<?php

namespace Box\Spout\Writer\XLSX\Helper;

use Box\Spout\Writer\Common\Helper\AbstractStyleHelper;
use Box\Spout\Writer\Style\Color;
use Box\Spout\Writer\Style\Style;

/**
 * Class StyleHelper
 * This class provides helper functions to manage styles
 *
 * @package Box\Spout\Writer\XLSX\Helper
 */
class StyleHelper extends AbstractStyleHelper {

	/**
	 * @var array
	 */
	protected $registeredFills = array();

	/**
	 * @var array [STYLE_ID] => [FILL_ID] maps a style to a fill declaration
	 */
	protected $styleIdToFillMappingTable = array();

	/**
	 * Excel preserves two default fills with index 0 and 1
	 * Since Excel is the dominant vendor - we play along here
	 *
	 * @var int The fill index counter for custom fills.
	 */
	protected $fillIndex = 2;

	/**
	 * @var array
	 */
	protected $registeredBorders = array();

	/**
	 * @var array [STYLE_ID] => [BORDER_ID] maps a style to a border declaration
	 */
	protected $styleIdToBorderMappingTable = array();

	/**
	 * XLSX specific operations on the registered styles
	 *
	 * @param \Box\Spout\Writer\Style\Style $style
	 * @return \Box\Spout\Writer\Style\Style
	 */
	public function registerStyle( $style ) {
		$registeredStyle = parent::registerStyle( $style );
		$this->registerFill( $registeredStyle );
		$this->registerBorder( $registeredStyle );
		return $registeredStyle;
	}

	/**
	 * Register a fill definition
	 *
	 * @param \Box\Spout\Writer\Style\Style $style
	 */
	protected function registerFill( $style ) {
		 $styleId = $style->getId();

		// Currently - only solid backgrounds are supported
		// so $backgroundColor is a scalar value (RGB Color)
		$backgroundColor = $style->getBackgroundColor();

		if ( $backgroundColor ) {
			$isBackgroundColorRegistered = isset( $this->registeredFills[ $backgroundColor ] );

			// We need to track the already registered background definitions
			if ( $isBackgroundColorRegistered ) {
				$registeredStyleId                           = $this->registeredFills[ $backgroundColor ];
				$registeredFillId                            = $this->styleIdToFillMappingTable[ $registeredStyleId ];
				$this->styleIdToFillMappingTable[ $styleId ] = $registeredFillId;
			} else {
				$this->registeredFills[ $backgroundColor ]   = $styleId;
				$this->styleIdToFillMappingTable[ $styleId ] = $this->fillIndex++;
			}
		} else {
			// The fillId maps a style to a fill declaration
			// When there is no background color definition - we default to 0
			$this->styleIdToFillMappingTable[ $styleId ] = 0;
		}
	}

	/**
	 * Register a border definition
	 *
	 * @param \Box\Spout\Writer\Style\Style $style
	 */
	protected function registerBorder( $style ) {
		$styleId = $style->getId();

		if ( $style->shouldApplyBorder() ) {
			$border           = $style->getBorder();
			$serializedBorder = serialize( $border );

			$isBorderAlreadyRegistered = isset( $this->registeredBorders[ $serializedBorder ] );

			if ( $isBorderAlreadyRegistered ) {
				$registeredStyleId                             = $this->registeredBorders[ $serializedBorder ];
				$registeredBorderId                            = $this->styleIdToBorderMappingTable[ $registeredStyleId ];
				$this->styleIdToBorderMappingTable[ $styleId ] = $registeredBorderId;
			} else {
				$this->registeredBorders[ $serializedBorder ]  = $styleId;
				$this->styleIdToBorderMappingTable[ $styleId ] = count( $this->registeredBorders );
			}
		} else {
			// If no border should be applied - the mapping is the default border: 0
			$this->styleIdToBorderMappingTable[ $styleId ] = 0;
		}
	}


	/**
	 * For empty cells, we can specify a style or not. If no style are specified,
	 * then the software default will be applied. But sometimes, it may be useful
	 * to override this default style, for instance if the cell should have a
	 * background color different than the default one or some borders
	 * (fonts property don't really matter here).
	 *
	 * @param int $styleId
	 * @return bool Whether the cell should define a custom style
	 */
	public function shouldApplyStyleOnEmptyCell( $styleId ) {
		$hasStyleCustomFill    = ( isset( $this->styleIdToFillMappingTable[ $styleId ] ) && $this->styleIdToFillMappingTable[ $styleId ] !== 0 );
		$hasStyleCustomBorders = ( isset( $this->styleIdToBorderMappingTable[ $styleId ] ) && $this->styleIdToBorderMappingTable[ $styleId ] !== 0 );

		return ( $hasStyleCustomFill || $hasStyleCustomBorders );
	}


	/**
	 * Returns the content of the "styles.xml" file, given a list of styles.
	 *
	 * @return string
	 */
	public function getStylesXMLFileContent() {
		 $content = <<<EOD
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<styleSheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
EOD;

		$content .= $this->getFontsSectionContent();
		$content .= $this->getFillsSectionContent();
		$content .= $this->getBordersSectionContent();
		$content .= $this->getCellStyleXfsSectionContent();
		$content .= $this->getCellXfsSectionContent();
		$content .= $this->getCellStylesSectionContent();

