<?php
/* This library is LGPL
 * written by Louis-Philippe Huberdeau
 *
 * vim: fdm=marker tabstop=4 shiftwidth=4 noet:
 *
 * This file contains the base elements of the graphic
 * rendering engine.
 */

/** Rules for implementers!
 * You must support all methods.
 * Size and locations are float values from 0 to 1
 * (0,0) is top left
 * Angles are given in degrees, are counter-clockwise and start from (1,0)
 * Pie radius size is calculated against the smallest size (width or height)
 * All styles located in testRenderer must be supported and have the expected behavior
 * Styles are implementation specific and are only generated via getStyle
 * Unknown style should return GRenderer::getStyle( $name )
 * Use VI fold markers and include the config line in the header
 * Prefix internal functions (private or protected) using an underscore
 * Text coordinates are top-left corner of the string (bottom left when vertical)
 *
 * Detailed list in GraphEngineDev
 */

class GRenderer // {{{1
{
	function addLink( $target, $left, $top, $right, $bottom, $title = null ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function drawLine( $x1, $y1, $x2, $y2, $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function drawRectangle( $left, $top, $right, $bottom, $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function drawPie( $centerX, $centerY, $radius, $begin, $end, $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function drawText( $text, $left, $right, $height, $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function getTextWidth( $text, $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function getTextHeight( $style ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function getStyle( $name ) // {{{2
	{
		return null;
	}

	function httpOutput( $filename ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function writeToStream( $stream ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function _getRawColor( $name ) // {{{2
	{
		switch( $name )
		{
		case 'red':			return array( 'r' => 0xCC, 'g' => 0x00, 'b' => 0x00 );
		case 'green':		return array( 'r' => 0x00, 'g' => 0xCC, 'b' => 0x00 );
		case 'blue':		return array( 'r' => 0x00, 'g' => 0x00, 'b' => 0xCC );
		case 'yellow':		return array( 'r' => 0xFF, 'g' => 0xFF, 'b' => 0x00 );
		case 'orange':		return array( 'r' => 0xFF, 'g' => 0x99, 'b' => 0x00 );
		case 'lightgreen':	return array( 'r' => 0x99, 'g' => 0xFF, 'b' => 0x99 );
		case 'lightblue':	return array( 'r' => 0x66, 'g' => 0x99, 'b' => 0xFF );
		
		case 'black':		return array( 'r' => 0x00, 'g' => 0x00, 'b' => 0x00 );
		case 'white':		return array( 'r' => 0xFF, 'g' => 0xFF, 'b' => 0xFF );

		case 'gray':		return array( 'r' => 0xDD, 'g' => 0xDD, 'b' => 0xDD );

		default:			return array( 'r' => 0x00, 'g' => 0x00, 'b' => 0x00 );
		}
	}
} // }}}1

class Fake_GRenderer extends GRenderer // {{{1
{
	var $renderer;
	var $left;
	var $top;
	var $width;
	var $height;
	
	function Fake_GRenderer( &$renderer, $left, $top, $right, $bottom )
	{
		$this->renderer = &$renderer;
		$this->left = $left;
		$this->top = $top;
		$this->width = $right - $left;
		$this->height = $bottom - $top;
	}
	
	function addLink( $target, $left, $top, $right, $bottom, $title = null ) // {{{2
	{
		$this->renderer->addLink(
			$target,
			$left * $this->width + $this->left,
			$top * $this->height + $this->top,
			$right * $this->width + $this->left,
			$bottom * $this->height + $this->top,
			$title
		);
	}

	function drawLine( $x1, $y1, $x2, $y2, $style ) // {{{2
	{
		$this->renderer->drawLine(
			$x1 * $this->width + $this->left,
			$y1 * $this->height + $this->top,
			$x2 * $this->width + $this->left,
			$y2 * $this->height + $this->top,
			$style
		);
	}

	function drawRectangle( $left, $top, $right, $bottom, $style ) // {{{2
	{
		$this->renderer->drawRectangle(
			$left * $this->width + $this->left,
			$top * $this->height + $this->top,
			$right * $this->width + $this->left,
			$bottom * $this->height + $this->top,
			$style
		);
	}

	function drawPie( $centerX, $centerY, $radius, $begin, $end, $style ) // {{{2
	{
		$this->renderer->drawPie(
			$centerX * $this->width + $this->left,
			$centerY * $this->height + $this->top,
			$radius * $this->width,
			$begin,
			$end,
			$style
		);
	}

	function drawText( $text, $left, $right, $height, $style ) // {{{2
	{
		$this->renderer->drawText(
			$text,
			$left * $this->width + $this->left,
			$right * $this->width + $this->left,
			$height * $this->height + $this->top,
			$style
		);
	}

	function getTextWidth( $text, $style ) // {{{2
	{
		// Make sure the font size does not get smaller with scale
		return $this->renderer->getTextWidth( $text, $style ) / $this->width;
	}

	function getTextHeight( $style ) // {{{2
	{
		// Make sure the font size does not get smaller with scale
		return $this->renderer->getTextHeight( $style ) / $this->height;
	}

