<?php

namespace League\Plates\Template;

use League\Plates\Extension\ExtensionInterface;
use LogicException;

/**
 * A template function.
 */
class Func
{
    /**
     * The function name.
     * @var string
     */
    protected $name;

    /**
     * The function callback.
     * @var callable
     */
    protected $callback;

    /**
     * Create new Func instance.
     * @param string   $name
     * @param callable $callback
     */
    public function __construct($name, $callback)
    {
        $this->setName($name);
        $this->setCallback($callback);
    }

    /**
     * Set the function name.
     * @param  string $name
     * @return Func
     */
    public function setName($name)
    {
        if (preg_match('/^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$/', $name) !== 1) {
            throw new LogicException(
                'Not a valid function name.'
            );
        }

        $this->name = $name;

        return $this;
    }

    /**
     * Get the function name.
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set the function callback
     * @param  callable $callback
     * @return Func
     */
    public function setCallback($callback)
    {
        if (!is_callable($callback, true)) {
            throw new LogicException(
                'Not a valid function callback.'
            );
        }

        $this->callback = $callback;

        return $this;
    }

    /**
     * Get the function callback.
     * @return callable
     */
    public function getCallback()
    {
        return $this->callback;
    }

    /**
     * Call the function.
     * @param  Template $template
     * @param  array    $arguments
     * @return mixed
     */
    public function call(Template $template = null, $arguments = array())
    {
        if (is_array($this->callback) and
            isset($this->callback[0]) and
            $this->callback[0] instanceof ExtensionInterface
        ) {
            $this->callback[0]->template = $template;
        }

        return call_user_func_array($this->callback, $arguments);
    }
}