class InflowCategory < ActiveRecord::Base
end

class OutflowCategory < ActiveRecord::Base
end

class CreateMovementCategories < ActiveRecord::Migration
  def change
    create_table :movement_categories do |t|
      t.string :name
      t.references :user, index: true, foreign_key: true

      t.timestamps null: false
    end

    add_reference :inflows, :movement_category, index: true, foreign_key: true
    add_reference :outflows, :movement_category, index: true, foreign_key: true

    InflowCategory.find_each do |category|
      inflows = Inflow.where(inflow_category_id: category.id)

      new_category = if MovementCategory.where(name: category.name).any?
        MovementCategory.where(name: category.name).first
      else
        MovementCategory.create!(
          name: category.name,
          user_id: category.user_id,
          created_at: category.created_at,
          updated_at: category.updated_at
        )
      end

      inflows.update_all(movement_category_id: new_category.id)
    end

    OutflowCategory.find_each do |category|
      outflows = Outflow.where(outflow_category_id: category.id)

      new_category = if MovementCategory.where(name: category.name).any?
        MovementCategory.where(name: category.name).first
      else
        MovementCategory.create!(
          name: category.name,
          user_id: category.user_id,
          created_at: category.created_at,
          updated_at: category.updated_at
        )
      end

      outflows.update_all(movement_category_id: new_category.id)
    end

    remove_column :inflows, :inflow_category_id
    remove_column :outflows, :outflow_category_id

    drop_table :inflow_categories
    drop_table :outflow_categories
  end
end