(headlines)
news_df['published_at'] = pd.to_datetime(news_df['published_at'], errors='coerce', utc=True)
print(f"✅ Live news loaded: {len(news_df)} headlines from {news_df['source'].nunique()} sources")

from transformers import pipeline
from sentence_transformers import SentenceTransformer
import faiss
import re

# ── Load lightweight models ───────────────────────────────────────────────────
print("Loading sentiment pipeline...")
sentiment_pipeline = pipeline(
    "sentiment-analysis",
    model="distilbert-base-uncased-finetuned-sst-2-english",
    truncation=True, max_length=512
)

print("Loading NLI pipeline (DeBERTa)...")
nli_pipeline = pipeline(
    "zero-shot-classification",
    model="cross-encoder/nli-deberta-v3-small",
    device=-1  # CPU
)

print("Loading sentence embedding model...")
embedder = SentenceTransformer("sentence-transformers/all-MiniLM-L6-v2")

print("✅ All models loaded.")

# ── Build FAISS Vector Index of Trusted Facts ─────────────────────────────────
TRUSTED_FACTS = [
    "Water boils at 100 degrees Celsius at sea level.",
    "The Earth orbits the Sun, not the other way around.",
    "The speed of light in a vacuum is approximately 299,792 kilometers per second.",
    "DNA carries genetic information in living organisms.",
    "The Great Wall of China is not visible from space with the naked eye.",
    "Humans and chimpanzees share approximately 98.7% of their DNA.",
    "The moon is approximately 384,400 kilometers from Earth.",
    "Mount Everest is the highest mountain above sea level at 8,849 meters.",
    "Vaccines work by stimulating the immune system to recognize pathogens.",
    "The human brain contains approximately 86 billion neurons.",
    "Carbon dioxide concentration in the atmosphere has increased since industrialization.",
    "The Eiffel Tower is located in Paris, France.",
    "Python was created by Guido van Rossum and first released in 1991.",
    "Shakespeare wrote Hamlet, Macbeth, and Romeo and Juliet.",
    "The United States has 50 states.",
    "Albert Einstein published the special theory of relativity in 1905.",
    "Antibiotics are not effective against viral infections.",
    "The Pacific Ocean is the largest ocean on Earth.",
    "The human body has 206 bones in adulthood.",
    "Climate change is driven primarily by human greenhouse gas emissions according to scientific consensus.",
]

# Encode and index
fact_embeddings = embedder.encode(TRUSTED_FACTS, convert_to_numpy=True)
dim = fact_embeddings.shape[1]
faiss_index = faiss.IndexFlatL2(dim)
faiss_index.add(fact_embeddings.astype(np.float32))

print(f"✅ FAISS index built with {faiss_index.ntotal} trusted facts (dim={dim})")

# ── Feature Extraction Functions ──────────────────────────────────────────────

SOURCE_CREDIBILITY = {
    'bbc.co.uk': 0.92, 'reuters.com': 0.94, 'apnews.com': 0.93,
    'nytimes.com': 0.88, 'theguardian.com': 0.87, 'nature.com': 0.98,
    'who.int': 0.97, 'cdc.gov': 0.97, 'infowars.com': 0.05,
    'naturalnews.com': 0.08, 'breitbart.com': 0.22, 'synthetic': 0.50,
    'BBC': 0.92, 'Reuters': 0.94, 'AP': 0.93,
}

FAKE_DOI_PATTERN = re.compile(
    r'10\.\d{4,}/[a-zA-Z0-9./_-]+'
)
IMPOSSIBLE_YEAR = re.compile(r'\b(19[0-2]\d|2[1-9]\d{2})\b')
INVENTED_INSTITUTIONS = re.compile(
    r'(Institute of [A-Z][a-z]+ [A-Z][a-z]+|Foundation for [A-Z][a-z]+ Research)',
    re.IGNORECASE
)

def get_sentiment_score(text: str) -> float:
    try:
        result = sentiment_pipeline(text[:512])[0]
        score = result['score']
        return score if result['label'] == 'POSITIVE' else -score
    except:
        return 0.0

def get_source_credibility(source: str) -> float:
    for domain, score in SOURCE_CREDIBILITY.items():
        if domain.lower() in source.lower():
            return score
    return 0.5

def get_citation_anomaly_score(text: str) -> float:
    score = 0.0
    if FAKE_DOI_PATTERN.search(text): score += 0.3
    if IMPOSSIBLE_YEAR.search(text): score += 0.3
    if INVENTED_INSTITUTIONS.search(text): score += 0.4
    return min(score, 1.0)

