"""
Utilities to render attribution visualizations for a text-interpretability web app.
Uses Plotly for heatmaps and inline HTML for text-based visualizations.
"""

import plotly.graph_objects as go
import numpy as np
from html import escape
from typing import List, Dict, Optional, Tuple, Any

from .utils import get_color_scale, format_feature_label, matplotlib_to_plotly

# Dummy placeholders so functions that reference these names still type-check,
# but we do NOT import heavy deps like shapiq / shap / numba in this environment.
InteractionValues = None  # type: ignore
sentence_plot = None
shap = None
plt = None

_SPEX_TEXT_STYLE = """
<style id="spex-text-view-style">
.spex-text-view {
    --spex-bg: #f7f5f2;
    --spex-border: #e3e3ec;
    --spex-card-bg: #ffffff;
    --spex-card-shadow: 0 14px 30px rgba(32, 25, 40, 0.08);
    --spex-text: #3d2c36;
    font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    background: var(--spex-bg);
    border: 1px solid var(--spex-border);
    border-radius: 18px;
    padding: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
}
.spex-text-card {
    flex: 3 1 520px;
    background: var(--spex-card-bg);
    border: 1px solid var(--spex-border);
    border-radius: 18px;
    padding: 18px;
    box-shadow: var(--spex-card-shadow);
}
.spex-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 12px;
    gap: 8px;
}
.spex-card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--spex-text);
}
.spex-card-subtitle {
    font-size: 13px;
    color: #7f6f86;
}
.spex-token-grid {
    display: block;
    font-size: 16px;
    line-height: 2;
    color: #111111;
    word-break: break-word;
    white-space: pre-wrap;
}
.spex-token {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    vertical-align: baseline;
    padding: 2px 6px;
    margin: 0 2px;
    border-radius: 12px;
    border: 1px solid transparent;
    background: rgba(225, 225, 223, 0.45);
    box-decoration-break: clone;
    transition: box-shadow 0.15s ease, background 0.15s ease;
    }
.spex-token:hover {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
}
.spex-token-score {
    display: block;
    font-size: 11px;
    font-weight: 600;
    color: #111111;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 2px;
}
.spex-token-text {
    font-size: inherit;
    color: #111111;
    white-space: inherit;
}
.spex-token-plain {
    color: #111111;
    white-space: pre-wrap;
}
.spex-side-panel {
    flex: 1 1 220px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.spex-side-card {
    background: #fefcf8;
    border: 1px dashed var(--spex-border);
    border-radius: 16px;
    padding: 16px;
}
.spex-side-card strong {
    display: block;
    font-size: 15px;
    color: var(--spex-text);
    margin-bottom: 6px;
}
.spex-legend-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 12px 0;
}
.spex-legend-label {
    font-size: 12px;
    color: #6f5a72;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}
.spex-legend-gradient {
    flex: 1;
    height: 10px;
    border-radius: 999px;
    background: linear-gradient(90deg, #dd1313, #e1e1df, #016d01);
}
.spex-legend-note {
    font-size: 12px;
    color: #6f5a72;
    margin: 0;
}
.spex-raw-text {
    flex-basis: 100%;
    background: #ffffff;
    border: 1px solid var(--spex-border);
    border-radius: 16px;
    padding: 16px;
    box-shadow: 0 10px 18px rgba(32, 25, 40, 0.06);
}
.spex-raw-text strong {
    display: block;
    font-size: 14px;
    color: #6f5a72;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 6px;
}
.spex-raw-text p {
    margin: 0;
    font-size: 13px;
    line-height: 1.6;
    white-space: pre-wrap;
    color: #4a3b4e;
}
.spex-empty {
    flex-basis: 100%;
    text-align: center;
    font-size: 14px;
    color: #7f6f86;
}
@media (max-width: 900px) {
    .spex-text-card,
    .spex-side-panel {
        flex: 1 1 100%;
    }
}
</style>
"""

_NEGATIVE_RGB = (221, 19, 19)
_POSITIVE_RGB = (1, 109, 1)
_NEUTRAL_RGB = (225, 225, 223)


def _format_text_segment(value: str, preserve_blank: bool = False) -> str:
    safe = escape(value or "")
    safe = safe.replace("\n", "<br />")
    if not safe and preserve_blank:
        return "&nbsp;"
    return safe or ""


def _normalize_span(span: Any, text_length: int) -> Tuple[int, int]:
    if isinstance(span, dict):
        start = span.get("start", span.get("begin", 0))
        end = span.get("end", span.get("stop", span.get("finish", 0)))
    else:
        start, end = span

