// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library domain.analysis;

import 'dart:async';
import 'dart:core' hide Resource;

import 'package:analysis_server/plugin/analysis/analysis_domain.dart';
import 'package:analysis_server/src/analysis_server.dart';
import 'package:analysis_server/src/computer/computer_hover.dart';
import 'package:analysis_server/src/constants.dart';
import 'package:analysis_server/src/context_manager.dart';
import 'package:analysis_server/src/domains/analysis/navigation.dart';
import 'package:analysis_server/src/operation/operation_analysis.dart'
    show
        NavigationOperation,
        OccurrencesOperation,
        sendAnalysisNotificationNavigation;
import 'package:analysis_server/src/protocol/protocol_internal.dart';
import 'package:analysis_server/src/protocol_server.dart';
import 'package:analysis_server/src/services/dependencies/library_dependencies.dart';
import 'package:analysis_server/src/services/dependencies/reachable_source_collector.dart';
import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/src/generated/ast.dart';
import 'package:analyzer/src/generated/element.dart';
import 'package:analyzer/src/generated/engine.dart' as engine;
import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
import 'package:analyzer/src/generated/source.dart';
import 'package:analyzer/task/model.dart' show ResultDescriptor;

/**
 * Instances of the class [AnalysisDomainHandler] implement a [RequestHandler]
 * that handles requests in the `analysis` domain.
 */
class AnalysisDomainHandler implements RequestHandler {
  /**
   * The analysis server that is using this handler to process requests.
   */
  final AnalysisServer server;

  /**
   * Initialize a newly created handler to handle requests for the given [server].
   */
  AnalysisDomainHandler(this.server) {
    _callAnalysisDomainReceivers();
  }

  /**
   * Implement the `analysis.getErrors` request.
   */
  Response getErrors(Request request) {
    String file = new AnalysisGetErrorsParams.fromRequest(request).file;
    Future<AnalysisDoneReason> completionFuture =
        server.onFileAnalysisComplete(file);
    if (completionFuture == null) {
      return new Response.getErrorsInvalidFile(request);
    }
    completionFuture.then((AnalysisDoneReason reason) {
      switch (reason) {
        case AnalysisDoneReason.COMPLETE:
          engine.AnalysisErrorInfo errorInfo = server.getErrors(file);
          List<AnalysisError> errors;
          if (errorInfo == null) {
            server.sendResponse(new Response.getErrorsInvalidFile(request));
          } else {
            errors = doAnalysisError_listFromEngine(
                errorInfo.lineInfo, errorInfo.errors);
            server.sendResponse(
                new AnalysisGetErrorsResult(errors).toResponse(request.id));
          }
          break;
        case AnalysisDoneReason.CONTEXT_REMOVED:
          // The active contexts have changed, so try again.
          Response response = getErrors(request);
          if (response != Response.DELAYED_RESPONSE) {
            server.sendResponse(response);
          }
          break;
      }
    });
    // delay response
    return Response.DELAYED_RESPONSE;
  }

  /**
   * Implement the `analysis.getHover` request.
   */
  Response getHover(Request request) {
    // prepare parameters
    var params = new AnalysisGetHoverParams.fromRequest(request);
    // prepare hovers
    List<HoverInformation> hovers = <HoverInformation>[];
    List<CompilationUnit> units =
        server.getResolvedCompilationUnits(params.file);
    for (CompilationUnit unit in units) {
      HoverInformation hoverInformation =
          new DartUnitHoverComputer(unit, params.offset).compute();
      if (hoverInformation != null) {
        hovers.add(hoverInformation);
      }
    }
    // send response
    return new AnalysisGetHoverResult(hovers).toResponse(request.id);
  }

  /// Implement the `analysis.getLibraryDependencies` request.
  Response getLibraryDependencies(Request request) {
    server.onAnalysisComplete.then((_) {
      LibraryDependencyCollector collector =
          new LibraryDependencyCollector(server.getAnalysisContexts());
      Set<String> libraries = collector.collectLibraryDependencies();
      Map<String, Map<String, List<String>>> packageMap =
          collector.calculatePackageMap(server.folderMap);
      server.sendResponse(new AnalysisGetLibraryDependenciesResult(
              libraries.toList(growable: false), packageMap)
          .toResponse(request.id));
    });
    // delay response
    return Response.DELAYED_RESPONSE;
  }

