<?php
/**
 * Copyright (C) 2018-2022 Graham Breach
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/**
 * For more information, please contact <graham@goat1000.com>
 */

namespace Goat1000\SVGGraph;

/**
 * Class for defining marker graphics as symbols
 */
class Markers {

  private $graph;

  public function __construct(&$graph)
  {
    $this->graph =& $graph;
  }

  /**
   * Creates contents of a marker
   */
  private function createContent($type, $size, $fill, $stroke_width,
    $stroke_colour, $opacity, $angle, $more = null)
  {
    $marker = ['fill' => $fill];
    if(!empty($stroke_colour) && $stroke_colour != 'none') {
      $marker['stroke'] = $stroke_colour;
      if(!empty($stroke_width))
        $marker['stroke-width'] = $stroke_width;
    }
    if($opacity > 0.0 && $opacity < 1.0)
      $marker['opacity'] = $opacity;

    // check for custom or image markers
    $content = null;
    if($type[0] == '<') {
      $content = $type;
      $type = 'custom';
    } elseif(strncmp($type, 'image:', 6) == 0) {
      $svg_text = new Text($this->graph);
      $image_path = $svg_text->substr($type, 6);
      $type = 'image';
    } elseif(strncmp($type, 'figure:', 7) == 0) {
      $svg_text = new Text($this->graph);
      $figure = $svg_text->substr($type, 7);
      $type = 'figure';
    }

    $a = $size; // will be repeated a lot, and 'a' is smaller
    $element = 'path';
    switch($type) {
    case 'triangle' :
      $o = $a * tan(M_PI / 6);
      $h = $a / cos(M_PI / 6);
      $marker['d'] = new PathData('M', $a, $o, 'L', 0, -$h, 'L', -$a, $o, 'z');
      break;
    case 'diamond' :
      $marker['d'] = new PathData('M', 0, -$a, 'L', $a, 0, 0, $a, -$a, 0, 'z');
      break;
    case 'square' :
      $element = 'rect';
      $marker['x'] = $marker['y'] = -$a;
      $marker['width'] = $marker['height'] = $a * 2;
      break;
    case 'x' :
      $xform = new Transform;
      $xform->rotate(45);
      $marker['transform'] = $xform;
      // no break - 'x' is a cross rotated by 45 degrees
    case 'cross' :
      $t = $a / 4;
      $marker['d'] = new PathData('M', -$a, -$t);
      $marker['d']->add('L', -$a, $t, -$t, $t, -$t, $a);
      $marker['d']->add($t, $a, $t, $t, $a, $t);
      $marker['d']->add($a, -$t, $t, -$t, $t, -$a);
      $marker['d']->add(-$t, -$a, -$t, -$t, 'z');
      break;
    case 'octagon' :
      $t = $a * sin(M_PI / 8);
      $marker['d'] = new PathData('M', $t, -$a);
      $marker['d']->add('L', $a, -$t, $a, $t, $t, $a, -$t, $a);
      $marker['d']->add(-$a, $t, -$a, -$t, -$t, -$a, 'z');
      break;
    case 'star' :
      $t = $a * 0.382;
      $x1 = $t * sin(M_PI * 0.8);
      $y1 = $t * cos(M_PI * 0.8);
      $x2 = $a * sin(M_PI * 0.6);
      $y2 = $a * cos(M_PI * 0.6);
      $x3 = $t * sin(M_PI * 0.4);
      $y3 = $t * cos(M_PI * 0.4);
      $x4 = $a * sin(M_PI * 0.2);
      $y4 = $a * cos(M_PI * 0.2);
      $marker['d'] = new PathData('M', 0, -$a);
      $marker['d']->add('L', $x1, $y1, $x2, $y2, $x3, $y3, $x4, $y4, 0, $t);
      $marker['d']->add(-$x4, $y4, -$x3, $y3, -$x2, $y2, -$x1, $y1, 'z');
      break;
    case 'threestar' :
      $t = $a / 4;
      $t1 = $t * cos(M_PI / 6);
      $t2 = $t * sin(M_PI / 6);
      $a1 = $a * cos(M_PI / 6);
      $a2 = $a * sin(M_PI / 6);
      $marker['d'] = new PathData('M', 0, -$a);
      $marker['d']->add('L', $t1, -$t2, $a1, $a2, 0, $t);
      $marker['d']->add(-$a1, $a2, -$t1, -$t2, 'z');
      break;
    case 'fourstar' :
      $t = $a / 4;
      $marker['d'] = new PathData('M', 0, -$a, 'L', $t, -$t, $a, 0, $t, $t);
      $marker['d']->add(0, $a, -$t, $t, -$a, 0, -$t, -$t, 'z');
      break;
    case 'eightstar' :
      $t = $a * sin(M_PI / 8);
      $marker['d'] = new PathData('M', 0, -$t);
      $marker['d']->add('L', $t, -$a, $t, -$t, $a, -$t, $t, 0);
      $marker['d']->add($a, $t, $t, $t, $t, $a, 0, $t);
      $marker['d']->add(-$t, $a, -$t, $t, -$a, $t, -$t, 0);
      $marker['d']->add(-$a, -$t, -$t, -$t, -$t, -$a, 'z');
      break;
    case 'asterisk' :
      $t = $a / 3;
      $x1 = $a * sin(M_PI * 0.9);
      $y1 = $a * cos(M_PI * 0.9);
      $x2 = $t * sin(M_PI * 0.8);
      $y2 = $t * cos(M_PI * 0.8);
      $x3 = $a * sin(M_PI * 0.7);
      $y3 = $a * cos(M_PI * 0.7);
      $x4 = $a * sin(M_PI * 0.5);
      $y4 = $a * cos(M_PI * 0.5);
      $x5 = $t * sin(M_PI * 0.4);
      $y5 = $t * cos(M_PI * 0.4);
      $x6 = $a * sin(M_PI * 0.3);
      $y6 = $a * cos(M_PI * 0.3);
      $x7 = $a * sin(M_PI * 0.1);
      $y7 = $a * cos(M_PI * 0.1);
      $marker['d'] = new PathData('M', $x1, $y1);
      $marker['d']->add('L', $x2, $y2, $x3, $y3, $x4, $y4, $x5, $y5);
      $marker['d']->add($x6, $y6, $x7, $y7, 0, $t, -$x7, $y7);
      $marker['d']->add(-$x6, $y6, -$x5, $y5, -$x4, $y4, -$x3, $y3);
      $marker['d']->add(-$x2, $y2, -$x1, $y1, 'z');
      break;
    case 'pentagon' :
      $x1 = $a * sin(M_PI * 0.4);
      $y1 = $a * cos(M_PI * 0.4);
      $x2 = $a * sin(M_PI * 0.2);
      $y2 = $a * cos(M_PI * 0.2);
      $marker['d'] = new PathData('M', 0, -$a);
      $marker['d']->add('L', $x1, -$y1, $x2, $y2, -$x2, $y2, -$x1, -$y1, 'z');
      break;
    case 'hexagon' :
      $x = $a * sin(M_PI / 3);
      $y = $a * cos(M_PI / 3);
      $marker['d'] = new PathData('M', 0, -$a);
      $marker['d']->add('L', $x, -$y, $x, $y, 0, $a, -$x, $y, -$x, -$y, 'z');
      break;
    case 'image' :
      $element = 'image';
      $marker['xlink:href'] = $image_path;
      $marker['x'] = $marker['y'] = -$size;
      $marker['width'] = $size * 2;
      $marker['height'] = $size * 2;
      break;
    case 'custom' :
      $element = 'g';
      break;
    case 'figure' :
      $element = 'g';
      $figure_id = $this->graph->figures->getFigure($figure);
      if(empty($figure_id))
        throw new \Exception('Figure [' . $figure . '] not defined');
      return [$figure_id];
      break;
    case 'circle' :
    default :
      $element = 'circle';
      $marker['r'] = $size;
    }

