<?php

/**
 * The extension class used by twig..
 *
 * @author     Time.ly Network Inc.
 * @since      2.0
 *
 * @package    AI1EC
 * @subpackage AI1EC.Validator
 */
class Ai1ec_Twig_Ai1ec_Extension extends Twig_Extension {

    /**
     * @var Ai1ec_Registry_Object
     */
    protected $_registry;

    /**
     * Inject the registry object.
     *
     * @param Ai1ec_Registry_Object $registry
     */
    public function set_registry( Ai1ec_Registry_Object $registry ) {
        $this->_registry = $registry;
    }

    /* (non-PHPdoc)
     * @see Twig_Extension::getFunctions()
     */
    public function getFunctions() {
        return array(
            'wp_nonce_field'               => new Twig_Function_Method( $this, 'wp_nonce_field' ),
            'do_meta_boxes'                => new Twig_Function_Method( $this, 'do_meta_boxes' ),
            'fb'                           => new Twig_Function_Method( $this, 'fb' ),
            'ai1ec_disable_content_output' => new Twig_Function_Method( $this, 'ai1ec_disable_content_output' )
        );
    }

    /**
     * Twig callback - return a list of filters registered by this extension.
     *
     * @return array
     */
    public function getFilters() {
        return array(
            new Twig_SimpleFilter( 'truncate',          array( $this, 'truncate' ) ),
            new Twig_SimpleFilter( 'timespan',          array( $this, 'timespan' ) ),
            new Twig_SimpleFilter( 'avatar',            array( $this, 'avatar' ) ),
            new Twig_SimpleFilter( 'avatar_url',        array( $this, 'avatar_url' ) ),
            new Twig_SimpleFilter( 'remove_avatar_url', array( $this, 'remove_avatar_url' ) ),
            new Twig_SimpleFilter( 'remove_paragraph',  array( $this, 'remove_paragraph' ) ),
            new Twig_SimpleFilter( 'hour_to_datetime',  array( $this, 'hour_to_datetime' ) ),
            new Twig_SimpleFilter( 'weekday',           array( $this, 'weekday' ) ),
            new Twig_SimpleFilter( 'day',               array( $this, 'day' ) ),
            new Twig_SimpleFilter( 'month',             array( $this, 'month' ) ),
            new Twig_SimpleFilter( 'year',              array( $this, 'year' ) ),
            new Twig_SimpleFilter( 'theme_img_url',     array( $this, 'theme_img_url' ) ),
            new Twig_SimpleFilter( 'date_i18n',         array( $this, 'date_i18n' ) ),
            new Twig_SimpleFilter( 'dropdown_filter',   array( $this, 'dropdown_filter' ),
                array( 'is_safe' => array( 'html' ) )
            ),
            new Twig_SimpleFilter( '__',                'Ai1ec_I18n::__' ),
        );
    }

    /**
     * Twig callback - return a list of tests registered by this extension.
     *
     * @return array
     */
    public function getTests() {
        return array(
            new Twig_SimpleTest( 'string', array( $this, 'is_string' ) ),
        );
    }

    /**
     * Get HTML markup for the post's "avatar" image according conditional
     * fallback model.
     *
     * Accepts an ordered array of named avatar $fallbacks. Also accepts a string
     * of space-separated classes to add to the default classes.
     * @param   Ai1ec_Event $event          The event to get the avatar for
     * @param   array|null  $fallback_order Order of fallback in searching for
     *                                      images, or null to use default
     * @param   string      $classes        A space-separated list of CSS classes
     *                                      to apply to the outer <div> element.
     * @param   boolean     $wrap_permalink Whether to wrap the element in a link
     *                                      to the event details page.
     *
     * @return  string                   String of HTML if image is found
     */
    public function avatar(
        Ai1ec_Event $event,
        $fallback_order = null,
        $classes = '',
        $wrap_permalink = true
    ) {
        return $this->_registry->get( 'view.event.avatar' )
            ->get_event_avatar(
                $event,
                $fallback_order,
                $classes,
                $wrap_permalink
            );
    }

