module GovukPublishingComponents
  class AuditComponents
    attr_reader :data

    def initialize(path)
      # paths to key file locations
      @templates_path = "app/views/govuk_publishing_components/components"
      @stylesheets_path = "app/assets/stylesheets/govuk_publishing_components/components"
      @print_stylesheets_path = "app/assets/stylesheets/govuk_publishing_components/components/print"
      @javascripts_path = "app/assets/javascripts/govuk_publishing_components/components"
      @tests_path = "spec/components"
      @javascript_tests_path = "spec/javascripts/components"
      @helpers_path = "lib/govuk_publishing_components/presenters"

      @all_templates = Dir["#{path}/#{@templates_path}/*.erb"].sort
      @templates_full_path = "#{path}/#{@templates_path}/"

      @component_numbers = {
        template: 0,
        stylesheet: 0,
        print_stylesheet: 0,
        javascript: 0,
        test: 0,
        javascript_test: 0,
        helper: 0,
      }

      @data = {
        gem_found: false,
      }
      @data = compile_data(path) if Dir.exist?(path)
    end

  private

    def compile_data(path)
      {
        gem_found: true,
        component_code: clean_files(@all_templates, @templates_full_path).sort,
        components_containing_components: find_all_partials_in(@all_templates),
        component_file_details: get_component_file_details(path),
        component_numbers: @component_numbers,
      }
    end

    def get_component_file_details(path)
      component_templates = clean_files(@all_templates, @templates_full_path).sort
      details = []
      component_templates.each do |component|
        component_detail = {
          name: component,
          link: get_component_link(component),
        }
        file_details = [
          {
            type: "template",
            file: "#{[path, @templates_path].join('/')}/_#{component.gsub(' ', '_')}.html.erb",
          },
          {
            type: "stylesheet",
            file: "#{[path, @stylesheets_path].join('/')}/_#{component.gsub(' ', '-')}.scss",
          },
          {
            type: "print_stylesheet",
            file: "#{[path, @stylesheets_path].join('/')}/_#{component.gsub(' ', '-')}.scss",
          },
          {
            type: "javascript",
            file: "#{[path, @javascripts_path].join('/')}/#{component.gsub(' ', '-')}.js",
          },
          {
            type: "test",
            file: "#{[path, @tests_path].join('/')}/#{component.gsub(' ', '_')}_spec.rb",
          },
          {
            type: "javascript_test",
            file: "#{[path, @javascript_tests_path].join('/')}/#{component.gsub(' ', '-')}-spec.js",
          },
          {
            type: "helper",
            file: "#{[path, @helpers_path].join('/')}/#{component.gsub(' ', '_')}_helper.rb",
          },
        ]
        file_details.each do |detail|
          component_detail = component_detail.merge(get_component_asset_detail(detail, component))
        end

        details << component_detail
      end

      details
    end

    def get_component_asset_detail(detail, component)
      details = {}
      type = detail[:type]
      file = detail[:file]
      details["#{type}_exists".to_sym] = false
      if File.file?(file)
        # we don't have separate print stylesheets anymore
        # so check the main stylesheet for print styles
        if type == "print_stylesheet"
          unless File.foreach(file).grep(/(media-type: print)/).empty?
            details["#{type}_exists".to_sym] = true
            @component_numbers[type.to_sym] += 1
          end
        else
          @component_numbers[type.to_sym] += 1
          details["#{type}_exists".to_sym] = true
          details["#{type}_lines".to_sym] = count_lines_in(file)
          details["#{type}_link".to_sym] = get_asset_link(type, component)
        end
      end

      details
    end

    def count_lines_in(file)
      File.read(file).each_line.count
    end

    def clean_files(files, replace)
      files.map { |file| clean_file_name(file.gsub(replace, "")) }.sort
    end

    def clean_file_name(name)
      name.tr("/_-", " ")
        .gsub(".html.erb", "")
        .gsub(".erb", "")
        .gsub(".scss", "")
        .gsub(".js", "")
        .gsub("spec", "")
        .gsub(".rb", "")
        .gsub("helper", "")
        .strip
    end

    def get_component_name_from_full_path(path)
      path.gsub(/.*\K\/_/, "/")
        .gsub(@templates_full_path, "")
        .gsub(".html.erb", "")
        .gsub(".erb", "")
        .tr('\"\'', "")
    end

    # create link to component guide page for a given component e.g. 'component name'
    def get_component_link(component)
      "/component-guide/#{component.gsub(' ', '_')}"
    end

    def find_all_partials_in(templates)
      components = []

      templates.each do |template|
        partials_found = true
        components_to_search = [template]
        components_found = []

        while partials_found
          extra_components = find_partials_in(components_to_search)

          if extra_components.any?
            components_found << extra_components
            components_to_search = extra_components
          else
            partials_found = false
            components_found = components_found.flatten.reject { |c| c.include?("/") }

            if components_found.any?
              component_name = clean_file_name(get_component_name_from_full_path(template))
              components << {
                component: component_name,
                link: get_component_link(component_name),
                sub_components: components_found.uniq.sort.map { |name| clean_file_name(name) },
              }
            end
          end
        end
      end

      components.sort_by { |c| c[:component] }
    end

    def find_partials_in(components)
      extra_components = []
      components.each do |component|
        extra_components << components_within_component(component)
      end

      extra_components.flatten.uniq.sort
    end

    def components_within_component(file)
      file = get_component_name_from_full_path(file)
      file = "#{@templates_full_path}#{file}.html.erb".sub(/.*\K\//, "/_")
      data = File.read(file)
      match = data.scan(/["']{1}(govuk_publishing_components\/components\/[\/a-z_-]+["']{1})/)
      match.flatten.uniq.map(&:to_s).sort.map do |m|
        m.gsub("govuk_publishing_components/components/", "").tr('\"\'', "")
      end
    end

    def get_asset_link(a_thing, component)
      url = "https://github.com/alphagov"
      repo = "govuk_publishing_components"
      blob = "blob/main"
      link = nil
      link = "#{url}/#{repo}/#{blob}/#{@templates_path}/_#{component.gsub(' ', '_')}.html.erb" if a_thing == "template"
      link = "#{url}/#{repo}/#{blob}/#{@stylesheets_path}/_#{component.gsub(' ', '-')}.scss" if a_thing == "stylesheet"
      link = "#{url}/#{repo}/#{blob}/#{@print_stylesheets_path}/_#{component.gsub(' ', '-')}.scss" if a_thing == "print_stylesheet"
      link = "#{url}/#{repo}/#{blob}/#{@javascripts_path}/#{component.gsub(' ', '-')}.js" if a_thing == "javascript"
      link = "#{url}/#{repo}/#{blob}/#{@tests_path}/#{component.gsub(' ', '_')}_spec.rb" if a_thing == "test"
      link = "#{url}/#{repo}/#{blob}/#{@javascript_tests_path}/#{component.gsub(' ', '-')}-spec.js" if a_thing == "javascript_test"
      link = "#{url}/#{repo}/#{blob}/#{@helpers_path}/#{component.gsub(' ', '_')}_helper.rb" if a_thing == "helper"

      link
    end
  end
end