OpenMeteoApi

Section

Mix.install([
  {:vega_lite, "~> 0.1.11"},
  {:kino_vega_lite, "~> 0.1.8"},
  {:req , "~> 0.5.0"}
])

alias VegaLite, as: Vl

# 60.1699° N, 24.9384°  Helsinki
params = %{
  "latitude" => "60.1699",
  "longitude" =>"24.9384",
  "current" => "temperature_2m,wind_speed_10m"
}

defmodule OpenMeteoAPI do
  alias VegaLite, as: Vl
  @url_meteo "https://api.open-meteo.com/v1/forecast"
  @lat "60.1699"
  @lon "24.9384"
  def wind_speed_helsinki() do
    resp =
      Req.get!(@url_meteo,
        params: %{
          "latitude" => @lat,
          "longitude" => @lon,
          "current" => "wind_speed_10m"
        }
      )

    body = OpenMeteoAPI.get_body(resp)
    %{"current" => %{"wind_speed_10m" => wind_speed}} = body
    wind_speed
  end

  def forecast_wind_speed() do
    resp =
      Req.get!(@url_meteo,
        params: %{
          "latitude" => @lat,
          "longitude" => @lon,
          "hourly" => "wind_speed_10m"
        }
      )

    body = OpenMeteoAPI.get_body(resp)
    %{"hourly" => %{"time" => times, "wind_speed_10m" => winds}} = body

    # plot_forecast( times , winds)
    plot_forecast(times, winds)
  end

  def plot_forecast(dates, values) do
    parsed_dates = Enum.map(dates, &parse_naive_datetime/1)

    data =
      Enum.zip(parsed_dates, values)
      |> Enum.map(fn {date, val} -> %{date: date, value: val} end)

    v1 =
      Vl.new(width: 400, height: 200, title: "Hourly wind")
      |> Vl.data_from_values(data)
      |> Vl.mark(:line)
      |> Vl.encode_field(:x, "date", type: :temporal)
      |> Vl.encode_field(:y, "value", type: :quantitative)

    v1
  end

  def get_body(%{body: _meteo_data}) do
    _meteo_data
  end

  def parse_naive_datetime(datetime_str) do
    case NaiveDateTime.from_iso8601(datetime_str) do
      {:ok, dt} ->
        dt
      {:error, :invalid_format} ->
        # Try appending ":00" to fix missing seconds
        {:ok, dt} = NaiveDateTime.from_iso8601(datetime_str <> ":00")
        dt
    end
  end
end

OpenMeteoAPI.forecast_wind_speed()

name = Kino.Input.text("Your name")

button = Kino.Control.button("Click me!")

Req.get!(url, params: params )
    |> OpenMeteoAPI.handle_response_meteo