"""visualize.py — Plotly interactive plots for parliamentary embeddings.

Produces self-contained HTML files.

Functions:
  plot_umap_scatter   — 2D scatter of fused motion embeddings, coloured by cluster
  plot_mp_trajectory  — Line plot of MP drift across windows
  plot_political_axis — Bar chart of MP scores on the ideological axis
"""

import logging
from typing import Dict, List, Optional

import numpy as np

_logger = logging.getLogger(__name__)


def _require_plotly():
    try:
        import plotly.graph_objects as go
        import plotly.express as px

        return go, px
    except ImportError:
        raise ImportError("plotly is not installed. Install it with: uv add plotly")


def plot_umap_scatter(
    motion_ids: List[int],
    coords: List[List[float]],
    labels: Optional[List[int]] = None,
    window_id: Optional[str] = None,
    output_path: str = "analysis_umap.html",
) -> str:
    """Produce a 2D scatter plot of UMAP-reduced fused embeddings.

    Args:
        motion_ids:  Motion IDs (used as hover labels)
        coords:      List of [x, y] coordinates
        labels:      Optional cluster labels (integer per motion)
        window_id:   Window label for the plot title
        output_path: Where to write the self-contained HTML

    Returns the output_path on success.
    """
    go, px = _require_plotly()

    xs = [c[0] for c in coords]
    ys = [c[1] for c in coords]
    color = labels if labels is not None else [0] * len(motion_ids)
    title = f"UMAP — fused motion embeddings" + (f" ({window_id})" if window_id else "")

    fig = px.scatter(
        x=xs,
        y=ys,
        color=[str(c) for c in color],
        hover_name=[str(mid) for mid in motion_ids],
        title=title,
        labels={"x": "UMAP-1", "y": "UMAP-2", "color": "Cluster"},
    )
    fig.write_html(output_path, include_plotlyjs="cdn")
    _logger.info("UMAP scatter written to %s", output_path)
    return output_path


def plot_mp_trajectory(
    trajectories: Dict[str, Dict],
    mp_names: Optional[List[str]] = None,
    output_path: str = "analysis_trajectory.html",
) -> str:
    """Line plot of MP drift across time windows.

    Args:
        trajectories: Output of analysis.trajectory.compute_trajectories()
        mp_names:     Subset of MPs to plot (default: all)
        output_path:  Output HTML file path

    Returns the output_path on success.
    """
    go, px = _require_plotly()

    if mp_names is None:
        mp_names = list(trajectories.keys())

    fig = go.Figure()

    for mp in mp_names:
        if mp not in trajectories:
            continue
        data = trajectories[mp]
        windows = data["windows"]
        drifts_cumulative = [0.0] + list(np.cumsum(data["drift"]))
        # Plot cumulative drift per window transition
        x_labels = windows[: len(drifts_cumulative)]
        fig.add_trace(
            go.Scatter(
                x=x_labels,
                y=drifts_cumulative,
                mode="lines+markers",
                name=mp,
            )
        )

    fig.update_layout(
        title="MP Political Drift Over Time (Cumulative)",
        xaxis_title="Window",
        yaxis_title="Cumulative Drift",
    )
    fig.write_html(output_path, include_plotlyjs="cdn")
    _logger.info("Trajectory plot written to %s", output_path)
    return output_path


def plot_political_axis(
    scores: Dict[str, float],
    party_of: Optional[Dict[str, str]] = None,
    window_id: Optional[str] = None,
    n_top: int = 30,
    output_path: str = "analysis_political_axis.html",
) -> str:
    """Horizontal bar chart of MP scores on the ideological axis.

    Args:
        scores:      {mp_name: score} from political_axis module
        party_of:    Optional {mp_name: party} for colour-coding
        window_id:   Window label for the title
        n_top:       Show only the top/bottom n MPs by score
        output_path: Output HTML path

    Returns the output_path on success.
    """
    go, px = _require_plotly()

    # Sort by score
    sorted_items = sorted(scores.items(), key=lambda kv: kv[1])

    # Take n_top from each end if list is large
    if len(sorted_items) > 2 * n_top:
        sorted_items = sorted_items[:n_top] + sorted_items[-n_top:]

    names = [item[0] for item in sorted_items]
    vals = [item[1] for item in sorted_items]
    colors = (
        [party_of.get(n, "Unknown") for n in names]
        if party_of
        else ["Unknown"] * len(names)
    )

    title = "MP Ideological Axis Score" + (f" ({window_id})" if window_id else "")

    fig = px.bar(
        x=vals,
        y=names,
        color=colors,
        orientation="h",
        title=title,
        labels={"x": "Score (← left — right →)", "y": "MP", "color": "Party"},
    )
    fig.update_layout(yaxis={"categoryorder": "total ascending"})
    fig.write_html(output_path, include_plotlyjs="cdn")
    _logger.info("Political axis chart written to %s", output_path)
    return output_path