defmodule DaProductApp.Repo.Migrations.CreatePayoutBatches do
  use Ecto.Migration

  @moduledoc """
  Aggregated payout batches sent to Mercury Settlement Bank after Finance
  Team 2-level approval of the Settlement MIS.

  Each approved settlement_mis generates one payout_batch. The encrypted
  payout file is generated at this stage and transmitted to the bank via
  API or SFTP per the agreed format (see ShukriaPayout sample).

  Also handles re-payout batches for rejected payout_items.
  """

  def change do
    create table(:payout_batches) do
      add :settlement_mis_id, :bigint,
          comment: "FK settlement_mis.id — NULL for re-payout batches"
      add :payout_date, :date, null: false
      add :batch_type, :string, size: 20, null: false, default: "regular",
          comment: "regular | re_payout (for rejected payment re-initiation)"
      add :total_merchants, :integer, default: 0
      add :total_items, :integer, default: 0
      add :total_amount, :decimal, precision: 14, scale: 2, default: 0
      add :currency, :string, size: 5, default: "AED"

      # File generation
      add :file_path, :string, size: 500,
          comment: "Path to encrypted payout file"
      add :file_name, :string, size: 255
      add :encryption_method, :string, size: 20,
          comment: "AES256 | PGP — per bank agreement"

      # Transmission
      add :transmission_method, :string, size: 10,
          comment: "API | SFTP — per bank agreement"
      add :status, :string, size: 20, null: false, default: "generated",
          comment: "generated | transmitted | confirmed | partial_reject | failed"
      add :transmitted_at, :naive_datetime
      add :transmission_reference, :string, size: 100,
          comment: "Reference returned by bank on submission"

      # Confirmation
      add :confirmed_at, :naive_datetime
      add :confirmed_item_count, :integer
      add :rejected_item_count, :integer

      add :inserted_at, :naive_datetime, null: false
      add :updated_at, :naive_datetime, null: false
    end

    create index(:payout_batches, [:payout_date])
    create index(:payout_batches, [:status])
    create index(:payout_batches, [:settlement_mis_id])
    create index(:payout_batches, [:batch_type])
  end
end