source: branches/2521_ProblemRefactoring/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Completion/CSharpParameterCompletionEngine.cs

// 
// CSharpParameterCompletionEngine.cs
//  
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
// 
// Copyright (c) 2011 Xamarin Inc. (http://xamarin.com)
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using ICSharpCode.NRefactory.Editor;
using ICSharpCode.NRefactory.Completion;
using System.Collections.Generic;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;
using ICSharpCode.NRefactory.CSharp.Resolver;
using ICSharpCode.NRefactory.CSharp.TypeSystem;
using System.Linq;

namespace ICSharpCode.NRefactory.CSharp.Completion
{
  public class CSharpParameterCompletionEngine : CSharpCompletionEngineBase
  {
    internal IParameterCompletionDataFactory factory;
    
    public CSharpParameterCompletionEngine(IDocument document, ICompletionContextProvider completionContextProvider, IParameterCompletionDataFactory factory, IProjectContent content, CSharpTypeResolveContext ctx) : base (content, completionContextProvider, ctx)
    {
      if (document == null) {
        throw new ArgumentNullException("document");
      }
      if (factory == null) {
        throw new ArgumentNullException("factory");
      }
      this.document = document;
      this.factory = factory;
    }

    public ExpressionResult GetIndexerBeforeCursor()
    {
      SyntaxTree baseUnit;
      if (currentMember == null && currentType == null) { 
        return null;
      }
      baseUnit = ParseStub("x]");
      
      //var memberLocation = currentMember != null ? currentMember.Region.Begin : currentType.Region.Begin;
      var mref = baseUnit.GetNodeAt(location, n => n is IndexerExpression); 
      AstNode expr;
      if (mref is IndexerExpression) {
        expr = ((IndexerExpression)mref).Target;
      } else {
        return null;
      }
      
      return new ExpressionResult((AstNode)expr, baseUnit);
    }
    
    public ExpressionResult GetConstructorInitializerBeforeCursor()
    {
      SyntaxTree baseUnit;
      if (currentMember == null && currentType == null) { 
        return null;
      }
      baseUnit = ParseStub("a) {}", false);
      
      var expr = baseUnit.GetNodeAt <ConstructorInitializer>(location); 
      if (expr == null) {
        return null;
      }
      return new ExpressionResult((AstNode)expr, baseUnit);
    }
    
    public ExpressionResult GetTypeBeforeCursor()
    {
      SyntaxTree baseUnit;
      if (currentMember == null && currentType == null) { 
        return null;
      }
      baseUnit = ParseStub("x> a");
      
      //var memberLocation = currentMember != null ? currentMember.Region.Begin : currentType.Region.Begin;
      var expr = baseUnit.GetNodeAt<AstType>(location.Line, location.Column + 1);
      if (expr == null)
        return null;
      // '>' position
      return new ExpressionResult((AstNode)expr, baseUnit);
    }

    public ExpressionResult GetMethodTypeArgumentInvocationBeforeCursor()
    {
      SyntaxTree baseUnit;
      if (currentMember == null && currentType == null) { 
        return null;
      }
      baseUnit = ParseStub("x>.A ()");
      
      //var memberLocation = currentMember != null ? currentMember.Region.Begin : currentType.Region.Begin;
      var expr = baseUnit.GetNodeAt<MemberReferenceExpression>(location.Line, location.Column + 1);
      if (expr == null)
        return null;
      return new ExpressionResult((AstNode)expr, baseUnit);
    }



