defmodule DaProductApp.Partners.Merchant do
  @moduledoc """
  Merchant schema representing stores/businesses enrolled under partners.
  
  Merchants are the actual stores/businesses where customers make payments.
  Each merchant belongs to a partner (acquirer/aggregator).
  """
  use Ecto.Schema
  import Ecto.Changeset

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id

  schema "merchants" do
    field :merchant_code, :string         # Unique merchant identifier
    field :brand_name, :string         # Business name
    field :merchant_vpa, :string          # UPI VPA (e.g., merchant@partner)
    field :business_type, :string         # "RETAIL", "ECOMMERCE", "SERVICES"
    field :business_category, :string     # "GROCERY", "RESTAURANT", "PHARMACY"
    field :static_qr_code, :string        # Static QR for the merchant
    field :qr_enabled, :boolean, default: true
    field :dynamic_qr_enabled, :boolean, default: false
    field :max_transaction_limit, :decimal
    field :daily_transaction_limit, :decimal
    field :settlement_frequency, :string, default: "T+1"  # "T+0", "T+1", "WEEKLY"
    field :settlement_account_intl, :string    # Merchant's bank account
    field :contact_person, :string
    field :contact_email, :string
    field :contact_phone, :string
    field :address, :string
    field :city, :string
    field :state, :string
    field :pincode, :string
    field :gstin, :string                 # GST identification number
    field :pan, :string                   # PAN card number
    field :intl_status, :string, default: "ACTIVE"  # "ACTIVE", "SUSPENDED", "INACTIVE"
    field :onboarded_at, :utc_datetime
    field :last_transaction_at, :utc_datetime

    belongs_to :partner, DaProductApp.Partners.Partner
    has_many :transactions, DaProductApp.Transactions.Transaction

    timestamps(type: :utc_datetime)
  end

  def changeset(merchant, attrs) do
    merchant
    |> cast(attrs, [
      :merchant_code, :merchant_name, :merchant_vpa, :business_type, 
      :business_category, :static_qr_code, :qr_enabled, :dynamic_qr_enabled,
      :max_transaction_limit, :daily_transaction_limit, :settlement_frequency,
      :settlement_account, :contact_person, :contact_email, :contact_phone,
      :address, :city, :state, :pincode, :gstin, :pan, :status,
      :onboarded_at, :last_transaction_at, :partner_id
    ])
    |> validate_required([:merchant_code, :merchant_name, :merchant_vpa, :partner_id])
    |> validate_inclusion(:business_type, ["RETAIL", "ECOMMERCE", "SERVICES"])
    |> validate_inclusion(:settlement_frequency, ["T+0", "T+1", "WEEKLY"])
    |> validate_inclusion(:status, ["ACTIVE", "SUSPENDED", "INACTIVE"])
    |> validate_format(:contact_email, ~r/@/)
    |> validate_format(:merchant_vpa, ~r/^[\w\.-]+@[\w\.-]+$/)
    |> unique_constraint(:merchant_code)
    |> unique_constraint(:merchant_vpa)
  end
end