# frozen_string_literal: true

require "dependabot/file_parsers/java/gradle"

module Dependabot
  module FileParsers
    module Java
      class Gradle
        class PropertyValueFinder
          PROPERTY_DECLARATION_REGEX =
            /(?:^|\s+|ext.)(?<name>[^\s=]+)\s*=\s*['"](?<value>[^\s]+)['"]/.
            freeze

          def initialize(dependency_files:)
            @dependency_files = dependency_files
          end

          def property_details(property_name:, callsite_buildfile:)
            # If the root project was specified, just look in the top-level
            # buildfile
            if property_name.start_with?("rootProject.")
              property_name = property_name.sub("rootProject.", "")
              return properties(top_level_buildfile).fetch(property_name, nil)
            end

            # If this project was specified strip the specifier
            if property_name.start_with?("project.")
              property_name = property_name.sub("project.", "")
            end

            # If a `properties` prefix was specified strip that out, too
            if property_name.start_with?("properties.")
              property_name = property_name.sub("properties.", "")
            end

            # Look for a property in the callsite buildfile. If that fails, look
            # for the property in the top-level buildfile
            if properties(callsite_buildfile).fetch(property_name, nil)
              return properties(callsite_buildfile).fetch(property_name)
            end

            properties(top_level_buildfile).fetch(property_name, nil)
          end

          def property_value(property_name:, callsite_buildfile:)
            property_details(
              property_name: property_name,
              callsite_buildfile: callsite_buildfile
            )&.fetch(:value)
          end

          private

          attr_reader :dependency_files

          def properties(buildfile)
            @properties ||= {}
            return @properties[buildfile.name] if @properties[buildfile.name]

            @properties[buildfile.name] = {}
            prepared_content(buildfile).scan(PROPERTY_DECLARATION_REGEX) do
              declaration_string = Regexp.last_match.to_s.strip
              captures = Regexp.last_match.named_captures
              name = captures.fetch("name").sub(/^ext\./, "")
              @properties[buildfile.name][name] = {
                value: captures.fetch("value"),
                declaration_string: declaration_string,
                file: buildfile.name
              }
            end

            @properties[buildfile.name]
          end

          def prepared_content(buildfile)
            # Remove any comments
            buildfile.content.
              gsub(%r{(?<=^|\s)//.*$}, "\n").
              gsub(%r{(?<=^|\s)/\*.*?\*/}m, "")
          end

          def top_level_buildfile
            @top_level_buildfile ||=
              dependency_files.find { |f| f.name == "build.gradle" }
          end
        end
      end
    end
  end
end