<?php

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

class CreateTableCommentsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('table_comments', function (Blueprint $table) {
            $table->increments('id');
            $table->timestamps();
            $table->unsignedInteger('ancestor_id')->index()->nullable();
            $table->unsignedInteger('author_id')->index();
            $table->unsignedInteger('data_table_id')->index();
            $table->text('message');

            $table->foreign('data_table_id')->references('id')->on('data_tables')
                ->onDelete('cascade');

            $table->foreign('author_id')->references('id')->on('users')
                ->onDelete('cascade');

            $table->foreign('ancestor_id')->references('id')->on('comments')
                ->onDelete('set null');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('table_comments');
    }
}