defmodule Microwaveprop.ContactsFixtures do
  @moduledoc """
  Factory helpers for creating Contact records in tests.

  Uses globally-unique `qso_timestamp` microseconds (via
  `System.unique_integer([:positive, :monotonic])`) to prevent
  `contacts_dedup_idx` unique-constraint violations when async
  tests across different modules run in parallel and would
  otherwise insert contacts with identical dedup-key columns.
  """

  alias Microwaveprop.Radio.Contact
  alias Microwaveprop.Repo

  @doc """
  Creates a contact with unique dedup-key column values.

  Override any field by passing it in `attrs`. Pass `:user_id` to
  associate the contact with a user.

  Returns the created `%Contact{}`.
  """
  @spec create_contact(map()) :: Contact.t()
  def create_contact(attrs \\ %{}) do
    # Globally-unique second offset so every contact has a distinct
    # dedup key (band, qso_timestamp, stations, grids). The column is
    # timestamp(0), so microsecond offsets are truncated.
    unique_s = System.unique_integer([:positive, :monotonic])

    default = %{
      station1: "W5XD",
      station2: "K5TR",
      qso_timestamp: DateTime.shift(~U[2026-03-28 18:00:00Z], second: unique_s),
      mode: "CW",
      band: Decimal.new("1296"),
      grid1: "EM12",
      grid2: "EM00",
      pos1: %{"lat" => 32.9, "lon" => -97.0},
      pos2: %{"lat" => 30.3, "lon" => -97.7},
      distance_km: Decimal.new("295")
    }

    merged = Map.merge(default, attrs)
    {user_id, changeset_attrs} = Map.pop(merged, :user_id)

    {:ok, contact} =
      %Contact{user_id: user_id}
      |> Contact.changeset(changeset_attrs)
      |> Repo.insert()

    contact
  end
end