invoiceninja/database/migrations/2015_07_08_114333_simplify_tasks.php

<?php

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

class SimplifyTasks extends Migration {

	/**
	 * Run the migrations.
	 *
	 * @return void
	 */
	public function up()
	{
        $tasks = \App\Models\Task::all();

        foreach ($tasks as $task) {
            $startTime = strtotime($task->start_time);            
            if (!$task->time_log || !count(json_decode($task->time_log))) {
                $task->time_log = json_encode([[$startTime, $startTime + $task->duration]]);
                $task->save();
            } elseif ($task->getDuration() != intval($task->duration)) {
                $task->time_log = json_encode([[$startTime, $startTime + $task->duration]]);
                $task->save();
            }
        }

        Schema::table('tasks', function($table)
        {
            $table->dropColumn('start_time');
            $table->dropColumn('duration');
            $table->dropColumn('break_duration');
            $table->dropColumn('resume_time');
        });

        Schema::table('users', function($table)
        {
            $table->boolean('dark_mode')->default(false)->nullable();
        });

        Schema::table('users', function($table)
        {
            $table->dropColumn('theme_id');
        });

	}

	/**
	 * Reverse the migrations.
	 *
	 * @return void
	 */
	public function down()
	{
        Schema::table('tasks', function($table)
        {
            $table->timestamp('start_time')->nullable();
            $table->integer('duration')->nullable();
            $table->timestamp('resume_time')->nullable();
            $table->integer('break_duration')->nullable();
        });

        Schema::table('users', function($table)
        {
            $table->dropColumn('dark_mode');
        });
        Schema::table('users', function($table)
        {
            $table->integer('theme_id')->nullable();
        });
	}

}