defmodule NetcdfNif do
  @moduledoc """
  Documentation for NetcdfNif.

  See the `c_src/netcdf_nif.c` file for detailed documentation on
  functions and parameters.

  Also, see the `test.exs` file for a sample Elixir script and
  `test.erl` for the Erlang version.

    iex> c "test.exs"
    NetcdfNif.Test.run()

  Inspect the `hello.nc` file with

    ncdump hello.nc
  """

  @on_load :load_nifs

  def load_nifs() do
    #:erlang.load_nif('./priv/netcdf_nif_ex', 0)
    path = Path.join([:code.priv_dir(:netcdf_nif), "netcdf_nif_ex"])
    case :erlang.load_nif(path, 0) do
      :ok -> :ok
      error -> {:error, error}
    end
  end

  @doc """
  nc type for a variable

  https://docs.unidata.ucar.edu/netcdf-c/current/netcdf_8h.html#afe40bef4fdf46f2820e9cd64c64a11b5
  """
  def nc_type(:nat) do
    0
  end
  def nc_type(:byte) do
    1
  end
  def nc_type(:char) do
    2
  end
  def nc_type(:short) do
    3
  end
  def nc_type(:int) do
    4
  end
  def nc_type(:long) do
    nc_type(:int)
  end
  def nc_type(:float) do
    5
  end
  def nc_type(:double) do
    6
  end
  def nc_type(:ubyte) do
    7
  end
  def nc_type(:ushort) do
    8
  end
  def nc_type(:uint) do
    9
  end
  def nc_type(:int64) do
    10
  end
  def nc_type(:uint64) do
    11
  end
  def nc_type(:string) do
    12
  end

  @doc """
  Create the NetCDF file.

  Argument is file path.

  Returns the file id.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__datasets.html#ga041eacc9554e03d78a154a76e31e5b30

  ## Example

      iex> NetcdfNif.nc_create("hello.nc")
      6255
  """
  def nc_create(_) do
    :nif_not_loaded
  end

  @doc """
  Close the NetCDF file.

  Argument is file id.

  Returns nil.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__datasets.html#ga07cbeee9c98b5b21713df60310edc3b1

  ## Example

      iex> NetcdfNif.nc_close(6255)
      nil
  """
  def nc_close(_) do
    :nif_not_loaded
  end

  @doc """
  Define a dimension.

  Arguments are: file id, dimension name, dimension size.

  Returns dimension id.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__dimensions.html#ga6a1e2683ca1acf91437b790979ac7b8a

  ## Example
      iex> NetcdfNif.nc_def_dim(6255, 'latitude', 6)
      111
  """
  def nc_def_dim(_, _, _) do
    :nif_not_loaded
  end

  @doc """
  Define a variable.

  Arguments are: file id, variable name, nc type, number of dimensions, dimension id.

  Returns variable id.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__variables.html#gac7e8662c51f3bb07d1fc6d6c6d9052c8

  ## Example
      iex> NetcdfNif.nc_def_var(6255, 'latitude', NetcdfNif.nc_type(:double), 1, 111)
      222
  """
  def nc_def_var(_, _, _, _, _) do
    :nif_not_loaded
  end

  @doc """
  Define a text attribute for a variable.

  Arguments are: file id, variable id, attribute name, attribute value (string).

  https://docs.unidata.ucar.edu/netcdf-c/current/group__attributes.html#ga4fbf52b467add3788ecbf17d211af079

  ## Example
      iex> NetcdfNif.nc_put_att_text(6255, 222, 'units', 'degrees_north')
  """
  def nc_put_att_text(_, _, _, _) do
    :nif_not_loaded
  end

  @doc """
  Define a double attribute for a variable.

  Arguments are: file id, variable id, attribute name, attribute value (double).

  Can be used to, e.g., specify `_FillValue` as described here:
  https://docs.unidata.ucar.edu/netcdf-c/current/fill_values.html

  https://docs.unidata.ucar.edu/netcdf-c/current/group__attributes.html#ga4fbf52b467add3788ecbf17d211af079

  ## Example
      iex> NetcdfNif.nc_put_att_double(6255, 222, '_FillValue', 1.0)
  """
  def nc_put_att_double(_, _, _, _) do
    :nif_not_loaded
  end

  def nc_enddef(_) do
    :nif_not_loaded
  end

  @doc """
  Put a single (double) value into given variable.

  Arguments are: file id, variable id, value (of double type).

  Returns nil.

  *NOTE* It still needs some work as I'm not sure of the `indexp` variable.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__variables.html#ga29e99cbc7ed704a14100e17d9eec8a66

  ## Example
      iex> NetcdfNif.nc_put_var1_double(6255, 222, 1.0)
      nil
  """
  def nc_put_var1_double(_, _, _) do
    :nif_not_loaded
  end

  @doc """
  Put a list of (double) values into given variable.

  Arguments are: file id, variable id, list of doubles.

  Returns nil.

  https://docs.unidata.ucar.edu/netcdf-c/current/group__variables.html#ga29e99cbc7ed704a14100e17d9eec8a66

  ## Example
      iex> NetcdfNif.nc_put_var_double(6255, 222, {1.0, 2.0, 3.0})
      nil
  """
  def nc_put_var_double(_, _, _) do
    :nif_not_loaded
  end
end