Ability to save, list, and load characters

.gitignore

@@ -30,3 +30,4 @@ ex_ttrpg_dev
 
 # Ignore custom/local rule system configs
 /local_system_configs/
+/local_characters/

lib/globals.ex

@@ -3,6 +3,7 @@ defmodule ExTTRPGDev.Globals do
   Module which defines globals like project paths
   """
   @project_root File.cwd!()
+  @characters_path Path.join(~w(#{@project_root} local_characters))
   @system_configs_path Path.join(~w(#{@project_root} priv system_configs))
   @local_system_configs_path Path.join(~w(#{@project_root} local_system_configs))
   @license_file_name "license.md"
@@ -21,6 +22,19 @@ defmodule ExTTRPGDev.Globals do
     @project_root
   end
 
+  @doc """
+  The path to where characters are stored on your machine
+
+  ## Examples
+
+      iex> ExTTRPGDev.Globals.characters_path()
+      "/full/path/to/project/ex_ttrpg_dev/priv/characters"
+
+  """
+  def characters_path do
+    @characters_path
+  end
+
   @doc """
   The path to where system configs are stored
 

lib/rule_systems/characters.ex

@@ -2,11 +2,116 @@ defmodule ExTTRPGDev.RuleSystems.Characters do
   @moduledoc """
   This module handles the definition of rule system characters, and what they do
   """
+  alias ExTTRPGDev.Globals
+
+  defmodule CharacterMetadata do
+    @moduledoc """
+    Metadata for an individual charater
+    """
+    defstruct [:slug, :rule_system]
+  end
 
   defmodule Character do
     @moduledoc """
     Definition of an individual character
     """
-    defstruct [:name, :ability_scores, :rule_system]
+    defstruct [:name, :ability_scores, :metadata]
+  end
+
+  def from_json!(character_json) when is_bitstring(character_json) do
+    character_json
+    |> Poison.decode!(
+      as: %Character{
+        metadata: %CharacterMetadata{
+          rule_system: %ExTTRPGDev.RuleSystems.Metadata{}
+        }
+      }
+    )
+  end
+
+  @doc """
+  Get the file path for a character
+
+  ## Examples
+
+      iex> Characters.character_file_path!(%Character{metadata: %CharacterMetadata{slug: "mr_whiskers"}})
+      "mr_whiskers.json"
+  """
+  def character_file_path!(%Character{metadata: %CharacterMetadata{slug: slug}}),
+    do: character_file_path!(slug)
+
+  def character_file_path!(character_slug) when is_bitstring(character_slug) do
+    Path.join(Globals.characters_path(), "#{character_slug}.json")
+  end
+
+  @doc """
+  Returns a boolean as to whether the character exists on disk
+
+  ## Examples
+
+      iex> Characters.character_exists?(%Characters.Character{name: "This Character exists"})
+      true
+
+      iex> Characters.Character_exists?(%Characters.Character{name: "This character doesn't exist})
+      false
+  """
+  def character_exists?(%Character{} = character) do
+    character
+    |> character_file_path!
+    |> File.exists?()
+  end
+
+  @doc """
+  Saves the given character to disk. Error is raised if character already exists unless `overwrite` is set to true
+
+  ## Example
+
+      iex> Characters.save_character!(%Characters.Character{name: "doesn't exist yet"})
+      :ok
+
+      iex> Characters.save_character!(%Characters.Character{name: "exists already"})
+      :error, :character already exists
+
+      iex> Characters.save_character!(%Characters.Character{name: "exists already"}, true)
+      :ok
+  """
+  def save_character!(
+        %Character{} = character,
+        overwrite \\ false
+      ) do
+    if character_exists?(character) and not overwrite do
+      raise "Character named #{character.name} already exsts. To overwrite, pass `overwrite` as true"
+    else
+      File.mkdir_p!(Globals.characters_path())
+      File.write!(character_file_path!(character), Poison.encode!(character))
+    end
+  end
+
+  @doc """
+  List saved characters
+
+  ## Example
+
+      iex> Characters.list_characters!()
+      [%Character{}, %Character{}, ...]
+  """
+  def list_characters!() do
+    Globals.characters_path()
+    |> File.ls!()
+    |> Enum.map(fn x -> String.trim_trailing(x, ".json") end)
+  end
+
+  @doc """
+  Load a saved character
+
+  ## Example
+
+      iex> Character.load_character!("misu_park_the_cat")
+      %Character{}
+  """
+  def load_character!(character_slug) do
+    character_file_path!(character_slug)
+    |> File.read!()
+    |> from_json!()
   end
 end

