<?php
/**
 * WMW Gitea Importer – PHP 7.4 kompatibel
 */
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class WMW_Gitea_Importer {

    /** @var string */
    private $api_base;
    /** @var string */
    private $owner;
    /** @var string */
    private $repo;
    /** @var string */
    private $token;

    public function __construct( $gitea_url, $owner, $repo, $token = '' ) {
        $base           = rtrim( preg_replace( '#/(wiki.*)?$#', '', $gitea_url ), '/' );
        $this->api_base = $base . '/api/v1';
        $this->owner    = $owner;
        $this->repo     = $repo;
        $this->token    = $token;
    }

    // ── API ───────────────────────────────────────────────────────────────────

    private function api_get( $endpoint ) {
        $url  = $this->api_base . $endpoint;
        $args = array(
            'timeout' => 20,
            'headers' => array( 'Accept' => 'application/json' ),
        );
        if ( $this->token ) {
            $args['headers']['Authorization'] = 'token ' . $this->token;
        }
        $resp = wp_remote_get( $url, $args );
        if ( is_wp_error( $resp ) ) {
            return $resp;
        }
        $code = wp_remote_retrieve_response_code( $resp );
        if ( 200 !== $code ) {
            return new WP_Error( 'api_error', 'Gitea antwortet mit Status ' . $code . ' – URL: ' . $url );
        }
        $body = json_decode( wp_remote_retrieve_body( $resp ), true );
        if ( JSON_ERROR_NONE !== json_last_error() ) {
            return new WP_Error( 'json_error', 'Ungültige JSON-Antwort von: ' . $url );
        }
        return $body;
    }

    // ── Öffentliche Methoden ──────────────────────────────────────────────────

    public function list_pages() {
        $endpoint = '/repos/' . rawurlencode( $this->owner ) . '/' . rawurlencode( $this->repo ) . '/wiki/pages?limit=50';
        $result   = $this->api_get( $endpoint );
        if ( is_wp_error( $result ) ) {
            return $result;
        }
        if ( ! is_array( $result ) ) {
            return new WP_Error( 'invalid_response', 'Ungültige API-Antwort.' );
        }
        $pages = array();
        foreach ( $result as $page ) {
            if ( ! is_array( $page ) ) {
                continue;
            }
            $last = '';
            if ( isset( $page['last_commit']['created'] ) ) {
                $last = $page['last_commit']['created'];
            }
            $pages[] = array(
                'title'        => isset( $page['title'] ) ? $page['title'] : '',
                'last_updated' => $last,
            );
        }
        return $pages;
    }

    public function get_page( $page_name ) {
        $endpoint = '/repos/' . rawurlencode( $this->owner ) . '/' . rawurlencode( $this->repo ) . '/wiki/page/' . rawurlencode( $page_name );
        $result   = $this->api_get( $endpoint );
        if ( is_wp_error( $result ) ) {
            return $result;
        }
        if ( ! is_array( $result ) ) {
            return new WP_Error( 'invalid_response', 'Ungültige Seitenantwort für: ' . $page_name );
        }
        $markdown = '';
        if ( ! empty( $result['content_base64'] ) ) {
            $markdown = base64_decode( $result['content_base64'] ); // phpcs:ignore
        }
        if ( empty( $markdown ) && ! empty( $result['content'] ) ) {
            $markdown = $result['content'];
        }
        $title = isset( $result['title'] ) ? $result['title'] : $page_name;
        return array(
            'title'   => $title,
            'content' => self::markdown_to_html( $markdown ),
            'raw'     => $markdown,
        );
    }

    public function import_all( $wiki_id, $skip_pages = array( 'Home', '_Sidebar' ), $update_existing = false ) {
        $log = array( 'imported' => 0, 'updated' => 0, 'skipped' => 0, 'errors' => array() );

        $pages = $this->list_pages();
        if ( is_wp_error( $pages ) ) {
            $log['errors'][] = $pages->get_error_message();
            return $log;
        }

        foreach ( $pages as $p ) {
            $title = $p['title'];

            if ( in_array( $title, $skip_pages, true ) ) {
                $log['skipped']++;
                continue;
            }

