<?php
/**
 * Blog-local Connector V2 outbox schema lifecycle.
 */

if (!defined('ABSPATH')) { exit; }
class Akkedli_V2_Outbox_Schema
{
    const VERSION = 1, OPTION = 'akkedli_v2_outbox_schema';
    public static function table() { global $wpdb; return $wpdb->prefix . 'akkedli_v2_outbox'; }
    public static function maybe_install()
    {
        if (self::ready()) {
            return true;
        }
        return self::install();
    }
    public static function ready()
    {
        return (int) get_option(self::OPTION, 0) >= self::VERSION && self::schema_ready();
    }
    public static function install()
    {
        global $wpdb;
        if ((int) get_option(self::OPTION, 0) > self::VERSION) {
            return self::schema_ready();
        }
        if (!function_exists('dbDelta')) {
            require_once ABSPATH . 'wp-admin/includes/upgrade.php';
        }
        $table = self::table();
        $collation = $wpdb->get_charset_collate();
        $sql = "CREATE TABLE {$table} (
            id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
            event_id char(64) NOT NULL,
            order_key char(64) NOT NULL,
            operation varchar(12) NOT NULL,
            envelope longtext NULL,
            state varchar(24) NOT NULL,
            capture_attempts tinyint(3) unsigned NOT NULL DEFAULT 0,
            attempts tinyint(3) unsigned NOT NULL DEFAULT 0,
            next_attempt_gmt datetime NOT NULL,
            lease_owner char(64) NULL,
            lease_expires_gmt datetime NULL,
            last_outcome varchar(32) NULL,
            created_gmt datetime NOT NULL,
            updated_gmt datetime NOT NULL,
            completed_gmt datetime NULL,
            PRIMARY KEY  (id),
            UNIQUE KEY event_id (event_id),
            KEY due (state,next_attempt_gmt,id),
            KEY lease (state,lease_expires_gmt,id),
            KEY order_fifo (order_key,id)
        ) {$collation};";
        dbDelta($sql);
        if (!self::schema_ready()) {
            return false;
        }
        update_option(self::OPTION, self::VERSION, false);
        return (int) get_option(self::OPTION, 0) === self::VERSION;
    }
    private static function schema_ready()
    {
        global $wpdb;
        $table = self::table();
        if (!self::table_exists()) {
            return false;
        }
        $columns = $wpdb->get_col("SHOW COLUMNS FROM {$table}", 0); $rows = $wpdb->get_results("SHOW INDEX FROM {$table}", ARRAY_A);
        $indexes = array();
        foreach (is_array($rows) ? $rows : array() as $row) {
            if (!isset($row['Key_name'], $row['Non_unique'], $row['Seq_in_index'], $row['Column_name'])) { return false; }
            $indexes[$row['Key_name'] . ':' . $row['Non_unique'] . ':' . $row['Seq_in_index']] = $row['Column_name'];
        }
        $required_columns = array('id', 'event_id', 'order_key', 'operation', 'envelope', 'state',
            'capture_attempts', 'attempts', 'next_attempt_gmt', 'lease_owner', 'lease_expires_gmt',
            'last_outcome', 'created_gmt', 'updated_gmt', 'completed_gmt');
        $required_indexes = array('PRIMARY:0:1' => 'id', 'event_id:0:1' => 'event_id',
            'due:1:1' => 'state', 'due:1:2' => 'next_attempt_gmt', 'due:1:3' => 'id',
            'lease:1:1' => 'state', 'lease:1:2' => 'lease_expires_gmt', 'lease:1:3' => 'id',
            'order_fifo:1:1' => 'order_key', 'order_fifo:1:2' => 'id');
        return is_array($columns) && !array_diff($required_columns, $columns)
            && !array_diff_assoc($required_indexes, $indexes);
    }
    private static function table_exists()
    {
        global $wpdb; $table = self::table();
        return $table === $wpdb->get_var($wpdb->prepare('SHOW TABLES LIKE %s', $wpdb->esc_like($table)));
    }
}