lib/rule_systems/rule_system.ex

@@ -101,10 +101,19 @@ defmodule ExTTRPGDev.RuleSystems.RuleSystem do
         abilities: %Abilities{} = abilities,
         metadata: %Metadata{} = metadata
       }) do
+    name = Faker.Person.name()
+
     %Characters.Character{
-      name: Faker.Person.name(),
+      name: name,
       ability_scores: Abilities.gen_scores(abilities),
-      rule_system: metadata
+      metadata: %Characters.CharacterMetadata{
+        slug:
+          name
+          |> String.downcase()
+          |> String.replace(~r/[!#$%&()*+,.:;<=>?@\^_`'{|}~-]/, "")
+          |> String.replace(" ", "_"),
+        rule_system: metadata
+      }
     }
   end
 end

test/characters_test.exs

@@ -0,0 +1,90 @@
+defmodule ExTTRPGDevTest.Characters do
+  use ExUnit.Case
+  alias ExTTRPGDev.RuleSystems.Characters
+  alias ExTTRPGDev.RuleSystems.RuleSystem
+  alias ExTTRPGDev.RuleSystems
+
+  doctest ExTTRPGDev.RuleSystems.Characters,
+    except: [
+      character_file_path!: 1,
+      character_exists?: 1,
+      save_character!: 1,
+      save_character!: 2,
+      list_characters!: 0,
+      load_character!: 1
+    ]
+
+  def build_test_character do
+    RuleSystems.list_systems()
+    |> List.first()
+    |> RuleSystems.load_system!()
+    |> RuleSystem.gen_character!()
+  end
+
+  def save_test_character do
+    character = build_test_character()
+    Characters.save_character!(character)
+    character
+  end
+
+  def delete_test_character(%Characters.Character{} = character) do
+    File.rm(Characters.character_file_path!(character))
+  end
+
+  test "character_exists?/1" do
+    character = build_test_character()
+    assert not Characters.character_exists?(character)
+
+    Characters.save_character!(character)
+    assert Characters.character_exists?(character)
+
+    # cleanup
+    delete_test_character(character)
+  end
+
+  test "save_character!/1" do
+    character = build_test_character()
+    assert not Characters.character_exists?(character)
+
+    Characters.save_character!(character)
+    assert Characters.character_exists?(character)
+
+    assert_raise RuntimeError, fn -> Characters.save_character!(character) end
+
+    # cleanup
+    delete_test_character(character)
+  end
+
+  test "save_character!/2" do
+    character = build_test_character()
+    assert not Characters.character_exists?(character)
+
+    Characters.save_character!(character)
+    assert Characters.character_exists?(character)
+
+    Characters.save_character!(character, true)
+    assert Characters.character_exists?(character)
+
+    # cleanup
+    delete_test_character(character)
+  end
+
+  test "list_characters!/0" do
+    characters_list_first = Characters.list_characters!()
+    character = save_test_character()
+    characters_list_second = Characters.list_characters!()
+    assert Enum.count(characters_list_first) < Enum.count(characters_list_second)
+    assert Enum.member?(characters_list_second, character.metadata.slug)
+
+    # cleanup
+    delete_test_character(character)
+  end
+
+  test "load_character/1" do
+    character = save_test_character()
+    loaded_character = Characters.load_character!(character.metadata.slug)
+    assert character == loaded_character
+
+    delete_test_character(character)
+  end
+end

test/rule_systems_test.exs

@@ -141,7 +141,9 @@ defmodule ExTTRPGDevTest.RuleSystems do
     generated_character = RuleSystems.RuleSystem.gen_character!(dnd_5e_srd)
 
     assert generated_character.name != nil
-    assert generated_character.rule_system == dnd_5e_srd.metadata
+    assert generated_character.metadata.slug != nil
+    assert not String.contains?(generated_character.metadata.slug, " ")
+    assert generated_character.metadata.rule_system == dnd_5e_srd.metadata
 
     # Assert that each ability spec is found within the generated character's ability_scores
     dnd_5e_srd.abilities.specs