<?php

declare(strict_types=1);

use Core\Database;
use Core\Migration;

return new class extends Migration
{
    public function up(Database $database): void
    {
        $tableExists = $database->first(
            "SELECT 1 AS tbl FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'campaign_audit'"
        );

        if ($tableExists) {
            return;
        }

        // No foreign key on id: audit records must survive deletion of the
        // campaign row they reference (that deletion is itself audited as 'D').
        $database->execute(
            "CREATE TABLE campaign_audit (
                audit_id   INT IDENTITY(1,1) NOT NULL,
                id         INT           NOT NULL,
                action     CHAR(1)       NOT NULL,
                fields     NVARCHAR(MAX) NOT NULL,
                username   NVARCHAR(255) NOT NULL DEFAULT 'system',
                created_at DATETIME      NOT NULL DEFAULT CURRENT_TIMESTAMP,
                CONSTRAINT PK_campaign_audit        PRIMARY KEY (audit_id),
                CONSTRAINT CHK_campaign_audit_action CHECK (action IN ('I','U','D','R'))
            )"
        );

        $database->execute(
            'CREATE INDEX IX_campaign_audit_id ON campaign_audit (id)'
        );
    }

    public function down(Database $database): void
    {
        $database->execute('DROP TABLE IF EXISTS campaign_audit');
    }
};