<?php

namespace WP_CLI\I18n;

use Gettext\Generators\PhpArray;
use Gettext\Translation;
use Gettext\Translations;

/**
 * PHP array file generator.
 *
 * Returns output in the form WordPress uses.
 */
class PhpArrayGenerator extends PhpArray {
    public static $options = [
        'includeHeaders' => false,
    ];

    /**
     * {@inheritdoc}
     */
    public static function toString( Translations $translations, array $options = [] ) {
        $array = static::generate( $translations, $options );

        return '<?php' . PHP_EOL . 'return ' . static::var_export( $array ) . ';';
    }

    /**
     * Generates an array with the translations.
     *
     * @param Translations $translations
     * @param array        $options
     *
     * @return array
     */
    public static function generate( Translations $translations, array $options = [] ) {
        $options += static::$options;

        return static::toArray( $translations, $options['includeHeaders'] );
    }

    /**
     * Returns an array containing headers and translations.
     *
     * @param Translations $translations
     * @param bool         $include_headers
     * @param bool         $force_array Unused.
     *
     * @return array
     */
    protected static function toArray( Translations $translations, $include_headers, $force_array = false ) {
        $messages = [];

        $result = [
            'domain'       => $translations->getDomain(),
            'plural-forms' => $translations->getHeader( 'Plural-Forms' ),
        ];

        $language = $translations->getLanguage();
        if ( null !== $language ) {
            $result['language'] = $language;
        }

        $headers_allowlist = [
            'POT-Creation-Date'  => 'pot-creation-date',
            'PO-Revision-Date'   => 'po-revision-date',
            'Project-Id-Version' => 'project-id-version',
            'X-Generator'        => 'x-generator',
        ];

        foreach ( $translations->getHeaders() as $name => $value ) {
            if ( isset( $headers_allowlist[ $name ] ) ) {
                $result[ $headers_allowlist[ $name ] ] = $value;
            }
        }

        /**
         * @var Translation $translation
         */
        foreach ( $translations as $translation ) {
            if ( $translation->isDisabled() || ! $translation->hasTranslation() ) {
                continue;
            }

            $context  = $translation->getContext();
            $original = $translation->getOriginal();

            $key = $context ? $context . "\4" . $original : $original;

            if ( $translation->hasPluralTranslations() ) {
                $msg_translations = $translation->getPluralTranslations();
                array_unshift( $msg_translations, $translation->getTranslation() );
                $messages[ $key ] = implode( "\0", $msg_translations );
            } else {
                $messages[ $key ] = $translation->getTranslation();
            }
        }

        $result['messages'] = $messages;

        return $result;
    }

    /**
     * Determines if the given array is a list.
     *
     * An array is considered a list if its keys consist of consecutive numbers from 0 to count($array)-1.
     *
     * Polyfill for array_is_list() in PHP 8.1.
     *
     * @see https://github.com/symfony/polyfill-php81/tree/main
     *
     * @since 4.0.0
     *
     * @codeCoverageIgnore
     *
     * @param array<mixed> $arr The array being evaluated.
     * @return bool True if array is a list, false otherwise.
     */
    private static function array_is_list( array $arr ) {
        if ( function_exists( 'array_is_list' ) ) {
            // phpcs:ignore PHPCompatibility.FunctionUse.NewFunctions.array_is_listFound
            return array_is_list( $arr );
        }

        if ( ( array() === $arr ) || ( array_values( $arr ) === $arr ) ) {
            return true;
        }

        $next_key = -1;

        foreach ( $arr as $k => $v ) {
            if ( ++$next_key !== $k ) {
                return false;
            }
        }

        return true;
    }

    /**
     * Outputs or returns a parsable string representation of a variable.
     *
     * Like {@see var_export()} but "minified", using short array syntax
     * and no newlines.
     *
     * @since 4.0.0
     *
     * @param mixed $value The variable you want to export.
     * @return string The variable representation.
     */
    private static function var_export( $value ) {
        if ( ! is_array( $value ) ) {
            return var_export( $value, true );
        }

        $entries = array();

        $is_list = self::array_is_list( $value );

        foreach ( $value as $key => $val ) {
            $entries[] = $is_list ? self::var_export( $val ) : var_export( $key, true ) . '=>' . self::var_export( $val );
        }

        return '[' . implode( ',', $entries ) . ']';
    }
}