# frozen_string_literal: true


module Solargraph
  module LanguageServer
    class Host
      # An asynchronous diagnosis reporter.

      #

      class Diagnoser
        # @param host [Host]

        def initialize host
          @host = host
          @mutex = Mutex.new
          @queue = []
          @stopped = true
        end

        # Schedule a file to be diagnosed.

        #

        # @param uri [String]

        # @return [void]

        def schedule uri
          mutex.synchronize { queue.push uri }
        end

        # Stop the diagnosis thread.

        #

        # @return [void]

        def stop
          @stopped = true
        end

        # True is the diagnoser is stopped.

        #

        # @return [Boolean]

        def stopped?
          @stopped
        end

        # Start the diagnosis thread.

        #

        # @return [self]

        def start
          return unless @stopped
          @stopped = false
          Thread.new do
            until stopped?
              tick
              sleep 0.1
            end
          end
          self
        end

        # Perform diagnoses.

        #

        # @return [void]

        def tick
          return if queue.empty? || host.synchronizing?
          if !host.options['diagnostics']
            mutex.synchronize { queue.clear }
            return
          end
          current = mutex.synchronize { queue.shift }
          return if queue.include?(current)
          host.diagnose current
        end

        private

        # @return [Host]

        attr_reader :host

        # @return [Mutex]

        attr_reader :mutex

        # @return [Array]

        attr_reader :queue
      end
    end
  end
end