# frozen_string_literal: true

module Jekyll
  class ThemeBuilder
    SCAFFOLD_DIRECTORIES = %w(
      assets _layouts _includes _sass
    ).freeze

    attr_reader :name, :path, :code_of_conduct

    def initialize(theme_name, opts)
      @name = theme_name.to_s.tr(" ", "_").squeeze("_")
      @path = Pathname.new(File.expand_path(name, Dir.pwd))
      @code_of_conduct = !!opts["code_of_conduct"]
    end

    def create!
      create_directories
      create_starter_files
      create_gemspec
      create_accessories
      initialize_git_repo
    end

    def user_name
      @user_name ||= `git config user.name`.chomp
    end

    def user_email
      @user_email ||= `git config user.email`.chomp
    end

    private

    def root
      @root ||= Pathname.new(File.expand_path("../", __dir__))
    end

    def template_file(filename)
      [
        root.join("theme_template", "#{filename}.erb"),
        root.join("theme_template", filename.to_s),
      ].find(&:exist?)
    end

    def template(filename)
      erb.render(template_file(filename).read)
    end

    def erb
      @erb ||= ERBRenderer.new(self)
    end

    def mkdir_p(directories)
      Array(directories).each do |directory|
        full_path = path.join(directory)
        Jekyll.logger.info "create", full_path.to_s
        FileUtils.mkdir_p(full_path)
      end
    end

    def write_file(filename, contents)
      full_path = path.join(filename)
      Jekyll.logger.info "create", full_path.to_s
      File.write(full_path, contents)
    end

    def create_directories
      mkdir_p(SCAFFOLD_DIRECTORIES)
    end

    def create_starter_files
      %w(page post default).each do |layout|
        write_file("_layouts/#{layout}.html", template("_layouts/#{layout}.html"))
      end
    end

    def create_gemspec
      write_file("Gemfile", template("Gemfile"))
      write_file("#{name}.gemspec", template("theme.gemspec"))
    end

    def create_accessories
      accessories = %w(README.md LICENSE.txt)
      accessories << "CODE_OF_CONDUCT.md" if code_of_conduct
      accessories.each do |filename|
        write_file(filename, template(filename))
      end
    end

    def initialize_git_repo
      Jekyll.logger.info "initialize", path.join(".git").to_s
      Dir.chdir(path.to_s) { `git init` }
      write_file(".gitignore", template("gitignore"))
    end

    class ERBRenderer
      extend Forwardable

      def_delegator :@theme_builder, :name, :theme_name
      def_delegator :@theme_builder, :user_name, :user_name
      def_delegator :@theme_builder, :user_email, :user_email

      def initialize(theme_builder)
        @theme_builder = theme_builder
      end

      def jekyll_version_with_minor
        Jekyll::VERSION.split(".").take(2).join(".")
      end

      def theme_directories
        SCAFFOLD_DIRECTORIES
      end

      def render(contents)
        ERB.new(contents).result binding
      end
    end
  end
end
