<?php

declare(strict_types=1);

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

/**
 * Who changed what, and what it said before.
 *
 * Several people edit the same translated JSON with no record of any of it.
 * The gap that matters most is publishing: `pages.publish` exists as a
 * separate permission precisely because putting something on the public site
 * is a bigger act than writing it — and until now nothing recorded who did it.
 */
return new class extends Migration
{
    public function up(): void
    {
        Schema::create('revisions', function (Blueprint $table) {
            $table->id();

            $table->morphs('revisionable');

            // Null for something done by the scheduler or a command: honest
            // about it rather than blaming the last person who logged in.
            $table->foreignId('user_id')->nullable()->constrained()->nullOnDelete();
            $table->string('user_name')->nullable();

            $table->string('event', 20);

            /*
             * Only what changed, old and new. Storing whole records would make
             * this table larger than the content it describes.
             *
             * Not called `changes`: Eloquent declares a `$changes` property of
             * its own for dirty tracking, and a column of that name is shadowed
             * by it — `$revision->changes` would silently return the ORM's
             * array instead of this column.
             */
            $table->jsonb('changeset')->nullable();

            $table->timestamp('created_at')->nullable();

            $table->index(['revisionable_type', 'revisionable_id', 'created_at'], 'revisions_record_index');
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('revisions');
    }
};