defmodule Polymarket.Schemas.MarketResolvedEvent do
  @moduledoc """
  Market resolved event. Announces that a market has settled, naming the
  winning asset and its outcome.
  """

  use TypedEctoSchema

  alias Polymarket.JsonUtil
  alias Polymarket.Schemas.Coerce
  alias Polymarket.Schemas.EventMessage

  @primary_key false

  @derive Jason.Encoder
  typed_embedded_schema do
    field(:id, :string)
    field(:market, :string)
    field(:assets_ids, {:array, :string})
    field(:winning_asset_id, :string)
    # Free-form outcome label, e.g. "Yes", "No", "Over", or a team name.
    field(:winning_outcome, :string)
    field(:tags, {:array, :string})
    # Unix epoch in milliseconds, delivered as a string (e.g. "1782494011246").
    field(:timestamp, :integer)
    field(:event_type, :string)

    embeds_one(:event_message, EventMessage)
  end

  @required [:id, :market, :winning_asset_id, :winning_outcome, :timestamp, :event_type]

  @doc """
  Builds a `MarketResolvedEvent` from a decoded (atom-keyed) websocket message,
  coercing each value to its field type. Returns
  `{:error, {:missing_fields, fields}}` when a required field is absent.
  """
  @spec from_attrs(map()) :: {:ok, t()} | {:error, {:missing_fields, [atom()]}}
  def from_attrs(attrs) do
    attrs = JsonUtil.snake_case_keys(attrs)

    %__MODULE__{
      id: attrs["id"],
      market: attrs["market"],
      assets_ids: attrs["assets_ids"],
      winning_asset_id: attrs["winning_asset_id"],
      winning_outcome: attrs["winning_outcome"],
      tags: attrs["tags"],
      timestamp: Coerce.to_int(attrs["timestamp"]),
      event_type: attrs["event_type"],
      event_message: Coerce.embed(EventMessage, attrs["event_message"])
    }
    |> Coerce.require_fields(@required)
  end
end