<?php
defined( 'WPINC' ) or die;

if ( ! class_exists( 'GeneratePress_Pro_CSS' ) ) :
/**
 * Creates minified css via PHP.
 *
 * @author  Carlos Rios
 * Modified by Tom Usborne for GeneratePress
 */
class GeneratePress_Pro_CSS {

	/**
	 * The css selector that you're currently adding rules to
	 *
	 * @access protected
	 * @var string
	 */
	protected $_selector = '';

	/**
	 * Stores the final css output with all of its rules for the current selector.
	 *
	 * @access protected
	 * @var string
	 */
	protected $_selector_output = '';

	/**
	 * Stores all of the rules that will be added to the selector
	 *
	 * @access protected
	 * @var string
	 */
	protected $_css = '';

	/**
	 * The string that holds all of the css to output
	 *
	 * @access protected
	 * @var string
	 */
	protected $_output = '';

	/**
	 * Stores media queries
	 *
	 * @var null
	 */
	protected $_media_query = null;

	/**
	 * The string that holds all of the css to output inside of the media query
	 *
	 * @access protected
	 * @var string
	 */
	protected $_media_query_output = '';

	/**
	 * Sets a selector to the object and changes the current selector to a new one
	 *
	 * @access public
	 * @since  1.0
	 *
	 * @param  string $selector - the css identifier of the html that you wish to target
	 * @return $this
	 */
	public function set_selector( $selector = '' ) {
		// Render the css in the output string everytime the selector changes
		if( $this->_selector !== '' ){
			$this->add_selector_rules_to_output();
		}
		$this->_selector = $selector;
		return $this;
	}

	/**
	 * Adds a css property with value to the css output
	 *
	 * @access public
	 * @since  1.0
	 *
	 * @param  string $property - the css property
	 * @param  string $value - the value to be placed with the property
	 * @param  string $og_default - check to see if the value matches the default
	 * @param  string $unit - the unit for the value (px)
	 * @return $this
	 */
	public function add_property( $property, $value, $og_default = false, $unit = false ) {
		// Add our unit to our value if it exists
		if ( $unit && '' !== $unit ) {
			$value = $value . $unit;
			if ( '' !== $og_default ) {
				$og_default = $og_default . $unit;
			}
		}

		// If we don't have a value or our value is the same as our og default, bail
		if ( empty( $value ) || $og_default == $value )
			return false;

		$this->_css .= $property . ':' . $value . ';';
		return $this;
	}

	/**
	 * Sets a media query in the class
	 *
	 * @since  1.1
	 * @param  string $value
	 * @return $this
	 */
	public function start_media_query( $value ) {
		// Add the current rules to the output
		$this->add_selector_rules_to_output();

		// Add any previous media queries to the output
		if ( ! empty( $this->_media_query ) ) {
			$this->add_media_query_rules_to_output();
		}

		// Set the new media query
		$this->_media_query = $value;
		return $this;
	}

	/**
	 * Stops using a media query.
	 *
	 * @see    start_media_query()
	 *
	 * @since  1.1
	 * @return $this
	 */
	public function stop_media_query() {
		return $this->start_media_query( null );
	}

	/**
	 * Adds the current media query's rules to the class' output variable
	 *
	 * @since  1.1
	 * @return $this
	 */
	private function add_media_query_rules_to_output() {
		if( !empty( $this->_media_query_output ) ) {
			$this->_output .= sprintf( '@media %1$s{%2$s}', $this->_media_query, $this->_media_query_output );

			// Reset the media query output string
			$this->_media_query_output = '';
		}
		return $this;
	}

	/**
	 * Adds the current selector rules to the output variable
	 *
	 * @access private
	 * @since  1.0
	 *
	 * @return $this
	 */
	private function add_selector_rules_to_output() {
		if( !empty( $this->_css ) ) {
			$this->_selector_output = $this->_selector;
			$selector_output = sprintf( '%1$s{%2$s}', $this->_selector_output, $this->_css );

			// Add our CSS to the output
			if ( ! empty( $this->_media_query ) ) {
				$this->_media_query_output .= $selector_output;
				$this->_css = '';
			} else {
				$this->_output .= $selector_output;
			}

			// Reset the css
			$this->_css = '';
		}

		return $this;
	}

	/**
	 * Returns the minified css in the $_output variable
	 *
	 * @access public
	 * @since  1.0
	 *
	 * @return string
	 */
	public function css_output()
	{
		// Add current selector's rules to output
		$this->add_selector_rules_to_output();

		// Output minified css
		return $this->_output;
	}

}
endif;