"""Rendering and polychromy Utilities Module.

This module provides visualization and coordinate transformation utilities for profile rendering.
"""

from __future__ import annotations

import math
from collections.abc import Callable

from sec_interp.core.domain import GeologySegment


def calculate_bounds(
    topo_data: list[tuple[float, float]],
    geol_data: list[GeologySegment] | None = None,
) -> dict[str, float]:
    """Calculate the bounding box for all profile data with padding.

    Calculates the minimum and maximum distance and elevation across topography
    and optional geological segments.

    Args:
        topo_data: List of (distance, elevation) tuples for topography.
        geol_data: Optional list of geological segments.

    Returns:
        Bounds containing 'min_d', 'max_d', 'min_e', 'max_e' with 5% padding.

    """
    dists = [p[0] for p in topo_data]
    elevs = [p[1] for p in topo_data]

    if geol_data:
        for segment in geol_data:
            dists.extend([p[0] for p in segment.points])
            elevs.extend([p[1] for p in segment.points])

    min_d, max_d = min(dists), max(dists)
    min_e, max_e = min(elevs), max(elevs)

    # Avoid division by zero
    if max_d == min_d:
        max_d = min_d + 100
    if max_e == min_e:
        max_e = min_e + 10

    # Add 5% padding
    d_range = max_d - min_d
    e_range = max_e - min_e

    return {
        "min_d": min_d - d_range * 0.05,
        "max_d": max_d + d_range * 0.05,
        "min_e": min_e - e_range * 0.05,
        "max_e": max_e + e_range * 0.05,
    }


def create_coordinate_transform(
    bounds: dict[str, float],
    view_w: int,
    view_h: int,
    margin: int,
    vert_exag: float = 1.0,
) -> Callable[[float, float], tuple[float, float]]:
    """Create a coordinate transformation function for screen projection.

    Returns a function that transforms data coordinates (distance, elevation)
    to pixel coordinates (x, y) based on the provided view dimensions.

    Args:
        bounds: Dictionary with 'min_d', 'max_d', 'min_e', 'max_e'.
        view_w: Screen/view width in pixels.
        view_h: Screen/view height in pixels.
        margin: Plot margin in pixels.
        vert_exag: Vertical exaggeration multiplier (default 1.0).

    Returns:
        A function `transform(dist, elev) -> (x, y)` converting data to pixels.

    """
    data_w = bounds["max_d"] - bounds["min_d"]
    data_h = bounds["max_e"] - bounds["min_e"]

    # Calculate potential scales for each axis
    potential_scale_x = (view_w - 2 * margin) / data_w
    potential_scale_y = (view_h - 2 * margin) / data_h

    # Use the smaller scale as the base to ensure everything fits
    # This gives us a 1:1 aspect ratio when vert_exag = 1.0
    base_scale = min(potential_scale_x, potential_scale_y)

    # Apply base scale to both axes
    scale_x = base_scale
    scale_y = base_scale * vert_exag  # Apply vertical exaggeration

    def transform(dist: float, elev: float) -> tuple[float, float]:
        """Convert data coordinates to screen coordinates."""
        x = margin + (dist - bounds["min_d"]) * scale_x
        y = view_h - margin - (elev - bounds["min_e"]) * scale_y
        return x, y

    return transform


def calculate_interval(data_range: float) -> float:
    """Calculate a 'nice' interval for axis labels based on the data range.

    Args:
        data_range: The total range of data values (e.g., max_d - min_d).

    Returns:
        A human-readable interval (e.g., 1, 2, 5, 10, etc.) for grid lines.

    """
    magnitude = 10 ** math.floor(math.log10(data_range))
    normalized = data_range / magnitude

    THRESHOLD_SMALL = 2
    THRESHOLD_LARGE = 5

    if normalized < THRESHOLD_SMALL:
        return magnitude * 0.5

    if normalized < THRESHOLD_LARGE:
        return magnitude

    return magnitude * 2
