<?php

namespace WP_CLI\I18n;

use Gettext\Generators\Po as PoGenerator;
use Gettext\Translations;
use Gettext\Utils\ParsedComment;

/**
 * POT file generator.
 *
 * The only difference to the existing PO file generator is that this
 * adds some comments at the very beginning of the file.
 */
class PotGenerator extends PoGenerator {
    protected static $comments_before_headers = [];

    /**
     * Text to include as a comment before the start of the PO contents
     *
     * Doesn't need to include # in the beginning of lines, these are added automatically.
     *
     * @param string $comment File comment.
     */
    public static function setCommentBeforeHeaders( $comment ) {
        $comments = explode( "\n", $comment );

        foreach ( $comments as $line ) {
            if ( '' !== trim( $line ) ) {
                static::$comments_before_headers[] = '# ' . $line;
            }
        }
    }

    /**
     * {@parentDoc}.
     */
    public static function toString( Translations $translations, array $options = [] ) {
        $lines   = static::$comments_before_headers;
        $lines[] = 'msgid ""';
        $lines[] = 'msgstr ""';

        $plural_form = $translations->getPluralForms();
        $plural_size = is_array( $plural_form ) ? ( $plural_form[0] - 1 ) : 1;

        foreach ( $translations->getHeaders() as $name => $value ) {
            $lines[] = sprintf( '"%s: %s\\n"', $name, $value );
        }

        $lines[] = '';

        foreach ( $translations as $translation ) {
            /** @var \Gettext\Translation $translation */
            if ( $translation->hasComments() ) {
                foreach ( $translation->getComments() as $comment ) {
                    $lines[] = '# ' . $comment;
                }
            }

            if ( $translation->hasExtractedComments() ) {
                $unique_comments = array();

                /** @var ParsedComment|string $comment */
                foreach ( $translation->getExtractedComments() as $comment ) {
                    $comment = ( $comment instanceof ParsedComment ? $comment->getComment() : $comment );
                    if ( ! in_array( $comment, $unique_comments, true ) ) {
                        $lines[]           = '#. ' . $comment;
                        $unique_comments[] = $comment;
                    }
                }
            }

            foreach ( $translation->getReferences() as $reference ) {
                $lines[] = '#: ' . $reference[0] . ( null !== $reference[1] ? ':' . $reference[1] : '' );
            }

            if ( $translation->hasFlags() ) {
                $lines[] = '#, ' . implode( ',', $translation->getFlags() );
            }

            $prefix = $translation->isDisabled() ? '#~ ' : '';

            if ( $translation->hasContext() ) {
                $lines[] = $prefix . 'msgctxt ' . self::convertString( $translation->getContext() );
            }

            self::addLines( $lines, $prefix . 'msgid', $translation->getOriginal() );

            if ( $translation->hasPlural() ) {
                self::addLines( $lines, $prefix . 'msgid_plural', $translation->getPlural() );

                for ( $i = 0; $i <= $plural_size; $i++ ) {
                    self::addLines( $lines, $prefix . 'msgstr[' . $i . ']', '' );
                }
            } else {
                self::addLines( $lines, $prefix . 'msgstr', $translation->getTranslation() );
            }

            $lines[] = '';
        }

        return implode( "\n", $lines );
    }

    /**
     * Escapes and adds double quotes to a string.
     *
     * @param string $text Multiline string.
     *
     * @return string[]
     */
    protected static function multilineQuote( $text ) {
        $lines = explode( "\n", $text );
        $last  = count( $lines ) - 1;

        foreach ( $lines as $k => $line ) {
            if ( $k === $last ) {
                $lines[ $k ] = self::convertString( $line );
            } else {
                $lines[ $k ] = self::convertString( $line . "\n" );
            }
        }

        return $lines;
    }

    /**
     * Add one or more lines depending whether the string is multiline or not.
     *
     * @param array  &$lines Array lines should be added to.
     * @param string $name   Name of the line, e.g. msgstr or msgid_plural.
     * @param string $value  The line to add.
     */
    protected static function addLines( array &$lines, $name, $value ) {
        $newlines = self::multilineQuote( $value );

        if ( count( $newlines ) === 1 ) {
            $lines[] = $name . ' ' . $newlines[0];
        } else {
            $lines[] = $name . ' ""';

            foreach ( $newlines as $line ) {
                $lines[] = $line;
            }
        }
    }
}