    IEnumerable<IMethod> CollectMethods(AstNode resolvedNode, MethodGroupResolveResult resolveResult)
    {
      var lookup = new MemberLookup(ctx.CurrentTypeDefinition, Compilation.MainAssembly);
      bool onlyStatic = false;
      if (resolvedNode is IdentifierExpression && currentMember != null && currentMember.IsStatic || resolveResult.TargetResult is TypeResolveResult) {
        onlyStatic = true;
      }
      var methods = new List<IMethod>();
      foreach (var method in resolveResult.Methods) {
        if (method.IsConstructor) {
          continue;
        }
        if (!lookup.IsAccessible (method, true))
          continue;
        if (onlyStatic && !method.IsStatic) {
          continue;
        }
        if (method.IsShadowing) {
          for (int j = 0; j < methods.Count; j++) {
            if (ParameterListComparer.Instance.Equals(methods[j].Parameters, method.Parameters)) {
              methods.RemoveAt (j);
              j--;
            }
          }
        }
        methods.Add (method);
      }
      foreach (var m in methods) {
        yield return m;
      }
      foreach (var extMethods in resolveResult.GetEligibleExtensionMethods (true)) {
        foreach (var method in extMethods) {
          if (methods.Contains (method))
            continue;
          yield return new ReducedExtensionMethod (method);
        }
      }
    }

    IEnumerable<IProperty> GetAccessibleIndexers(IType type)
    {
      var lookup = new MemberLookup(ctx.CurrentTypeDefinition, Compilation.MainAssembly);
      var properties = new List<IProperty>();
      foreach (var property in type.GetProperties ()) {
        if (!property.IsIndexer)
          continue;
        if (!lookup.IsAccessible (property, true))
          continue;
        if (property.IsShadowing) {
          for (int j = 0; j < properties.Count; j++) {
            if (ParameterListComparer.Instance.Equals(properties[j].Parameters, property.Parameters)) {
              properties.RemoveAt (j);
              j--;
            }
          }
        }

        properties.Add (property);
      }
      return properties;
    }
    
    public IParameterDataProvider GetParameterDataProvider(int offset, char completionChar)
    {
      //Ignoring completionChar == '\0' because it usually means moving with arrow keys, tab or enter
      //we don't want to trigger on those events but it probably should be handled somewhere else
      //since our job is to resolve method and not to decide when to display tooltip or not
      if (offset <= 0 || completionChar == '\0') {
        return null;
      }
      SetOffset (offset);
      int startOffset;
      string text;
      if (currentMember == null && currentType == null) {
        //In case of attributes parse all file
        startOffset = 0;
        text = document.Text;
      } else {
        var memberText = GetMemberTextToCaret ();
        text = memberText.Item1;
        startOffset = document.GetOffset (memberText.Item2);
      }

      var parenStack = new Stack<int> ();
      var chevronStack = new Stack<int> ();
      var squareStack = new Stack<int> ();
      var bracketStack = new Stack<int> ();

      var lex = new MiniLexer (text);
      bool failed = lex.Parse ((ch, off) => {
        if (lex.IsInString || lex.IsInChar || lex.IsInVerbatimString || lex.IsInSingleComment || lex.IsInMultiLineComment || lex.IsInPreprocessorDirective)
          return false;
        switch (ch) {
        case '(':
          parenStack.Push (startOffset + off);
          break;
        case ')':
          if (parenStack.Count == 0) {
            return true;
          }
          parenStack.Pop ();
          break;
        case '<':
          chevronStack.Push (startOffset + off);
          break;
        case '>':
          //Don't abort if we don't have macthing '<' for '>' it could be if (i > 0) Foo($
          if (chevronStack.Count == 0) {
            return false;
          }
          chevronStack.Pop ();
          break;
        case '[':
          squareStack.Push (startOffset + off);
          break;
        case ']':
          if (squareStack.Count == 0) {
            return true;
          }
          squareStack.Pop ();
          break;
        case '{':
          bracketStack.Push (startOffset + off);
          break;
        case '}':
          if (bracketStack.Count == 0) {
            return true;
          }
          bracketStack.Pop ();
          break;
        }
        return false;
      });
      if (failed)
        return null;
      int result = -1;
      if (parenStack.Count > 0)
        result = parenStack.Pop ();
      if (squareStack.Count > 0)
        result = Math.Max (result, squareStack.Pop ());
      if (chevronStack.Count > 0)
        result = Math.Max (result, chevronStack.Pop ());

