module Steep
  module Server
    class TypeCheckWorker < BaseWorker
      attr_reader :project, :assignment, :service
      attr_reader :commandline_args
      attr_reader :current_type_check_guid

      WorkspaceSymbolJob = _ = Struct.new(:query, :id, keyword_init: true)
      StatsJob = _ = Struct.new(:id, keyword_init: true)
      StartTypeCheckJob = _ = Struct.new(:guid, :changes, keyword_init: true)
      TypeCheckCodeJob = _ = Struct.new(:guid, :path, keyword_init: true)
      ValidateAppSignatureJob = _ = Struct.new(:guid, :path, keyword_init: true)
      ValidateLibrarySignatureJob = _ = Struct.new(:guid, :path, keyword_init: true)
      GotoJob = _ = Struct.new(:id, :kind, :params, keyword_init: true) do
        # @implements GotoJob

        def self.implementation(id:, params:)
          new(
            kind: :implementation,
            id: id,
            params: params
          )
        end

        def self.definition(id:, params:)
          new(
            kind: :definition,
            id: id,
            params: params
          )
        end

        def self.type_definition(id:, params:)
          new(
            kind: :type_definition,
            id: id,
            params: params
          )
        end

        def implementation?
          kind == :implementation
        end

        def definition?
          kind == :definition
        end

        def type_definition?
          kind == :type_definition
        end
      end

      include ChangeBuffer

      def initialize(project:, reader:, writer:, assignment:, commandline_args:)
        super(project: project, reader: reader, writer: writer)

        @assignment = assignment
        @service = Services::TypeCheckService.new(project: project)
        @buffered_changes = {}
        @mutex = Mutex.new()
        @queue = Queue.new
        @commandline_args = commandline_args
        @current_type_check_guid = nil
      end

      def handle_request(request)
        case request[:method]
        when "initialize"
          load_files(project: project, commandline_args: commandline_args)
          writer.write({ id: request[:id], result: nil})
        when "textDocument/didChange"
          collect_changes(request)
        when "workspace/symbol"
          query = request[:params][:query]
          queue << WorkspaceSymbolJob.new(id: request[:id], query: query)
        when "workspace/executeCommand"
          case request[:params][:command]
          when "steep/stats"
            queue << StatsJob.new(id: request[:id])
          end
        when "$/typecheck/start"
          params = request[:params]
          enqueue_typecheck_jobs(params)
        when "textDocument/definition"
          queue << GotoJob.definition(id: request[:id], params: request[:params])
        when "textDocument/implementation"
          queue << GotoJob.implementation(id: request[:id], params: request[:params])
        when "textDocument/typeDefinition"
          queue << GotoJob.type_definition(id: request[:id], params: request[:params])
        end
      end

      def enqueue_typecheck_jobs(params)
        guid = params[:guid]

        @current_type_check_guid = guid

        pop_buffer() do |changes|
          Steep.logger.info { "Enqueueing StartTypeCheckJob for guid=#{guid}" }
          queue << StartTypeCheckJob.new(guid: guid, changes: changes)
        end

        priority_paths = Set.new(params[:priority_uris].map {|uri| Steep::PathHelper.to_pathname(uri) || raise })
        library_paths = params[:library_uris].map {|uri| Steep::PathHelper.to_pathname(uri) || raise }
        signature_paths = params[:signature_uris].map {|uri| Steep::PathHelper.to_pathname(uri) || raise }
        code_paths = params[:code_uris].map {|uri| Steep::PathHelper.to_pathname(uri) || raise }

        library_paths.each do |path|
          if priority_paths.include?(path)
            Steep.logger.info { "Enqueueing ValidateLibrarySignatureJob for guid=#{guid}, path=#{path}" }
            queue << ValidateLibrarySignatureJob.new(guid: guid, path: path)
          end
        end

        code_paths.each do |path|
          if priority_paths.include?(path)
            Steep.logger.info { "Enqueueing TypeCheckCodeJob for guid=#{guid}, path=#{path}" }
            queue << TypeCheckCodeJob.new(guid: guid, path: path)
          end
        end

        signature_paths.each do |path|
          if priority_paths.include?(path)
            Steep.logger.info { "Enqueueing ValidateAppSignatureJob for guid=#{guid}, path=#{path}" }
            queue << ValidateAppSignatureJob.new(guid: guid, path: path)
          end
        end

        library_paths.each do |path|
          unless priority_paths.include?(path)
            Steep.logger.info { "Enqueueing ValidateLibrarySignatureJob for guid=#{guid}, path=#{path}" }
            queue << ValidateLibrarySignatureJob.new(guid: guid, path: path)
          end
        end

        code_paths.each do |path|
          unless priority_paths.include?(path)
            Steep.logger.info { "Enqueueing TypeCheckCodeJob for guid=#{guid}, path=#{path}" }
            queue << TypeCheckCodeJob.new(guid: guid, path: path)
          end
        end

        signature_paths.each do |path|
          unless priority_paths.include?(path)
            Steep.logger.info { "Enqueueing ValidateAppSignatureJob for guid=#{guid}, path=#{path}" }
            queue << ValidateAppSignatureJob.new(guid: guid, path: path)
          end
        end
      end

