import gradio as gr
import pickle
import re
from scipy.sparse import hstack

# ── Load models ──────────────────────────────────────────────────────────────
tfidf      = pickle.load(open("tfidf.pkl",  "rb"))
count_vec  = pickle.load(open("count.pkl",  "rb"))
xgb        = pickle.load(open("xgb.pkl",    "rb"))


# ── Core logic ────────────────────────────────────────────────────────────────
def clean(text: str) -> str:
    text = text.lower()
    text = re.sub(r"[^a-zA-Z]", " ", text)
    return text


def predict(news_text: str):
    if not news_text or not news_text.strip():
        return (
            "⚠️  Please enter some news text to analyse.",
            "—",
            "—",
        )

    cleaned  = clean(news_text)
    t1       = tfidf.transform([cleaned])
    t2       = count_vec.transform([cleaned])
    features = hstack([t1, t2])

    proba      = xgb.predict_proba(features)[0]
    fake_prob  = proba[1]
    real_prob  = proba[0]
    confidence = max(fake_prob, real_prob) * 100

    if fake_prob > 0.5:
        verdict    = "❌  FAKE NEWS DETECTED"
        summary    = (
            f"Our model is **{confidence:.1f}%** confident this article "
            f"contains misinformation or fabricated content."
        )
        conf_label = f"{confidence:.1f}% Fake Confidence"
    else:
        verdict    = "✅  REAL NEWS VERIFIED"
        summary    = (
            f"Our model is **{confidence:.1f}%** confident this article "
            f"is credible and factually grounded."
        )
        conf_label = f"{confidence:.1f}% Real Confidence"

    return verdict, summary, conf_label


# ── Custom CSS — dark purple / Cisco-inspired ─────────────────────────────────
CSS = """
/* ── Google Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Rajdhani:wght@400;500;600;700&family=Source+Sans+3:wght@300;400;600&display=swap');

/* ── Palette ──
   --cisco-navy    : #0d1117
   --cisco-deep    : #12102b
   --cisco-purple  : #1e1a4a
   --cisco-mid     : #2d2870
   --cisco-accent  : #49c5f1   (Cisco cyan)
   --cisco-violet  : #7b5ea7
   --cisco-text    : #cdd6f4
*/

body, .gradio-container {
    background: #0d1117 !important;
    font-family: 'Source Sans 3', sans-serif !important;
    color: #cdd6f4 !important;
}

/* ── Animated gradient background ── */
.gradio-container::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    background:
        radial-gradient(ellipse 80% 60% at 20%  10%, rgba(73,197,241,.08) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 80%  80%, rgba(123,94,167,.12) 0%, transparent 55%),
        radial-gradient(ellipse 100% 80% at 50% 50%, rgba(30,26,74,1)    0%, #0d1117       100%);
    animation: bgPulse 10s ease-in-out infinite alternate;
}
@keyframes bgPulse {
    from { opacity: .85; }
    to   { opacity: 1;   }
}

/* ── Header / hero ── */
.hero-header {
    text-align: center;
    padding: 2.4rem 1rem 1rem;
    border-bottom: 1px solid rgba(73,197,241,.18);
    margin-bottom: 1.8rem;
}
.hero-logo {
    display: inline-flex;
    align-items: center;
    gap: .6rem;
    font-family: 'Rajdhani', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: #49c5f1;
    margin-bottom: .7rem;
}
.hero-logo svg { flex-shrink: 0; }
.hero-title {
    font-family: 'Rajdhani', sans-serif;
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 700;
    letter-spacing: .04em;
    color: #ffffff;
    line-height: 1.1;
    margin: 0 0 .45rem;
}
.hero-title span { color: #49c5f1; }
.hero-sub {
    font-size: .95rem;
    color: #8b9ab8;
    max-width: 560px;
    margin: 0 auto;
    line-height: 1.55;
}

