<?php
/**
 * I18N: WP_Translations class.
 *
 * @package WordPress
 * @subpackage I18N
 * @since 6.5.0
 */

/**
 * Class WP_Translations.
 *
 * @since 6.5.0
 *
 * @property-read array<string, string> $headers
 * @property-read array<string, string[]> $entries
 */
class WP_Translations {
    /**
     * Text domain.
     *
     * @since 6.5.0
     * @var string
     */
    protected $textdomain = 'default';

    /**
     * Translation controller instance.
     *
     * @since 6.5.0
     * @var WP_Translation_Controller
     */
    protected $controller;

    /**
     * Constructor.
     *
     * @since 6.5.0
     *
     * @param WP_Translation_Controller $controller I18N controller.
     * @param string                    $textdomain Optional. Text domain. Default 'default'.
     */
    public function __construct( WP_Translation_Controller $controller, string $textdomain = 'default' ) {
        $this->controller = $controller;
        $this->textdomain = $textdomain;
    }

    /**
     * Magic getter for backward compatibility.
     *
     * @since 6.5.0
     *
     * @param string $name Property name.
     * @return mixed
     */
    public function __get( string $name ) {
        if ( 'entries' === $name ) {
            $entries = $this->controller->get_entries( $this->textdomain );

            $result = array();

            foreach ( $entries as $original => $translations ) {
                $result[] = $this->make_entry( $original, $translations );
            }

            return $result;
        }

        if ( 'headers' === $name ) {
            return $this->controller->get_headers( $this->textdomain );
        }

        return null;
    }

    /**
     * Builds a Translation_Entry from original string and translation strings.
     *
     * @see MO::make_entry()
     *
     * @since 6.5.0
     *
     * @param string $original     Original string to translate from MO file. Might contain
     *                             0x04 as context separator or 0x00 as singular/plural separator.
     * @param string $translations Translation strings from MO file.
     * @return Translation_Entry Entry instance.
     */
    private function make_entry( $original, $translations ): Translation_Entry {
        $entry = new Translation_Entry();

        // Look for context, separated by \4.
        $parts = explode( "\4", $original );
        if ( isset( $parts[1] ) ) {
            $original       = $parts[1];
            $entry->context = $parts[0];
        }

        $entry->singular     = $original;
        $entry->translations = explode( "\0", $translations );
        $entry->is_plural    = count( $entry->translations ) > 1;

        return $entry;
    }

    /**
     * Translates a plural string.
     *
     * @since 6.5.0
     *
     * @param string|null $singular Singular string.
     * @param string|null $plural   Plural string.
     * @param int|float   $count    Count. Should be an integer, but some plugins pass floats.
     * @param string|null $context  Context.
     * @return string|null Translation if it exists, or the unchanged singular string.
     */
    public function translate_plural( $singular, $plural, $count = 1, $context = '' ) {
        if ( null === $singular || null === $plural ) {
            return $singular;
        }

        $translation = $this->controller->translate_plural( array( $singular, $plural ), (int) $count, (string) $context, $this->textdomain );
        if ( false !== $translation ) {
            return $translation;
        }

        // Fall back to the original with English grammar rules.
        return ( 1 === (int) $count ? $singular : $plural );
    }

    /**
     * Translates a singular string.
     *
     * @since 6.5.0
     *
     * @param string|null $singular Singular string.
     * @param string|null $context  Context.
     * @return string|null Translation if it exists, or the unchanged singular string
     */
    public function translate( $singular, $context = '' ) {
        if ( null === $singular ) {
            return null;
        }

        $translation = $this->controller->translate( $singular, (string) $context, $this->textdomain );
        if ( false !== $translation ) {
            return $translation;
        }

        // Fall back to the original.
        return $singular;
    }
}