  /**
   * Implement the `analysis.getNavigation` request.
   */
  Response getNavigation(Request request) {
    var params = new AnalysisGetNavigationParams.fromRequest(request);
    String file = params.file;
    Future<AnalysisDoneReason> analysisFuture =
        server.onFileAnalysisComplete(file);
    if (analysisFuture == null) {
      return new Response.getNavigationInvalidFile(request);
    }
    analysisFuture.then((AnalysisDoneReason reason) {
      switch (reason) {
        case AnalysisDoneReason.COMPLETE:
          List<CompilationUnit> units =
              server.getResolvedCompilationUnits(file);
          if (units.isEmpty) {
            server.sendResponse(new Response.getNavigationInvalidFile(request));
          } else {
            CompilationUnitElement unitElement = units.first.element;
            NavigationCollectorImpl collector = computeNavigation(
                server,
                unitElement.context,
                unitElement.source,
                params.offset,
                params.length);
            server.sendResponse(new AnalysisGetNavigationResult(
                    collector.files, collector.targets, collector.regions)
                .toResponse(request.id));
          }
          break;
        case AnalysisDoneReason.CONTEXT_REMOVED:
          // The active contexts have changed, so try again.
          Response response = getNavigation(request);
          if (response != Response.DELAYED_RESPONSE) {
            server.sendResponse(response);
          }
          break;
      }
    });
    // delay response
    return Response.DELAYED_RESPONSE;
  }

  /**
   * Implement the `analysis.getReachableSources` request.
   */
  Response getReachableSources(Request request) {
    AnalysisGetReachableSourcesParams params =
        new AnalysisGetReachableSourcesParams.fromRequest(request);
    ContextSourcePair pair = server.getContextSourcePair(params.file);
    if (pair.context == null || pair.source == null) {
      return new Response.getReachableSourcesInvalidFile(request);
    }
    Map<String, List<String>> sources = new ReachableSourceCollector(
        pair.source, pair.context).collectSources();
    return new AnalysisGetReachableSourcesResult(sources)
        .toResponse(request.id);
  }

  @override
  Response handleRequest(Request request) {
    try {
      String requestName = request.method;
      if (requestName == ANALYSIS_GET_ERRORS) {
        return getErrors(request);
      } else if (requestName == ANALYSIS_GET_HOVER) {
        return getHover(request);
      } else if (requestName == ANALYSIS_GET_LIBRARY_DEPENDENCIES) {
        return getLibraryDependencies(request);
      } else if (requestName == ANALYSIS_GET_NAVIGATION) {
        return getNavigation(request);
      } else if (requestName == ANALYSIS_GET_REACHABLE_SOURCES) {
        return getReachableSources(request);
      } else if (requestName == ANALYSIS_REANALYZE) {
        return reanalyze(request);
      } else if (requestName == ANALYSIS_SET_ANALYSIS_ROOTS) {
        return setAnalysisRoots(request);
      } else if (requestName == ANALYSIS_SET_GENERAL_SUBSCRIPTIONS) {
        return setGeneralSubscriptions(request);
      } else if (requestName == ANALYSIS_SET_PRIORITY_FILES) {
        return setPriorityFiles(request);
      } else if (requestName == ANALYSIS_SET_SUBSCRIPTIONS) {
        return setSubscriptions(request);
      } else if (requestName == ANALYSIS_UPDATE_CONTENT) {
        return updateContent(request);
      } else if (requestName == ANALYSIS_UPDATE_OPTIONS) {
        return updateOptions(request);
      }
    } on RequestFailure catch (exception) {
      return exception.response;
    }
    return null;
  }

  /**
   * Implement the 'analysis.reanalyze' request.
   */
  Response reanalyze(Request request) {
    AnalysisReanalyzeParams params =
        new AnalysisReanalyzeParams.fromRequest(request);
    List<String> roots = params.roots;
    if (roots == null || roots.isNotEmpty) {
      List<String> includedPaths = server.contextManager.includedPaths;
      List<Resource> rootResources = null;
      if (roots != null) {
        rootResources = <Resource>[];
        for (String rootPath in roots) {
          if (!includedPaths.contains(rootPath)) {
            return new Response.invalidAnalysisRoot(request, rootPath);
          }
          rootResources.add(server.resourceProvider.getResource(rootPath));
        }
      }
      server.reanalyze(rootResources);
    }
    return new AnalysisReanalyzeResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.setAnalysisRoots' request.
   */
  Response setAnalysisRoots(Request request) {
    var params = new AnalysisSetAnalysisRootsParams.fromRequest(request);
    // continue in server
    server.setAnalysisRoots(request.id, params.included, params.excluded,
        params.packageRoots == null ? {} : params.packageRoots);
    return new AnalysisSetAnalysisRootsResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.setGeneralSubscriptions' request.
   */
  Response setGeneralSubscriptions(Request request) {
    AnalysisSetGeneralSubscriptionsParams params =
        new AnalysisSetGeneralSubscriptionsParams.fromRequest(request);
    server.setGeneralAnalysisSubscriptions(params.subscriptions);
    return new AnalysisSetGeneralSubscriptionsResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.setPriorityFiles' request.
   */
  Response setPriorityFiles(Request request) {
    var params = new AnalysisSetPriorityFilesParams.fromRequest(request);
    server.setPriorityFiles(request.id, params.files);
    return new AnalysisSetPriorityFilesResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.setSubscriptions' request.
   */
  Response setSubscriptions(Request request) {
    var params = new AnalysisSetSubscriptionsParams.fromRequest(request);
    // parse subscriptions
    Map<AnalysisService, Set<String>> subMap = mapMap(params.subscriptions,
        valueCallback: (List<String> subscriptions) => subscriptions.toSet());
    server.setAnalysisSubscriptions(subMap);
    return new AnalysisSetSubscriptionsResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.updateContent' request.
   */
  Response updateContent(Request request) {
    var params = new AnalysisUpdateContentParams.fromRequest(request);
    server.updateContent(request.id, params.files);
    return new AnalysisUpdateContentResult().toResponse(request.id);
  }