def get_semantic_similarity(text: str, k: int = 3) -> float:
    try:
        emb = embedder.encode([text], convert_to_numpy=True).astype(np.float32)
        distances, _ = faiss_index.search(emb, k)
        avg_dist = np.mean(distances[0])
        similarity = 1.0 / (1.0 + avg_dist)
        return float(np.clip(similarity, 0, 1))
    except:
        return 0.5

def get_nli_contradiction_score(claim: str, references: list) -> float:
    try:
        result = nli_pipeline(
            claim,
            candidate_labels=["entailment", "neutral", "contradiction"],
            hypothesis_template="This claim is related to: {}",
        )
        scores = dict(zip(result['labels'], result['scores']))
        return float(scores.get('contradiction', 0.0))
    except:
        return 0.5

def retrieve_reference_sentences(claim: str, k: int = 5) -> list:
    try:
        emb = embedder.encode([claim], convert_to_numpy=True).astype(np.float32)
        _, indices = faiss_index.search(emb, k)
        return [TRUSTED_FACTS[i] for i in indices[0] if i < len(TRUSTED_FACTS)]
    except:
        return TRUSTED_FACTS[:k]

print("✅ Feature extraction functions defined.")

# ── A. Fake News Classifier (LIAR → 3-class) ──────────────────────────────────
from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import train_test_split
from sklearn.metrics import classification_report

LIAR_MAP = {
    'pants-fire': 'misinformation',
    'false': 'misinformation',
    'barely-true': 'uncertain',
    'half-true': 'uncertain',
    'mostly-true': 'credible',
    'true': 'credible',
}

liar_sample = liar_df.sample(min(500, len(liar_df)), random_state=42).copy()
liar_sample['label_3'] = liar_sample['label'].map(LIAR_MAP).fillna('uncertain')

print("Encoding LIAR statements...")
X_liar = embedder.encode(liar_sample['statement'].tolist(), show_progress_bar=False)
y_liar = liar_sample['label_3'].values

X_train, X_test, y_train, y_test = train_test_split(X_liar, y_liar, test_size=0.2, random_state=42)

fake_news_clf = LogisticRegression(max_iter=500, random_state=42)
fake_news_clf.fit(X_train, y_train)
print("✅ Fake news classifier trained.")

# ── B. Hallucination Scorer ───────────────────────────────────────────────────
def score_hallucination(claim: str) -> dict:
    try:
        references = retrieve_reference_sentences(claim, k=5)
        contradiction_score = get_nli_contradiction_score(claim, references)
        similarity = get_semantic_similarity(claim)
        citation_anomaly = get_citation_anomaly_score(claim)

        raw_risk = (
            0.50 * contradiction_score +
            0.30 * (1 - similarity) + 
            0.20 * citation_anomaly
        )
        hallucination_risk = int(np.clip(raw_risk * 100, 0, 100))

        return {
            'hallucination_risk': hallucination_risk,
            'contradiction_score': round(contradiction_score, 3),
            'semantic_similarity': round(similarity, 3),
            'evidence_snippets': references[:3]
        }
    except Exception as e:
        return {'hallucination_risk': 50, 'contradiction_score': 0.5,
                'semantic_similarity': 0.5, 'evidence_snippets': [], 'error': str(e)}

print("✅ Hallucination scorer working.")

# ── C. Event Volatility Forecaster ───────────────────────────────────────────
try:
    from statsforecast import StatsForecast
    from statsforecast.models import AutoARIMA
    HAS_STATSFORECAST = True
except ImportError:
    HAS_STATSFORECAST = False
    print("⚠️  statsforecast not available, using EWMA fallback.")

def compute_volatility_series(df: pd.DataFrame, window: int = 7) -> pd.Series:
    df = df.copy().sort_values('published_at')
    sentiments = df['headline'].apply(get_sentiment_score)
    volatility = sentiments.rolling(window=min(window, len(df)), min_periods=1).std().fillna(0)
    return volatility

def forecast_volatility(series: pd.Series, horizon: int = 3) -> dict:
    if HAS_STATSFORECAST and len(series) >= 10:
        try:
            sf_df = pd.DataFrame({
                'unique_id': 'news_vol',
                'ds': pd.date_range(start='2024-01-01', periods=len(series), freq='D'),
                'y': series.values
            })
            sf = StatsForecast(models=[AutoARIMA()], freq='D')
            forecast = sf.forecast(df=sf_df, h=horizon)
            forecasted_values = forecast['AutoARIMA'].values.tolist()
            trend = 'rising' if forecasted_values[-1] > series.mean() else 'stable'
            return {'method': 'AutoARIMA', 'forecast': forecasted_values, 'trend': trend}
        except:
            pass

    ewma = series.ewm(span=min(5, len(series))).mean()
    last = ewma.iloc[-1]
    forecasted = [last * (1 + 0.02 * i) for i in range(1, horizon + 1)]
    trend = 'rising' if forecasted[-1] > series.mean() else 'stable'
    return {'method': 'EWMA', 'forecast': forecasted, 'trend': trend}

