<?php

/*
 * This file is part of Twig.
 *
 * (c) 2009 Fabien Potencier
 * (c) 2009 Armin Ronacher
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Default base class for compiled templates.
 *
 * @package twig
 * @author  Fabien Potencier <fabien@symfony.com>
 */
abstract class Twig_Template implements Twig_TemplateInterface
{
    static protected $cache = array();

    protected $parents;
    protected $env;
    protected $blocks;
    protected $traits;

    /**
     * Constructor.
     *
     * @param Twig_Environment $env A Twig_Environment instance
     */
    public function __construct(Twig_Environment $env)
    {
        $this->env = $env;
        $this->blocks = array();
        $this->traits = array();
    }

    /**
     * Returns the template name.
     *
     * @return string The template name
     */
    abstract public function getTemplateName();

    /**
     * {@inheritdoc}
     */
    public function getEnvironment()
    {
        return $this->env;
    }

    /**
     * Returns the parent template.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @return Twig_TemplateInterface|false The parent template or false if there is no parent
     */
    public function getParent(array $context)
    {
        $parent = $this->doGetParent($context);
        if (false === $parent) {
            return false;
        } elseif ($parent instanceof Twig_Template) {
            $name = $parent->getTemplateName();
            $this->parents[$name] = $parent;
            $parent = $name;
        } elseif (!isset($this->parents[$parent])) {
            $this->parents[$parent] = $this->env->loadTemplate($parent);
        }

        return $this->parents[$parent];
    }

    protected function doGetParent(array $context)
    {
        return false;
    }

    public function isTraitable()
    {
        return true;
    }

    /**
     * Displays a parent block.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @param string $name    The block name to display from the parent
     * @param array  $context The context
     * @param array  $blocks  The current set of blocks
     */
    public function displayParentBlock($name, array $context, array $blocks = array())
    {
        if (isset($this->traits[$name])) {
            $this->traits[$name][0]->displayBlock($name, $context, $blocks);
        } elseif (false !== $parent = $this->getParent($context)) {
            $parent->displayBlock($name, $context, $blocks);
        } else {
            throw new Twig_Error_Runtime(sprintf('The template has no parent and no traits defining the "%s" block', $name), -1, $this->getTemplateName());
        }
    }

    /**
     * Displays a block.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @param string $name    The block name to display
     * @param array  $context The context
     * @param array  $blocks  The current set of blocks
     */
    public function displayBlock($name, array $context, array $blocks = array())
    {
        if (isset($blocks[$name])) {
            $b = $blocks;
            unset($b[$name]);
            call_user_func($blocks[$name], $context, $b);
        } elseif (isset($this->blocks[$name])) {
            call_user_func($this->blocks[$name], $context, $blocks);
        } elseif (false !== $parent = $this->getParent($context)) {
            $parent->displayBlock($name, $context, array_merge($this->blocks, $blocks));
        }
    }

    /**
     * Renders a parent block.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @param string $name    The block name to render from the parent
     * @param array  $context The context
     * @param array  $blocks  The current set of blocks
     *
     * @return string The rendered block
     */
    public function renderParentBlock($name, array $context, array $blocks = array())
    {
        ob_start();
        $this->displayParentBlock($name, $context, $blocks);

        return ob_get_clean();
    }

    /**
     * Renders a block.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @param string $name    The block name to render
     * @param array  $context The context
     * @param array  $blocks  The current set of blocks
     *
     * @return string The rendered block
     */
    public function renderBlock($name, array $context, array $blocks = array())
    {
        ob_start();
        $this->displayBlock($name, $context, $blocks);

        return ob_get_clean();
    }

    /**
     * Returns whether a block exists or not.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * This method does only return blocks defined in the current template
     * or defined in "used" traits.
     *
     * It does not return blocks from parent templates as the parent
     * template name can be dynamic, which is only known based on the
     * current context.
     *
     * @param string $name The block name
     *
     * @return Boolean true if the block exists, false otherwise
     */
    public function hasBlock($name)
    {
        return isset($this->blocks[$name]);
    }

    /**
     * Returns all block names.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @return array An array of block names
     *
     * @see hasBlock
     */
    public function getBlockNames()
    {
        return array_keys($this->blocks);
    }

    /**
     * Returns all blocks.
     *
     * This method is for internal use only and should never be called
     * directly.
     *
     * @return array An array of blocks
     *
     * @see hasBlock
     */
    public function getBlocks()
    {
        return $this->blocks;
    }

    /**
     * {@inheritdoc}
     */
    public function display(array $context, array $blocks = array())
    {
        $this->displayWithErrorHandling($this->mergeContextWithGlobals($context), $blocks);
    }

    /**
     * {@inheritdoc}
     */
    public function render(array $context)
    {
        $level = ob_get_level();
        ob_start();
        try {
            $this->display($context);
        } catch (Exception $e) {
            while (ob_get_level() > $level) {
                ob_end_clean();
            }

            throw $e;
        }

        return ob_get_clean();
    }

    protected function mergeContextWithGlobals(array $context)
    {
        // we don't use array_merge as the context being generally
        // bigger than globals, this code is faster.
        foreach ($this->env->getGlobals() as $key => $value) {
            if (!array_key_exists($key, $context)) {
                $context[$key] = $value;
            }
        }

        return $context;
    }

    protected function displayWithErrorHandling(array $context, array $blocks = array())
    {
        try {
            $this->doDisplay($context, $blocks);
        } catch (Twig_Error $e) {
            throw $e;
        } catch (Exception $e) {
            throw new Twig_Error_Runtime(sprintf('An exception has been thrown during the rendering of a template ("%s").', $e->getMessage()), -1, null, $e);
        }
    }