      def handle_job(job)
        case job
        when StartTypeCheckJob
          Steep.logger.info { "Processing StartTypeCheckJob for guid=#{job.guid}" }
          service.update(changes: job.changes)

        when ValidateAppSignatureJob
          if job.guid == current_type_check_guid
            Steep.logger.info { "Processing ValidateAppSignature for guid=#{job.guid}, path=#{job.path}" }
            service.validate_signature(path: project.relative_path(job.path)) do |path, diagnostics|
              formatter = Diagnostic::LSPFormatter.new({}, **{})

              writer.write(
                method: :"textDocument/publishDiagnostics",
                params: LSP::Interface::PublishDiagnosticsParams.new(
                  uri: Steep::PathHelper.to_uri(job.path),
                  diagnostics: diagnostics.map {|diagnostic| formatter.format(diagnostic) }.uniq
                )
              )
            end

            typecheck_progress(path: job.path, guid: job.guid)
          end

        when ValidateLibrarySignatureJob
          if job.guid == current_type_check_guid
            Steep.logger.info { "Processing ValidateLibrarySignature for guid=#{job.guid}, path=#{job.path}" }
            service.validate_signature(path: job.path) do |path, diagnostics|
              formatter = Diagnostic::LSPFormatter.new({}, **{})

              writer.write(
                method: :"textDocument/publishDiagnostics",
                params: LSP::Interface::PublishDiagnosticsParams.new(
                  uri: Steep::PathHelper.to_uri(job.path),
                  diagnostics: diagnostics.map {|diagnostic| formatter.format(diagnostic) }.uniq.compact
                )
              )
            end

            typecheck_progress(path: job.path, guid: job.guid)
          end

        when TypeCheckCodeJob
          if job.guid == current_type_check_guid
            Steep.logger.info { "Processing TypeCheckCodeJob for guid=#{job.guid}, path=#{job.path}" }
            service.typecheck_source(path: project.relative_path(job.path)) do |path, diagnostics|
              target = project.target_for_source_path(path)
              formatter = Diagnostic::LSPFormatter.new(target&.code_diagnostics_config || {})

              writer.write(
                method: :"textDocument/publishDiagnostics",
                params: LSP::Interface::PublishDiagnosticsParams.new(
                  uri: Steep::PathHelper.to_uri(job.path),
                  diagnostics: diagnostics.map {|diagnostic| formatter.format(diagnostic) }.uniq.compact
                )
              )
            end

            typecheck_progress(path: job.path, guid: job.guid)
          end

        when WorkspaceSymbolJob
          writer.write(
            id: job.id,
            result: workspace_symbol_result(job.query)
          )
        when StatsJob
          writer.write(
            id: job.id,
            result: stats_result().map(&:as_json)
          )
        when GotoJob
          writer.write(
            id: job.id,
            result: goto(job)
          )
        end
      end

      def typecheck_progress(guid:, path:)
        writer.write(
          method: "$/typecheck/progress",
          params: { guid: guid, path: path }
        )
      end

      def workspace_symbol_result(query)
        Steep.measure "Generating workspace symbol list for query=`#{query}`" do
          indexes = project.targets.map {|target| service.signature_services[target.name].latest_rbs_index }

          provider = Index::SignatureSymbolProvider.new(project: project, assignment: assignment)
          provider.indexes.push(*indexes)

          symbols = provider.query_symbol(query)

          symbols.map do |symbol|
            LSP::Interface::SymbolInformation.new(
              name: symbol.name,
              kind: symbol.kind,
              location: symbol.location.yield_self do |location|
                path = Pathname(location.buffer.name)
                {
                  uri: Steep::PathHelper.to_uri(project.absolute_path(path)),
                  range: {
                    start: { line: location.start_line - 1, character: location.start_column },
                    end: { line: location.end_line - 1, character: location.end_column }
                  }
                }
              end,
              container_name: symbol.container_name
            )
          end
        end
      end

      def stats_result
        calculator = Services::StatsCalculator.new(service: service)

        project.targets.each.with_object([]) do |target, stats|
          service.source_files.each_value do |file|
            next unless target.possible_source_file?(file.path)
            absolute_path = project.absolute_path(file.path)
            next unless assignment =~ absolute_path

            stats << calculator.calc_stats(target, file: file)
          end
        end
      end

      def goto(job)
        path = Steep::PathHelper.to_pathname(job.params[:textDocument][:uri]) or return []
        line = job.params[:position][:line] + 1
        column = job.params[:position][:character]

        goto_service = Services::GotoService.new(type_check: service, assignment: assignment)
        locations =
          case
          when job.definition?
            goto_service.definition(path: path, line: line, column: column)
          when job.implementation?
            goto_service.implementation(path: path, line: line, column: column)
          when job.type_definition?
            goto_service.type_definition(path: path, line: line, column: column)
          else
            raise
          end

        locations.map do |loc|
          path =
            case loc
            when RBS::Location
              Pathname(loc.buffer.name)
            else
              Pathname(loc.source_buffer.name)
            end

          path = project.absolute_path(path)

          {
            uri: Steep::PathHelper.to_uri(path).to_s,
            range: loc.as_lsp_range
          }
        end
      end
    end
  end
end