<?php

namespace AcyMailing\Helpers;

defined('ABSPATH') || die('Restricted Access');

use AcyMailing\Core\AcymObject;
use AcyMailing\Types\CharsetType;

class EncodingHelper extends AcymObject
{
    public function change(string $data, string $inputCharset, string $outputCharset): string
    {
        $inputCharset = strtoupper(trim($inputCharset));
        $outputCharset = strtoupper(trim($outputCharset));

        $supportedEncodings = [
            'BIG5',
            'ISO-8859-1',
            'ISO-8859-2',
            'ISO-8859-3',
            'ISO-8859-4',
            'ISO-8859-5',
            'ISO-8859-6',
            'ISO-8859-7',
            'ISO-8859-8',
            'ISO-8859-9',
            'ISO-8859-10',
            'ISO-8859-13',
            'ISO-8859-14',
            'ISO-8859-15',
            'ISO-2022-JP',
            'US-ASCII',
            'UTF-7',
            'UTF-8',
            'UTF-16',
            'WINDOWS-1251',
            'WINDOWS-1252',
            'ARMSCII-8',
            'ISO-8859-16',
        ];
        if (!in_array($inputCharset, $supportedEncodings)) {
            acym_enqueueMessage(acym_translationSprintf('ACYM_ENCODING_NOT_SUPPORTED_X', $inputCharset), 'error');
        } elseif (!in_array($outputCharset, $supportedEncodings)) {
            acym_enqueueMessage(acym_translationSprintf('ACYM_ENCODING_NOT_SUPPORTED_X', $outputCharset), 'error');
        }

        if ($inputCharset == $outputCharset) {
            return $data;
        }

        if ($inputCharset === 'UTF-8' && $outputCharset === 'ISO-8859-1') {
            $data = str_replace(['€', '„', '“'], ['EUR', '"', '"'], $data);
        }

        if (function_exists('iconv')) {
            // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_set_error_handler -- Catching iconv errors for clean handling.
            set_error_handler('AcyMailing\Helpers\acym_errorHandlerEncoding');
            $encodedData = iconv($inputCharset, $outputCharset.'//IGNORE', $data);
            restore_error_handler();
            //Sometimes the function does not return error but remove the whole content...
            if (!empty($encodedData) && !acym_errorHandlerEncoding(-1)) {
                return $encodedData;
            }
        }

        if (function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($data, $outputCharset, $inputCharset);
        }

        if ($inputCharset === 'UTF-8' && $outputCharset === 'ISO-8859-1') {
            return acym_utf8Decode($data);
        }

        if ($inputCharset === 'ISO-8859-1' && $outputCharset === 'UTF-8') {
            return acym_utf8Encode($data);
        }

        return $data;
    }

    public function detectEncoding(string &$content): string
    {
        if (!function_exists('mb_check_encoding')) {
            return '';
        }

        $toTest = ['UTF-8'];
        //Depending on the current language, we test based on other charset...

        $tag = acym_getLanguageTag();

        // If you're greek, we check based on the greek charset first!
        if ($tag == 'el-GR') {
            $toTest[] = 'ISO-8859-7';
        }
        $toTest[] = 'ISO-8859-1';
        $toTest[] = 'ISO-8859-2';
        $toTest[] = 'Windows-1252';

        foreach ($toTest as $oneEncoding) {
            if (mb_check_encoding($content, $oneEncoding)) {
                return $oneEncoding;
            }
        }

        // Could not detect it...
        return '';
    }

    public function encodingField(string $name, string $selected): void
    {
        acym_select(
            [
                'binary' => 'Binary',
                'quoted' => 'Quoted-printable',
                '7bit' => '7 Bit',
                '8bit' => '8 Bit',
                'base64' => 'Base 64',
            ],
            $name,
            $selected,
            [
                'class' => 'acym__select',
                'acym-data-infinite' => '',
                'style' => 'max-width: 200px;',
            ],
            '',
            '',
            'config_encoding',
            false,
            true
        );
    }

    public function charsetField(string $name, string $selected, array $attribs = [], bool $display = false): string
    {
        $charsetType = new CharsetType();

        return acym_select(
            $charsetType->charsets,
            $name,
            $selected,
            $attribs,
            '',
            '',
            null,
            false,
            $display
        );
    }
}

/**
 * Logs the errors happening in the iconv function in order to know if we can use its result or not
 *
 * @return bool true if an error occurred
 */
function acym_errorHandlerEncoding(int $errno, string $errstr = ''): bool
{
    static $error = false;
    if ($errno === -1) {
        //return the value of the static flag and re init it
        $currentError = $error;
        $error = false;

        return $currentError;
    }
    //set the satic flag
    $error = true;

    //no need to display the notice
    return true;
}