    /**
     * Debug function to be used in twig templates with Firebug/FirePHP
     *
     * @param mixed $object
     */
    public function fb( $object ) {
        if ( function_exists( 'fb' ) ) {
            fb( $object );
        }
    }
    /**
     * Get URL for avatar.
     *
     * Accepts an ordered array of named avatar $fallbacks.
     * @param   Ai1ec_Event $event          The event to get the avatar for.
     * @param   array|null  $fallback_order Order of fallback in searching for
     *                                      images, or null to use default.
     *
     * @return  string                   URL if image is found.
     */
    public function avatar_url(
        Ai1ec_Event $event,
        $fallback_order = null
    ) {
        return $this->_registry->get( 'view.event.avatar' )
            ->get_event_avatar_url(
                $event,
                $fallback_order
            );
    }

    /**
     * Remove the avatar url from the content
     *
     * Accepts an ordered array of named avatar $fallbacks.
     * @param   Ai1ec_Event $event          The event to get the avatar for.
     * @param   array|null  $fallback_order Order of fallback in searching for
     *                                      images, or null to use default.
     *
     * @return  string                   URL if image is found.
     */
    public function remove_avatar_url(
        $content
    ) {
        return $this->_registry->get( 'view.event.avatar' )
            ->remove_avatar_url( $content );
    }

    /**
     * Remove the First paragraph (<p>....</p>) from the content
     * @return
     * <p>This is a text</p> returns This is a text
     * <p><p>This is a text</p></p> returns <p>This is a text</p>
     */
    public function remove_paragraph( $content ) {
        if ( preg_match( '/^<p>(.+)<\\/p>$/is', $content, $matches ) ) {
            return $matches[1];
        } else {
            return $content;
        }

    }

    /**
     * Check if provided value is a string.
     *
     * @param mixed $var Suspected string
     *
     * @return boolean True if it is a string, false otherwise.
     */
    public function is_string( $var ) {
        return is_string( $var );
    }

    /**
     * Convert an hour to an Ai1ec_Date_Time object.
     *
     * @param int $hour
     *
     * @return Ai1ec_Date_Time
     */
    public function hour_to_datetime( $hour ) {
        return $this->_registry->get( 'date.time', 'now', 'sys.default' )
            ->set_time( $hour, 0, 0 );
    }

    /**
     * Get the name of the weekday.
     *
     * @param int $unix_timestamp
     *
     * @return string
     */
    public function weekday( $unix_timestamp ) {
        return $this->_registry->get( 'date.time', $unix_timestamp )
            ->format_i18n( 'D' );
    }

    /**
     * Get the name of the day.
     *
     * @param int $unix_timestamp
     *
     * @return string
     */
    public function day( $unix_timestamp ) {
        return $this->_registry->get( 'date.time', $unix_timestamp )
            ->format_i18n( 'j' );
    }

    /**
     * Get the name of the month.
     *
     * @param int $unix_timestamp
     *
     * @return string
     */
    public function month( $unix_timestamp ) {
        return $this->_registry->get( 'date.time', $unix_timestamp )
            ->format_i18n( 'M' );
    }

    /**
     * Get the date's year
     *
     * @param int $unix_timestamp
     *
     * @return string
     */
    public function year( $unix_timestamp ) {
        return $this->_registry->get( 'date.time', $unix_timestamp )
            ->format_i18n( 'Y' );
    }

    /**
     * Get URL of the given image file in the calendar theme's directory.
     *
     * @param int $unix_timestamp
     *
     * @return string
     */
    public function theme_img_url( $image ) {
        $loader = $this->_registry->get( 'theme.loader' );
        return $loader->get_file( $image, array(), false )->get_url();
    }

    /**
     * Internationalize the given UNIX timestamp with the given format string.
     *
     * @param int $unix_timestamp
     * @param string $format
     *
     * @return string
     */
    public function date_i18n( $unix_timestamp, $format ) {
        return $this->_registry->get( 'date.time', $unix_timestamp )
            ->format_i18n( $format );
    }

