# frozen_string_literal: true

module Decidim
  module DecidimAwesome
    module ContextAnalyzers
      # Translates some Decidim URL path to detected participatory spaces and components
      class RequestAnalyzer
        class << self
          def context_for(request)
            analyzer = new request
            analyzer.extract_context!
            analyzer.context
          end

          # In the frontend there's no a 100% correspondence between url and manifest name
          def participatory_spaces_routes
            spaces = Decidim.participatory_space_manifests \
                            .filter { |space| !DecidimAwesome.config.participatory_spaces_routes_context.has_key?(space.name) } \
                            .to_h { |space| [space.name.to_s, space.name.to_s] }
            DecidimAwesome.config.participatory_spaces_routes_context.each do |manifest, routes|
              routes.each do |route|
                spaces[route.to_s] = manifest.to_s
              end
            end
            spaces
          end
        end

        def initialize(request)
          @request = request
          @context = {}
        end

        attr_reader :request, :context

        def extract_context!
          path = URI.parse(@request.url).path
          context_from_path path
        end

        private

        def process_admin_segments(segments)
          spaces = RequestAnalyzer.participatory_spaces_routes
          return unless spaces[segments[0]]

          @context[:participatory_space_manifest] = spaces[segments[0]]
          @context[:participatory_space_slug] = segments[1] if segments[1].present?

          return unless segments[2].presence == "components" && segments[3].present?

          @context[:component_id] = segments[3]
          # Try to infer component_manifest
          c = Component.find_by(id: segments[3])
          @context[:component_manifest] = c.manifest_name if c
        end

        def process_front_segments(segments)
          spaces = RequestAnalyzer.participatory_spaces_routes
          return unless spaces[segments[0]]

          @context[:participatory_space_manifest] = spaces[segments[0]]
          @context[:participatory_space_slug] = segments[1] if segments[1].present?

          return unless segments[2].presence == "f" && segments[3].present?

          @context[:component_id] = segments[3]
          # Try to infer component_manifest
          c = Component.find_by(id: segments[3])
          @context[:component_manifest] = c.manifest_name if c
        end

        def system_manifest?(path)
          patterns = [
            %r{^/admin/newsletters},
            %r{^/admin/moderations},
            %r{^/admin/users},
            %r{^/admin/organization},
            %r{^/admin/static_pages},
            %r{^/admin/logs}
          ]
          path.match(Regexp.union(patterns))
        end

        def context_from_path(path)
          if system_manifest?(path)
            @context[:participatory_space_manifest] = "system"
            return
          end

          segments = path.sub(%r{^/}, "").split("/")
          return if segments.blank?

          if segments[0] == "admin"
            segments.shift
            return process_admin_segments(segments)
          end
          process_front_segments(segments)
        end
      end
    end
  end
end