    try:
        start_i = int(start)
    except (TypeError, ValueError):
        start_i = 0
    try:
        end_i = int(end)
    except (TypeError, ValueError):
        end_i = start_i

    start_i = max(0, min(text_length, start_i))
    end_i = max(start_i, min(text_length, end_i))
    return start_i, end_i


def _color_for_value(value: float, max_abs: float) -> Tuple[str, str, str]:
    if max_abs <= 0:
        rgb = _NEUTRAL_RGB
        sign = "neutral"
    else:
        norm = max(-1.0, min(1.0, value / max_abs))
        t = (norm + 1.0) / 2.0
        if t < 0.5:
            local = t * 2.0
            rgb = tuple(
                int(round(_NEGATIVE_RGB[i] + (_NEUTRAL_RGB[i] - _NEGATIVE_RGB[i]) * local))
                for i in range(3)
            )
        else:
            local = (t - 0.5) * 2.0
            rgb = tuple(
                int(round(_NEUTRAL_RGB[i] + (_POSITIVE_RGB[i] - _NEUTRAL_RGB[i]) * local))
                for i in range(3)
            )
        sign = "positive" if norm > 0 else "negative" if norm < 0 else "neutral"

    r, g, b = rgb
    hex_color = f"#{r:02x}{g:02x}{b:02x}"
    intensity = min(1.0, abs(value) / max_abs) if max_abs > 0 else 0.0
    alpha = 0.25 + 0.45 * intensity
    background = f"rgba({r}, {g}, {b}, {alpha:.3f})"
    return hex_color, background, sign

def _build_sentence_interaction_values(values: List[float], method: str) -> Optional[InteractionValues]:
    if InteractionValues is None:
        return None
    n_players = len(values)
    if n_players == 0:
        return None
    lookup = {(i,): i for i in range(n_players)}
    index = "SV" if method == "shapley" else ("IV" if method == "influence" else "BV")
    return InteractionValues(
        values=np.array(values, dtype=float),
        index=index,
        max_order=1,
        n_players=n_players,
        min_order=1,
        interaction_lookup=lookup,
        estimated=False,
        baseline_value=0.0,
    )


# def create_attribution_heatmap(
#     features: List[str],
#     attributions: Dict[str, float],
#     method: str = "shapley",
#     title: Optional[str] = None
# ) -> go.Figure:
#     """
#     Create a feature-level attribution heatmap.

#     Args:
#         features: Ordered feature list (from mask_text or tokenizer).
#         attributions: Mapping from feature -> attribution value
#                       (e.g., from mobius_to_shapley/banzhaf).
#         method: "shapley" or "banzhaf" (used in the caption/labeling).
#         title: Optional chart title.

#     Returns:
#         A Plotly Figure object.

#     Example:
#         attrs = compute_attributions(model, context, answer, "shapley")
#         fig = create_attribution_heatmap(attrs["features"], attrs["values"], "shapley")
#     """
    # values = np.array([attributions.get(f, 0.0) for f in features], dtype=float)

    # if sentence_plot is not None:
    #     iv = _build_sentence_interaction_values(values.tolist(), method)
    #     if iv is not None:
    #         result = sentence_plot(
    #             iv,
    #             words=features,
    #             show=False,
    #             chars_per_line=80,
    #         )
    #         if result is not None:
    #             fig, _ = result
    #             return matplotlib_to_plotly(
    #                 fig,
    #                 title=title or f"{method.title()} token attributions",
    #                 height=max(300, 30 * len(features)),
    #             )

    # if shap is not None and plt is not None:
    #     explanation = shap.Explanation(
    #         values=np.array([values]),
    #         base_values=np.zeros(1),
    #         data=np.array([features], dtype=object),
    #         feature_names=features,
    #     )
    #     try:
    #         fig, ax = plt.subplots(
    #             figsize=(4, max(4, len(features) * 0.25)),
    #             constrained_layout=True,
    #         )
    #         shap.plots.heatmap(explanation, show=False, ax=ax)
    #         fig.canvas.draw()
    #         image = np.frombuffer(fig.canvas.tostring_rgb(), dtype=np.uint8)
    #         image = image.reshape(fig.canvas.get_width_height()[::-1] + (3,))
    #         plt.close(fig)

    #         plotly_fig = go.Figure(go.Image(z=image))
    #         plotly_fig.update_xaxes(visible=False)
    #         plotly_fig.update_yaxes(visible=False)
    #         plotly_fig.update_layout(
    #             title=title or f"{method.title()} token attributions (SHAP heatmap)",
    #             margin=dict(l=0, r=0, t=60, b=0),
    #         )
    #         return plotly_fig
    #     except ValueError:
    #         plt.close("all")

