refactor vote calculator, run mix format, address comments

Author: SophieDeBenedetto

config/cards.exs

@@ -15,7 +15,6 @@ config :pointing_party,
       Update the application to save an individual's vote and the final card points to the database.
       """
     },
-
     %{
       title: "Add Guardian dependency",
       description: """
@@ -34,5 +33,5 @@ config :pointing_party,
       description: """
       Update our existing authentication flow to use the newly created Auth module.
       """
-    },
+    }
   ]

lib/pointing_party/account.ex

@@ -11,6 +11,7 @@ defmodule PointingParty.Account do
 
   def create(attrs) do
     changeset = changeset(%Account{}, attrs)
+
     if changeset.valid? do
       account = apply_changes(changeset)
       {:ok, account}

lib/pointing_party/vote_calculator.ex

@@ -1,5 +1,4 @@
 defmodule PointingParty.VoteCalculator do
-
   def calculate_votes(users) do
     case winning_vote(users) do
       top_two when is_list(top_two) -> {"tie", top_two}
@@ -8,30 +7,64 @@ defmodule PointingParty.VoteCalculator do
   end
 
   def winning_vote(users) do
-    votes = Enum.map(users, fn {_username, %{metas: [%{points: points}]}} -> points end)
-    calculated_votes = Enum.reduce(votes, %{}, fn vote, acc ->
-      acc
-      |> Map.get_and_update(vote, &({&1, (&1 || 0) + 1}))
-      |> elem(1)
-    end)
-    total_votes = length(votes)
-
-    majority_share = total_votes / 2 |> Float.floor()
-    majority = Enum.reduce_while(calculated_votes, nil, fn {point, vote_count}, _acc ->
-      if vote_count == total_votes or rem(vote_count, total_votes) > majority_share do
-        {:halt, point}
-      else
-        {:cont, nil}
-      end
-    end)
-
-    if is_nil(majority) do
-      calculated_votes
-      |> Enum.sort_by(&elem(&1, 1))
-      |> Enum.take(2)
-      |> Enum.map(&elem(&1, 0))
-    else
-      majority
-    end
+    initial_score_card()
+    |> get_points(users)
+    |> calculate_vote_ratios()
+    |> calculate_majority()
+    |> handle_tie()
+  end
+
+  def initial_score_card do
+    %{votes: nil, calculated_votes: nil, majority: nil}
+  end
+
+  defp get_points(score_card, users) do
+    votes =
+      users
+      |> Enum.map(fn {_username, %{metas: [%{points: points}]}} ->
+        points
+      end)
+
+    update_score_card(score_card, :votes, votes)
+  end
+
+  defp calculate_vote_ratios(%{votes: votes} = score_card) do
+    calculated_votes =
+      Enum.reduce(votes, %{}, fn vote, acc ->
+        acc
+        |> Map.get_and_update(vote, &{&1, (&1 || 0) + 1})
+        |> elem(1)
+      end)
+
+    update_score_card(score_card, :calculated_votes, calculated_votes)
+  end
+
+  defp calculate_majority(score_card) do
+    total_votes = length(score_card.votes)
+    majority_share = (total_votes / 2) |> Float.floor()
+
+    majority =
+      Enum.reduce_while(score_card.calculated_votes, nil, fn {point, vote_count}, _acc ->
+        if vote_count == total_votes or rem(vote_count, total_votes) > majority_share do
+          {:halt, point}
+        else
+          {:cont, nil}
+        end
+      end)
+
+    update_score_card(score_card, :majority, majority)
+  end
+
+  defp handle_tie(%{majority: nil, calculated_votes: calculated_votes}) do
+    calculated_votes
+    |> Enum.sort_by(&elem(&1, 1))
+    |> Enum.take(2)
+    |> Enum.map(&elem(&1, 0))
+  end
+
+  defp handle_tie(%{majority: majority}), do: majority
+
+  defp update_score_card(score_card, key, value) do
+    Map.put(score_card, key, value)
   end
 end

lib/pointing_party_web/channels/presence.ex

@@ -1,4 +1,5 @@
 defmodule PointingPartyWeb.Presence do
-  use Phoenix.Presence, otp_app: :pointing_party,
-                        pubsub_server: PointingParty.PubSub
+  use Phoenix.Presence,
+    otp_app: :pointing_party,
+    pubsub_server: PointingParty.PubSub
 end

lib/pointing_party_web/channels/room_channel.ex

@@ -19,7 +19,7 @@ defmodule PointingPartyWeb.RoomChannel do
   end
 
   def handle_in("user_estimated", %{"points" => points}, socket) do
-    Presence.update(socket, socket.assigns.username, &(Map.put(&1, :points, points)))
+    Presence.update(socket, socket.assigns.username, &Map.put(&1, :points, points))
 
     if everyone_voted?(socket) do
       finalize_voting(socket)
@@ -62,6 +62,7 @@ defmodule PointingPartyWeb.RoomChannel do
   end
 
   defp initialize_state(%{assigns: %{cards: _cards}} = socket), do: socket
+
   defp initialize_state(socket) do
     [first | cards] = Card.cards()
 

lib/pointing_party_web/controllers/session_controller.ex

@@ -15,13 +15,13 @@ defmodule PointingPartyWeb.SessionController do
         |> put_session(:username, username)
         |> redirect(to: "/cards")
         |> halt()
+
       {:error, changeset} ->
         render(conn, "new.html", changeset: changeset)
     end
   end
 
   def delete(conn, _params) do
-    clear_session(conn)
-    |> redirect(to: "/login") |> halt()
+    clear_session(conn) |> redirect(to: "/login") |> halt()
   end
 end

lib/pointing_party_web/plugs/auth.ex

@@ -12,6 +12,6 @@ defmodule PointingPartyWeb.Plugs.Auth do
   end
 
   defp authenticate(conn) do
-     get_session(conn, :username)
+    get_session(conn, :username)
   end
 end

priv/repo/migrations/20190708014847_create_cards.exs

@@ -3,11 +3,10 @@ defmodule PointingParty.Repo.Migrations.CreateCards do
 
   def change do
     create table(:cards) do
-      add :title, :string
-      add :description, :string
+      add(:title, :string)
+      add(:description, :string)
 
       timestamps()
     end
-
   end
 end

priv/repo/migrations/20190714140153_add_points_to_cards.exs

@@ -3,7 +3,7 @@ defmodule PointingParty.Repo.Migrations.AddPointsToCards do
 
   def change do
     alter table("cards") do
-      add :points, :integer, default: 0
+      add(:points, :integer, default: 0)
     end
   end
 end

priv/repo/seeds.exs

@@ -10,7 +10,6 @@
 # We recommend using the bang functions (`insert!`, `update!`
 # and so on) as they will fail if something goes wrong.
 
-
 alias PointingParty.{Card, Repo}
 
 cards = [
@@ -21,7 +20,7 @@ cards = [
   %{title: "Fifth card", description: "This is a description of the fifth card."},
   %{title: "Sixth card", description: "This is a description of the sixth card."},
   %{title: "Seventh card", description: "This is a description of the seventh card."},
-  %{title: "Eighth card", description: "This is a description of the eighth card."},
+  %{title: "Eighth card", description: "This is a description of the eighth card."}
 ]
 
 Enum.each(cards, fn card ->