Add download, json-parsing

issues/config/config.exs

@@ -0,0 +1,3 @@
+use Mix.Config
+
+config :issues, github_url: "https://api.github.com"

issues/lib/issues/cli.ex

@@ -7,7 +7,9 @@ defmodule Issues.CLI do
   """
 
   def run(argv) do
-    parse_args(argv)
+    argv
+    |> parse_args
+    |> process
   end
 
   @doc """
@@ -38,4 +40,22 @@ defmodule Issues.CLI do
   def args_to_internal_representation(_) do # either bad arg or --help
     :help
   end
+
+  def process(:help) do
+    IO.puts """
+    usage: issues <user> <project> [count | #{@default_count}]
+    """
+    System.halt(0)
+  end
+
+  def process({user, project, count}) do
+    Issues.GithubIssues.fetch(user, project)
+    |> decode_response()
+  end
+
+  def decode_response({:ok, body}), do: body
+  def decode_response({:error, error}) do
+    IO.puts "Error fetching from Github: #{error["message"]}"
+    System.halt(2)
+  end
 end

issues/lib/issues/github_issues.ex

@@ -0,0 +1,30 @@
+defmodule Issues.GithubIssues do
+  
+  @user_agent [ { "User-agent", "Elixir dave@pragprog.com" } ]
+  # use a module attribute to fetch the value at compile time
+  @github_url Application.get_env(:issues, :github_url)
+  
+  def fetch(user, project) do
+    issues_url(user, project)
+    |> HTTPoison.get(@user_agent)
+    |> handle_response 
+  end
+
+  def issues_url(user, project) do
+    "#{@github_url}/repos/#{user}/#{project}/issues"
+  end
+
+  def handle_response( {:ok, %{status_code: status_code, body: body}} ) do
+    {
+      status_code |> check_for_error(),
+      body |> Poison.Parser.parse!()
+    }
+  end
+
+  def handle_response( {_, %{status_code: _, body: body}} ) do
+    { :error, body }
+  end
+
+  defp check_for_error(200), do: :ok
+  defp check_for_error(_), do: :error
+end

issues/mix.exs

@@ -21,6 +21,8 @@ defmodule Issues.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
+      {:httpoison, "~> 1.8.0"},
+      {:poison, "~> 5.0"},
       # {:dep_from_hexpm, "~> 0.3.0"},
       # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
     ]