3 files changed, 171 insertions, 0 deletions
diff --git a/lib/exdatadog.ex b/lib/exdatadog.ex
new file mode 100644
index 0000000..cb1c559
--- /dev/null
+++ b/lib/exdatadog.ex
@@ -0,0 +1,123 @@
+defmodule Exdatadog do
+  @moduledoc """
+  HTTPoison Client for exdatadog
+  """
+  use HTTPoison.Base
+
+  alias Exdatadog.Client
+  alias HTTPoison.Response
+
+  @user_agent [{"user-agent", "exdatadog"}]
+
+  @type response :: {integer, any} | map
+
+  @spec process_response_body(binary) :: map
+  def process_response_body(""), do: nil
+  def process_response_body(body), do: Poison.decode!(body)
+
+  @spec process_response(HTTPoison.Response.t) :: response
+  def process_response(%Response{status_code: status_code, body: body}) do
+    {status_code, body}
+  end
+
+  def post(path, client, body) do
+    _request(:post, url(client, path), client.auth, body)
+  end
+
+  def get(path, client, params \\ [], _ \\ []) do
+    url =
+      client
+      |> url(path)
+      |> add_params_to_url(params)
+
+    _request(:get, url, client.auth)
+
+  end
+
+  def _request(method, url, auth, body \\ "") do
+    json_request(method,
+                 add_params_to_url(url, auth_params(auth)),
+                 body,
+                 @user_agent)
+  end
+
+  def json_request(method, url, body \\ "", headers \\ [], options \\ []) do
+    raw_request(method, url, Poison.encode!(body), headers, options)
+  end
+
+  def raw_request(method, url, body \\ "", headers \\ [], options \\ []) do
+    method
+    |> request!(url, body, headers, options)
+    |> process_response
+  end
+
+  @spec url(Exdatadog.Client.t, binary) :: binary
+  defp url(_client = %Client{endpoint: endpoint}, path) do
+    endpoint <> path
+  end
+
+  @doc """
+  Take an existing URI and add addition parameters, merging as necessary
+
+  ## Examples
+      iex> add_params_to_url("http://example.com/wat", [])
+      "http://example.com/wat"
+      iex> add_params_to_url("http://example.com/wat", [q: 1])
+      "http://example.com/wat?q=1"
+      iex> add_params_to_url("http://example.com/wat", [q: 1, t: 2])
+      "http://example.com/wat?q=1&t=2"
+      iex> add_params_to_url("http://example.com/wat", %{q: 1, t: 2})
+      "http://example.com/wat?q=1&t=2"
+      iex> add_params_to_url("http://example.com/wat?q=1&t=2", [])
+      "http://example.com/wat?q=1&t=2"
+      iex> add_params_to_url("http://example.com/wat?q=1", [t: 2])
+      "http://example.com/wat?q=1&t=2"
+      iex> add_params_to_url("http://example.com/wat?q=1", [q: 3, t: 2])
+      "http://example.com/wat?q=3&t=2"
+      iex> add_params_to_url("http://example.com/wat?q=1&s=4", [q: 3, t: 2])
+      "http://example.com/wat?q=3&s=4&t=2"
+      iex> add_params_to_url("http://example.com/wat?q=1&s=4", %{q: 3, t: 2})
+      "http://example.com/wat?q=3&s=4&t=2"
+
+  """
+  @spec add_params_to_url(binary, list) :: binary
+  def add_params_to_url(url, params) do
+    url
+    |> URI.parse
+    |> merge_uri_params(params)
+    |> to_string
+  end
+
+  defp merge_uri_params(uri, []), do: uri
+  defp merge_uri_params(%URI{query: nil} = uri, params)
+      when is_list(params) or is_map(params) do
+    uri
+    |> Map.put(:query, URI.encode_query(params))
+  end
+  defp merge_uri_params(%URI{} = uri, params)
+      when is_list(params) or is_map(params) do
+    uri
+    |> Map.update!(:query, fn q ->
+      q
+      |> URI.decode_query
+      |> Map.merge(param_list_to_map_with_string_keys(params))
+      |> URI.encode_query
+    end)
+  end
+
+  defp param_list_to_map_with_string_keys(list)
+      when is_list(list) or is_map(list) do
+    for {key, value} <- list, into: Map.new do
+      {"#{key}", value}
+    end
+  end
+
+  def auth_params(%{api_key: api_key, app_key: app_key}) do
+    [application_key: app_key, api_key: api_key]
+  end
+  def auth_params(%{api_key: api_key}) do
+    [api_key: api_key]
+  end
+  def auth_params(_), do: []
+
+end
diff --git a/lib/exdatadog/client.ex b/lib/exdatadog/client.ex
new file mode 100644
index 0000000..02c1017
--- /dev/null
+++ b/lib/exdatadog/client.ex
@@ -0,0 +1,33 @@
+defmodule Exdatadog.Client do
+  @moduledoc """
+  Datadog Client record for endpoint and authentication data
+  """
+
+  import Exdatadog.Config, only: [get_env_var: 2]
+
+  defstruct auth: nil, endpoint: "https://app.datadoghq.com/"
+
+  @type auth :: %{api_key: binary, app_key: binary} | %{api_key: binary}
+  @type t :: %__MODULE__{auth: auth, endpoint: binary}
+
+  @spec new() :: t
+  def new() do
+    auth = %{api_key: get_env_var(:exdatadog, :api_key),
+             app_key: get_env_var(:exdatadog, :app_key)}
+    %__MODULE__{auth: auth}
+  end
+
+  @spec new(auth) :: t
+  def new(auth), do: %__MODULE__{auth: auth}
+
+  @spec new(auth, binary) :: t
+  def new(auth, endpoint) do
+    endpoint = if String.ends_with?(endpoint, "/") do
+      endpoint
+    else
+      endpoint <> "/"
+    end
+    %__MODULE__{auth: auth, endpoint: endpoint}
+  end
+
+end
diff --git a/lib/exdatadog/config.ex b/lib/exdatadog/config.ex
new file mode 100644
index 0000000..f686309
--- /dev/null
+++ b/lib/exdatadog/config.ex
@@ -0,0 +1,15 @@
+defmodule Exdatadog.Config do
+  @moduledoc """
+  Provides helper functions for interacting with Application variables
+  """
+
+  def get_env_var(app, key, default \\ nil) do
+    app
+    |> Application.get_env(key, default)
+    |> case do
+      {:system, env_key} -> System.get_env(env_key)
+      env_var -> env_var
+    end
+  end
+
+end