# TODO: extract to gem?

class Releaser
  def initialize(options = {})
    @project_name = options.delete(:project_name) do
      fail "project_name is needed!"
    end

    @gem_name = options.delete(:gem_name) do
      fail "gem_name is needed!"
    end

    @github_repo = options.delete(:github_repo) do
      fail "github_repo is needed!"
    end

    @version = options.delete(:version) do
      fail "version is needed!"
    end
  end

  def full
    rubygems
    github
  end

  def rubygems
    input = nil
    loop do
      STDOUT.puts "Release #{@project_name} #{@version} to RubyGems? (y/n)"
      input = STDIN.gets.chomp.downcase
      break if %w(y n).include?(input)
    end

    exit if input == "n"

    Rake::Task["release"].invoke
  end

  def github
    tag_name = "v#{@version}"

    require "gems"

    _verify_released
    _verify_tag_pushed

    require "octokit"
    gh_client = Octokit::Client.new(netrc: true)

    gh_release = _detect_gh_release(gh_client, tag_name, true)
    return unless gh_release

    STDOUT.puts "Draft release for #{tag_name}:\n"
    STDOUT.puts gh_release.body
    STDOUT.puts "\n-------------------------\n\n"

    _confirm_publish

    return unless _update_release(gh_client, gh_release, tag_name)

    gh_release = _detect_gh_release(gh_client, tag_name, false)

    _success_summary(gh_release, tag_name)
  end

  private

  def _verify_released
    if @version != Gems.info(@gem_name)["version"]
      STDOUT.puts "#{@project_name} #{@version} is not yet released."
      STDOUT.puts "Please release it first with: rake release:gem"
      exit
    end
  end

  def _verify_tag_pushed
    tags = `git ls-remote --tags origin`.split("\n")
    return if tags.detect { |tag| tag =~ /v#{@version}$/ }

    STDOUT.puts "The tag v#{@version} has not yet been pushed."
    STDOUT.puts "Please push it first with: rake release:gem"
    exit
  end

  def _success_summary(gh_release, tag_name)
    href = gh_release.rels[:html].href
    STDOUT.puts "GitHub release #{tag_name} has been published!"
    STDOUT.puts "\nPlease enjoy and spread the word!"
    STDOUT.puts "Lack of inspiration? Here's a tweet you could improve:\n\n"
    STDOUT.puts "Just released #{@project_name} #{@version}! #{href}"
  end

  def _detect_gh_release(gh_client, tag_name, draft)
    gh_releases = gh_client.releases(@github_repo)
    gh_releases.detect { |r| r.tag_name == tag_name && r.draft == draft }
  end

  def _confirm_publish
    input = nil
    loop do
      STDOUT.puts "Would you like to publish this GitHub release now? (y/n)"
      input = STDIN.gets.chomp.downcase
      break if %w(y n).include?(input)
    end

    exit if input == "n"
  end

  def _update_release(gh_client, gh_release, tag_name)
    result = gh_client.update_release(gh_release.rels[:self].href, draft: false)
    return true if result
    STDOUT.puts "GitHub release #{tag_name} couldn't be published!"
    false
  end
end