# ── D. Final Risk Score Aggregator ────────────────────────────────────────────
W_HALLUCINATION  = 0.40
W_FAKE_NEWS      = 0.35
W_CITATION       = 0.15
W_SIMILARITY     = 0.10

COLOR_MAP = {
    'confirmed':     'rgba(52, 199, 89, 0.15)',
    'uncertain':     'rgba(255, 204, 0, 0.15)',
    'misinformation':'rgba(255, 59, 48, 0.15)',
    'hallucination': 'rgba(175, 82, 222, 0.15)',
}

def get_fake_news_probability(text: str) -> tuple[str, float]:
    try:
        emb = embedder.encode([text])
        proba = fake_news_clf.predict_proba(emb)[0]
        classes = fake_news_clf.classes_
        label = classes[np.argmax(proba)]
        confidence = float(np.max(proba))
        return label, confidence
    except:
        return 'uncertain', 0.5

def analyze_text(text: str, source: str = 'unknown') -> dict:
    try:
        halu_result  = score_hallucination(text)
        fake_label, fake_conf = get_fake_news_probability(text)
        citation_score = get_citation_anomaly_score(text)
        similarity     = get_semantic_similarity(text)
        credibility    = get_source_credibility(source)

        fake_risk = {'misinformation': 0.9, 'uncertain': 0.5, 'credible': 0.1}.get(fake_label, 0.5)

        combined_risk = (
            W_HALLUCINATION * (halu_result['hallucination_risk'] / 100) +
            W_FAKE_NEWS     * fake_risk +
            W_CITATION      * citation_score +
            W_SIMILARITY    * (1 - similarity)
        )
        combined_risk = float(np.clip(combined_risk, 0, 1))

        if combined_risk < 0.25:
            status = 'confirmed'
        elif combined_risk < 0.55:
            status = 'uncertain'
        elif halu_result['hallucination_risk'] > 60:
            status = 'hallucination'
        else:
            status = 'misinformation'

        confidence = abs(combined_risk - 0.5) * 2

        tooltip = (
            f"{status.title()} risk: {int(combined_risk*100)}%. "
            f"Hallucination: {halu_result['hallucination_risk']}%. "
            f"Source credibility: {int(credibility*100)}%."
        )

        return {
            'text': text,
            'status': status,
            'color': COLOR_MAP[status],
            'hallucination_risk': halu_result['hallucination_risk'],
            'fake_news_label': fake_label,
            'combined_risk': round(combined_risk, 3),
            'confidence': round(confidence, 3),
            'volatility_index': round(1 - similarity, 3),
            'tooltip_message': tooltip,
            'evidence_snippets': halu_result['evidence_snippets']
        }
    except Exception as e:
        return {
            'text': text, 'status': 'uncertain', 'color': COLOR_MAP['uncertain'],
            'hallucination_risk': 50, 'fake_news_label': 'uncertain',
            'combined_risk': 0.5, 'confidence': 0.0, 'volatility_index': 0.5,
            'tooltip_message': f'Analysis failed gracefully: {str(e)}',
            'evidence_snippets': []
        }

# ── E. Main Web Application with Gradio ───────────────────────────────────────
def predict(text):
    return analyze_text(text)

with gr.Blocks(theme=gr.themes.Soft()) as demo:
    gr.Markdown("# 🛡️ AI Risk & Fact-Checking Dashboard")
    gr.Markdown("Analyze text for hallucination risk, fake news probability, and citation anomalies.")
    
    with gr.Row():
        with gr.Column():
            input_text = gr.Textbox(
                lines=5, 
                placeholder="Enter a claim or news snippet here...", 
                label="Text to Analyze"
            )
            submit_btn = gr.Button("Analyze Risk", variant="primary")
        
        with gr.Column():
            output_json = gr.JSON(label="Detailed Analysis Results")
            
    submit_btn.click(fn=predict, inputs=input_text, outputs=output_json)
    
    gr.Examples(
        examples=[
            "The moon is made of cheese.",
            "Water boils at 100 degrees Celsius at sea level.",
            "According to a 2031 study from the Institute of Neural Enhancement, humans only use 10% of their brain.",
            "Global temperatures hit record highs in 2024.",
        ],
        inputs=input_text
    )

if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", server_port=7860)