/* ── Panel cards ── */
.panel-card {
    background: rgba(30,26,74,.55) !important;
    border: 1px solid rgba(73,197,241,.14) !important;
    border-radius: 10px !important;
    backdrop-filter: blur(12px);
    padding: 1.4rem !important;
    transition: border-color .3s;
}
.panel-card:hover { border-color: rgba(73,197,241,.35) !important; }

/* ── Textarea ── */
textarea {
    background: rgba(13,17,23,.75) !important;
    border: 1px solid rgba(73,197,241,.22) !important;
    border-radius: 8px !important;
    color: #cdd6f4 !important;
    font-family: 'Source Sans 3', sans-serif !important;
    font-size: .95rem !important;
    resize: vertical !important;
    transition: border-color .25s, box-shadow .25s !important;
}
textarea:focus {
    border-color: #49c5f1 !important;
    box-shadow: 0 0 0 3px rgba(73,197,241,.12) !important;
    outline: none !important;
}
textarea::placeholder { color: #4a5568 !important; }

/* ── Labels ── */
label span, .block > label {
    font-family: 'Rajdhani', sans-serif !important;
    font-size: .78rem !important;
    font-weight: 600 !important;
    letter-spacing: .12em !important;
    text-transform: uppercase !important;
    color: #49c5f1 !important;
}

/* ── Analyse button ── */
button#analyse-btn, .gr-button-primary {
    font-family: 'Rajdhani', sans-serif !important;
    font-size: 1.05rem !important;
    font-weight: 700 !important;
    letter-spacing: .12em !important;
    text-transform: uppercase !important;
    background: linear-gradient(135deg, #2d2870 0%, #1e1a4a 100%) !important;
    border: 1px solid #49c5f1 !important;
    color: #49c5f1 !important;
    border-radius: 8px !important;
    padding: .75rem 2rem !important;
    cursor: pointer !important;
    transition: background .25s, box-shadow .25s, transform .15s !important;
    width: 100% !important;
}
button#analyse-btn:hover, .gr-button-primary:hover {
    background: linear-gradient(135deg, #3d37a0 0%, #2d2870 100%) !important;
    box-shadow: 0 0 22px rgba(73,197,241,.35) !important;
    transform: translateY(-1px) !important;
}
button#analyse-btn:active, .gr-button-primary:active {
    transform: translateY(0) !important;
}

/* ── Clear / secondary button ── */
.gr-button-secondary {
    font-family: 'Rajdhani', sans-serif !important;
    font-size: .88rem !important;
    font-weight: 600 !important;
    letter-spacing: .1em !important;
    text-transform: uppercase !important;
    background: transparent !important;
    border: 1px solid rgba(73,197,241,.3) !important;
    color: #8b9ab8 !important;
    border-radius: 8px !important;
    transition: border-color .2s, color .2s !important;
}
.gr-button-secondary:hover {
    border-color: #49c5f1 !important;
    color: #49c5f1 !important;
}

/* ── Verdict output ── */
#verdict-box textarea, #verdict-box input {
    font-family: 'Rajdhani', sans-serif !important;
    font-size: 1.35rem !important;
    font-weight: 700 !important;
    text-align: center !important;
    letter-spacing: .05em !important;
    border-radius: 8px !important;
    border: 1px solid rgba(73,197,241,.22) !important;
    background: rgba(13,17,23,.6) !important;
    color: #ffffff !important;
    padding: 1rem !important;
}

/* ── Summary / confidence outputs ── */
#summary-box textarea, #conf-box textarea,
#summary-box input,  #conf-box input {
    background: rgba(13,17,23,.5) !important;
    border: 1px solid rgba(73,197,241,.14) !important;
    border-radius: 8px !important;
    color: #cdd6f4 !important;
    font-size: .92rem !important;
    text-align: center !important;
}

/* ── Horizontal divider ── */
hr {
    border: none !important;
    border-top: 1px solid rgba(73,197,241,.15) !important;
    margin: 1.2rem 0 !important;
}

