From 96a4d76e3c0321a2adddc9dbb3fa1415b3da5db3 Mon Sep 17 00:00:00 2001
From: Eduardo Gurgel <eduardo@gurgel.me>
Date: Sun, 18 May 2014 16:11:10 +1200
Subject: [PATCH] Support multiple values same key on /get

---
 lib/httparrot/general_request_info.ex | 23 ++++++++++++++++++++++-
 test/general_request_info_test.exs    | 21 +++++++++++++++++++--
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/lib/httparrot/general_request_info.ex b/lib/httparrot/general_request_info.ex
index e80189a..bc15750 100644
--- a/lib/httparrot/general_request_info.ex
+++ b/lib/httparrot/general_request_info.ex
@@ -6,8 +6,29 @@ defmodule HTTParrot.GeneralRequestInfo do
     {{ip, _port}, req} = :cowboy_req.peer(req)
 
     ip = :inet_parse.ntoa(ip) |> to_string
-    if args == [], do: args = [{}]
+    args = flatten_dict(args)
 
     {[args: args, headers: headers, url: url, origin: ip], req}
   end
+
+  @doc """
+  Group by keys and if duplicated keys, aggregate them as a list
+
+  iex> flatten_dict([a: "v1", a: "v2", b: "v3"])
+  %{a: ["v1", "v2"], b: "v3"}
+  """
+  @spec flatten_dict(list) :: map
+  def flatten_dict([]), do: %{}
+  def flatten_dict(args) do
+    Enum.group_by(args, %{}, fn {k, _} -> k end)
+      |> Enum.traverse(fn {k1, v1} ->
+           values = Enum.map(v1, fn {_, v2} -> v2 end)
+             |> Enum.reverse
+             |> flatten_if_list_of_one
+           {k1, values}
+         end)
+  end
+
+  defp flatten_if_list_of_one([h]), do: h
+  defp flatten_if_list_of_one(list), do: list
 end
diff --git a/test/general_request_info_test.exs b/test/general_request_info_test.exs
index 9cbd32b..67a40c9 100644
--- a/test/general_request_info_test.exs
+++ b/test/general_request_info_test.exs
@@ -11,6 +11,8 @@ defmodule HTTParrot.GeneralRequestInfoTest do
     unload :cowboy_req
   end
 
+  doctest HTTParrot.GeneralRequestInfo
+
   test "returns a list of args, headers, url and original ip" do
     qs_vals = [{"a", "b"}]
     headers = [header1: "value 1", header2: "value 2"]
@@ -21,7 +23,22 @@ defmodule HTTParrot.GeneralRequestInfoTest do
     expect(:cowboy_req, :url, 1, {url, :req4})
     expect(:cowboy_req, :peer, 1, {{ip, :host}, :req5})
 
-    assert retrieve(:req1) == {[args: qs_vals, headers: headers, url: url, origin: "127.1.2.3"], :req5}
+    assert retrieve(:req1) == {[args: %{"a" => "b"}, headers: headers, url: url, origin: "127.1.2.3"], :req5}
+
+    assert validate :cowboy_req
+  end
+
+  test "returns a list of args with duplicated keys, headers, url and original ip" do
+    qs_vals = [{"a", "b"}, {"a", "c"}]
+    headers = [header1: "value 1", header2: "value 2"]
+    ip = {127, 1, 2, 3}
+    url = "http://localhost/get?a=b&a=c"
+    expect(:cowboy_req, :qs_vals, 1, {qs_vals, :req2})
+    expect(:cowboy_req, :headers, 1, {headers, :req3})
+    expect(:cowboy_req, :url, 1, {url, :req4})
+    expect(:cowboy_req, :peer, 1, {{ip, :host}, :req5})
+
+    assert retrieve(:req1) == {[args: %{"a" => ["b", "c"]}, headers: headers, url: url, origin: "127.1.2.3"], :req5}
 
     assert validate :cowboy_req
   end
@@ -36,7 +53,7 @@ defmodule HTTParrot.GeneralRequestInfoTest do
     expect(:cowboy_req, :url, 1, {url, :req4})
     expect(:cowboy_req, :peer, 1, {{ip, :host}, :req5})
 
-    assert retrieve(:req1) == {[args: [{}], headers: headers, url: url, origin: "127.1.2.3"], :req5}
+    assert retrieve(:req1) == {[args: %{}, headers: headers, url: url, origin: "127.1.2.3"], :req5}
 
     assert validate :cowboy_req
   end