    /**
     * Truncate a string after $length characters, appending $read_more string
     * at end of truncation.
     *
     * @param number $length        Length to truncate string to.
     * @param string $read_more     What string to append if truncated.
     * @param string $html_entities Whether to treat input string as HTML with
     *                              possible &asdf; entities
     * @return string
     */
    public function truncate(
        $string,
        $length = 35,
        $read_more = '...',
        $html_entities = true
    ) {
        // Truncate multibyte encodings differently, if supported.
        if ( function_exists( 'mb_strimwidth' ) ) {
            // First decode entities if requested.
            if ( $html_entities ) {
                $string = html_entity_decode( $string, ENT_QUOTES, 'UTF-8' );
            }
            // Truncate string.
            $string = mb_strimwidth( $string, 0, $length, $read_more, 'UTF-8' );
            // Reencode entities if requested.
            if ( $html_entities ) {
                $string = htmlentities( $string, ENT_QUOTES, 'UTF-8' );
            }
        }
        else {
            // First decode entities if requested.
            if ( $html_entities ) {
                $string = html_entity_decode( $string, ENT_QUOTES );
            }
            // Truncate string.
            $read_more = strlen( $string ) > 35 ? $read_more : '';
            $string = substr( $string, 0, 35 ) . $read_more;
            // Reencode entities if requested.
            if ( $html_entities ) {
                $string = html_entity_decode( $string, ENT_QUOTES );
            }
        }

        return $string;
    }

    /**
     * Filter string allowing ampersand symbols to be displayed.
     * at end of truncation.
     *
     * @param string $string        String to process.
     * @return string
     */
    public function dropdown_filter(
        $string
    ) {
        $string = htmlspecialchars( $string );
        $string = preg_replace( '/&amp;/', '&', $string );
        return $string;
    }

    /**
     * Generate a timespan HTML block for an event.
     *
     * @param Ai1ec_Event $event              Event to generate timespan for.
     * @param string      $start_date_display Start date display format.
     *
     * @return string Rendered HTML timespan block.
     */
    public function timespan(
        Ai1ec_Event $event,
        $start_date_display = 'long'
    ) {
        return $this->_registry->get( 'view.event.time' )
            ->get_timespan_html( $event, $start_date_display );
    }

    /**
     * Meta-Box template function
     *
     * @since 2.5.0
     *
     * @param string|object $screen Screen identifier
     * @param string $context box context
     * @param mixed $object gets passed to the box callback function as first parameter
     * @return int number of meta_boxes
     */
    public function do_meta_boxes( $screen, $context, $object ) {
        do_meta_boxes( $screen, $context, $object );
    }

    /**
     * Retrieve or display nonce hidden field for forms.
     *
     * The nonce field is used to validate that the contents of the form came from
     * the location on the current site and not somewhere else. The nonce does not
     * offer absolute protection, but should protect against most cases. It is very
     * important to use nonce field in forms.
     *
     * The $action and $name are optional, but if you want to have better security,
     * it is strongly suggested to set those two parameters. It is easier to just
     * call the function without any parameters, because validation of the nonce
     * doesn't require any parameters, but since crackers know what the default is
     * it won't be difficult for them to find a way around your nonce and cause
     * damage.
     *
     * The input name will be whatever $name value you gave. The input value will be
     * the nonce creation value.
     *
     * @package WordPress
     * @subpackage Security
     * @since 2.0.4
     *
     * @param string $action Optional. Action name.
     * @param string $name Optional. Nonce name.
     * @param bool $referer Optional, default true. Whether to set the referer field for validation.
     * @param bool $echo Optional, default true. Whether to display or return hidden form field.
     * @return string Nonce field.
     */
    public function wp_nonce_field( $action = -1, $name = "_wpnonce", $referer = true , $echo = true ) {
        wp_nonce_field( $action, $name, $referer, $echo );
    }

    /* (non-PHPdoc)
     * @see Twig_ExtensionInterface::getName()
     */
    public function getName() {
        return 'ai1ec';
    }

    /**
     * Hooks into the_content filter to disable its output.
     *
     * @return void Method does not return.
     */
    public function ai1ec_disable_content_output() {
        $this->_registry->get( 'calendar.state' )->set_append_content( false );
    }
}