// 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/src/analysis_server.dart';
import 'package:analysis_server/src/computer/computer_hover.dart';
import 'package:analysis_server/src/computer/computer_navigation.dart';
import 'package:analysis_server/src/constants.dart';
import 'package:analysis_server/src/protocol_server.dart';
import 'package:analysis_server/src/services/dependencies/library_dependencies.dart';
import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/src/generated/ast.dart';
import 'package:analyzer/src/generated/engine.dart' as engine;

/**
 * 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);

  /**
   * 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 {
            DartUnitNavigationComputer computer =
                new DartUnitNavigationComputer();
            _GetNavigationAstVisitor visitor = new _GetNavigationAstVisitor(
                params.offset, params.offset + params.length, computer);
            for (CompilationUnit unit in units) {
              unit.accept(visitor);
            }
            server.sendResponse(new AnalysisGetNavigationResult(
                    computer.files, computer.targets, computer.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;
  }

  @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_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;
      });
    }
    server.updateOptions(updaters);
    return new AnalysisUpdateOptionsResult().toResponse(request.id);
  }
}

/**
 * An AST visitor that computer navigation regions in the givne region.
 */
class _GetNavigationAstVisitor extends UnifyingAstVisitor {
  final int rangeStart;
  final int rangeEnd;
  final DartUnitNavigationComputer computer;

  _GetNavigationAstVisitor(this.rangeStart, this.rangeEnd, this.computer);

  bool isInRange(int offset) {
    return rangeStart <= offset && offset <= rangeEnd;
  }

  @override
  visitNode(AstNode node) {
    // The node ends before the range starts.
    if (node.end < rangeStart) {
      return;
    }
    // The node starts after the range ends.
    if (node.offset > rangeEnd) {
      return;
    }
    // The node starts or ends in the range.
    if (isInRange(node.offset) || isInRange(node.end)) {
      computer.compute(node);
      return;
    }
    super.visitNode(node);
  }
}