<?php

class Qs_Form_Decorator_FormElements extends Zend_Form_Decorator_FormElements
{
    public function render($content)
    {
        $form = $this->getElement();
        if ((!$form instanceof Zend_Form) && (!$form instanceof Zend_Form_DisplayGroup)) {
            return $content;
        }

        $separator = $this->getSeparator();
        $translator = $form->getTranslator();
        $items = [];
        $view = $form->getView();
        $wrappers = $this->getOption('wrappers');
        /** @var Zend_Form_Element|Zend_Form|Zend_Form_DisplayGroup $item */
        foreach ($form as $item) {
            $item->setView($view)->setTranslator($translator);
            $items[$item->getName()] = $item->render();
        }
        if ($wrappers) {
            $items = $this->applyWrappers($items, $wrappers);
        }
        $elementContent = implode($separator, $items);

        switch ($this->getPlacement()) {
            case self::PREPEND:
                return $elementContent . $separator . $content;
            case self::APPEND:
            default:
                return $content . $separator . $elementContent;
        }
    }

    /**
     * @param array $elements
     * @param array $decorators
     * @param null $name - assign name for further wrapping
     * @return $this
     */
    public function addWrapper(array $elements, array $decorators, $name = null)
    {
        $wrappers = (array) $this->getOption('wrappers');
        if (null === $name) {
            $wrappers[] = compact('elements', 'decorators');
        } else {
            $wrappers[$name] = compact('elements', 'decorators');
        }
        $this->setOption('wrappers', $wrappers);
        return $this;
    }

    protected function applyWrappers(array $items, array $wrappers)
    {
        foreach ($wrappers as $name => $options) {
            $items = $this->applyWrapper($items, $options, $name);
        }
        return $items;
    }

    protected function applyWrapper(array $items, $wrapper, $name)
    {
        if (!array_key_exists('elements', $wrapper) || empty($wrapper['elements'])) {
            trigger_error('Invalid elements for wrapper "' . $name  . '"');
            return $this;
        }
        if (!array_key_exists('decorators', $wrapper) || empty($wrapper['decorators'])) {
            trigger_error('Invalid decorators for wrapper "' . $name  . '"');
            return $this;
        }
        $decorators = $this->_getDecorators($wrapper['decorators']);
        $content = '';
        $result = [];

        if (empty($name) || is_numeric($name)) {
            $names = array_filter(array_keys($items), 'intval');
            $name = (empty($names)) ? 0 : (int) max($names) + 1;
        }
        foreach (array_keys($items) as $itemName) {
            if (!in_array($itemName, $wrapper['elements'])) {
                $result[$itemName] = $items[$itemName];
            } else {
                $content .= $items[$itemName];
                if (!array_key_exists($name, $result)) {
                    $result[$name] = '';
                }
            }
        }
        $result[$name] = $this->renderDecorators($decorators, $content);
        return $result;
    }

    protected function renderDecorators($decorators, $content)
    {
        /** @var \Zend_Form_Decorator_Interface $decorator */
        foreach ($decorators as $decorator) {
            $content = $decorator->render($content);
        }
        return $content;
    }

    protected function _getDecorators(array $decoratorsInfo)
    {
        $decorators = [];
        foreach ($decoratorsInfo as $decoratorInfo) {
            $decorators[] = $this->_getDecorator($decoratorInfo);
        }
        return $decorators;
    }

    /**
     * @param $decoratorInfo
     * @return $this|Zend_Form_Decorator_Interface
     * @throws Zend_Form_Exception
     */
    protected function _getDecorator($decoratorInfo)
    {
        if ($decoratorInfo instanceof Zend_Form_Decorator_Interface) {
            return $decoratorInfo;
        } elseif (is_string($decoratorInfo)) {
            return $this->_loadDecorator($decoratorInfo);
        } elseif (is_array($decoratorInfo)) {
            $argc = count($decoratorInfo);
            $options = [];
            if (isset($decoratorInfo['decorator'])) {
                $decorator = $decoratorInfo['decorator'];
                if (isset($decoratorInfo['options'])) {
                    $options = $decoratorInfo['options'];
                }
                return $this->_loadDecorator($decorator, $options);
            } else {
                switch (true) {
                    case (0 == $argc):
                        break;
                    case (1 <= $argc):
                        $decorator = array_shift($decoratorInfo);
                    case (2 <= $argc):
                        $options = array_shift($decoratorInfo);
                    default:
                        return $this->_loadDecorator($decorator, $options);
                        break;
                }
            }
        } else {
            throw new Zend_Form_Exception('Invalid wrapper decorator');
        }
        return $this;
    }

    protected function _loadDecorator($name, $options = [])
    {
        $class = $this->getElement()->getPluginLoader(Qs_Form::DECORATOR)->load($name);
        if (null === $options) {
            $decorator = new $class;
        } else {
            $decorator = new $class($options);
        }
        $name = $decorator->getOption('name');
        $decorator->setElement(new Zend_Form_Element_Hidden($name ? $name : 'custom'));
        return $decorator;
    }
}