defmodule Alpa.Models.Bar do
  @moduledoc """
  OHLCV bar data model for market data.
  """
  use TypedStruct
  import Alpa.Helpers, only: [parse_decimal: 1, parse_datetime: 1]

  typedstruct do
    field(:symbol, String.t())
    field(:timestamp, DateTime.t())
    field(:open, Decimal.t())
    field(:high, Decimal.t())
    field(:low, Decimal.t())
    field(:close, Decimal.t())
    field(:volume, integer())
    field(:trade_count, integer())
    field(:vwap, Decimal.t())
  end

  @doc """
  Parse bar data from API response.
  """
  @spec from_map(map(), String.t() | nil) :: t()
  def from_map(data, symbol \\ nil) when is_map(data) do
    %__MODULE__{
      symbol: symbol || data["S"],
      timestamp: parse_datetime(data["t"]),
      open: parse_decimal(data["o"]),
      high: parse_decimal(data["h"]),
      low: parse_decimal(data["l"]),
      close: parse_decimal(data["c"]),
      volume: data["v"],
      trade_count: data["n"],
      vwap: parse_decimal(data["vw"])
    }
  end

  @doc """
  Parse multiple bars from API response.
  """
  @spec from_response(map()) :: %{String.t() => [t()]} | [t()] | map()
  def from_response(%{"bars" => nil}), do: %{}

  def from_response(%{"bars" => bars}) when is_map(bars) do
    Map.new(bars, fn {symbol, bar_list} ->
      {symbol, Enum.map(bar_list, &from_map(&1, symbol))}
    end)
  end

  def from_response(%{"bars" => bars}) when is_list(bars) do
    Enum.map(bars, &from_map/1)
  end

  def from_response(data), do: data
end