    # order = np.argsort(-np.abs(values))
    # sorted_features = [features[i] for i in order]
    # sorted_values = values[order]

    # max_abs = float(np.max(np.abs(sorted_values))) if sorted_values.size else 1.0
    # max_abs = max(max_abs, 1e-6)
    # colorscale = get_color_scale("shapley" if method == "shapley" else method)

    # heatmap = go.Heatmap(
    #     z=sorted_values[:, None],
    #     x=["Attribution"],
    #     y=[format_feature_label(f, max_length=30) for f in sorted_features],
    #     colorscale=colorscale,
    #     zmid=0.0,
    #     zmin=-max_abs,
    #     zmax=max_abs,
    #     colorbar=dict(title=f"{method.title()} value"),
    #     hovertemplate="%{y}<br>%{x}: %{z:.4f}<extra></extra>",
    #     showscale=True,
    #     text=[f"{v:.3f}" for v in sorted_values],
    #     texttemplate="%{text}",
    #     textfont={"color": "black"},
    # )

    # fig = go.Figure(data=[heatmap])
    # fig.update_layout(
    #     title=title or f"{method.title()} token attributions",
    #     xaxis=dict(showticklabels=False),
    #     yaxis=dict(autorange="reversed"),
    #     margin=dict(l=120, r=40, t=60, b=40),
    #     height=max(300, 20 * len(sorted_features)),
    # )
    # return fig
    # --- Build numpy array of original values --------------------------
def create_attribution_heatmap(
    features: List[str],
    attributions: Dict[str, float],
    method: str = "shapley",
    title: Optional[str] = None,
) -> go.Figure:
    # 1. Pull raw values from backend
    raw_values = np.array([attributions.get(f, 0.0) for f in features], dtype=float)

    # No features -> empty figure
    if raw_values.size == 0:
        return go.Figure()

    # 2. Decide how much to rescale
    max_abs = float(np.max(np.abs(raw_values)))
    scale = 1.0
    colorbar_title = f"{method.title()} value"

    if max_abs > 0.0 and max_abs < 1e-4:
        # Values are extremely small (like 1e-6 etc.) → blow them up
        scale = 1.0 / max_abs
        colorbar_title = f"{method.title()} (×{scale:.0e})"

    values = raw_values * scale

    # 3. (Optional) use shapiq sentence_plot if available
    if sentence_plot is not None:
        iv = _build_sentence_interaction_values(values.tolist(), method)
        if iv is not None:
            result = sentence_plot(
                iv,
                words=features,
                show=False,
                chars_per_line=80,
            )
            if result is not None:
                fig, _ = result
                return matplotlib_to_plotly(
                    fig,
                    title=title or f"{method.title()} token attributions",
                    height=max(300, 30 * len(features)),
                )

    # 4. Plain Plotly heatmap (keep original order on y-axis)
    sorted_features = features
    sorted_values = values

    abs_vals = np.abs(sorted_values)
    vmax = float(np.percentile(abs_vals, 95)) if abs_vals.size else 1.0
    vmax = max(vmax, 1e-6)

    colorscale = get_color_scale("shapley" if method == "shapley" else method)

    heatmap = go.Heatmap(
        z=sorted_values[:, None],
        x=["Attribution"],
        y=[format_feature_label(f, max_length=60) for f in sorted_features],
        colorscale=colorscale,
        zmid=0.0,
        zmin=-vmax,
        zmax=vmax,
        colorbar=dict(title=colorbar_title),
        hovertemplate="%{y}<br>%{x}: %{z:.4f}<extra></extra>",
        showscale=True,
    )

    fig = go.Figure(data=[heatmap])
    fig.update_layout(
        title=title or f"{method.title()} token attributions",
        xaxis=dict(showticklabels=False),
        yaxis=dict(autorange="reversed"),
        margin=dict(l=140, r=40, t=60, b=40),
        height=max(320, 22 * len(sorted_features)),
    )
    return fig

def create_interactive_text_heatmap(
    text: str,
    feature_spans: List[Any],  # list of (start, end) or dict spans
    attributions: List[Any],
    method: str = "shapley",
) -> str:
    """
    Render a Spectral Explain–style text view with token chips, legend, and raw text.

    Args:
        text: Original text that generated the attributions.
        feature_spans: Character spans identifying each token/feature.
        attributions: Numeric attribution values aligned with feature_spans.
        method: Attribution method label.

