from html import escape
import streamlit as st

ARTICLE_CARD_STYLES = """
<style>
    .nl-article-card {
        background: #ffffff;
        border: 1px solid #d8dee9;
        border-radius: 8px;
        padding: 1rem;
        margin: 0.65rem 0 0.9rem 0;
    }

    .nl-article-header {
        display: flex;
        align-items: flex-start;
        justify-content: space-between;
        gap: 1rem;
    }

    .nl-article-source {
        color: #64748b;
        font-size: 0.78rem;
        font-weight: 700;
        letter-spacing: 0.04em;
        margin-bottom: 0.25rem;
        text-transform: uppercase;
    }

    .nl-article-card h4 {
        color: #15202b;
        font-size: 1rem;
        line-height: 1.35;
        margin: 0;
    }

    .nl-article-card p {
        color: #475569;
        line-height: 1.55;
        margin: 0.65rem 0 0.8rem 0;
    }

    .nl-label {
        border: 1px solid;
        border-radius: 999px;
        font-size: 0.75rem;
        font-weight: 800;
        padding: 0.25rem 0.55rem;
        white-space: nowrap;
    }

    .nl-confidence-row {
        color: #64748b;
        display: flex;
        justify-content: space-between;
        font-size: 0.82rem;
        margin-bottom: 0.3rem;
    }

    .nl-confidence-row strong {
        color: #15202b;
    }

    .nl-confidence-track {
        background: #eef2f7;
        border-radius: 999px;
        height: 0.45rem;
        overflow: hidden;
        width: 100%;
    }

    .nl-confidence-track div {
        height: 100%;
    }

    .nl-read-link {
        color: #2457c5;
        display: inline-block;
        font-weight: 800;
        margin-top: 0.75rem;
        text-decoration: none;
    }

    .nl-read-link:hover {
        color: #1f4dac;
        text-decoration: underline;
    }

    @media (max-width: 760px) {
        .nl-article-header {
            flex-direction: column;
            gap: 0.5rem;
        }
    }
</style>
"""


def inject_article_card_styles() -> None:
    st.markdown(ARTICLE_CARD_STYLES, unsafe_allow_html=True)


def _safe_text(value: object, fallback: str = "") -> str:
    if value is None:
        return fallback
    text = str(value).strip()
    return text or fallback


def _label_style(label: str) -> tuple[str, str]:
    if label.lower() == "biased":
        return "#c24138", "#fff4f2"
    return "#247857", "#effaf5"

def smart_truncate(text, limit=80):
    if len(text) <= limit:
        return text
    return text[:limit].rsplit(" ", 1)[0] + "..."

def render_article_card(article: dict, debug: bool = False) -> None:
    label = _safe_text(article.get("text_label"), "Unknown")
    confidence = float(article.get("confidence", 0) or 0)
    source = _safe_text(article.get("source"), "Unknown source")
    source_bias = _safe_text(article.get("source_bias"), "Unknown bias")
    source_bias_provenance = _safe_text(article.get("source_bias_provenance"))
    source_meta = f"{source} / {source_bias}"
    if source_bias_provenance and source_bias_provenance != "manual_demo":
        source_meta = f"{source_meta} / {source_bias_provenance}"
    url = _safe_text(article.get("url"), "#")

    description = _safe_text(article.get("description"))
    fallback_text = _safe_text(article.get("text"))[:280]
    excerpt = description or fallback_text or "No article excerpt was returned by the API."
    title = _safe_text(article.get("title")) or smart_truncate(excerpt, 80)

    accent, soft = _label_style(label)
    confidence_pct = max(0, min(confidence, 1)) * 100

    st.markdown(
        f"""
        <div class="nl-article-card">
            <div class="nl-article-header">
                <div>
                    <div class="nl-article-source">{escape(source_meta)}</div>
                    <h4>{escape(title)}</h4>
                </div>
                <span class="nl-label" style="color:{accent}; background:{soft}; border-color:{accent};">
                    {escape(label)}
                </span>
            </div>
            <p>{escape(excerpt)}</p>
            <div class="nl-confidence-row">
                <span>Confidence</span>
                <strong>{confidence:.2f}</strong>
            </div>
            <div class="nl-confidence-track">
                <div style="width:{confidence_pct:.0f}%; background:{accent};"></div>
            </div>
            <a class="nl-read-link" href="{escape(url)}" target="_blank" rel="noopener noreferrer">
                Read article
            </a>
        </div>
        """,
        unsafe_allow_html=True,
    )

    if debug:
        with st.expander("Model internals", expanded=False):
            if "similarity_score" in article:
                st.caption(f"Similarity score: {article['similarity_score']:.4f}")
            if "probabilities" in article:
                st.json(article["probabilities"])