	function getStyle( $name ) // {{{2
	{
		return $this->renderer->getStyle( $name );
	}

	function httpOutput( $filename ) // {{{2
	{
		$this->renderer->httpOutput( $filename );
	}

	function writeToStream( $stream ) // {{{2
	{
		$this->renderer->writeToStream( $stream );
	}
} // }}}1

class DataHandler // {{{
{
	/**
	 * Provides means to hook into the data display sequence to add decorations
	 * or external behaviour.
	 *
	 * Called every time a data entry is displayed by the engine. Handlers are
	 * registered by Graphic::addDataHandler(). No implementations are provided
	 * with the distribution.
	 *
	 * @param renderer		The renderer instance on which the rendering is performed.
	 *						This instance may not be cached for other purposes.
	 * @param positionData	Indicates the coordinate of the data to be rendered. 
	 *						Coordinates are renderer-specific. This value is provided
	 *						as an associative array. (x,y) is provided for single-point
	 *						data. (top,left,bottom,right) is provided for regions.
	 * @param series		The key of the source series of the data.
	 * @param entryIndex	The zero-based index of the entry in the series.
	 */
	function handle( $renderer, $positionData, $series, $entryIndex )
	{
		die( "Abstract Function Call" );
	}
} // }}}

class Graphic // {{{1
{
	var $legend;
	var $title;
	var $parameters;
	var $dataHandlers;

	function Graphic() // {{{2
	{
		$this->legend = array();
		$this->parameters = array();
		$this->dataHandlers = array();
	}
	
	function setTitle( $title ) // {{{2
	{
		$this->title = $title;
	}

	function addLegend( $color, $value, $url = null ) // {{{2
	{
		// $color name
		// $value label
		$this->legend[] = array( $color, $value, $url );
	}

	function addDataHandler( $handler ) // {{{2
	{
		if( is_a($handler, 'DataHandler') )
			$this->dataHandlers[] = $handler;
	}

	function getRequiredSeries() // {{{2
	{
		// Returns an associative array with series name as key
		// Value has to be true if the series is required.
		die( "Abstract Function Call" );
	}

	function draw( &$renderer ) // {{{2
	{
		$top = 0;
		$left = 0;
		$bottom = 1;
		$right = 1;

		$layout = $this->_layout();

		if( $layout['title-active'] || empty( $this->title ) )
		{
			$top += 0.1;
			$renderer->drawText( $this->title, 0, 1, 0.04, $renderer->getStyle( $layout['title-font'] ) );
		}

		if( $layout['legend-active'] && count( $this->legend ) > 0 && $layout['legend-location'] != 'static' )
			$this->_drawLegend( $renderer, $left, $top, $right, $bottom, $layout );

		$left += $layout['content-margin'];
		$right -= $layout['content-margin'];
		$top += $layout['content-margin'];
		$bottom -= $layout['content-margin'];
		$this->_drawContent( new Fake_GRenderer( $renderer, $left, $top, $right, $bottom ) );

		if( $layout['legend-active'] && count( $this->legend ) > 0 && $layout['legend-location'] == 'static' )
			$this->_drawLegend( $renderer, $left, $top, $right, $bottom, $layout );
	}

	function setData( $data ) // {{{2
	{
		if( !is_array( $data ) )
			return false;

		foreach( $this->getRequiredSeries() as $key => $value )
			if( $value && ( !array_key_exists( $key, $data ) || !is_array( $data[$key] ) ) )
				return false;

		foreach( $data as $key => $values )
		{
			if( !is_array( $values ) )
				return false;

			$data[$key] = array_values( $values );
		}

		return $this->_handleData( $data );
	}

	function setParam( $name, $value ) // {{{2
	{
		$this->parameters[$name] = $value;
	}

	function _getColor() // {{{2
	{
		static $index = 0;
		$colors = array(
			'Red',
			'Green',
			'Blue',
			'Yellow',
			'Orange',
			'LightGreen',
			'LightBlue'
		);

		return $colors[$index++ % count($colors)];
	}
	
	function _drawLegend( &$renderer, &$left, &$top, &$right, &$bottom, $layout ) // {{{2
	{
		$box_size = $layout['legend-box-size'];
		$padding = $layout['legend-padding'];
		$margin = $layout['legend-margin'];

		$legend_font = $renderer->getStyle( $layout['legend-font'] );
		$font_height = $renderer->getTextHeight( $legend_font );

		// Calculate size {{{3
		$item_size = array();
		foreach( $this->legend as $key => $value )
			$item_size[$key] = $renderer->getTextWidth( $value[1], $legend_font );

		$width = 0;
		$height = 0;
		$single_height = max( $font_height, $box_size );
		switch( $layout['legend-orientation'] )
		{
		case 'horizontal':
			$height = $single_height + 2 * $padding;
			$width = 
				array_sum( $item_size ) // text width
				+ (1 + count( $item_size ) ) * $padding // padding between items 
				+ ( $box_size + $padding ) * count( $item_size ); // box and box padding
			break;
		case 'vertical':
			$height = $single_height * count( $item_size ) + (1 + count( $item_size ) ) * $padding;
			$width = max( $item_size ) + 3 * $padding + $box_size;
			break;
		}