    /**
     * Auto-generated method to display the template with the given context.
     *
     * @param array $context An array of parameters to pass to the template
     * @param array $blocks  An array of blocks to pass to the template
     */
    abstract protected function doDisplay(array $context, array $blocks = array());

    /**
     * Returns a variable from the context.
     *
     * @param array   $context           The context
     * @param string  $item              The variable to return from the context
     * @param Boolean $ignoreStrictCheck Whether to ignore the strict variable check or not
     *
     * @return The content of the context variable
     *
     * @throws Twig_Error_Runtime if the variable does not exist and Twig is running in strict mode
     */
    protected function getContext($context, $item, $ignoreStrictCheck = false)
    {
        if (!array_key_exists($item, $context)) {
            if ($ignoreStrictCheck || !$this->env->isStrictVariables()) {
                return null;
            }

            throw new Twig_Error_Runtime(sprintf('Variable "%s" does not exist', $item));
        }

        return $context[$item];
    }

    /**
     * Returns the attribute value for a given array/object.
     *
     * @param mixed   $object            The object or array from where to get the item
     * @param mixed   $item              The item to get from the array or object
     * @param array   $arguments         An array of arguments to pass if the item is an object method
     * @param string  $type              The type of attribute (@see Twig_TemplateInterface)
     * @param Boolean $isDefinedTest     Whether this is only a defined check
     * @param Boolean $ignoreStrictCheck Whether to ignore the strict attribute check or not
     *
     * @return mixed The attribute value, or a Boolean when $isDefinedTest is true, or null when the attribute is not set and $ignoreStrictCheck is true
     *
     * @throws Twig_Error_Runtime if the attribute does not exist and Twig is running in strict mode and $isDefinedTest is false
     */
    protected function getAttribute($object, $item, array $arguments = array(), $type = Twig_TemplateInterface::ANY_CALL, $isDefinedTest = false, $ignoreStrictCheck = false)
    {
        $item = (string) $item;

        // array
        if (Twig_TemplateInterface::METHOD_CALL !== $type) {
            if ((is_array($object) && array_key_exists($item, $object))
                || ($object instanceof ArrayAccess && isset($object[$item]))
            ) {
                if ($isDefinedTest) {
                    return true;
                }

                return $object[$item];
            }

            if (Twig_TemplateInterface::ARRAY_CALL === $type) {
                if ($isDefinedTest) {
                    return false;
                }

                if ($ignoreStrictCheck || !$this->env->isStrictVariables()) {
                    return null;
                }

                if (is_object($object)) {
                    throw new Twig_Error_Runtime(sprintf('Key "%s" in object (with ArrayAccess) of type "%s" does not exist', $item, get_class($object)));
                // array
                } else {
                    throw new Twig_Error_Runtime(sprintf('Key "%s" for array with keys "%s" does not exist', $item, implode(', ', array_keys($object))));
                }
            }
        }

        if (!is_object($object)) {
            if ($isDefinedTest) {
                return false;
            }

            if ($ignoreStrictCheck || !$this->env->isStrictVariables()) {
                return null;
            }

            throw new Twig_Error_Runtime(sprintf('Item "%s" for "%s" does not exist', $item, is_array($object) ? 'Array' : $object));
        }

        $class = get_class($object);

        // object property
        if (Twig_TemplateInterface::METHOD_CALL !== $type) {
            /* apparently, this is not needed as this is already covered by the array_key_exists() call below
            if (!isset(self::$cache[$class]['properties'])) {
                foreach (get_object_vars($object) as $k => $v) {
                    self::$cache[$class]['properties'][$k] = true;
                }
            }
            */

            if (isset($object->$item) || array_key_exists($item, $object)) {
                if ($isDefinedTest) {
                    return true;
                }

                if ($this->env->hasExtension('sandbox')) {
                    $this->env->getExtension('sandbox')->checkPropertyAllowed($object, $item);
                }

                return $object->$item;
            }
        }

        // object method
        if (!isset(self::$cache[$class]['methods'])) {
            self::$cache[$class]['methods'] = array_change_key_case(array_flip(get_class_methods($object)));
        }

        $lcItem = strtolower($item);
        if (isset(self::$cache[$class]['methods'][$lcItem])) {
            $method = $item;
        } elseif (isset(self::$cache[$class]['methods']['get'.$lcItem])) {
            $method = 'get'.$item;
        } elseif (isset(self::$cache[$class]['methods']['is'.$lcItem])) {
            $method = 'is'.$item;
        } elseif (isset(self::$cache[$class]['methods']['__call'])) {
            $method = $item;
        } else {
            if ($isDefinedTest) {
                return false;
            }

            if ($ignoreStrictCheck || !$this->env->isStrictVariables()) {
                return null;
            }

            throw new Twig_Error_Runtime(sprintf('Method "%s" for object "%s" does not exist', $item, get_class($object)));
        }

        if ($isDefinedTest) {
            return true;
        }

        if ($this->env->hasExtension('sandbox')) {
            $this->env->getExtension('sandbox')->checkMethodAllowed($object, $method);
        }

        $ret = call_user_func_array(array($object, $method), $arguments);

        // hack to be removed when macro calls are refactored
        if ($object instanceof Twig_TemplateInterface) {
            return new Twig_Markup($ret, $this->env->getCharset());
        }

        return $ret;
    }

    /**
     * This method is only useful when testing Twig. Do not use it.
     */
    static public function clearCache()
    {
        self::$cache = array();
    }
}