		$content .= <<<EOD
</styleSheet>
EOD;

		return $content;
	}

	/**
	 * Returns the content of the "<fonts>" section.
	 *
	 * @return string
	 */
	protected function getFontsSectionContent() {
		$content = '<fonts count="' . count( $this->styleIdToStyleMappingTable ) . '">';

		/** @var \Box\Spout\Writer\Style\Style $style */
		foreach ( $this->getRegisteredStyles() as $style ) {
			$content .= '<font>';

			$content .= '<sz val="' . $style->getFontSize() . '"/>';
			$content .= '<color rgb="' . Color::toARGB( $style->getFontColor() ) . '"/>';
			$content .= '<name val="' . $style->getFontName() . '"/>';

			if ( $style->isFontBold() ) {
				$content .= '<b/>';
			}
			if ( $style->isFontItalic() ) {
				$content .= '<i/>';
			}
			if ( $style->isFontUnderline() ) {
				$content .= '<u/>';
			}
			if ( $style->isFontStrikethrough() ) {
				$content .= '<strike/>';
			}

			$content .= '</font>';
		}

		$content .= '</fonts>';

		return $content;
	}

	/**
	 * Returns the content of the "<fills>" section.
	 *
	 * @return string
	 */
	protected function getFillsSectionContent() {
		// Excel reserves two default fills
		$fillsCount = count( $this->registeredFills ) + 2;
		$content    = sprintf( '<fills count="%d">', $fillsCount );

		$content .= '<fill><patternFill patternType="none"/></fill>';
		$content .= '<fill><patternFill patternType="gray125"/></fill>';

		// The other fills are actually registered by setting a background color
		foreach ( $this->registeredFills as $styleId ) {
			/** @var Style $style */
			$style = $this->styleIdToStyleMappingTable[ $styleId ];

			$backgroundColor = $style->getBackgroundColor();
			$content        .= sprintf(
				'<fill><patternFill patternType="solid"><fgColor rgb="%s"/></patternFill></fill>',
				$backgroundColor
			);
		}

		$content .= '</fills>';

		return $content;
	}

	/**
	 * Returns the content of the "<borders>" section.
	 *
	 * @return string
	 */
	protected function getBordersSectionContent() {
		// There is one default border with index 0
		$borderCount = count( $this->registeredBorders ) + 1;

		$content = '<borders count="' . $borderCount . '">';

		// Default border starting at index 0
		$content .= '<border><left/><right/><top/><bottom/></border>';

		foreach ( $this->registeredBorders as $styleId ) {
			/** @var \Box\Spout\Writer\Style\Style $style */
			$style    = $this->styleIdToStyleMappingTable[ $styleId ];
			$border   = $style->getBorder();
			$content .= '<border>';

			// @link https://github.com/box/spout/issues/271
			$sortOrder = array( 'left', 'right', 'top', 'bottom' );

			foreach ( $sortOrder as $partName ) {
				if ( $border->hasPart( $partName ) ) {
					/** @var $part \Box\Spout\Writer\Style\BorderPart */
					$part     = $border->getPart( $partName );
					$content .= BorderHelper::serializeBorderPart( $part );
				}
			}

			$content .= '</border>';
		}

		$content .= '</borders>';

		return $content;
	}

	/**
	 * Returns the content of the "<cellStyleXfs>" section.
	 *
	 * @return string
	 */
	protected function getCellStyleXfsSectionContent() {
		return <<<EOD
<cellStyleXfs count="1">
    <xf borderId="0" fillId="0" fontId="0" numFmtId="0"/>
</cellStyleXfs>
EOD;
	}

	/**
	 * Returns the content of the "<cellXfs>" section.
	 *
	 * @return string
	 */
	protected function getCellXfsSectionContent() {
		 $registeredStyles = $this->getRegisteredStyles();

		$content = '<cellXfs count="' . count( $registeredStyles ) . '">';

		foreach ( $registeredStyles as $style ) {
			$styleId  = $style->getId();
			$fillId   = $this->styleIdToFillMappingTable[ $styleId ];
			$borderId = $this->styleIdToBorderMappingTable[ $styleId ];

			$content .= '<xf numFmtId="0" fontId="' . $styleId . '" fillId="' . $fillId . '" borderId="' . $borderId . '" xfId="0"';

			if ( $style->shouldApplyFont() ) {
				$content .= ' applyFont="1"';
			}

			$content .= sprintf( ' applyBorder="%d"', $style->shouldApplyBorder() ? 1 : 0 );

			if ( $style->shouldWrapText() ) {
				$content .= ' applyAlignment="1">';
				$content .= '<alignment wrapText="1"/>';
				$content .= '</xf>';
			} else {
				$content .= '/>';
			}
		}

		$content .= '</cellXfs>';

		return $content;
	}

	/**
	 * Returns the content of the "<cellStyles>" section.
	 *
	 * @return string
	 */
	protected function getCellStylesSectionContent() {
		return <<<EOD
<cellStyles count="1">
    <cellStyle builtinId="0" name="Normal" xfId="0"/>
</cellStyles>
EOD;
	}
}