            $existing = get_posts( array(
                'post_type'      => 'wmw_article',
                'post_status'    => 'any',
                'title'          => $title,
                'posts_per_page' => 1,
                'meta_query'     => array(
                    array( 'key' => '_wmw_wiki_id', 'value' => $wiki_id ),
                ),
            ) );

            if ( $existing && ! $update_existing ) {
                $log['skipped']++;
                continue;
            }

            $page_data = $this->get_page( $title );
            if ( is_wp_error( $page_data ) ) {
                $log['errors'][] = 'Fehler bei "' . $title . '": ' . $page_data->get_error_message();
                continue;
            }

            $post_data = array(
                'post_type'    => 'wmw_article',
                'post_title'   => $page_data['title'],
                'post_content' => $page_data['content'],
                'post_status'  => 'publish',
            );

            if ( $existing && $update_existing ) {
                $post_data['ID'] = $existing[0]->ID;
                $result          = wp_update_post( $post_data, true );
                if ( ! is_wp_error( $result ) ) {
                    $log['updated']++;
                }
            } else {
                $result = wp_insert_post( $post_data, true );
                if ( ! is_wp_error( $result ) ) {
                    $log['imported']++;
                }
            }

            if ( is_wp_error( $result ) ) {
                $log['errors'][] = 'WP-Fehler bei "' . $title . '": ' . $result->get_error_message();
                continue;
            }

            update_post_meta( $result, '_wmw_wiki_id', absint( $wiki_id ) );
            update_post_meta(
                $result,
                '_wmw_gitea_source',
                $this->api_base . '/repos/' . rawurlencode( $this->owner ) . '/' . rawurlencode( $this->repo ) . '/wiki/page/' . rawurlencode( $title )
            );

            $auto_cat = self::guess_category( $title );
            if ( $auto_cat ) {
                $term = term_exists( $auto_cat, 'wmw_category' );
                if ( ! $term ) {
                    $term = wp_insert_term( $auto_cat, 'wmw_category' );
                }
                if ( ! is_wp_error( $term ) ) {
                    $term_id = is_array( $term ) ? (int) $term['term_id'] : (int) $term;
                    wp_set_object_terms( $result, $term_id, 'wmw_category', true );
                }
            }
        }

        return $log;
    }

    // ── Markdown → HTML ───────────────────────────────────────────────────────

    public static function markdown_to_html( $md ) {
        if ( empty( $md ) ) {
            return '';
        }

        // Gitea [[Wiki-Links]]
        $md = preg_replace( '/\[\[([^\]|]+)\|([^\]]+)\]\]/', '[$2]($1)', $md );
        $md = preg_replace( '/\[\[([^\]]+)\]\]/', '[$1]($1)', $md );

        // Code-Blöcke sichern
        $code_blocks = array();
        $md = preg_replace_callback(
            '/```(\w*)\n(.*?)```/s',
            function ( $m ) use ( &$code_blocks ) {
                $lang  = '';
                if ( ! empty( $m[1] ) ) {
                    $lang = ' class="language-' . esc_attr( $m[1] ) . '"';
                }
                $token = '%%CB_' . count( $code_blocks ) . '%%';
                $code_blocks[ $token ] = '<pre><code' . $lang . '>' . esc_html( $m[2] ) . '</code></pre>';
                return $token;
            },
            $md
        );

        // Inline Code
        $md = preg_replace( '/`([^`\n]+)`/', '<code>$1</code>', $md );

        // Überschriften
        $md = preg_replace( '/^######\s+(.+)$/m', '<h6>$1</h6>', $md );
        $md = preg_replace( '/^#####\s+(.+)$/m',  '<h5>$1</h5>', $md );
        $md = preg_replace( '/^####\s+(.+)$/m',   '<h4>$1</h4>', $md );
        $md = preg_replace( '/^###\s+(.+)$/m',    '<h3>$1</h3>', $md );
        $md = preg_replace( '/^##\s+(.+)$/m',     '<h2>$1</h2>', $md );
        $md = preg_replace( '/^#\s+(.+)$/m',      '<h1>$1</h1>', $md );

        // Formatierung
        $md = preg_replace( '/\*\*\*(.+?)\*\*\*/s', '<strong><em>$1</em></strong>', $md );
        $md = preg_replace( '/\*\*(.+?)\*\*/s',     '<strong>$1</strong>', $md );
        $md = preg_replace( '/\*(.+?)\*/s',         '<em>$1</em>', $md );
        $md = preg_replace( '/__(.+?)__/s',         '<strong>$1</strong>', $md );
        $md = preg_replace( '/_([^_\s][^_]*)_/',   '<em>$1</em>', $md );
        $md = preg_replace( '/~~(.+?)~~/s',         '<del>$1</del>', $md );

