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system/Language/Language.php

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+<?php
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Language;
+
+use Config\Services;
+use MessageFormatter;
+
+/**
+ * Handle system messages and localization.
+ *
+ * Locale-based, built on top of PHP internationalization.
+ */
+class Language
+{
+    /**
+     * Stores the retrieved language lines
+     * from files for faster retrieval on
+     * second use.
+     *
+     * @var array
+     */
+    protected $language = [];
+
+    /**
+     * The current language/locale to work with.
+     *
+     * @var string
+     */
+    protected $locale;
+
+    /**
+     * Boolean value whether the intl
+     * libraries exist on the system.
+     *
+     * @var bool
+     */
+    protected $intlSupport = false;
+
+    /**
+     * Stores filenames that have been
+     * loaded so that we don't load them again.
+     *
+     * @var array
+     */
+    protected $loadedFiles = [];
+
+    public function __construct(string $locale)
+    {
+        $this->locale = $locale;
+
+        if (class_exists('MessageFormatter')) {
+            $this->intlSupport = true;
+        }
+    }
+
+    /**
+     * Sets the current locale to use when performing string lookups.
+     *
+     * @return $this
+     */
+    public function setLocale(?string $locale = null)
+    {
+        if ($locale !== null) {
+            $this->locale = $locale;
+        }
+
+        return $this;
+    }
+
+    public function getLocale(): string
+    {
+        return $this->locale;
+    }
+
+    /**
+     * Parses the language string for a file, loads the file, if necessary,
+     * getting the line.
+     *
+     * @return string|string[]
+     */
+    public function getLine(string $line, array $args = [])
+    {
+        // if no file is given, just parse the line
+        if (strpos($line, '.') === false) {
+            return $this->formatMessage($line, $args);
+        }
+
+        // Parse out the file name and the actual alias.
+        // Will load the language file and strings.
+        [$file, $parsedLine] = $this->parseLine($line, $this->locale);
+
+        $output = $this->getTranslationOutput($this->locale, $file, $parsedLine);
+
+        if ($output === null && strpos($this->locale, '-')) {
+            [$locale] = explode('-', $this->locale, 2);
+
+            [$file, $parsedLine] = $this->parseLine($line, $locale);
+
+            $output = $this->getTranslationOutput($locale, $file, $parsedLine);
+        }
+
+        // if still not found, try English
+        if ($output === null) {
+            [$file, $parsedLine] = $this->parseLine($line, 'en');
+
+            $output = $this->getTranslationOutput('en', $file, $parsedLine);
+        }
+
+        $output = $output ?? $line;
+
+        return $this->formatMessage($output, $args);
+    }
+
+    /**
+     * @return array|string|null
+     */
+    protected function getTranslationOutput(string $locale, string $file, string $parsedLine)
+    {
+        $output = $this->language[$locale][$file][$parsedLine] ?? null;
+        if ($output !== null) {
+            return $output;
+        }
+
+        foreach (explode('.', $parsedLine) as $row) {
+            if (! isset($current)) {
+                $current = $this->language[$locale][$file] ?? null;
+            }
+
+            $output = $current[$row] ?? null;
+            if (is_array($output)) {
+                $current = $output;
+            }
+        }
+
+        if ($output !== null) {
+            return $output;
+        }
+
+        $row = current(explode('.', $parsedLine));
+        $key = substr($parsedLine, strlen($row) + 1);
+
+        return $this->language[$locale][$file][$row][$key] ?? null;
+    }
+
+    /**
+     * Parses the language string which should include the
+     * filename as the first segment (separated by period).
+     */
+    protected function parseLine(string $line, string $locale): array
+    {
+        $file = substr($line, 0, strpos($line, '.'));
+        $line = substr($line, strlen($file) + 1);
+
+        if (! isset($this->language[$locale][$file]) || ! array_key_exists($line, $this->language[$locale][$file])) {
+            $this->load($file, $locale);
+        }
+
+        return [$file, $line];
+    }
+
+    /**
+     * Advanced message formatting.
+     *
+     * @param array|string $message
+     * @param string[]     $args
+     *
+     * @return array|string
+     */
+    protected function formatMessage($message, array $args = [])
+    {
+        if (! $this->intlSupport || $args === []) {
+            return $message;
+        }
+
+        if (is_array($message)) {
+            foreach ($message as $index => $value) {
+                $message[$index] = $this->formatMessage($value, $args);
+            }
+
+            return $message;
+        }
+
+        return MessageFormatter::formatMessage($this->locale, $message, $args);
+    }
+
+    /**
+     * Loads a language file in the current locale. If $return is true,
+     * will return the file's contents, otherwise will merge with
+     * the existing language lines.
+     *
+     * @return array|void
+     */
+    protected function load(string $file, string $locale, bool $return = false)
+    {
+        if (! array_key_exists($locale, $this->loadedFiles)) {
+            $this->loadedFiles[$locale] = [];
+        }
+
+        if (in_array($file, $this->loadedFiles[$locale], true)) {
+            // Don't load it more than once.
+            return [];
+        }
+
+        if (! array_key_exists($locale, $this->language)) {
+            $this->language[$locale] = [];
+        }
+
+        if (! array_key_exists($file, $this->language[$locale])) {
+            $this->language[$locale][$file] = [];
+        }
+
+        $path = "Language/{$locale}/{$file}.php";
+
+        $lang = $this->requireFile($path);
+
+        if ($return) {
+            return $lang;
+        }
+
+        $this->loadedFiles[$locale][] = $file;
+
+        // Merge our string
+        $this->language[$locale][$file] = $lang;
+    }
+
+    /**
+     * A simple method for including files that can be
+     * overridden during testing.
+     */
+    protected function requireFile(string $path): array
+    {
+        $files   = Services::locator()->search($path, 'php', false);
+        $strings = [];
+
+        foreach ($files as $file) {
+            // On some OS's we were seeing failures
+            // on this command returning boolean instead
+            // of array during testing, so we've removed
+            // the require_once for now.
+            if (is_file($file)) {
+                $strings[] = require $file;
+            }
+        }
+
+        if (isset($strings[1])) {
+            $strings = array_replace_recursive(...$strings);
+        } elseif (isset($strings[0])) {
+            $strings = $strings[0];
+        }
+
+        return $strings;
+    }
+}