		// Calculate position {{{3
		$x = 0;
		$y = 0;
		switch( $layout['legend-location'] )
		{
		case 'left':
			$y = $top + ( $bottom - $top ) / 2 - $height / 2;
			$x = $left + $margin;
			$left += 2 * $margin + $width;
			break;
		case 'right':
			$y = $top + ( $bottom - $top ) / 2 - $height / 2;
			$x = $right - $margin - $width;
			$right -= 2 * $margin + $width;
			break;
		case 'bottom':
			$x = $left + ( $right - $left ) / 2 - $width / 2;
			$y = $bottom - $margin - $height;
			$bottom -= 2 * $margin + $height;
			break;
		case 'top':
			$x = $left + ( $right - $left ) / 2 - $width / 2;
			$y = $top + $margin;
			$top += 2 * $margin + $height;
			break;
		case 'static':
			switch( $layout['legend-location-rel'] )
			{
			case 'top-left':
				$x = $layout['legend-location-x'] + $margin;
				$y = $layout['legend-location-y'] + $margin;
				break;
			case 'top-right':
				$x = $layout['legend-location-x'] - $width - $margin;
				$y = $layout['legend-location-y'] + $margin;
				break;
			case 'bottom-left':
				$x = $layout['legend-location-x'] + $margin;
				$y = $layout['legend-location-y'] - $height - $margin;
				break;
			case 'bottom-right':
				$x = $layout['legend-location-x'] - $width - $margin;
				$y = $layout['legend-location-y'] - $height - $margin;
				break;
			case 'center':
				$x = $layout['legend-location-x'] - $width / 2;
				$y = $layout['legend-location-y'] - $height / 2;
				break;
			}
			break;
		}

		// Draw the thing {{{3
		$renderer->drawRectangle( $x, $y, $x + $width, $y + $height, $renderer->getStyle( $layout['legend-style'] ) );
		$box_offset = 0;
		$text_offset = 0;
		if( $box_size > $font_height )
			$text_offset = ( $box_size - $font_height ) / 2;
		else
			$box_offset = ( $font_height - $box_size ) / 2;

		$x += $padding;
		$y += $padding;

		foreach( $this->legend as $key => $info )
		{
			list( $color, $value, $url ) = $info;
			$this->_drawLegendBox( 
				new Fake_GRenderer( 
					$renderer, 
					$x, 
					$y + $box_offset, 
					$x + $box_size, 
					$y + $box_size + $box_offset ), 
				$color );

			switch( $layout['legend-orientation'] )
			{
			case 'horizontal':
				$renderer->drawText( 
					$value, 
					$x + $box_size + $padding, 
					$x + $box_size + $padding + $item_size[$key],
					$y + $text_offset, 
					$legend_font );
				
				if( ! empty( $url ) )
					$renderer->addLink(
						$url,
						$x + $padding,
						$y + $box_offset,
						$x + $box_size + $padding + $item_size[$key],
						$y + $box_offset + $box_size,
						$value );

				$x += $box_size + $padding * 2 + $item_size[$key];

				break;
			case 'vertical':
				$renderer->drawText( 
					$value, 
					$x + $box_size + $padding, 
					$x - $padding + $width, 
					$y + $text_offset, 
					$legend_font );
				
				if( ! empty( $url ) )
					$renderer->addLink(
						$url,
						$x,
						$y + $box_offset,
						$x + $width,
						$y + $box_offset + $box_size,
						$value);

				$y += $padding + $single_height;
				break;
			}
		}
		// }}}3
	}
	
	function _drawContent( &$renderer ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function _drawLegendBox( &$renderer ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function _handleData( $data ) // {{{2
	{
		die( "Abstract Function Call" );
	}

	function _default() // {{{2
	{
		return array(
			'title-active' => true,
			'title-font' => 'Normal-Text-Center', // Any Text style name
			'legend-active' => true,
			'legend-font' => 'Large-Text', // Any Text style name
			'legend-location' => 'right', // left, right, bottom, top, static
			'legend-location-x' => 1, // static only, x location
			'legend-location-y' => 1, // static only, y location
			'legend-location-rel' => 'bottom-right', // static only, relative postion (top-left, top-right, bottom-left, bottom-right, center
			'legend-orientation' => 'vertical', // horizontal, vertical
			'legend-style' => 'FillStroke-White', // Any FillStroke style name
			'legend-box-size' => 0.03,
			'legend-margin' => 0.01,
			'legend-padding' => 0.01,
			'content-margin' => 0.02
		);
	}

	function _layout() // {{{2
	{
		// Planning some user-preferences, until then, defaults.
		return array_merge( $this->_default(), $this->parameters );
	}

	function _notify( $renderer, $positionData, $series, $index ) // {{{2
	{
		foreach( $this->dataHandlers as $handler )
			$handler->handle( $renderer, $positionData, $series, $index );
	}
} // }}}1
