<?php

/** DomFramework
  * @package domframework
  * @author Dominique Fournier <dominique@fournier38.fr>
  * @license BSD
  */

namespace Domframework;

/** The X axis management */
class GraphAxisX extends GraphAxisHorizontal
{
    /** The angle choosed to draw the graph
      */
    private $angle;

    /** The padding between the label and the axis
      */
    private $padding = 7;

    /** The heigth of the labels + padding (it is the base of the graph) in pixels
      */
    private $height;

    /** The number of chars to be displayed in one label
      */
    protected $nbcharsLabel = 0;

    /** Look for the height of the X axis based on the angle of the text when it
      * will be drawn
      * @param resource $gd The resource to modify
      */
    public function getHeight($gd)
    {
        // Look for the angle of the value. Start Horizontally (angle=0), then
        // try 45°, then finish at 90°. As all the values must in the same angle,
        // test all the values. If one is bad, change the angle and retry all the
        // values
        $width = null;
        if ($this->numerical) {
            if ($this->max === null) {
                throw new \Exception(dgettext(
                    "domframework",
                    "The max is not defined for graphAxisHorizontal"
                ), 406);
            }
            $powMax = intval(log10($this->max));
            $tenPercent = round($this->max / pow(10, $powMax), 1) + 0.1;
            $labelMax = $tenPercent * pow(10, $powMax);
            $this->nbcharsLabel = strlen($labelMax);
            $bbox = imagettfbbox(
                $this->fontsize,
                $this->angle,
                $this->fontfile,
                $labelMax
            );
            $height = abs($bbox[4] - $bbox[0]);
            $this->height = $height + 2 * $this->padding;
            return $this->height;
        } else {
            if ($this->data === null) {
                return 0;
            }
            foreach (array(0, 45, 90) as $this->angle) {
                $bboxMaxHeight = 0;
                foreach ($this->data as $key => $value) {
                    if ($width === null) {
                        $width = $this->positionMax($value) - $this->positionMin($value);
                    }
                    // Look for the bounding box around the text. The bounding is not
                    // write on the image and return the coordinates for the text box
                    $bbox = imagettfbbox(
                        $this->fontsize,
                        $this->angle,
                        $this->fontfile,
                        $value
                    );
                    if (abs($bbox[4] - $bbox[0]) > $width) {
                        continue 2;
                    }
                    $bboxMaxHeight = max($bboxMaxHeight, abs($bbox[5] - $bbox[1]));
                }
                // All the values are OK : we have found the angle : break the angle
                // loop
                break;
            }
        }
        $this->height = $bboxMaxHeight + 2 * $this->padding;
        return $bboxMaxHeight + 2 * $this->padding;
    }

    /** Draw the axis
      * @param resource $gd The resource to modify
      */
    public function draw($gd)
    {
        $axisColor = Color::allocateFromText($gd, $this->axisColor);
        if ($this->numerical) {
            if ($this->angle === null) {
                $this->getHeight($gd);
            }
            if ($this->data === null) {
                return;
            }
            foreach ($this->data as $key => $value) {
                $position = $this->position($value);

                // Draw the labels
                $bbox = imagettfbbox(
                    $this->fontsize,
                    $this->angle,
                    $this->fontfile,
                    $value
                );
                $width = abs($bbox[4] - $bbox[0]);
                $x = $position - $width / 2;
                $y = $this->bottom - $this->padding;
                // The font color is forced to black
                imagettftext(
                    $gd,
                    $this->fontsize,
                    $this->angle,
                    $x,
                    $y,
                    Color::allocateFromText($gd, "black"),
                    $this->fontfile,
                    $value
                );

                // Draw the scale
                imageline(
                    $gd,
                    $position,
                    $this->bottom - $this->height + 1,
                    $position,
                    $this->bottom - $this->height + 1 + $this->padding,
                    $axisColor
                );

                // Draw the grid
                $this->drawGrid($gd, $this->bottom - $this->height, $position);
            }

            // Draw the axis
            $y = $this->bottom - $this->height + 1;
            imageline($gd, $this->left, $y, $this->right, $y, $axisColor);
        } else {
            if ($this->angle === null) {
                $this->getHeight($gd);
            }
            if ($this->data === null) {
                return;
            }
            foreach ($this->data as $key => $value) {
                $position = $this->position($value);

                // Draw the labels
                $bbox = imagettfbbox(
                    $this->fontsize,
                    $this->angle,
                    $this->fontfile,
                    $value
                );
                $width = abs($bbox[4] - $bbox[0]);
                $x = $position - $width / 2;
                $y = $this->bottom - $this->padding;
                // The font color is forced to black
                imagettftext(
                    $gd,
                    $this->fontsize,
                    $this->angle,
                    $x,
                    $y,
                    Color::allocateFromText($gd, "black"),
                    $this->fontfile,
                    $value
                );

                // Draw the separators
                $y = $this->bottom - $this->height + 1;
                $xmin = $this->positionMin($value);
                $xmax = $this->positionMax($value);
                imageline($gd, $xmin, $y, $xmin, $y + $this->padding, $axisColor);
                imageline($gd, $xmax, $y, $xmax, $y + $this->padding, $axisColor);

                // Draw the grid
                $this->drawGrid($gd, $this->bottom - $this->height, $position);
            }

            // Draw the axis
            $y = $this->bottom - $this->height + 1;
            imageline($gd, $this->left, $y, $this->right, $y, $axisColor);
        }
    }

    /** Draw the grid
      * @param resource $gd The resource to modify
      * @param integer $width The width of the labels on the axis
      * @param integer|float $position The position to draw
      */
    protected function drawGrid($gd, $width, $position)
    {
        if ($this->gridColor === null || $this->gridColor === "transparent") {
            return;
        }
        $gridColor = Color::allocateFromText($gd, $this->gridColor);
        if ($position === null) {
            return;
        }
        $y = $this->bottom - $this->height;
        imageline($gd, $position, $y, $position, $this->top, $gridColor);
    }
}