Add a PHP interface to work with the language data

Additional changes in this PR include,

  * Added composer.json
  * Refactored the folder structure.
  * Added editorconfig.
  * Added PHPCS and formatted existing code.
  * Changes to use a single license - GPL-2.0-or-later
  * ESLint related fixes

Bug: T218639

src/util/ulsdata2json.php

@@ -0,0 +1,111 @@
+<?php
+/**
+ * Script to create the language data in JSON format for ULS.
+ *
+ * Copyright (C) 2012 Alolita Sharma, Amir Aharoni, Arun Ganesh, Brandon Harris,
+ * Niklas Laxström, Pau Giner, Santhosh Thottingal, Siebrand Mazeland and other
+ * contributors. See CREDITS for a list.
+ *
+ * @file
+ * @ingroup Extensions
+ * @license GPL-2.0-or-later
+ */
+
+include __DIR__ . '/spyc.php';
+
+print "Reading langdb.yaml...\n";
+$yamlLangdb = file_get_contents( __DIR__ . '/../../data/langdb.yaml' );
+$parsedLangdb = spyc_load( $yamlLangdb );
+
+$supplementalDataFilename = 'supplementalData.xml';
+$supplementalDataUrl =
+	// phpcs:ignore Generic.Files.LineLength
+	"https://raw.githubusercontent.com/unicode-org/cldr/master/common/supplemental/supplementalData.xml";
+
+$curl = curl_init( $supplementalDataUrl );
+$supplementalDataFile = fopen( $supplementalDataFilename, 'w' );
+
+curl_setopt( $curl, CURLOPT_FILE, $supplementalDataFile );
+curl_setopt( $curl, CURLOPT_HEADER, 0 );
+
+print "Trying to download $supplementalDataUrl...\n";
+$curlSuccess = curl_exec( $curl );
+curl_close( $curl );
+fclose( $supplementalDataFile );
+
+if ( !$curlSuccess ) {
+	die( "Failed to download CLDR data from $supplementalDataUrl.\n" );
+}
+print "Downloaded $supplementalDataFilename, trying to parse...\n";
+
+$supplementalData = simplexml_load_file( $supplementalDataFilename );
+
+if ( !( $supplementalData instanceof SimpleXMLElement ) ) {
+	die( "Attempt to load CLDR data from $supplementalDataFilename failed.\n" );
+}
+
+print "CLDR supplemental data parsed successfully, reading territories info...\n";
+$parsedLangdb['territories'] = [];
+
+foreach ( $supplementalData->territoryInfo->territory as $territoryRecord ) {
+	$territoryAtributes = $territoryRecord->attributes();
+	$territoryCodeAttr = $territoryAtributes['type'];
+	$territoryCode = (string)$territoryCodeAttr[0];
+	$parsedLangdb['territories'][$territoryCode] = [];
+
+	foreach ( $territoryRecord->languagePopulation as $languageRecord ) {
+		$languageAttributes = $languageRecord->attributes();
+		$languageCodeAttr = $languageAttributes['type'];
+		// Lower case is a convention for language codes in ULS.
+		// '_' is used in CLDR for compound codes and it's replaced with '-' here.
+
+		$normalisedCode = strtr( strtolower( (string)$languageCodeAttr[0] ), '_', '-' );
+
+		$parsedLangdb['territories'][$territoryCode][] = $normalisedCode;
+
+		// In case of codes with variants, also add the base because ULS might consider
+		// them as separate languages, e.g. zh, zh-hant and zh-hans.
+		if ( strpos( $normalisedCode, '-' ) !== false ) {
+			$parts = explode( '-', $normalisedCode );
+			$parsedLangdb['territories'][$territoryCode][] = $parts[0];
+		}
+	}
+}
+
+foreach ( $parsedLangdb['territories'] as $territoryCode => $languages ) {
+	foreach ( $languages as $index => $language ) {
+		if ( !isset( $parsedLangdb['languages'][$language] ) ) {
+			echo "Unknown language $language for territory $territoryCode\n";
+			unset( $parsedLangdb['territories'][$territoryCode][$index] );
+			continue;
+		}
+
+		$data = $parsedLangdb['languages'][$language];
+		if ( count( $data ) === 1 ) {
+			echo "Redirect for language $language to {$data[0]} territory $territoryCode\n";
+			$parsedLangdb['territories'][$territoryCode][$index] = $data[0];
+			continue;
+		}
+	}
+
+	// Clean-up to save space
+	if ( count( $parsedLangdb['territories'][$territoryCode] ) === 0 ) {
+		unset( $parsedLangdb['territories'][$territoryCode] );
+		continue;
+	}
+
+	// Remove duplicates we might have created
+	$parsedLangdb['territories'][$territoryCode] =
+		array_unique( $parsedLangdb['territories'][$territoryCode] );
+
+	// We need to renumber or json conversion thinks these are objects
+	$parsedLangdb['territories'][$territoryCode] =
+		array_values( $parsedLangdb['territories'][$territoryCode] );
+}
+
+print "Writing JSON langdb...\n";
+$jsonVerbose = json_encode( $parsedLangdb, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE );
+// For making diff review easier.
+file_put_contents( '../language-data.json', $jsonVerbose );
+
+print "Done.\n";