    Returns:
        Styled HTML that can be injected into the Gradio Text View tab.
    """
    if len(feature_spans) != len(attributions):
        raise ValueError("feature_spans and attributions must have the same length")

    source_text = text or ""
    text_len = len(source_text)

    tokens: List[Dict[str, Any]] = []
    numeric_values: List[float] = []
    for idx, (span, raw_value) in enumerate(zip(feature_spans, attributions), start=1):
        start, end = _normalize_span(span, text_len)
        snippet = source_text[start:end]
        try:
            value = float(raw_value)
        except (TypeError, ValueError):
            value = 0.0

        tokens.append(
            {
                "index": idx,
                "text": snippet,
                "value": value,
                "start": start,
                "end": end,
            }
        )
        numeric_values.append(value)

    if not tokens:
        fallback = _format_text_segment(source_text) or "No text available."
        return (
            f"{_SPEX_TEXT_STYLE}"
            '<div class="spex-text-view">'
            '<div class="spex-empty">No feature spans were provided for this example.</div>'
            f'<div class="spex-raw-text"><strong>Raw text</strong><p>{fallback}</p></div>'
            "</div>"
        )

    max_abs = max((abs(v) for v in numeric_values), default=0.0)
    max_abs = max_abs or 1.0
    method_label = (method or "attribution").title()

    flow_parts: List[str] = []
    cursor = 0
    for token in tokens:
        start = token["start"]
        end = token["end"]
        if cursor < start:
            plain = _format_text_segment(source_text[cursor:start], preserve_blank=True)
            if plain:
                flow_parts.append(f'<span class="spex-token-plain">{plain}</span>')

        color_hex, background, sign = _color_for_value(token["value"], max_abs)
        tooltip = escape(
            f"{method_label} · chars [{token['start']}:{token['end']}] · {token['value']:+.4f}"
        )
        text_html = _format_text_segment(token["text"], preserve_blank=True) or "&nbsp;"
        flow_parts.append(
            f'<span class="spex-token spex-token--{sign}" '
            f'data-token-index="{token["index"]}" '
            f'data-attr="{token["value"]:.6f}" '
            f'style="background-color:{background}; border-color:{color_hex};" '
            f'title="{tooltip}">'
            f'<span class="spex-token-text">{text_html}</span>'
            "</span>"
        )
        cursor = end

    if cursor < len(source_text):
        trailing = _format_text_segment(source_text[cursor:], preserve_blank=True)
        if trailing:
            flow_parts.append(f'<span class="spex-token-plain">{trailing}</span>')

    flow_html = "".join(flow_parts) or "&nbsp;"

    legend = (
        '<div class="spex-side-card">'
        f"<strong>{method_label} legend</strong>"
        '<div class="spex-legend-bar">'
        '<span class="spex-legend-label">Negative</span>'
        '<div class="spex-legend-gradient"></div>'
        '<span class="spex-legend-label">Positive</span>'
        "</div>"
        f'<p class="spex-legend-note">Normalized by max |value| = {max_abs:.4f}. Hover tokens for exact scores.</p>'
        "</div>"
    )

    raw_text_block = ""
    if source_text:
        raw_text_block = (
            '<div class="spex-raw-text">'
            "<strong>Raw text</strong>"
            f"<p>{_format_text_segment(source_text)}</p>"
            "</div>"
        )

    body = (
        f"{_SPEX_TEXT_STYLE}"
        '<div class="spex-text-view">'
        '<div class="spex-text-card">'
        '<div class="spex-card-header">'
        '<div>'
        '<div class="spex-card-title">Context</div>'
        f'<div class="spex-card-subtitle">{method_label} token attributions</div>'
        "</div>"
        f'<div class="spex-card-subtitle">Tokens: {len(tokens)}</div>'
        "</div>"
        f'<div class="spex-token-grid">{flow_html}</div>'
        "</div>"
        f'<div class="spex-side-panel">{legend}</div>'
        f"{raw_text_block}"
        "</div>"
    )
    return body


def normalize_attributions(
    attributions: Dict[str, float],
    method: str = "minmax"
) -> Dict[str, float]:
    """
    Normalize attribution values for visualization.

    Args:
        attributions: Raw attribution dict {feature: value}.
        method: Normalization mode: "minmax" or "zscore".

    Returns:
        A dict with normalized values using the same keys as the input.
    """
    if not attributions:
        return {}

    values = np.array(list(attributions.values()), dtype=float)

    if method == "zscore":
        mean = float(values.mean())
        std = float(values.std())
        if std == 0:
            std = 1.0
        normalized = (values - mean) / std
    else:  # default to min-max
        v_min = float(values.min())
        v_max = float(values.max())
        if v_max - v_min == 0:
            normalized = np.zeros_like(values)
        else:
            normalized = (values - v_min) / (v_max - v_min)
            normalized = normalized * 2 - 1  # center at 0 for diverging scales

    return {key: float(val) for key, val in zip(attributions.keys(), normalized)}