<?php

/**
 * Point: The most basic geometry type. All other geometries
 * are built out of Points.
 */
class Point extends Geometry
{
	public $coords = array(2);
	protected $geom_type = 'Point';
	protected $dimension = 2;

	/**
	 * Constructor
	 *
	 * @param numeric $x The x coordinate (or longitude)
	 * @param numeric $y The y coordinate (or latitude)
	 * @param numeric $z The z coordinate (or altitude) - optional
	 */
	public function __construct($x = null, $y = null, $z = null)
	{

		// Check if it's an empty point
		if ($x === null && $y === null) {
			$this->coords = array(null, null);
			$this->dimension = 0;
			return;
		}

		// Basic validation on x and y
		if (!is_numeric($x) || !is_numeric($y)) {
			throw new Exception("Cannot construct Point. x and y should be numeric");
		}

		// Check to see if this is a 3D point
		if ($z !== null) {
			if (!is_numeric($z)) {
				throw new Exception("Cannot construct Point. z should be numeric");
			}
			$this->dimension = 3;
		}

		// Convert to floatval in case they are passed in as a string or integer etc.
		$x = floatval($x);
		$y = floatval($y);
		$z = floatval($z);

		// Add poitional elements
		if ($this->dimension == 2) {
			$this->coords = array($x, $y);
		}
		if ($this->dimension == 3) {
			$this->coords = array($x, $y, $z);
		}
	}

	/**
	 * Get X (longitude) coordinate
	 *
	 * @return float The X coordinate
	 */
	public function x()
	{
		return $this->coords[0];
	}

	/**
	 * Returns Y (latitude) coordinate
	 *
	 * @return float The Y coordinate
	 */
	public function y()
	{
		return $this->coords[1];
	}

	/**
	 * Returns Z (altitude) coordinate
	 *
	 * @return float The Z coordinate or NULL is not a 3D point
	 */
	public function z()
	{
		if ($this->dimension == 3) {
			return $this->coords[2];
		} else return null;
	}

	/**
	 * Author : Adam Cherti
	 * inverts x and y coordinates
	 * Useful with old applications still using lng lat
	 *
	 * @return void
	 * */
	public function invertxy()
	{
		$x=$this->coords[0];
		$this->coords[0]=$this->coords[1];
		$this->coords[1]=$x;
	}


	// A point's centroid is itself
	public function centroid()
	{
		return $this;
	}

	public function getBBox()
	{
		return array(
		'maxy' => $this->getY(),
		'miny' => $this->getY(),
		'maxx' => $this->getX(),
		'minx' => $this->getX(),
		);
	}

	public function asArray($assoc = false)
	{
		return $this->coords;
	}

	public function area()
	{
		return 0;
	}

	public function length()
	{
		return 0;
	}

	public function greatCircleLength()
	{
		return 0;
	}

	public function haversineLength()
	{
		return 0;
	}

	// The boundary of a point is itself
	public function boundary()
	{
		return $this;
	}

	public function dimension()
	{
		return 0;
	}

	public function isEmpty()
	{
		if ($this->dimension == 0) {
			return true;
		} else {
			return false;
		}
	}

	public function numPoints()
	{
		return 1;
	}

	public function getPoints()
	{
		return array($this);
	}

	public function equals($geometry)
	{
		if (get_class($geometry) != 'Point') {
			return false;
		}
		if (!$this->isEmpty() && !$geometry->isEmpty()) {
			/**
			 * @see: http://php.net/manual/en/function.bccomp.php
			 * @see: http://php.net/manual/en/language.types.float.php
			 * @see: http://tubalmartin.github.io/spherical-geometry-php/#LatLng
			 */
			return (abs($this->x() - $geometry->x()) <= 1.0E-9 && abs($this->y() - $geometry->y()) <= 1.0E-9);
		} elseif ($this->isEmpty() && $geometry->isEmpty()) {
			return true;
		} else {
			return false;
		}
	}

	public function isSimple()
	{
		return true;
	}

	// Not valid for this geometry type
	public function numGeometries()
	{
		return null; }
	public function geometryN($n)
	{
		return null; }
	public function startPoint()
	{
		return null; }
	public function endPoint()
	{
		return null; }
	public function isRing()
	{
		return null; }
	public function isClosed()
	{
		return null; }
	public function pointN($n)
	{
		return null; }
	public function exteriorRing()
	{
		return null; }
	public function numInteriorRings()
	{
		return null; }
	public function interiorRingN($n)
	{
		return null; }
	public function pointOnSurface()
	{
		return null; }
	public function explode()
	{
		return null; }
}