<?php
namespace Clusterlane\Core;

if ( ! defined( 'ABSPATH' ) ) exit;

// phpcs:disable WordPress.DB.DirectDatabaseQuery, WordPress.DB.SlowDBQuery
// -- One-time move of the plugin's own tables and keys. Every interpolated name comes from the fixed
//    lists below plus $wpdb->prefix; nothing user-supplied reaches a query.

/**
 * Legacy — takes over the data of ClusterIQ, the plugin's earlier name (1.3.0).
 *
 * ClusterIQ stored everything under cci_ / clusteriq names. On the first
 * boot after the switch, Clusterlane renames its tables, copies its options,
 * renames post meta and moves the role capabilities, so a site keeps its
 * clusters, history, settings (including the encrypted AI key) and access
 * rules. Runs once per site; on multisite each site migrates the first time
 * Clusterlane boots there.
 *
 * While ClusterIQ itself is still active, nothing is moved and Clusterlane
 * does not start: a notice asks the user to deactivate ClusterIQ (a button
 * to WordPress's own Deactivate action). The move happens on the first
 * request after that. Clusterlane never deactivates a plugin by itself.
 */
final class Legacy {

    /** Set when the move is done (or there was nothing to move). */
    const DONE = 'clusterlane_migrated';

    /** Guards against two requests moving the data at the same time. */
    const LOCK = 'clusterlane_migrating';

    /** One-time notice for the admin after the move. */
    const NOTICE = 'clusterlane_migrated_notice';

    /** Plugin files of ClusterIQ (free and Pro, any folder) and its predecessor. */
    const OLD_FILE = '#(^|/)(clusteriq|content-cluster-intelligence)\.php$#';

    const TABLES = [ 'links', 'clusters', 'post_metrics', 'ai_cache', 'custom_members', 'tms_skipped', 'cluster_post_class', 'snapshots', 'activity' ];

    const OPTIONS = [ 'settings', 'db_version', 'caps_version', 'ai_usage', 'chosen_pillars', 'cluster_sections', 'cluster_groups', 'data_version', 'last_snapshot', 'render_log', 'page_queue', 'hub_relations' ];

    const POST_META = [ 'gap_cluster', 'elementor_backup', 'seo_check', 'seo_check_min', 'seo_original', 'page_stats' ];

    const CAPS = [
        'manage_clusteriq'    => 'manage_clusterlane',
        'use_clusteriq'       => 'use_clusterlane',
        'use_clusteriq_ai'    => 'use_clusterlane_ai',
        'clusteriq_add_links' => 'clusterlane_add_links',
        'clusteriq_write_seo' => 'clusterlane_write_seo',
    ];

    /* ------------------------------------------------------------------
       Entry points
    ------------------------------------------------------------------ */

    /**
     * Called first thing in Plugin::boot(). Cheap once the site is done.
     *
     * @return bool false while ClusterIQ itself is still active: Clusterlane
     *              then waits (it only shows a notice) until the user
     *              deactivates ClusterIQ — it never switches a plugin off by itself.
     */
    public static function maybe_migrate(): bool {
        add_action( 'admin_notices', [ self::class, 'notice' ] );
        add_action( 'network_admin_notices', [ self::class, 'notice' ] );

        if ( get_option( self::DONE ) ) return true;

        if ( self::old_active() ) return false; // never move tables out from under a running ClusterIQ

        if ( ! self::has_old_data() ) {
            update_option( self::DONE, [ 'at' => time(), 'moved' => false ], true );
            return true;
        }

        if ( ! add_option( self::LOCK, time(), '', false ) ) {
            if ( time() - (int) get_option( self::LOCK, 0 ) < 5 * MINUTE_IN_SECONDS ) return true;
            update_option( self::LOCK, time(), false ); // a run that died: take over
        }

        self::migrate_site();
        if ( is_multisite() ) self::migrate_network();

        delete_option( self::LOCK );
        update_option( self::DONE, [ 'at' => time(), 'moved' => true ], true );
        set_transient( self::NOTICE, 1, DAY_IN_SECONDS );
        wp_cache_flush(); // post meta and roles were changed directly
        return true;
    }

    /**
     * While ClusterIQ is active: what to do, with a button for each active
     * copy that leads to WordPress's own Deactivate action (the user decides).
     * After the move: one confirmation.
     */
    public static function notice(): void {
        if ( ! current_user_can( 'activate_plugins' ) ) return;

        $old = array_values( array_filter( self::active_plugins(), static fn( $p ) => (bool) preg_match( self::OLD_FILE, $p ) ) );
        if ( $old && ! get_option( self::DONE ) ) {
            echo '<div class="notice notice-warning"><p><strong>Clusterlane:</strong> '
                . esc_html__( 'ClusterIQ is now called Clusterlane. Deactivate ClusterIQ to move your clusters, history, settings and access rules over — Clusterlane waits until then, so the two never run at the same time.', 'clusterlane' )
                . '</p><p>';
            foreach ( $old as $plugin ) {
                $network = is_multisite() && array_key_exists( $plugin, (array) get_site_option( 'active_sitewide_plugins', [] ) );
                $base    = $network ? network_admin_url( 'plugins.php' ) : admin_url( 'plugins.php' );
                $url     = wp_nonce_url( add_query_arg( [ 'action' => 'deactivate', 'plugin' => rawurlencode( $plugin ) ], $base ), 'deactivate-plugin_' . $plugin );
                echo '<a class="button button-primary" href="' . esc_url( $url ) . '">'
                    . esc_html(
                        /* translators: %s: plugin folder and file, e.g. clusteriq/clusteriq.php */
                        sprintf( __( 'Deactivate ClusterIQ (%s)', 'clusterlane' ), $plugin )
                    )
                    . '</a> ';
            }
            echo '</p></div>';
            return;
        }
        if ( get_transient( self::NOTICE ) ) {
            delete_transient( self::NOTICE );
            echo '<div class="notice notice-success is-dismissible"><p><strong>Clusterlane:</strong> '
                . esc_html__( 'Your ClusterIQ data has moved over: clusters, history, settings and access rules. The old ClusterIQ plugin can be deleted — deleting it no longer touches this data.', 'clusterlane' )
                . '</p></div>';
        }
    }