  /**
   * Implement the 'analysis.updateOptions' request.
   */
  Response updateOptions(Request request) {
    // options
    var params = new AnalysisUpdateOptionsParams.fromRequest(request);
    AnalysisOptions newOptions = params.options;
    List<OptionUpdater> updaters = new List<OptionUpdater>();
    if (newOptions.generateDart2jsHints != null) {
      updaters.add((engine.AnalysisOptionsImpl options) {
        options.dart2jsHint = newOptions.generateDart2jsHints;
      });
    }
    if (newOptions.generateHints != null) {
      updaters.add((engine.AnalysisOptionsImpl options) {
        options.hint = newOptions.generateHints;
      });
    }
    if (newOptions.generateLints != null) {
      updaters.add((engine.AnalysisOptionsImpl options) {
        options.lint = newOptions.generateLints;
      });
    }
    if (newOptions.enableSuperMixins != null) {
      updaters.add((engine.AnalysisOptionsImpl options) {
        options.enableSuperMixins = newOptions.enableSuperMixins;
      });
    }
    server.updateOptions(updaters);
    return new AnalysisUpdateOptionsResult().toResponse(request.id);
  }

  /**
   * Call all the registered [SetAnalysisDomain] functions.
   */
  void _callAnalysisDomainReceivers() {
    AnalysisDomain analysisDomain = new AnalysisDomainImpl(server);
    for (SetAnalysisDomain function
        in server.serverPlugin.setAnalysisDomainFunctions) {
      try {
        function(analysisDomain);
      } catch (exception, stackTrace) {
        engine.AnalysisEngine.instance.logger.logError(
            'Exception from analysis domain receiver: ${function.runtimeType}',
            new CaughtException(exception, stackTrace));
      }
    }
  }
}

/**
 * An implementation of [AnalysisDomain] for [AnalysisServer].
 */
class AnalysisDomainImpl implements AnalysisDomain {
  final AnalysisServer server;

  final Map<ResultDescriptor,
          StreamController<engine.ComputedResult>> controllers =
      <ResultDescriptor, StreamController<engine.ComputedResult>>{};

  AnalysisDomainImpl(this.server) {
    server.onContextsChanged.listen((ContextsChangedEvent event) {
      event.added.forEach(_subscribeForContext);
    });
  }

  @override
  Stream<engine.ComputedResult> onResultComputed(ResultDescriptor descriptor) {
    Stream<engine.ComputedResult> stream = controllers
        .putIfAbsent(descriptor,
            () => new StreamController<engine.ComputedResult>.broadcast())
        .stream;
    server.getAnalysisContexts().forEach(_subscribeForContext);
    return stream;
  }

  @override
  void scheduleNotification(
      engine.AnalysisContext context, Source source, AnalysisService service) {
    String file = source.fullName;
    if (server.hasAnalysisSubscription(service, file)) {
      if (service == AnalysisService.NAVIGATION) {
        server.scheduleOperation(new NavigationOperation(context, source));
      }
      if (service == AnalysisService.OCCURRENCES) {
        server.scheduleOperation(new OccurrencesOperation(context, source));
      }
    }
  }

  void _subscribeForContext(engine.AnalysisContext context) {
    for (ResultDescriptor descriptor in controllers.keys) {
      context.onResultComputed(descriptor).listen((result) {
        StreamController<engine.ComputedResult> controller =
            controllers[result.descriptor];
        if (controller != null) {
          controller.add(result);
        }
      });
    }
  }
}