/* ── Footer ── */
.footer-bar {
    text-align: center;
    padding: 1.2rem 0 .8rem;
    font-size: .78rem;
    color: #4a5568;
    border-top: 1px solid rgba(73,197,241,.1);
    margin-top: 2rem;
    letter-spacing: .06em;
}
.footer-bar a { color: #49c5f1; text-decoration: none; }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #0d1117; }
::-webkit-scrollbar-thumb { background: #2d2870; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #49c5f1; }
"""

# ── Hero HTML block ─────────────────────────────────────────────────────────
HERO_HTML = """
<div class="hero-header">
  <div class="hero-logo">
    <svg width="22" height="22" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
      <path d="M12 2L2 7l10 5 10-5-10-5z" fill="#49c5f1"/>
      <path d="M2 17l10 5 10-5" stroke="#49c5f1" stroke-width="1.8" stroke-linecap="round"/>
      <path d="M2 12l10 5 10-5" stroke="#7b5ea7" stroke-width="1.8" stroke-linecap="round"/>
    </svg>
    VeritasAI &nbsp;|&nbsp; Powered by XGBoost + NLP
  </div>
  <h1 class="hero-title">Fake News <span>Detection</span> Engine</h1>
  <p class="hero-sub">
    Paste any news article or headline below. Our machine-learning pipeline — 
    TF-IDF · CountVectorizer · XGBoost — will assess its credibility in milliseconds.
  </p>
</div>
"""

FOOTER_HTML = """
<div class="footer-bar">
  VeritasAI &nbsp;·&nbsp; Built with Gradio &amp; deployed on 
  <a href="https://huggingface.co/spaces" target="_blank">🤗 HuggingFace Spaces</a>
  &nbsp;·&nbsp; Model: XGBoost + TF-IDF/CountVec
</div>
"""


# ── Build Gradio UI ───────────────────────────────────────────────────────────
with gr.Blocks(css=CSS, title="VeritasAI — Fake News Detector") as demo:

    gr.HTML(HERO_HTML)

    with gr.Row():
        # ── Left column: input ──────────────────────────────────────────────
        with gr.Column(scale=6, elem_classes="panel-card"):
            news_input = gr.Textbox(
                label="News Article / Headline",
                placeholder=(
                    "Paste your news article, headline, or any text you want to "
                    "verify…\n\nExample: 'Scientists discover that drinking coffee "
                    "three times a day cures cancer, says new study.'"
                ),
                lines=12,
                max_lines=20,
            )
            with gr.Row():
                clear_btn   = gr.ClearButton(
                    components=[news_input],
                    value="Clear",
                    variant="secondary",
                    scale=1,
                )
                analyse_btn = gr.Button(
                    "🔍  Analyse",
                    variant="primary",
                    scale=3,
                    elem_id="analyse-btn",
                )

        # ── Right column: results ───────────────────────────────────────────
        with gr.Column(scale=4, elem_classes="panel-card"):
            gr.Markdown("### 📊 Analysis Results")

            verdict_out = gr.Textbox(
                label="Verdict",
                interactive=False,
                elem_id="verdict-box",
            )
            summary_out = gr.Textbox(
                label="Summary",
                interactive=False,
                lines=3,
                elem_id="summary-box",
            )
            conf_out = gr.Textbox(
                label="Confidence Score",
                interactive=False,
                elem_id="conf-box",
            )

            gr.HTML("<hr/>")

            gr.Markdown(
                """
                **How it works**  
                1. Text is lowercased & cleaned  
                2. Vectorised with **TF-IDF** + **CountVectorizer**  
                3. Features are stacked → fed to **XGBoost**  
                4. Probability threshold: **0.50**  
                """,
                elem_classes="how-it-works",
            )

    gr.HTML(FOOTER_HTML)

    # ── Wire up events ────────────────────────────────────────────────────────
    analyse_btn.click(
        fn=predict,
        inputs=[news_input],
        outputs=[verdict_out, summary_out, conf_out],
    )

    news_input.submit(
        fn=predict,
        inputs=[news_input],
        outputs=[verdict_out, summary_out, conf_out],
    )


# ── Entry point ───────────────────────────────────────────────────────────────
if __name__ == "__main__":
    demo.launch()