// 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:collection';

import 'package:analysis_server/src/analysis_server.dart';
import 'package:analysis_server/src/computer/computer_hover.dart';
import 'package:analysis_server/src/computer/error.dart';
import 'package:analysis_server/src/constants.dart';
import 'package:analysis_server/src/protocol.dart';
import 'package:analysis_services/constants.dart';
import 'package:analyzer/src/generated/ast.dart';
import 'package:analyzer/src/generated/engine.dart';


/**
 * 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 = request.getRequiredParameter(FILE).asString();
    server.onFileAnalysisComplete(file).then((_) {
      Response response = new Response(request.id);
      AnalysisErrorInfo errorInfo = server.getErrors(file);
      if (errorInfo == null) {
        response.setResult(ERRORS, []);
      } else {
        response.setResult(ERRORS, engineErrorInfoToJson(errorInfo));
      }
      server.sendResponse(response);
    }).catchError((message) {
      if (message is! String) {
        AnalysisEngine.instance.logger.logError(
            'Illegal error message during getErrors: $message');
        message = '';
      }
      Response response = new Response.getErrorsError(request, message);
      response.setResult(ERRORS, []);
      server.sendResponse(response);
    });
    // delay response
    return Response.DELAYED_RESPONSE;
  }

  /**
   * Implement the `analysis.getHover` request.
   */
  Response getHover(Request request) {
    // prepare parameters
    String file = request.getRequiredParameter(FILE).asString();
    int offset = request.getRequiredParameter(OFFSET).asInt();
    // prepare hovers
    List<Hover> hovers = <Hover>[];
    List<CompilationUnit> units = server.getResolvedCompilationUnits(file);
    for (CompilationUnit unit in units) {
      Hover hoverInformation =
          new DartUnitHoverComputer(unit, offset).compute();
      if (hoverInformation != null) {
        hovers.add(hoverInformation);
      }
    }
    // send response
    Response response = new Response(request.id);
    response.setResult(HOVERS, hovers);
    return 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_SET_ANALYSIS_ROOTS) {
        return setAnalysisRoots(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.setAnalysisRoots' request.
   */
  Response setAnalysisRoots(Request request) {
    // included
    RequestDatum includedDatum = request.getRequiredParameter(INCLUDED);
    List<String> includedPaths = includedDatum.asStringList();
    // excluded
    RequestDatum excludedDatum = request.getRequiredParameter(EXCLUDED);
    List<String> excludedPaths = excludedDatum.asStringList();
    // continue in server
    server.setAnalysisRoots(request.id, includedPaths, excludedPaths);
    return new Response(request.id);
  }

  /**
   * Implement the 'analysis.setPriorityFiles' request.
   */
  Response setPriorityFiles(Request request) {
    // files
    RequestDatum filesDatum = request.getRequiredParameter(FILES);
    List<String> files = filesDatum.asStringList();
    server.setPriorityFiles(request, files);
    return new Response(request.id);
  }

  /**
   * Implement the 'analysis.setSubscriptions' request.
   */
  Response setSubscriptions(Request request) {
    // parse subscriptions
    Map<AnalysisService, Set<String>> subMap;
    {
      RequestDatum subDatum = request.getRequiredParameter(SUBSCRIPTIONS);
      Map<String, List<String>> subStringMap = subDatum.asStringListMap();
      subMap = new HashMap<AnalysisService, Set<String>>();
      subStringMap.forEach((String serviceName, List<String> paths) {
        AnalysisService service =
            Enum2.valueOf(AnalysisService.VALUES, serviceName);
        if (service == null) {
          throw new RequestFailure(
              new Response.unknownAnalysisService(request, serviceName));
        }
        subMap[service] = new HashSet.from(paths);
      });
    }
    server.setAnalysisSubscriptions(subMap);
    return new Response(request.id);
  }

  /**
   * Implement the 'analysis.updateContent' request.
   */
  Response updateContent(Request request) {
    var changes = new HashMap<String, ContentChange>();
    RequestDatum filesDatum = request.getRequiredParameter(FILES);
    for (String file in filesDatum.keys) {
      RequestDatum changeDatum = filesDatum[file];
      ContentChange change = new ContentChange();
      switch (changeDatum[TYPE].asString()) {
        case ADD:
          change.contentOrReplacement = changeDatum[CONTENT].asString();
          break;
        case CHANGE:
          change.offset = changeDatum[OFFSET].asInt();
          change.length = changeDatum[LENGTH].asInt();
          change.contentOrReplacement = changeDatum[REPLACEMENT].asString();
          break;
        case REMOVE:
          break;
        default:
          return new Response.invalidParameter(
              request,
              changeDatum[TYPE].path,
              'be one of "add", "change", or "remove"');
      }
      changes[file] = change;
    }
    server.updateContent(changes);
    return new Response(request.id);
  }

  /**
   * Implement the 'analysis.updateOptions' request.
   */
  Response updateOptions(Request request) {
    // options
    RequestDatum optionsDatum = request.getRequiredParameter(OPTIONS);
    List<OptionUpdater> updaters = new List<OptionUpdater>();
    optionsDatum.forEachMap((String optionName, RequestDatum optionDatum) {
      if (optionName == ANALYZE_ANGULAR) {
        bool optionValue = optionDatum.asBool();
        updaters.add((AnalysisOptionsImpl options) {
          options.analyzeAngular = optionValue;
        });
      } else if (optionName == ANALYZE_POLYMER) {
        bool optionValue = optionDatum.asBool();
        updaters.add((AnalysisOptionsImpl options) {
          options.analyzePolymer = optionValue;
        });
      } else if (optionName == ENABLE_ASYNC) {
        // TODO(brianwilkerson) Uncomment this when the option is supported.
//        bool optionValue = optionDatum.asBool();
//        updaters.add((AnalysisOptionsImpl options) {
//          options.enableAsync = optionValue;
//        });
      } else if (optionName == ENABLE_DEFERRED_LOADING) {
        bool optionValue = optionDatum.asBool();
        updaters.add((AnalysisOptionsImpl options) {
          options.enableDeferredLoading = optionValue;
        });
      } else if (optionName == ENABLE_ENUMS) {
        // TODO(brianwilkerson) Uncomment this when the option is supported.
//        bool optionValue = optionDatum.asBool();
//        updaters.add((AnalysisOptionsImpl options) {
//          options.enableEnums = optionValue;
//        });
      } else if (optionName == GENERATE_DART2JS_HINTS) {
        bool optionValue = optionDatum.asBool();
        updaters.add((AnalysisOptionsImpl options) {
          options.dart2jsHint = optionValue;
        });
      } else if (optionName == GENERATE_HINTS) {
        bool optionValue = optionDatum.asBool();
        updaters.add((AnalysisOptionsImpl options) {
          options.hint = optionValue;
        });
      } else {
        throw new RequestFailure(
            new Response.unknownOptionName(request, optionName));
      }
    });
    server.updateOptions(updaters);
    return new Response(request.id);
  }
}


/**
 * A description of the change to the content of a file.
 */
class ContentChange {
  /**
   * If [offset] and [length] are null, the full content of the file (or null
   * if the file should be read from the filesystem).
   *
   * If [offset] and [length] are non-null, the replacement text which should
   * take the place of the [length] characters of the file starting at [offset].
   */
  String contentOrReplacement;

  int offset;
  int length;
}