appwrite

defmodule ImageGravity do
  @moduledoc """

  Provides constants and validation functions for image gravity (positioning) values.



  This module defines various image gravity options, such as `center`, `top-left`, `bottom-right`, etc.

  Helper functions are included to validate these gravity values, ensuring only recognized positioning options are used.

  """

  @center "center"
  @top_left "top-left"
  @top "top"
  @top_right "top-right"
  @left "left"
  @right "right"
  @bottom_left "bottom-left"
  @bottom "bottom"
  @bottom_right "bottom-right"

  @all_gravities [

    @center,

    @top_left,

    @top,

    @top_right,

    @left,

    @right,

    @bottom_left,

    @bottom,

    @bottom_right

  ]



  @doc """

  Guard clause to check if a given `image gravity` is a valid  image gravity code.



  ## Examples



      iex> ImageGravity.valid_gravity("center")

      true



      iex> ImageGravity.valid_gravity("down_right")

      false

  """
  @spec valid_gravity(String.t()) :: boolean()
  defguard valid_gravity(image_gravity) when image_gravity in @all_gravities



  @doc """

  Returns true if the given `gravity` is a valid image gravity value.



  ## Examples



      iex> ImageGravity.is_valid_gravity?("top-left")

      true



      iex> ImageGravity.is_valid_gravity?("middle")

      false

  """
  @spec is_valid_gravity?(String.t()) :: boolean()
  def is_valid_gravity?(gravity), do: gravity in @all_gravities

  @doc """

  Validates the given `gravity` and returns `{:ok, gravity}` if it is valid,

  or `{:error, "Invalid image gravity"}` otherwise.



  ## Examples



      iex> ImageGravity.validate_gravity("top-right")

      {:ok, "top-right"}



      iex> ImageGravity.validate_gravity("middle")

      {:error, "Invalid image gravity"}

  """
  @spec validate_gravity(String.t()) :: {:ok, String.t()} | {:error, String.t()}
  def validate_gravity(gravity) when gravity in @all_gravities, do: {:ok, gravity}
  def validate_gravity(_gravity), do: {:error, "Invalid image gravity"}

  @doc """

  Returns the given `gravity` if it is valid. Raises an `ArgumentError`

  if the `gravity` is invalid.



  ## Examples



      iex> ImageGravity.validate_gravity!("center")

      "center"



      iex> ImageGravity.validate_gravity!("middle")

      ** (ArgumentError) Invalid image gravity: "middle"

  """
  @spec validate_gravity!(String.t()) :: String.t()
  def validate_gravity!(gravity) do
    if gravity in @all_gravities do
      gravity
    else
      raise ArgumentError, "Invalid image gravity: #{inspect(gravity)}"
    end
  end
end