defmodule AiReplacePrompt do
  @moduledoc """
  Utility functions for generating AI image replacement prompts based on Supermaker.ai's blog.
  """

  @base_url "https://supermaker.ai/api"

  @doc """
  Builds a URL by appending optional parameters to a base URL.

  ## Examples

      iex> AiReplacePrompt.build_url("/images", [size: "small", format: "jpeg"])
      "https://supermaker.ai/api/images?size=small&format=jpeg"

      iex> AiReplacePrompt.build_url("/users")
      "https://supermaker.ai/api/users"
  """
  def build_url(path, params \\ []) when is_list(params) do
    url = @base_url <> path

    case params do
      [] -> url
      _ ->
        query_string =
          params
          |> Enum.map(fn {key, value} -> "#{key}=#{value}" end)
          |> Enum.join("&")

        "#{url}?#{query_string}"
    end
  end

  @doc """
  Generates a prompt for replacing an object in an image.

  ## Examples

      iex> AiReplacePrompt.generate_replace_prompt("dog", "cat", "realistic")
      "Replace the dog with a cat, in a realistic style."

      iex> AiReplacePrompt.generate_replace_prompt("sky", "sunset")
      "Replace the sky with a sunset, in a  style."
  """
  def generate_replace_prompt(object_to_replace, replacement_object, style \\ "") when is_binary(object_to_replace) and is_binary(replacement_object) and is_binary(style) do
    style_string =
      case style do
        "" -> ""
        _ -> ", in a #{style} style"
      end

    "Replace the #{object_to_replace} with a #{replacement_object}#{style_string}."
  end

  @doc """
  Creates a prompt specifically for changing the background of an image.

  ## Examples

      iex> AiReplacePrompt.generate_background_prompt("beach")
      "Replace the background with a beach."

      iex> AiReplacePrompt.generate_background_prompt("mountain landscape", "photorealistic")
      "Replace the background with a mountain landscape, in a photorealistic style."
  """
  def generate_background_prompt(new_background, style \\ "") when is_binary(new_background) and is_binary(style) do
    style_string =
      case style do
        "" -> ""
        _ -> ", in a #{style} style"
      end

    "Replace the background with a #{new_background}#{style_string}."
  end

  @doc """
  Generates a prompt to add an object to an image.

  ## Examples

      iex> AiReplacePrompt.generate_add_prompt("a cat", "sitting on a chair")
      "Add a cat sitting on a chair to the image."

      iex> AiReplacePrompt.generate_add_prompt("a UFO", "hovering over a field", "sci-fi")
      "Add a UFO hovering over a field to the image, in a sci-fi style."
  """
  def generate_add_prompt(new_object, description \\ "", style \\ "") when is_binary(new_object) and is_binary(description) and is_binary(style) do
    description_string =
      case description do
        "" -> ""
        _ -> " #{description}"
      end

    style_string =
      case style do
        "" -> ""
        _ -> ", in a #{style} style"
      end
    "Add #{new_object}#{description_string} to the image#{style_string}."
  end

  @doc """
  Combines multiple prompt segments into a single prompt.

  ## Examples

      iex> AiReplacePrompt.combine_prompts(["a cat", "sitting on a mat"])
      "a cat, sitting on a mat"

      iex> AiReplacePrompt.combine_prompts(["a dog", "running in the park", "happy"])
      "a dog, running in the park, happy"
  """
  def combine_prompts(prompt_segments) when is_list(prompt_segments) do
    prompt_segments
    |> Enum.join(", ")
  end
end