        // Bilder & Links
        $md = preg_replace( '/!\[([^\]]*)\]\(([^)]+)\)/', '<img src="$2" alt="$1" style="max-width:100%">', $md );
        $md = preg_replace( '/\[([^\]]+)\]\(([^)]+)\)/', '<a href="$2">$1</a>', $md );

        // Blockquote & HR
        $md = preg_replace( '/^>\s+(.+)$/m',              '<blockquote>$1</blockquote>', $md );
        $md = preg_replace( '/^(\-{3,}|\*{3,}|_{3,})$/m', '<hr>', $md );

        // Tabellen
        $md = preg_replace_callback(
            '/^(\|.+\|\n)+/m',
            array( 'WMW_Gitea_Importer', 'cb_table' ),
            $md
        );

        // Ungeordnete Listen
        $md = preg_replace_callback(
            '/^([ \t]*[\*\-\+] .+\n?)+/m',
            array( 'WMW_Gitea_Importer', 'cb_ul' ),
            $md
        );

        // Geordnete Listen
        $md = preg_replace_callback(
            '/^([ \t]*\d+\. .+\n?)+/m',
            array( 'WMW_Gitea_Importer', 'cb_ol' ),
            $md
        );

        // Absätze
        $blocks = preg_split( '/\n{2,}/', $md );
        $html   = '';
        foreach ( $blocks as $block ) {
            $block = trim( $block );
            if ( empty( $block ) ) {
                continue;
            }
            if ( preg_match( '/^<(h[1-6]|ul|ol|blockquote|pre|table|hr|img|%%CB_)/i', $block ) ) {
                $html .= $block . "\n";
            } else {
                $html .= '<p>' . nl2br( $block ) . "</p>\n";
            }
        }

        // Code-Blöcke zurücksetzen
        foreach ( $code_blocks as $token => $code_html ) {
            $html = str_replace( $token, $code_html, $html );
        }

        return $html;
    }

    /** @param array $m */
    private static function cb_table( $m ) {
        $rows  = array_filter( explode( "\n", trim( $m[0] ) ) );
        $html  = '<table>';
        $first = true;
        foreach ( $rows as $row ) {
            $row = trim( $row );
            if ( empty( $row ) ) {
                continue;
            }
            if ( preg_match( '/^\|[-|:\s]+\|$/', $row ) ) {
                continue; // Trennzeile
            }
            $cells = array_map( 'trim', explode( '|', trim( $row, '|' ) ) );
            $tag   = $first ? 'th' : 'td';
            $html .= '<tr>';
            foreach ( $cells as $cell ) {
                $html .= '<' . $tag . '>' . $cell . '</' . $tag . '>';
            }
            $html .= '</tr>';
            $first = false;
        }
        return $html . '</table>';
    }

    /** @param array $m */
    private static function cb_ul( $m ) {
        $lines = array_filter( explode( "\n", trim( $m[0] ) ) );
        $html  = '<ul>';
        foreach ( $lines as $line ) {
            $text  = preg_replace( '/^[ \t]*[\*\-\+] /', '', $line );
            $html .= '<li>' . $text . '</li>';
        }
        return $html . '</ul>';
    }

    /** @param array $m */
    private static function cb_ol( $m ) {
        $lines = array_filter( explode( "\n", trim( $m[0] ) ) );
        $html  = '<ol>';
        foreach ( $lines as $line ) {
            $text  = preg_replace( '/^[ \t]*\d+\. /', '', $line );
            $html .= '<li>' . $text . '</li>';
        }
        return $html . '</ol>';
    }

    /** @param string $title */
    private static function guess_category( $title ) {
        $map = array(
            'Installation'   => 'Grundlagen',
            'Befehle'        => 'Grundlagen',
            'Berechtigungen' => 'Grundlagen',
            'config'         => 'Konfiguration',
            'settings'       => 'Konfiguration',
            'visuals'        => 'Konfiguration',
            'PlaceholderAPI' => 'Extras',
            'Sicherheit'     => 'Extras',
        );
        return isset( $map[ $title ] ) ? $map[ $title ] : '';
    }
}