<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

namespace ExpressionEngine\Service\View;

use ExpressionEngine\Core\Provider;

/**
 * View
 */
class View
{
    /**
     * @var string The path to the view template file ex. '_shared/form'
     */
    protected $path;

    /**
     * @var ExpressionEngine\Core\Provider
     */
    protected $provider;

    /**
     * @var Parent view object, if the view is being extended
     */
    protected $parent;

    /**
     * @var Array of blocks in the current parsing pass
     */
    protected $blocks = array();

    /**
     * @var Array of variables in the current parsing pass
     */
    protected $processing = array();

    /**
     * @var Array of disabled view features
     */
    protected $disabled = array();

    /**
     * @var array An indexed array for storing the names of blocks consumed via
     * startBlock() and endBlock()
     */
    private $blockStack;

    /**
     * @var string A copy of the path argument sent to `render()` this avoids
     * a scope issue where `extract()` could override that value and try to
     * include something unintended.
     */
    private $path_for_parse;

    /**
     * Constructor
     *
     * @param String   $path    Path to the view file, ex: '_shared/form'
     * @param Provider $provider Provider for the current context
     */
    public function __construct($path, Provider $provider)
    {
        $this->path = $path;
        $this->provider = $provider;
    }

    /**
     * Renders the view
     *
     * @param Array $vars An associative array of variables to use inside the
     *   template. ex: "title" => "Hello World!"
     * @return String The rendered HTML
     */
    public function render(array $vars = array())
    {
        $path = $this->getPath();

        // TODO this conditional is part of the modals mess and needs to be
        // removed
        if (isset($vars['blocks']['modals']) && ! isset($this->blocks['modals'])) {
            $this->blocks['modals'] = $vars['blocks']['modals'];
            unset($vars['blocks']);
        }

        $vars['blocks'] = $this->blocks;

        $vars['ee_cp_viewmode'] = 'classic';
        if (ee()->input->cookie('ee_cp_viewmode')) {
            $vars['ee_cp_viewmode'] = ee()->input->cookie('ee_cp_viewmode');
        }
        if (ee()->input->cookie('collapsed_nav')) {
            $vars['collapsed_nav'] = ee()->input->cookie('collapsed_nav');
        }

        $this->processing = $vars;

        // parse the current view
        $output = $this->parse($path, $vars);

        if ($this->parent) {
            $vars['child_view'] = $output;

            $output = $this->parent->render($vars);
        }

        $this->processing = array();

        return $output;
    }

    /**
     * Load a view file, replace variables, and return the result
     *
     * @param  String $path Full path to a view file
     * @param  Array  $vars Variables to replace in the view file
     * @return String Parsed view file
     */
    protected function parse($path, $vars)
    {
        $this->path_for_parse = $path;

        extract($vars);

        ob_start();

        if ((version_compare(PHP_VERSION, '5.4.0') < 0 && @ini_get('short_open_tag') == false)) {
            echo eval('?>' . preg_replace("/;*\s*\?>/", "; ?>", str_replace('<?=', '<?php echo ', file_get_contents($this->path_for_parse))));
        } else {
            include($this->path_for_parse);
        }

        $buffer = ob_get_contents();

        ob_end_clean();

        return $buffer;
    }

    /**
     * Loads, renders, and (optionally) returns a sub-view
     *
     * @param String $view The name of the sub-view
     * @param Array  $vars Additional variables to pass to the sub-view
     * @param bool  $return Whether to return a string or output the results
     * @return String The parsed sub-view
     */
    public function embed($view, $vars = array(), $disable = array())
    {
        if (empty($vars)) {
            $vars = array();
        }

        $vars = array_merge($this->processing, $vars);
        $view = $this->make($view)->disable($disable);

        ob_start();
        echo $view->render($vars);

        ob_end_flush();
    }

    /**
     * Extend the current view with a parent view
     *
     * @param  String $which   Parent view
     * @param  array  $disable Items to disable in the parent view
     * @return void
     */
    public function extend($view, $vars = array(), $disable = array())
    {
        $vars = array_merge($this->processing, $vars);
        $this->parent = $this->make($view)->disable($disable);

        return $this->parent;
    }

    /**
     * Disable a view feature
     *
     * @param  String|Array $which Feature or features to disable
     * @return $this
     */
    public function disable($which)
    {
        if (! is_array($which)) {
            $which = array($which);
        }

        while ($el = array_pop($which)) {
            $this->disabled[] = $el;
        }

        return $this;
    }

    /**
     * Check if a view element or feature is disabled
     *
     * @param  String $which Name of a view element/feature
     * @return bool Is disabled?
     */
    public function disabled($which)
    {
        return in_array($which, $this->disabled);
    }

    /**
     * Check if a view element or feature is enabled
     *
     * @param  String $which Name of a view element/feature
     * @return bool Is enabled?
     */
    public function enabled($which)
    {
        return ! $this->disabled($which);
    }

    /**
     * Allows our Views to define blocks to be used in a template/layout provider.
     * This will start a new block overwriting any previously defined block of
     * the same name.
     *
     * @param str $name The name of the block
     */
    public function startBlock($name)
    {
        $this->blockStack[] = array($name, false);
        ob_start();
    }

    /**
     * Allows our Views to define blocks to be used in a template/layout provider
     * This will start a new block or append to a previously defined block of
     * the same name.
     *
     * @param str $name The name of the block
     */
    public function startOrAppendBlock($name)
    {
        $this->blockStack[] = array($name, true);
        ob_start();
    }

    /**
     * Ends the block storing the buffer on the View::blocks array based on the
     * most recently specified name via startBlock.
     */
    public function endBlock()
    {
        list($name, $append) = array_pop($this->blockStack);

        if ($name === null) {
            throw new \Exception('View: Attempted to end block without opening');
        }

        $buffer = '';

        if ($append && isset($this->blocks[$name])) {
            $buffer .= $this->blocks[$name];
        }

        $buffer .= ob_get_contents();
        ob_end_clean();

        // TODO Hack - revisit this
        if ($name == 'modals') {
            ee()->view->blocks['modals'] = $buffer;
        }

        if (isset($this->parent)) {
            $this->parent->blocks[$name] = $buffer;
        }
    }

    /**
     * Create a new view object. Change to the requested provider scope
     * if required to speed up new sub-views.
     *
     * It's tempting to pass the factory to this class or to grab a factory
     * instance from the provider to avoid the duplication with the factory's
     * `make()` method, but you still end up having to compare prefixes to ensure
     * subviews are correctly scoped. Which is to say: it's not worth the law
     * of demeter violation to get this DRY as it will end up being the same
     * length again.
     *
     * If anything the solution will likely come from a change to the providers.
     *
     * @param  String $view Subview name, potentially with prefix
     * @return View         The subview instance
     */
    protected function make($view)
    {
        $provider = $this->provider;

        if (strpos($view, ':')) {
            list($prefix, $view) = explode(':', $view, 2);

            if ($provider->getPrefix() != $prefix) {
                $provider = $provider->make('App')->get($prefix);
            }
        }

        return new static($view, $provider);
    }

    /**
     * Get the full server path to the view file backing this
     * view object.
     *
     * @return String The full server path
     */
    protected function getPath()
    {
        $path = $this->provider->getPath() . '/View';
        $old_path = $this->provider->getPath() . '/views';

        foreach (array($path, $old_path) as $path) {
            if (file_exists($path . '/' . $this->path . '.php')) {
                return $path . '/' . $this->path . '.php';
            }
        }

        throw new \Exception('View file not found: ' . htmlentities($this->path));
    }
}
// EOF
