# frozen_string_literal: true

require "pathname"
require "scmd"

module GGem; end

class GGem::Gemspec
  PUSH_HOST_META_KEY = "allowed_push_host"
  DEFAULT_PUSH_HOST  = "https://rubygems.org"
  BUILD_TO_DIRNAME   = "pkg"

  NotFoundError = Class.new(ArgumentError)
  LoadError     = Class.new(ArgumentError)
  CmdError      = Class.new(RuntimeError)

  attr_reader :path, :name, :version, :version_tag
  attr_reader :gem_file_name, :gem_file, :push_host

  def initialize(root_path)
    @root = Pathname.new(File.expand_path(root_path))
    raise NotFoundError unless @root.exist?
    @path = Pathname.new(Dir[File.join(@root, "{,*}.gemspec")].first.to_s)
    raise NotFoundError unless @path.exist?

    @spec        = load_gemspec(@path)
    @name        = @spec.name
    @version     = @spec.version
    @version_tag = "v#{@version}"

    @gem_file_name  = "#{@name}-#{@version}.gem"
    @gem_file       = File.join(BUILD_TO_DIRNAME, @gem_file_name)
    @built_gem_path = @root.join(@gem_file)

    @push_host = get_push_host(@spec)
  end

  def run_build_cmd
    run_cmd("gem build --verbose #{@path}").tap do
      gem_path = @root.join(@gem_file_name)
      run_cmd("mkdir -p #{@built_gem_path.dirname}")
      run_cmd("mv #{gem_path} #{@built_gem_path}")
    end
  end

  def run_install_cmd
    run_cmd("gem install #{@built_gem_path}")
  end

  def run_push_cmd
    run_cmd("gem push #{@built_gem_path} --host #{@push_host}")
  end

  private

  def run_cmd(cmd_string)
    cmd = Scmd.new(cmd_string)
    cmd.run
    unless cmd.success?
      raise(
        CmdError,
        "#{cmd_string}\n#{cmd.stderr.empty? ? cmd.stdout : cmd.stderr}",
      )
    end
    [cmd_string, cmd.exitstatus, cmd.stdout]
  end

  def load_gemspec(path)
    eval( # rubocop:disable Security/Eval
      path.read,
      TOPLEVEL_BINDING,
      path.expand_path.to_s,
    )
  rescue ScriptError, StandardError => ex
    original_line = ex.backtrace.find{ |line| line.include?(path.to_s) }
    msg =
      "There was a #{ex.class} while loading #{path.basename}: \n#{ex.message}"
    msg << " from\n  #{original_line}" if original_line
    msg << "\n"
    raise LoadError, msg
  end

  def get_push_host(spec)
    ENV["GGEM_PUSH_HOST"] ||
    get_meta(spec)[PUSH_HOST_META_KEY] ||
    DEFAULT_PUSH_HOST
  end

  def get_meta(spec)
    (spec.respond_to?(:metadata) ? spec.metadata : {}) || {}
  end
end