    /* ------------------------------------------------------------------
       The move
    ------------------------------------------------------------------ */

    private static function migrate_site(): void {
        global $wpdb;
        $had_mapping = false !== get_option( 'cci_caps_version', false ); // ClusterIQ had applied its role rights

        // 1. Tables: rename, so nothing is copied. Clusterlane's activation
        //    may already have created empty tables — those make way.
        foreach ( self::TABLES as $bare ) {
            $old = $wpdb->prefix . 'cci_' . $bare;
            $new = $wpdb->prefix . 'clusterlane_' . $bare;
            if ( ! self::table_exists( $old ) ) continue;
            if ( self::table_exists( $new ) ) {
                if ( (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i', $new ) ) > 0 ) continue; // already in use: keep it
                $wpdb->query( $wpdb->prepare( 'DROP TABLE %i', $new ) );
            }
            $wpdb->query( $wpdb->prepare( 'RENAME TABLE %i TO %i', $old, $new ) );
        }

        // 2. Options: ClusterIQ's values win over the defaults written on activation.
        foreach ( self::OPTIONS as $bare ) {
            $value = get_option( 'cci_' . $bare, null );
            if ( null === $value ) continue;
            update_option( 'clusterlane_' . $bare, $value, false );
            delete_option( 'cci_' . $bare );
        }
        delete_option( 'cci_page_lock' );

        // 3. Post meta.
        foreach ( self::POST_META as $bare ) {
            $wpdb->update( $wpdb->postmeta, [ 'meta_key' => '_clusterlane_' . $bare ], [ 'meta_key' => '_cci_' . $bare ] );
        }

        // 4. Capabilities: the new ones follow exactly what each role had, so
        //    a right an admin took away stays away.
        foreach ( wp_roles()->role_objects as $role ) {
            foreach ( self::CAPS as $old => $new ) {
                if ( isset( $role->capabilities[ $old ] ) ) {
                    $role->add_cap( $new, (bool) $role->capabilities[ $old ] );
                    $role->remove_cap( $old );
                } elseif ( $had_mapping && $role->has_cap( $new ) ) {
                    $role->remove_cap( $new );
                }
            }
        }
        // Rights given to single users.
        $users = get_users( [
            'blog_id'      => get_current_blog_id(),
            'meta_key'     => $wpdb->get_blog_prefix() . 'capabilities',
            'meta_value'   => 'clusteriq',
            'meta_compare' => 'LIKE',
            'fields'       => 'all',
        ] );
        foreach ( $users as $user ) {
            foreach ( self::CAPS as $old => $new ) {
                if ( isset( $user->caps[ $old ] ) ) {
                    $user->add_cap( $new, (bool) $user->caps[ $old ] );
                    $user->remove_cap( $old );
                }
            }
        }

        // 5. Short-lived data (undo snapshots, locks) and ClusterIQ's scheduled events.
        $wpdb->query(
            "DELETE FROM {$wpdb->options}
             WHERE option_name LIKE '\\_transient\\_cci\\_%' OR option_name LIKE '\\_transient\\_timeout\\_cci\\_%'"
        );
        wp_clear_scheduled_hook( 'cci_daily_snapshot' );
        wp_clear_scheduled_hook( 'cci_read_pages' );

        // Pages still waiting to be read: pick up where ClusterIQ left off.
        $queue = get_option( 'clusterlane_page_queue' );
        if ( ! empty( $queue ) && ! wp_next_scheduled( 'clusterlane_read_pages' ) ) {
            wp_schedule_single_event( time() + 60, 'clusterlane_read_pages' );
        }
    }

    /** The network-wide AI key and policy (multisite). */
    private static function migrate_network(): void {
        $value = get_site_option( 'cci_network_ai', null );
        if ( null === $value ) return;
        if ( null === get_site_option( 'clusterlane_network_ai', null ) ) {
            update_site_option( 'clusterlane_network_ai', $value );
        }
        delete_site_option( 'cci_network_ai' );
    }

    /* ------------------------------------------------------------------
       Helpers
    ------------------------------------------------------------------ */

    private static function has_old_data(): bool {
        global $wpdb;
        if ( false !== get_option( 'cci_settings', false ) || false !== get_option( 'cci_db_version', false ) ) return true;
        if ( is_multisite() && null !== get_site_option( 'cci_network_ai', null ) ) return true;
        return self::table_exists( $wpdb->prefix . 'cci_clusters' );
    }

    private static function table_exists( string $table ): bool {
        global $wpdb;
        return $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) ) === $table;
    }

    private static function old_active(): bool {
        foreach ( self::active_plugins() as $plugin ) {
            if ( preg_match( self::OLD_FILE, $plugin ) ) return true;
        }
        return false;
    }

    /** @return string[] */
    private static function active_plugins(): array {
        $active = (array) get_option( 'active_plugins', [] );
        if ( is_multisite() ) $active = array_merge( $active, array_keys( (array) get_site_option( 'active_sitewide_plugins', [] ) ) );
        return array_map( 'strval', $active );
    }
}