basic admin endgame view and add (#3)

Reviewed-on: #3

lib/chesstrainer/endgames/endgame.ex

@@ -0,0 +1,41 @@
+defmodule Chesstrainer.Endgames.Endgame do
+  @moduledoc """
+  A singular endgame entry
+  """
+
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @primary_key {:id, :binary_id, autogenerate: true}
+  @foreign_key_type :binary_id
+  schema "endgames" do
+    field :fen, :string
+    field :color, Ecto.Enum, values: [:white, :black]
+    field :key, :string
+    field :message, :string
+    field :notes, :string
+    field :result, Ecto.Enum, values: [:win, :loss, :draw]
+    field :rating, :integer
+    field :rating_deviation, :integer
+    field :times_attempted, :integer
+    field :times_solved, :integer
+
+    many_to_many :tags, Chesstrainer.Tags.Tag,
+      join_through: "endgames_tags",
+      on_replace: :delete
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc false
+  def changeset(endgame, attrs) do
+    endgame
+    |> cast(attrs, [:fen, :key, :message, :notes, :result, :rating, :color])
+    |> validate_required([:fen, :color], message: "Invalid FEN")
+    |> validate_required([:key, :result, :rating])
+    |> validate_format(:key, ~r/^(?=.{5,10}$)KQ*R*[NB]*P*\sv\sKQ*R*[NB]*P*$/,
+      message: "Key must follow pattern KQ.. v KQR.., max pieces 7"
+    )
+    |> unique_constraint(:fen, message: "FEN already exists")
+  end
+end