#!/usr/bin/env ruby
# frozen_string_literal: true

require 'thor'
require 'pathname'
require 'fileutils'

require_relative '../<%= gem_entry_folder_path %>'

class ::GenerateCommand < ::Thor
  include ::Thor::Actions

  # @return [Module]
  LIBRARY_MODULE = <%= root_module_name %>
  # @return [String]
  LIBRARY_NAME = '<%= gem_name %>'
  # @return [Pathname]
  ROOT_PATH = ::Pathname.new ::File.expand_path('..', __dir__)
  # @return [Pathname]
  GEM_ENTRY_FOLDER_PATH = ::Pathname.new '<%= gem_entry_folder_path %>'

  class << self
    # Define the generator's root folder
    #
    # @return [String]
    def source_root
      ::File.expand_path('..', __dir__)
    end
  end

  desc 'component NAME', 'Generate a new component with the specified NAME'

  # @param name [String]
  # @return [void]
  def component(name)
    name = snake_case(name)
    name = "#{name}_component" unless name.end_with? '_component'
    @name = name

    template 'templates/component.rb.tt', component_path
    component_assets_path.mkdir unless component_assets_path.exist?

    template 'templates/view.html.erb.tt', component_assets_path / 'view.html.erb'
    template 'templates/style.scss.tt', component_assets_path / 'style.scss'
    template 'templates/component_test.rb.tt', component_test_file_path

    append_file main_components_stylesheet_path, %(\n@import "../../../#{component_assets_path}/style.scss";)
  end

  private

  # @return [Pathname]
  def component_test_file_path
    components_test_folder_path / "#{@name}_test.rb"
  end

  # @return [Pathname]
  def main_components_stylesheet_path
    ROOT_PATH / 'assets' / 'stylesheets' / library_relative_path / 'components.scss'
  end

  # @return [Pathname]
  def components_test_folder_path
    ROOT_PATH / 'test' / library_relative_path / 'components'
  end

  # @return [Pathname]
  def library_relative_path
    @library_relative_path ||= ::Pathname.new LIBRARY_NAME.gsub('-', '/')
  end

  # @return [Pathname]
  def component_assets_path
    @component_assets_path ||= GEM_ENTRY_FOLDER_PATH / 'components' / @name
  end

  # @return [Pathname]
  def component_path
    @component_path ||= GEM_ENTRY_FOLDER_PATH / 'components' / file_name
  end

  # @return [String]
  def full_class_name
    "#{LIBRARY_MODULE}::#{class_name}"
  end

  # @return [String]
  def component_css_class
    "#{LIBRARY_NAME}--#{@name}"
  end

  # @return [String]
  def class_name
    @class_name ||= camelize(@name)
  end

  # @return [String]
  def file_name
    @file_name ||= "#{@name}.rb"
  end

  # @return [Class]
  def abstract_component
    LIBRARY_MODULE::ABSTRACT_COMPONENT
  end

  # Converts a string to camel/Pascal Case.
  #
  #     camelize('some_snake_case') #=> "SomeSnakeCase"
  #     camelize('some/snake_case') #=> "Some::SnakeCase"
  #
  # @param string [String]
  # @param uppercase_first_letter [Boolean]
  # @return [String]
  def camelize(string, uppercase_first_letter: true)
    string = if uppercase_first_letter
                string.sub(/^[a-z\d]*/, &:capitalize)
              else
                string.sub(/^(?:(?=\b|[A-Z_])|\w)/, &:downcase)
              end

    string.gsub!(%r{(?:_|(/))([a-z\d]*)}) do
      "#{::Regexp.last_match(1)}#{::Regexp.last_match(2).capitalize}"
    end
    string.gsub('/', '::')
  end

  # Converts a string in PascalCase or camelCase to snake_case.
  #
  #     snake_case('SomePascalCase') => "some_pascal_case"
  #     snake_case('Some::PascalCase') => "some/pascal_case"
  #
  # @param string [String]
  # @return [String]
  def snake_case(string)
    string.gsub(/([^A-Z])([A-Z]+)/, '\1_\2')
          .gsub(%r{::_|/_}, '/')
          .downcase
  end
end

::GenerateCommand.start