    // angle happens here because the shape might already have a transform
    if($angle != 0) {
      $xform = new Transform;
      $xform->rotate($angle);
      if(isset($marker['transform']))
        $marker['transform']->add($xform);
      else
        $marker['transform'] = $xform;
    }

    // extra attributes added at end
    if(is_array($more))
      $marker = array_merge($marker, $more);

    return $this->graph->element($element, $marker, null, $content);
  }

  /**
   * Creates a marker, returning its ID
   */
  public function create($type, $size, $fill, $stroke_width, $stroke_colour,
    $opacity, $angle, $more = null)
  {
    $marker_content = $this->createContent($type, $size, $fill, $stroke_width,
      $stroke_colour, $opacity, $angle, $more);

    // if the return is an array, it contains the ID
    if(is_array($marker_content))
      return $marker_content[0];
    return $this->graph->defs->defineSymbol($marker_content);
  }

  /**
   * Creates a SVG marker element, returning its ID
   */
  public function createSVGMarker($type, $size, $fill, $stroke_width, $stroke_colour,
    $opacity, $angle, $more = null)
  {
    $marker_content = $this->createContent($type, $size, $fill, $stroke_width,
      $stroke_colour, $opacity, $angle, $more);

    $sz = new Number($size);
    $sz2 = new Number($size * 2);
    $marker = [
      'viewBox' => "-{$sz} -{$sz} {$sz2} {$sz2}",
      'markerWidth' => $sz,
      'markerHeight' => $sz,
      'refX' => $sz,
      'orient' => 'auto',
    ];
    return $this->graph->defs->addElement('marker', $marker, $marker_content);
  }
}