<?php

namespace App\Support;

use App\Models\City;

/**
 * East-shore beach geometry shared by the world payload, the leisure
 * action validation and the position clamp.
 *
 * Every value derives from the city bounds so the sand always starts just
 * past the eastern road grid, whatever the city size is.
 */
class Beach
{
    /** Gap between the last grid road and the sand. */
    public const APPROACH = 4.0;

    /** Sand depth from the approach line to the shoreline. */
    public const SAND_DEPTH = 60.0;

    /** Sea depth beyond the shoreline. */
    public const SEA_DEPTH = 90.0;

    /** Half of the beach span along Z (covers the whole layout). */
    public const Z_HALF = 160.0;

    /**
     * Eastern edge of the road grid (same derivation the layout uses).
     */
    public static function layoutMaxX(City $city): float
    {
        return (float) (ceil(((float) $city->bounds_max_x) / 40) * 40 + 40);
    }

    /**
     * Where the sand begins (east of the grid).
     */
    public static function sandFrom(City $city): float
    {
        return self::layoutMaxX($city) + self::APPROACH;
    }

    /**
     * Shoreline (sand meets sea).
     */
    public static function sandTo(City $city): float
    {
        return self::sandFrom($city) + self::SAND_DEPTH;
    }

    /**
     * Far edge of the sea.
     */
    public static function seaTo(City $city): float
    {
        return self::sandTo($city) + self::SEA_DEPTH;
    }

    /**
     * Geometry descriptor sent to the world payload (single source of
     * truth for the client-side beach build).
     *
     * @return array{sand_from: float, sand_to: float, sea_to: float, z_min: float, z_max: float}
     */
    public static function geometry(City $city): array
    {
        return [
            'sand_from' => self::sandFrom($city),
            'sand_to' => self::sandTo($city),
            'sea_to' => self::seaTo($city),
            'z_min' => -self::Z_HALF,
            'z_max' => self::Z_HALF,
        ];
    }

    /**
     * Whether a point lies on the leisure beach (sand up to the shoreline).
     */
    public static function isOnBeach(City $city, float $x, float $z): bool
    {
        return $x >= self::sandFrom($city) - 1
            && $x <= self::sandTo($city) + 2
            && $z >= -self::Z_HALF
            && $z <= self::Z_HALF;
    }
}