Streamlit_NBA/streamlit_app/utils/court.py

import numpy as np
import pandas as pd
import plotly.graph_objects as go

from utils.charts import (
    AMBER,
    BORDER,
    COURT_FLOOR,
    COURT_LINE,
    MADE_EMERALD,
    MISS_CRIMSON,
    SURFACE,
    TEXT_WHITE,
)


def add_nba_half_court(fig: go.Figure) -> go.Figure:
    """Add empirically calibrated NBA half-court markings to a Plotly figure.

    Coordinate system (Basketball-Reference half-court pixel units, 1 ft ≈ 10 units):
    - Rim center: (240.0, 52.5)
    - Court width: 50 ft = 500 units (-10 to 490, centered at x=240)
    - Half-court length: 47 ft = 470 units (y=0 baseline to y=470 half-court line)
    - Paint / key: 16 ft wide (x=160..320), 19 ft deep (y=0..190)
    - Restricted area: 4 ft radius (r=40) around rim
    - Corner 3-point lines: 22 ft from basket center (x=20 and x=460), y=0..142.0
    - Above-the-break 3-point arc: 23.75 ft radius (r=237.5) around rim
    """
    # Outer half-court boundary
    fig.add_shape(
        type="rect", x0=-10, x1=490, y0=0, y1=470,
        line=dict(color=BORDER, width=2),
    )

    # Paint / Key (16ft wide, 19ft deep) with Hardwood Amber subtle tint
    fig.add_shape(
        type="rect", x0=160, x1=320, y0=0, y1=190,
        line=dict(color=COURT_LINE, width=1.8),
        fillcolor="rgba(224, 159, 62, 0.07)",
    )

    # Free throw circle (top half solid, bottom half dashed)
    theta_ft = np.linspace(0, np.pi, 50)
    fig.add_trace(
        go.Scatter(
            x=240 + 60 * np.cos(theta_ft),
            y=190 + 60 * np.sin(theta_ft),
            mode="lines",
            line=dict(color=COURT_LINE, width=1.8),
            showlegend=False,
            hoverinfo="skip",
        )
    )
    fig.add_trace(
        go.Scatter(
            x=240 + 60 * np.cos(-theta_ft),
            y=190 + 60 * np.sin(-theta_ft),
            mode="lines",
            line=dict(color=COURT_LINE, width=1.2, dash="dash"),
            showlegend=False,
            hoverinfo="skip",
        )
    )

    # Restricted area arc (4ft radius = 40 units)
    rim_x, rim_y = 240.0, 52.5
    theta_ra = np.linspace(0, np.pi, 30)
    fig.add_trace(
        go.Scatter(
            x=rim_x + 40 * np.cos(theta_ra),
            y=rim_y + 40 * np.sin(theta_ra),
            mode="lines",
            line=dict(color=COURT_LINE, width=1.8),
            showlegend=False,
            hoverinfo="skip",
        )
    )

    # Calibrated 3-point line:
    # Straight corner lines at x=20 and x=460 (22.0 ft from basket center)
    # intersecting the 23.75 ft (r=237.5) arc at y = 52.5 + sqrt(237.5^2 - 220^2) ≈ 142.0
    r_3pt = 237.5
    dx_corner = 220.0
    theta_3_start = np.arccos(dx_corner / r_3pt)
    corner_x_left = rim_x - dx_corner
    corner_x_right = rim_x + dx_corner
    corner_y = rim_y + r_3pt * np.sin(theta_3_start)

    fig.add_shape(
        type="line", x0=corner_x_left, x1=corner_x_left, y0=0, y1=corner_y,
        line=dict(color=COURT_LINE, width=2.2),
    )
    fig.add_shape(
        type="line", x0=corner_x_right, x1=corner_x_right, y0=0, y1=corner_y,
        line=dict(color=COURT_LINE, width=2.2),
    )

    theta_3 = np.linspace(theta_3_start, np.pi - theta_3_start, 80)
    fig.add_trace(
        go.Scatter(
            x=rim_x + r_3pt * np.cos(theta_3),
            y=rim_y + r_3pt * np.sin(theta_3),
            mode="lines",
            line=dict(color=COURT_LINE, width=2.2),
            showlegend=False,
            hoverinfo="skip",
        )
    )

