defmodule Swapi do
  @moduledoc """
  Simple wrapper for the Star Wars API
  """

  alias HTTPoison.Response

  @doc """
  Gets the root url with a list of available resources
  Example:
      iex> Swapi.root
      {:ok,  {...}}
  """
  def root do
    nil
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of people from the Star Wars Universe
  Example:
      iex> Swapi.people
      {:ok,  {[...]}}
      iex> Swapi.people(1)
      {:ok, {...ls(1) }}
  """
  def people(id \\ nil) do
    if id do {"people", id} else "people" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of films from the Star Wars Universe
  Example:
      iex> Swapi.films
      {:ok,  {[...]}}
      iex> Swapi.films(1)
      {:ok, {...ls(1) }}
  """
  def films(id \\ nil) do
    if id do {"films", id} else "films" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of vehicles from the Star Wars Universe
  Example:
      iex> Swapi.vehicles
      {:ok,  {[...]}}
      iex> Swapi.vehicles(1)
      {:ok, {...ls(1) }}
  """
  def vehicles(id \\ nil) do
    if id do {"vehicles", id} else "vehicles" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of starships from the Star Wars Universe
  Example:
      iex> Swapi.starships
      {:ok,  {[...]}}
      iex> Swapi.starships(1)
      {:ok, {...ls(1) }}
  """
  def starships(id \\ nil) do
    if id do {"starships", id} else "starships" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of planets from the Star Wars Universe
  Example:
      iex> Swapi.planets
      {:ok,  {[...]}}
      iex> Swapi.planets(1)
      {:ok, {...ls(1) }}
  """
  def planets(id \\ nil) do
    if id do {"planets", id} else "planets" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets an individual or list of species from the Star Wars Universe
  Example:
      iex> Swapi.species
      {:ok,  {[...]}}
      iex> Swapi.species(1)
      {:ok, {...ls(1) }}
  """
  def species(id \\ nil) do
    if id do {"species", id} else "species" end
    |> build_url
    |> get_data
  end

  @doc """
  Gets the schema for any specific resource
  Example:
      iex> Swapi.schema("people")
      {:ok,  {...}}
  """
  def schema(resource) do
    "http://swapi.co/api/#{resource}/schema"
    |> get_data
  end


  defp get_data(url) do
    url
    |> HTTPoison.get
    |> get_body
  end

  defp build_url({path, id}) do
    "http://swapi.co/api/#{path}/#{id}/"
  end

  defp build_url(path) do
    if path do
      "http://swapi.co/api/#{path}/"
    else
      "http://swapi.co/api/"
    end
  end

  defp get_body({:ok, %Response{status_code: 404}}), do: {:error, "Resource not found"}
  defp get_body({:ok, %Response{body: body}}), do: {:ok, body}

end