<?php
/**
 * Iframe page type embeds an iframe of URL of choice into the page.
 * CMS editor can choose width, height, or set it to attempt automatic size configuration.
 */

class IFramePage extends Page
{
    public static $db = array(
        'IFrameURL' => 'Text',
        'AutoHeight' => 'Boolean(1)',
        'AutoWidth' => 'Boolean(1)',
        'FixedHeight' => 'Int(500)',
        'FixedWidth' => 'Int(0)',
        'AlternateContent' => 'HTMLText',
        'BottomContent' => 'HTMLText',
        'ForceProtocol' => 'Varchar',
    );

    public static $defaults = array(
        'AutoHeight' => '1',
        'AutoWidth' => '1',
        'FixedHeight' => '500',
        'FixedWidth' => '0'
    );

    public static $description = 'Embeds an iframe into the body of the page.';
    
    public function getCMSFields()
    {
        $fields = parent::getCMSFields();

        $fields->removeFieldFromTab('Root.Main', 'Content');
        $fields->addFieldToTab('Root.Main', $url = new TextField('IFrameURL', 'Iframe URL'), 'Metadata');
        $url->setRightTitle('Can be absolute (<em>http://silverstripe.com</em>) or relative to this site (<em>about-us</em>).');
        $fields->addFieldToTab(
            'Root.Main',
            DropdownField::create('ForceProtocol', 'Force protocol?')
                ->setSource(array('http://' => 'http://', 'https://' => 'https://'))
                ->setEmptyString('')
                ->setDescription('Avoids mixed content warnings when iframe content is just available under a specific protocol'),
            'Metadata'
        );
        $fields->addFieldToTab('Root.Main', new CheckboxField('AutoHeight', 'Auto height (only works with same domain URLs)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new CheckboxField('AutoWidth', 'Auto width (100% of the available space)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new NumericField('FixedHeight', 'Fixed height (in pixels)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new NumericField('FixedWidth', 'Fixed width (in pixels)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new HtmlEditorField('Content', 'Content (appears above iframe)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new HtmlEditorField('BottomContent', 'Content (appears below iframe)'), 'Metadata');
        $fields->addFieldToTab('Root.Main', new HtmlEditorField('AlternateContent', 'Alternate Content (appears when user has iframes disabled)'), 'Metadata');

        return $fields;
    }

    /**
     * Compute class from the size parameters.
     */
    public function getClass()
    {
        $class = '';
        if ($this->AutoHeight) {
            $class .= 'iframepage-height-auto';
        }

        return $class;
    }

    /**
     * Compute style from the size parameters.
     */
    public function getStyle()
    {
        $style = '';

        // Always add fixed height as a fallback if autosetting or JS fails.
        $height = $this->FixedHeight;
        if (!$height) {
            $height = 800;
        }
        $style .= "height: {$height}px; ";

        if ($this->AutoWidth) {
            $style .= "width: 100%; ";
        } elseif ($this->FixedWidth) {
            $style .= "width: {$this->FixedWidth}px; ";
        }

        return $style;
    }

    /**
     * Ensure that the IFrameURL is a valid url and prevents XSS
     * 
     * @throws ValidationException
     * @return ValidationResult
     */
    public function validate()
    {
        $result = parent::validate();

        //whitelist allowed URL schemes
        $allowed_schemes = array('http', 'https');
        if ($matches = parse_url($this->IFrameURL)) {
            if (isset($matches['scheme']) && !in_array($matches['scheme'], $allowed_schemes)) {
                $result->error(_t('IFramePage.VALIDATION.BANNEDURLSCHEME', "This URL scheme is not allowed."));
            }
        }

        return $result;
    }
}

class IFramePage_Controller extends Page_Controller
{
    public function init()
    {
        parent::init();

        if ($this->ForceProtocol) {
            if ($this->ForceProtocol == 'http://' && Director::protocol() != 'http://') {
                return $this->redirect(preg_replace('#https://#', 'http://', $this->AbsoluteLink()));
            } elseif ($this->ForceProtocol == 'https://' && Director::protocol() != 'https://') {
                return $this->redirect(preg_replace('#http://#', 'https://', $this->AbsoluteLink()));
            }
        }

        if ($this->IFrameURL) {
            Requirements::javascript('iframe/javascript/iframe_page.js');
        }
    }
}