defmodule ShortcutApi.Epics do
  import ShortcutApi.ApiHelpers

  @behaviour ShortcutApi.EpicsBehavior
  @moduledoc """
  API wrapper for Shortcut Epics endpoints.
  See: https://developer.shortcut.com/api/rest/v3#Epics

  All functions require a valid Shortcut API token.
  """

  @type token :: String.t()
  @type epic_id :: pos_integer()
  @type response :: {:ok, map() | list(map())} | {:error, any()}

  @doc """
  Retrieves a single epic by ID.

  ## Parameters
    * `token` - Shortcut API token
    * `epic_id` - The ID of the epic to retrieve

  ## Examples

      iex> ShortcutApi.Epics.get_epic("token", 12345)
      {:ok, %{id: 12345, name: "Epic name"}}

  """
  @spec get_epic(token(), epic_id()) :: response()
  def get_epic(token, epic_id)
      when is_binary(token) and is_integer(epic_id) and epic_id > 0 do
    make_request(:get, "/epics/#{epic_id}", token)
  end

  @doc """
  Creates a new epic.

  ## Parameters
    * `token` - Shortcut API token
    * `params` - Map containing the epic parameters

  ## Required params
    * `:name` - Epic name
    * `:workflow_state_id` - The ID of the workflow state

  ## Examples

      iex> params = %{name: "New Epic", workflow_state_id: 123}
      iex> ShortcutApi.Epics.create_epic("token", params)
      {:ok, %{id: 12345, name: "New Epic"}}

  """
  @spec create_epic(token(), map()) :: response()
  def create_epic(token, params) when is_binary(token) and is_map(params) do
    with :ok <- validate_required(params, [:name, :workflow_state_id]) do
      make_request(:post, "/epics", token, json: params)
    end
  end

  @doc """
  Updates an existing epic.

  ## Parameters
    * `token` - Shortcut API token
    * `epic_id` - The ID of the epic to update
    * `params` - Map containing the update parameters

  ## Examples

      iex> params = %{name: "Updated Epic Name"}
      iex> ShortcutApi.Epics.update_epic("token", 12345, params)
      {:ok, %{id: 12345, name: "Updated Epic Name", ...}}

  """
  @spec update_epic(token(), epic_id(), map()) :: response()
  def update_epic(token, epic_id, params)
      when is_binary(token) and is_integer(epic_id) and epic_id > 0 and is_map(params) do
    make_request(:put, "/epics/#{epic_id}", token, json: params)
  end

  @doc """
  Deletes an epic.

  ## Parameters
    * `token` - Shortcut API token
    * `epic_id` - The ID of the epic to delete

  ## Examples

      iex> ShortcutApi.Epics.delete_epic("token", 12345)
      {:ok, %{}}

  """
  @spec delete_epic(token(), epic_id()) :: response()
  def delete_epic(token, epic_id)
      when is_binary(token) and is_integer(epic_id) and epic_id > 0 do
    make_request(:delete, "/epics/#{epic_id}", token)
  end

  @doc """
  Lists all epics.

  ## Parameters
    * `token` - Shortcut API token

  ## Examples

      iex> ShortcutApi.Epics.list_epics("token")
      {:ok, [%{id: 12345, name: "Epic name"}, ...]}

  """
  @spec list_epics(token()) :: response()
  def list_epics(token) when is_binary(token) do
    make_request(:get, "/epics", token)
  end

  @doc """
  Get the epic workflow state.

  ## Parameters
    * `token` - Shortcut API token

  ## Examples

      iex> ShortcutApi.Epics.get_epic_workflow("token")
      {:ok, %{states: [%{id: 123, name: "In Progress"}, ...]}}

  """
  @spec get_epic_workflow(token()) :: response()
  def get_epic_workflow(token) when is_binary(token) do
    make_request(:get, "/epic-workflow", token)
  end

  @doc """
  Get statistics for a specific epic.

  ## Parameters
    * `token` - Shortcut API token
    * `epic_id` - The ID of the epic to get stats for

  ## Examples

      iex> ShortcutApi.Epics.get_epic_stats("token", 12345)
      {:ok, %{num_points: 10, num_stories: 5, ...}}

  """
  @spec get_epic_stats(token(), epic_id()) :: response()
  def get_epic_stats(token, epic_id)
      when is_binary(token) and is_integer(epic_id) and epic_id > 0 do
    make_request(:get, "/epics/#{epic_id}/stats", token)
  end

  @doc """
  Get details about a specific epic state.

  ## Parameters
    * `token` - Shortcut API token
    * `state_id` - The ID of the epic state to retrieve

  ## Examples

      iex> ShortcutApi.Epics.get_epic_state("token", 12345)
      {:ok, %{id: 12345, name: "In Progress", ...}}

  """
  @spec get_epic_state(token(), pos_integer()) :: response()
  def get_epic_state(token, state_id)
      when is_binary(token) and is_integer(state_id) and state_id > 0 do
    make_request(:get, "/epic-workflow/states/#{state_id}", token)
  end
end

defmodule ShortcutApi.EpicsBehavior do
  @moduledoc """
  A behaviour for interacting with Shortcut Epics API endpoints.

  This module defines the required callbacks for operations related to epics,
  including retrieving, creating, updating, deleting, and managing epic states
  and statistics. Implementations of this behaviour must provide the necessary
  logic to handle interactions with the Shortcut API.

  All callbacks require a valid Shortcut API token.
  """
  @callback get_epic(token :: String.t(), epic_id :: pos_integer()) ::
              {:ok, map()} | {:error, any()}
  @callback create_epic(token :: String.t(), params :: map()) :: {:ok, map()} | {:error, any()}
  @callback update_epic(token :: String.t(), epic_id :: pos_integer(), params :: map()) ::
              {:ok, map()} | {:error, any()}
  @callback delete_epic(token :: String.t(), epic_id :: pos_integer()) ::
              {:ok, map()} | {:error, any()}
  @callback list_epics(token :: String.t()) :: {:ok, list(map())} | {:error, any()}
  @callback get_epic_workflow(token :: String.t()) :: {:ok, map()} | {:error, any()}
  @callback get_epic_stats(token :: String.t(), epic_id :: pos_integer()) ::
              {:ok, map()} | {:error, any()}
  @callback get_epic_state(token :: String.t(), state_id :: pos_integer()) ::
              {:ok, map()} | {:error, any()}
end