# Test script to verify batch number functionality

# First run this migration if not already run:
# mix ecto.migrate

# Test in IEx:
# iex> alias DaProductApp.{Repo, Transactions.Transaction, BatchNumber}
# 
# # Create a test batch number for a merchant
# iex> BatchNumber.changeset(%BatchNumber{}, %{
#        merchant_id: "Mercury_1234512", 
#        batch_number: "000005", 
#        date: ~D[2025-07-25]
#      }) |> Repo.insert()
#
# # Create a transaction and verify batch number is set automatically
# iex> Transaction.changeset(%Transaction{}, %{
#        merchant_id: "Mercury_1234512",
#        status: "pending"
#      }) |> Repo.insert()
#
# # The transaction should have batch_number "000005" automatically set

# Summary of what was implemented:
# 1. Added batch_number column to transactions table (migration)
# 2. Added batch_number field to Transaction schema
# 3. Added automatic batch number setting in changeset
# 4. When a transaction is created, it gets the latest batch number for that merchant_id