defmodule DuckDuck do
  @moduledoc false
  # Helper functions for finding release artifacts and uploading them.

  @no_api_token_msg """
  Couldn't find the API token! Please add a valid GitHub API token either

  - In the default location: `~/.goose_api_token`
  - In a config file like so

  ```
  # config/config.exs
  config :duckduck,
    owner: "the-mikedavis",
    repo: "duck_duck",
    token_file: "~/.duck_duck_token_file" # OR
    api_token: "MY_API_TOKEN"
  ```
  """

  # print in green
  def puts_success(str) do
    [:green, str]
    |> IO.ANSI.format()
    |> IO.puts()
  end

  # print in red
  def puts_failure(str) do
    [:red, str]
    |> IO.ANSI.format()
    |> IO.puts()
  end

  # given an app name, get the name of the release artifact
  @spec release_files(atom(), String.t(), Path.t()) :: Path.t()
  def release_files(app, tag, build_path) do
    [build_path, "rel", "#{app}", "releases", "#{tag}*", "#{app}.tar.gz"]
    |> Path.join()
    |> Path.wildcard()
  end

  @spec read_api_token() :: String.t() | no_return()
  def read_api_token do
    token_file =
      :duckduck
      |> Application.get_env(:token_file, "~/.goose_api_token")
      |> Path.expand()

    with :error <- Application.fetch_env(:duckduck, :api_token),
         false <- File.exists?(token_file) do
      puts_failure(@no_api_token_msg)
      System.halt(1)
    else
      {:ok, api_token} ->
        api_token

      true ->
        token_file
        |> File.read!()
        |> String.trim()
    end
  end

  @spec valid_token?(String.t(), String.t(), String.t()) :: boolean()
  def valid_token?(api_token, owner, repo) do
    headers = auth_header(api_token)

    owner
    |> build_token_check_url(repo)
    |> HTTPoison.get(headers)
    |> valid?()
  end

  @spec find_upload_url(String.t(), String.t(), String.t(), String.t()) :: String.t()
  def find_upload_url(api_token, owner, repo, tag) do
    headers = auth_header(api_token)

    owner
    |> build_tags_url(repo, tag)
    |> HTTPoison.get!(headers)
    |> Map.get(:body)
    |> Jason.decode!()
    |> validate_upload_url()
    |> case do
      {:error, :not_found} ->
        create_release_from_tag(api_token, owner, repo, tag)

      {:ok, url} ->
        url
    end
    |> String.replace(~r/\{.*\}/, "")
  end

  @spec create_release_from_tag(String.t(), String.t(), String.t(), String.t()) :: String.t()
  def create_release_from_tag(api_token, owner, repo, tag) do
    headers = auth_header(api_token)
    body = Jason.encode!(%{"tag_name" => tag})

    owner
    |> build_release_creation_url(repo)
    |> HTTPoison.post!(body, headers)
    |> Map.get(:body)
    |> Jason.decode!()
    |> Map.get("upload_url")
  end

  def upload(path, api_token, upload_url) do
    headers = auth_header(api_token)

    puts_success("Please wait. Uploading #{path}...")

    upload_url
    |> build_upload_asset_url(path)
    |> HTTPoison.post!({:file, path}, headers, timeout: 50_000, recv_timeout: 50_000)
    |> Map.get(:body)
    |> Jason.decode!()
    |> good_upload?()
  end

  @spec auth_header(String.t()) :: [{String.t(), String.t()}]
  defp auth_header(token), do: [{"Authorization", "token #{token}"}]

  @spec build_token_check_url(String.t(), String.t()) :: String.t()
  defp build_token_check_url(owner, repo) do
    "https://api.github.com/repos/#{owner}/#{repo}"
  end

  @spec build_tags_url(String.t(), String.t(), String.t()) :: String.t()
  defp build_tags_url(owner, repo, tag) do
    build_token_check_url(owner, repo) <> "/releases/tags/#{tag}"
  end

  @spec build_upload_asset_url(String.t(), String.t()) :: String.t()
  defp build_upload_asset_url(upload_url, asset_path) do
    upload_url <> "?name=" <> Path.basename(asset_path)
  end

  @spec build_release_creation_url(String.t(), String.t()) :: String.t()
  defp build_release_creation_url(owner, repo) do
    build_token_check_url(owner, repo) <> "/releases"
  end

  defp valid?({:ok, %HTTPoison.Response{}}), do: true
  defp valid?(_), do: false

  defp validate_upload_url(%{"message" => "Not Found"}),
    do: {:error, :not_found}

  defp validate_upload_url(%{"upload_url" => url}), do: {:ok, url}

  defp good_upload?(%{"errors" => [%{"code" => "already_exists"}]}) do
    puts_failure("""
    GitHub said that there's already a release artifact with this name for
    this tag! Make a new tag and trying again.
    """)
  end

  # denotes that a release was successfully uploaded
  defp good_upload?(%{"content_type" => "application/octet-stream"}) do
    puts_success("Release successfully uploaded")
  end
end