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

  @moduledoc """
  Daily Settlement MIS (Payment Output MIS) — header record.

  One row per settlement run date. Holds aggregated totals and the 2-level
  Finance Team approval workflow state.

  Workflow:
    generated → level1_approved (Level 1 Finance reviewer)
              → approved (Level 2 Finance approver)
              → payout file generated
    OR
    generated → discarded (with reason)

  See settlement_mis_items for line-level transaction detail.
  """

  def change do
    create table(:settlement_mis) do
      add :mis_date, :date, null: false,
          comment: "Settlement date this MIS covers"
      add :source_dump_ref, :string, size: 100,
          comment: "Dump file(s) this MIS was generated from"

      # Aggregated totals
      add :total_merchants, :integer, default: 0
      add :total_transactions, :integer, default: 0
      add :gross_total_amount, :decimal, precision: 14, scale: 2, default: 0
      add :total_mdr_charges, :decimal, precision: 14, scale: 2, default: 0
      add :total_vat, :decimal, precision: 14, scale: 2, default: 0
      add :total_ar_recovery, :decimal, precision: 14, scale: 2, default: 0
      add :total_adjustments, :decimal, precision: 14, scale: 2, default: 0
      add :total_net_payable, :decimal, precision: 14, scale: 2, default: 0
      add :currency, :string, size: 5, default: "AED"

      # 2-level Finance approval workflow
      add :approval_status, :string, size: 20, null: false, default: "pending",
          comment: "pending | level1_approved | approved | discarded"
      add :level1_reviewed_by, :bigint,
          comment: "users.id — Level 1 Finance reviewer"
      add :level1_reviewed_at, :naive_datetime
      add :level2_approved_by, :bigint,
          comment: "users.id — Level 2 Finance approver"
      add :level2_approved_at, :naive_datetime
      add :discarded_by, :bigint,
          comment: "users.id"
      add :discarded_at, :naive_datetime
      add :discard_reason, :text

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

    create unique_index(:settlement_mis, [:mis_date], name: :settlement_mis_date_unique)
    create index(:settlement_mis, [:approval_status])
    create index(:settlement_mis, [:mis_date])
  end
end