    # Center court circle arc at half-court line (y=470)
    theta_cc = np.linspace(np.pi, 2 * np.pi, 40)
    fig.add_trace(
        go.Scatter(
            x=rim_x + 60 * np.cos(theta_cc),
            y=470 + 60 * np.sin(theta_cc),
            mode="lines",
            line=dict(color=BORDER, width=1.8),
            showlegend=False,
            hoverinfo="skip",
        )
    )

    # Backboard & Rim (Hardwood Amber landmarks rendered on top)
    fig.add_shape(
        type="line", x0=210, x1=270, y0=40, y1=40,
        line=dict(color=AMBER, width=3),
    )
    fig.add_shape(
        type="circle", x0=232, x1=248, y0=44.5, y1=60.5,
        line=dict(color=AMBER, width=2.5),
        fillcolor="rgba(11, 15, 23, 0.85)",
    )
    return fig


def build_shot_chart_figure(shot_data: pd.DataFrame, player_name: str) -> go.Figure:
    """Create the Arena Nocturne half-court spatial telemetry figure for a player's shots."""
    fig = go.Figure()

    missed = shot_data[~shot_data["is_made"]]
    made = shot_data[shot_data["is_made"]]

    if not missed.empty:
        fig.add_trace(
            go.Scatter(
                x=missed["x"],
                y=missed["y"],
                mode="markers",
                name=f"Missed ({len(missed):,})",
                marker=dict(
                    size=6.5,
                    color="rgba(244, 63, 94, 0.20)",
                    line=dict(width=1.2, color=MISS_CRIMSON),
                ),
                customdata=np.stack(
                    [missed["shot_distance_zone"], missed["distance_ft"], missed["quarter_number"]],
                    axis=-1,
                ),
                hovertemplate=(
                    "<b>Missed FG</b><br>"
                    "Zone: %{customdata[0]}<br>"
                    "Distance: %{customdata[1]} ft<br>"
                    "Period: Q%{customdata[2]}<extra></extra>"
                ),
            )
        )

    if not made.empty:
        fig.add_trace(
            go.Scatter(
                x=made["x"],
                y=made["y"],
                mode="markers",
                name=f"Made ({len(made):,})",
                marker=dict(
                    size=7,
                    color=MADE_EMERALD,
                    opacity=0.88,
                    line=dict(width=0.7, color="#064E3B"),
                ),
                customdata=np.stack(
                    [made["shot_distance_zone"], made["distance_ft"], made["quarter_number"]],
                    axis=-1,
                ),
                hovertemplate=(
                    "<b>Made FG</b><br>"
                    "Zone: %{customdata[0]}<br>"
                    "Distance: %{customdata[1]} ft<br>"
                    "Period: Q%{customdata[2]}<extra></extra>"
                ),
            )
        )

    add_nba_half_court(fig)

    fig.update_layout(
        title=dict(
            text=f"{player_name} — Half-Court Spatial Telemetry ({len(shot_data):,} FGA)",
            font=dict(size=15, color=TEXT_WHITE),
        ),
        height=580,
        xaxis=dict(showgrid=False, zeroline=False, showticklabels=False, range=[-20, 500]),
        yaxis=dict(
            showgrid=False,
            zeroline=False,
            showticklabels=False,
            range=[-15, 480],
            scaleanchor="x",
        ),
        paper_bgcolor="rgba(0,0,0,0)",
        plot_bgcolor=COURT_FLOOR,
        font=dict(color=TEXT_WHITE),
        legend=dict(
            orientation="h",
            yanchor="bottom",
            y=1.01,
            xanchor="right",
            x=1,
            font=dict(size=12, color=TEXT_WHITE),
        ),
        hoverlabel=dict(
            bgcolor=SURFACE,
            bordercolor=AMBER,
            font=dict(color=TEXT_WHITE),
        ),
        margin=dict(l=10, r=10, t=45, b=10),
    )
    return fig