<?php

namespace Box\Spout\Writer\Common\Helper;

/**
 * Class AbstractStyleHelper
 * This class provides helper functions to manage styles
 *
 * @package Box\Spout\Writer\Common\Helper
 */
abstract class AbstractStyleHelper {

	/** @var array [SERIALIZED_STYLE] => [STYLE_ID] mapping table, keeping track of the registered styles */
	protected $serializedStyleToStyleIdMappingTable = array();

	/** @var array [STYLE_ID] => [STYLE] mapping table, keeping track of the registered styles */
	protected $styleIdToStyleMappingTable = array();

	/**
	 * @param \Box\Spout\Writer\Style\Style $defaultStyle
	 */
	public function __construct( $defaultStyle ) {
		// This ensures that the default style is the first one to be registered
		$this->registerStyle( $defaultStyle );
	}

	/**
	 * Registers the given style as a used style.
	 * Duplicate styles won't be registered more than once.
	 *
	 * @param \Box\Spout\Writer\Style\Style $style The style to be registered
	 * @return \Box\Spout\Writer\Style\Style The registered style, updated with an internal ID.
	 */
	public function registerStyle( $style ) {
		$serializedStyle = $style->serialize();

		if ( ! $this->hasStyleAlreadyBeenRegistered( $style ) ) {
			$nextStyleId = count( $this->serializedStyleToStyleIdMappingTable );
			$style->setId( $nextStyleId );

			$this->serializedStyleToStyleIdMappingTable[ $serializedStyle ] = $nextStyleId;
			$this->styleIdToStyleMappingTable[ $nextStyleId ]               = $style;
		}

		return $this->getStyleFromSerializedStyle( $serializedStyle );
	}

	/**
	 * Returns whether the given style has already been registered.
	 *
	 * @param \Box\Spout\Writer\Style\Style $style
	 * @return bool
	 */
	protected function hasStyleAlreadyBeenRegistered( $style ) {
		$serializedStyle = $style->serialize();

		// Using isset here because it is way faster than array_key_exists...
		return isset( $this->serializedStyleToStyleIdMappingTable[ $serializedStyle ] );
	}

	/**
	 * Returns the registered style associated to the given serialization.
	 *
	 * @param string $serializedStyle The serialized style from which the actual style should be fetched from
	 * @return \Box\Spout\Writer\Style\Style
	 */
	protected function getStyleFromSerializedStyle( $serializedStyle ) {
		$styleId = $this->serializedStyleToStyleIdMappingTable[ $serializedStyle ];
		return $this->styleIdToStyleMappingTable[ $styleId ];
	}

	/**
	 * @return \Box\Spout\Writer\Style\Style[] List of registered styles
	 */
	protected function getRegisteredStyles() {
		return array_values( $this->styleIdToStyleMappingTable );
	}

	/**
	 * Returns the default style
	 *
	 * @return \Box\Spout\Writer\Style\Style Default style
	 */
	protected function getDefaultStyle() {
		// By construction, the default style has ID 0
		return $this->styleIdToStyleMappingTable[0];
	}

	/**
	 * Apply additional styles if the given row needs it.
	 * Typically, set "wrap text" if a cell contains a new line.
	 *
	 * @param \Box\Spout\Writer\Style\Style $style The original style
	 * @param array $dataRow The row the style will be applied to
	 * @return \Box\Spout\Writer\Style\Style The updated style
	 */
	public function applyExtraStylesIfNeeded( $style, $dataRow ) {
		$updatedStyle = $this->applyWrapTextIfCellContainsNewLine( $style, $dataRow );
		return $updatedStyle;
	}

	/**
	 * Set the "wrap text" option if a cell of the given row contains a new line.
	 *
	 * @NOTE: There is a bug on the Mac version of Excel (2011 and below) where new lines
	 *        are ignored even when the "wrap text" option is set. This only occurs with
	 *        inline strings (shared strings do work fine).
	 *        A workaround would be to encode "\n" as "_x000D_" but it does not work
	 *        on the Windows version of Excel...
	 *
	 * @param \Box\Spout\Writer\Style\Style $style The original style
	 * @param array $dataRow The row the style will be applied to
	 * @return \Box\Spout\Writer\Style\Style The eventually updated style
	 */
	protected function applyWrapTextIfCellContainsNewLine( $style, $dataRow ) {
		 // if the "wrap text" option is already set, no-op
		if ( $style->hasSetWrapText() ) {
			return $style;
		}

		foreach ( $dataRow as $cell ) {
			if ( is_string( $cell ) && strpos( $cell, "\n" ) !== false ) {
				$style->setShouldWrapText();
				break;
			}
		}

		return $style;
	}
}