################################################################################
# Copyright 2015 Marcelo Gornstein <marcelog@gmail.com>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
################################################################################
defmodule RFC3986.Normalize do
  # fragment      = *( pchar / "/" / "?" )
  def parse(state = %{error: error}) when error != nil do
    state
  end

  def parse(state) do
    state |> port |> userinfo |> query_string
  end

  defp port(state = %{port: nil}) do
    state
  end

  defp port(state) do
    {p, _} = Integer.parse to_string(state.port)
    %{state | port: p}
  end

  defp userinfo(state = %{userinfo: nil}) do
    state
  end

  defp userinfo(state) do
    userinfo state, state.userinfo, []
  end

  defp userinfo(state, [?:|rest], acc) do
    %{state | username: Enum.reverse(acc), password: rest}
  end

  defp userinfo(state, [char|rest], acc) do
    userinfo state, rest, [char|acc]
  end

  defp query_string(state = %{query: nil}) do
    state
  end

  defp query_string(state) do
    query_string state, state.query, []
  end

  defp query_string(state, [], []) do
    state
  end

  defp query_string(state = %{query_string: map}, [], acc) do
    k = Enum.reverse acc
    %{state | query_string: Map.put(map, k, nil)}
  end

  defp query_string(state = %{query_string: map}, [?&|rest], acc) do
    k = Enum.reverse acc
    query_string %{state | query_string: Map.put(map, k, nil)}, rest, []
  end

  defp query_string(state = %{query_string: map}, [?=|rest], acc) do
    k = Enum.reverse acc
    {v, rest} = query_string_value rest
    query_string %{state | query_string: Map.put(map, k, v)}, rest, []
  end

  defp query_string(state, [char|rest], acc) do
    query_string state, rest, [char|acc]
  end

  defp query_string_value([]) do
    {nil, []}
  end

  defp query_string_value(text) do
    query_string_value text, []
  end

  defp query_string_value([], []) do
    {nil, []}
  end

  defp query_string_value([], acc) do
    {Enum.reverse(acc), []}
  end

  defp query_string_value([?&|rest], acc) do
    {Enum.reverse(acc), rest}
  end

  defp query_string_value([char|rest], acc) do
    query_string_value rest, [char|acc]
  end
end