CLD: New plugin for language detection via CLD2

cld/README.md

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+Compact Language Detector
+===
+CLD2 is an advanced language dectection library with a high reliability.
+
+This addon depends on the CLD PHP module which is not included in any Linux distribution.
+It needs to be built and installed by hand, which is not totally straightforward.
+
+Prerequisite
+---
+To be able to build the extension, you need the CLD module and the files for the PHP module development.
+On Debian you install the packages php-dev, libcld2-dev and libcld2-0.
+Make sure to have installed the correct PHP version.
+Means: When you have got both PHP 8.0 and 8.2 on your system, you have to install php8.0-dev as well.
+
+Installation
+---
+The original PHP extension is https://github.com/fntlnz/cld2-php-ext.
+However, it doesn't support PHP8.
+So https://github.com/hiteule/cld2-php-ext/tree/support-php8 has to be used.
+
+Download the source code:
+```
+wget https://github.com/hiteule/cld2-php-ext/archive/refs/heads/support-php8.zip
+```
+
+Unzip it:
+```
+unzip support-php8.zip
+```
+
+Change into the folder:
+```
+cd cld2-php-ext-support-php8/
+```
+
+Configure for the PHP Api version:
+```
+phpize
+```
+(if you have got several PHP versions on your system, execute the command with the version that you run Friendica with, e.g. `phpize8.0`)
+
+Create the Makefile:
+```
+./configure --with-cld2=/usr/include/cld2
+```
+
+Have a look at the line `checking for PHP includes`.
+When the output (for example `/usr/include/php/20220829` doesn't match the API version that you got from `phpize`, then you have to change all the version codes in your `Makefile` afterwards)
+
+Create the module:
+```
+make -j
+```
+
+Install it:
+```
+sudo make install
+```
+
+Change to the folder with the available modules. When you use PHP 8.0 on Debian it is:
+```
+cd /etc/php/8.0/mods-available
+```
+
+Create the file `cld.ini` with this content:
+```
+; configuration for php cld2 module
+; priority=20
+extension=cld2.so
+```
+
+Change to the folder `conf.d` in the folder of your `php.ini`.
+```
+cd /etc/php/8.0/cgi/conf.d
+```
+This depends on the way you installed the PHP support for your webserver. Instead of `cgi` it could also be `apache2` or `fpm`.
+
+Create a symbolic link to install the module:
+```
+ln -s /etc/php/8.0/mods-available/cld.ini
+```
+
+Then restart the apache or fpm (or whatever you use) to load the changed configuration.
+
+Call `/admin/phpinfo` on your webserver.
+You then see the PHP Info.
+Search for "cld2".
+The module is installed, when you find it here.
+**Only proceed when the module is installed**
+
+Now you can enable the addon.

cld/cld.php

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+<?php
+/**
+ * Name: Compact Language Detector
+ * Description: Improved language detection
+ * Version: 0.1
+ * Author: Michael Vogel <heluecht@pirati.ca>
+ */
+
+use Friendica\Core\Hook;
+use Friendica\Core\Logger;
+use Friendica\DI;
+
+function cld_install()
+{
+	Hook::register('get_language', 'addon/cld/cld.php', 'cld_get_language');
+}
+
+function cld_get_language(array &$data)
+{
+	if (!in_array('cld2', get_loaded_extensions())) {
+		Logger::warning('CLD2 is not installed.');
+		return;
+	}
+
+	$cld2 = new \CLD2Detector();
+
+	$cld2->setEncodingHint(CLD2Encoding::UTF8); // optional, hints about text encoding
+
+	$result = $cld2->detect($data['text']);
+	
+	if ($data['detected']) {
+		$original = array_key_first($data['detected']);
+	} else {
+		$original = '';
+	}
+
+	$detected = $result['language_code'];
+	if ($detected == 'pt') {
+		$detected = 'pt-PT';
+	} elseif ($detected == 'el') {
+		$detected = 'el-monoton';
+	} elseif ($detected == 'no') {
+		$detected = 'nb';
+	} elseif ($detected == 'zh') {
+		$detected = 'zh-Hans';
+	} elseif ($detected == 'zh-Hant') {
+		$detected = 'zh-hant';
+	}
+
+	if (!$result['is_reliable']) {
+		Logger::debug('Unreliable detection', ['original' => $original, 'detected' => $detected, 'name' => $result['language_name'], 'probability' => $result['language_probability'], 'text' => $data['text']]);
+		return;
+	}
+
+	if ($original == $detected) {
+//		return;
+	}
+
+	// Nur aus Testgründen
+	if (in_array($detected, ['xx-Qaai', 'ht', 'ga'])) {
+		return;
+	}
+
+	$available = array_keys(DI::l10n()->convertForLanguageDetection(DI::l10n()->getAvailableLanguages(true)));
+	
+	if (!in_array($detected, $available)) {
+		Logger::debug('Unsupported language', ['original' => $original, 'detected' => $detected, 'name' => $result['language_name'], 'probability' => $result['language_probability'], 'text' => $data['text']]);
+		return;
+	}
+
+	Logger::debug('Detected', ['original' => $original, 'detected' => $detected, 'name' => $result['language_name'], 'probability' => $result['language_probability'], 'text' => $data['text']]);
+
+//	Logger::debug('Detected different language', ['original' => $original, 'detected' => $detected, 'name' => $result['language_name'], 'probability' => $result['language_probability'], 'text' => $data['text']]);
+	$data['detected'] = [$detected => $result['language_probability'] / 100];
+}