<?php

/**
 * Класс для работы с почтой
 * http://en.wikipedia.org/wiki/MIME
 */

namespace ctiso;

use ctiso\Path,
    Exception;

class Mail
{
    /** @var string */
    public $_from;
    /** @var string */
    public $_to;
    /** @var string */
    public $_subject;
    /** @var string */
    public $content;
    /** @var string */
    public $copy;

    /** @var string */
    private $encoding;
    /** @var string */
    private $_notify = null;

    /** @var array */
    protected $attachment = array();
    /** @var string */
    protected $uniqid;
    /** @var string */
    protected $type = "text/plain";

    function __construct()
    {
        $this->setEncoding("UTF-8");
        $this->uniqid  = strtoupper(uniqid((string)time())); // Идентефикатор разделителя
    }

    /**
     * Установка отправителя
     */
    function from(string $name): void
    {
        // filter_var($name, FILTER_VALIDATE_EMAIL);
        $this->_from = $name;
    }

    /**
     * Установка получателя
     */
    function to(string $name): void
    {
        $this->_to = $name;
    }

    /**
     * @param string $name
     */
    function replyTo($name): void
    {}

    /**
     * Установка получателей копии
     */
    function copy(string $name): void
    {
        $this->copy = $name;
    }

    function notify(string $notify): void
    {
        $this->_notify = $notify;
    }

    /**
     * Тема письма
     */
    function subject(string $subject): void
    {
        $this->_subject = $subject;
    }

    /**
     * Текст письма
     */
    function setContent(string $text): void
    {
        $this->content = $text;
    }

    /**
     * Кодировка текста в письме
     */
    function setEncoding(string $encoding): void
    {
        $this->encoding = $encoding;
    }

    /**
     * Добавление вложения из файла
     * @param string $filename
     * @param string|false $name
     */
    function addAttachment(string $filename, $name = false): void
    {
        if (file_exists($filename)) {
            $file = fopen($filename, "rb");
            if (is_resource($file)) {
                $data = fread($file, filesize($filename));
                $this->attachment[] = ($name) ? [$data, $name] : [$data, basename($filename)];
            }
        }
    }

    /**
     * Установка типа содержимого
     * @param string $type
     */
    function setType($type): void
    {
        $this->type = $type;
    }

    /**
     * Добавление вложения из строки с указанием имени файла
     * @param string $data
     * @param string $name
     */
    function addAttachmentRaw($data, string $name): void
    {
        $this->attachment[] = [$data, $name];
    }

    /**
     * @param string $var
     * @param string $val
     */
    function quote($var, $val): string
    {
        return ";" . PHP_EOL . "\t" . $var . "=\"" . $val . "\"";
    }

    /**
     * Общий формат тегов MIME
     * @see http://tools.ietf.org/html/rfc2045
     *
     * @param string $name
     * @param string $value
     * @param array $args
     */
    function mimeTag($name, $value, array $args = []): string
    {
        assert(is_string($name));
        assert(is_string($value));

        return $name . ": " . $value . implode("", array_map([$this, 'quote'], array_keys($args), array_values($args))) . PHP_EOL;
    }

    /**
     *
     * @see http://tools.ietf.org/html/rfc2047
     */
    function encodedWord(string $text, string $encoding = 'B'): string
    {
        return "=?{$this->encoding}?$encoding?" . base64_encode($text) . "?=";
    }

    /**
     * Тело сообщения
     */
    function getMessage(): string
    {
        $message   = "--" . $this->uniqid . PHP_EOL;
        $message  .= $this->mimeTag("Content-Type", $this->type, ['charset' => $this->encoding]);
        $message  .= $this->mimeTag("Content-Transfer-Encoding", "8bit");
        $message  .= PHP_EOL . $this->content . PHP_EOL . PHP_EOL;

        /*
         * Вложения
         * http://tools.ietf.org/html/rfc2046#section-5.1.3
         */
        foreach ($this->attachment as $value) {
            list($data, $name) = $value;
            $message  .= "--" . $this->uniqid . PHP_EOL;
            $message  .= $this->mimeTag("Content-Type", "application/octet-stream", ['name' => basename($name)]);
            $message  .= $this->mimeTag("Content-Transfer-Encoding", "base64");
            $message  .= $this->mimeTag("Content-Disposition", "attachment", ['filename' => basename($name)]);
            $message  .= PHP_EOL . chunk_split(base64_encode($data)) . PHP_EOL;
        }

        return $message;
    }

    /**
     * Заголовок сообщения
     */
    function getHeader(): string
    {
        $head  = $this->mimeTag("MIME-Version", "1.0");
        $head .= $this->mimeTag("From", $this->_from);
        $head .= $this->mimeTag("X-Mailer", "CMS Tool");
        $head .= $this->mimeTag("Reply-To", $this->_from);
        if (is_string($this->_notify)) {
            $head .= $this->mimeTag("Disposition-Notification-To", "\"" . $this->_notify . "\" <" . $this->_from . ">");
        }
        $head .= $this->mimeTag("Content-Type", "multipart/mixed", ["boundary" => $this->uniqid]);
        if ($this->copy) {
            $head .= $this->mimeTag("BCC", $this->copy);
        }
        $head .= PHP_EOL;
        return $head;
    }

    function getSubject(): string
    {
        return $this->encodedWord($this->_subject);
    }

    /**
     * Вывод строки для сохранения в формате .eml
     */
    function eml(): string
    {
        return "To: " . $this->_to . PHP_EOL . "Subject: {$this->getSubject()}" . PHP_EOL . $this->getHeader() . $this->getMessage();
    }

    /**
     * Отправка почты
     */
    function send(): bool
    {
        $result = mail($this->_to, $this->getSubject(), $this->getMessage(), $this->getHeader());
        if (! $result) {
            file_put_contents(Path::resolveFile("send.eml"), $this->eml());
            throw new Exception('Невозможно отправить почту');
        }
        return $result;
    }

    function clear(): void
    {
        foreach ($this->attachment as $key => &$value) {
            unset($this->attachment[$key]);
        }
        $this->attachment = [];
    }
}