      //If we are inside { bracket we don't want to display anything
      if (bracketStack.Count > 0 && bracketStack.Pop () > result)
        return null;
      if (result == -1)
        return null;
      SetOffset (result + 1);
      ResolveResult resolveResult;
      switch (document.GetCharAt (result)) {
        case '(':
          var invoke = GetInvocationBeforeCursor(true) ?? GetConstructorInitializerBeforeCursor();
          if (invoke == null) {
            return null;
          }
          if (invoke.Node is ConstructorInitializer) {
            var init = (ConstructorInitializer)invoke.Node;
            if (init.ConstructorInitializerType == ConstructorInitializerType.This) {
              return factory.CreateConstructorProvider(document.GetOffset(invoke.Node.StartLocation), ctx.CurrentTypeDefinition, init);
            } else {
              var baseType = ctx.CurrentTypeDefinition.DirectBaseTypes.FirstOrDefault(bt => bt.Kind != TypeKind.Interface);
              if (baseType == null) {
                return null;
              }
              return factory.CreateConstructorProvider(document.GetOffset(invoke.Node.StartLocation), baseType);
            }
          }
          if (invoke.Node is ObjectCreateExpression) {
            var createType = ResolveExpression(((ObjectCreateExpression)invoke.Node).Type);
            if (createType.Result.Type.Kind == TypeKind.Unknown)
              return null;
            return factory.CreateConstructorProvider(document.GetOffset(invoke.Node.StartLocation), createType.Result.Type);
          }
          
          if (invoke.Node is ICSharpCode.NRefactory.CSharp.Attribute) {
            var attribute = ResolveExpression(invoke);
            if (attribute == null || attribute.Result == null) {
              return null;
            }
            return factory.CreateConstructorProvider(document.GetOffset(invoke.Node.StartLocation), attribute.Result.Type);
          }
          var invocationExpression = ResolveExpression(invoke);
          if (invocationExpression == null || invocationExpression.Result == null || invocationExpression.Result.IsError) {
            return null;
          }
          resolveResult = invocationExpression.Result;
          if (resolveResult is MethodGroupResolveResult) {
            return factory.CreateMethodDataProvider(document.GetOffset(invoke.Node.StartLocation), CollectMethods(invoke.Node, resolveResult as MethodGroupResolveResult));
          }
          if (resolveResult is MemberResolveResult) {
            var mr = resolveResult as MemberResolveResult;
            if (mr.Member is IMethod) {
              return factory.CreateMethodDataProvider(document.GetOffset(invoke.Node.StartLocation), new [] { (IMethod)mr.Member });
            }
          }
          
          if (resolveResult.Type.Kind == TypeKind.Delegate) {
            return factory.CreateDelegateDataProvider(document.GetOffset(invoke.Node.StartLocation), resolveResult.Type);
          }
          
          //        
          //        if (result.ExpressionContext == ExpressionContext.BaseConstructorCall) {
          //          if (resolveResult is ThisResolveResult)
          //            return new NRefactoryParameterDataProvider (textEditorData, resolver, resolveResult as ThisResolveResult);
          //          if (resolveResult is BaseResolveResult)
          //            return new NRefactoryParameterDataProvider (textEditorData, resolver, resolveResult as BaseResolveResult);
          //        }
          //        IType resolvedType = resolver.SearchType (resolveResult.ResolvedType);
          //        if (resolvedType != null && resolvedType.ClassType == ClassType.Delegate) {
          //          return new NRefactoryParameterDataProvider (textEditorData, result.Expression, resolvedType);
          //        }
          break;
        case '<':
          invoke = GetMethodTypeArgumentInvocationBeforeCursor();
          if (invoke != null) {
            var tExpr2 = ResolveExpression(invoke);
            if (tExpr2 != null && tExpr2.Result is MethodGroupResolveResult && !tExpr2.Result.IsError) {
              return factory.CreateTypeParameterDataProvider(document.GetOffset(invoke.Node.StartLocation), CollectMethods(invoke.Node, tExpr2.Result as MethodGroupResolveResult));
            }
          }
          invoke = GetTypeBeforeCursor();
          if (invoke == null || invoke.Node.StartLocation.IsEmpty) {
            return null;
          }
          var tExpr = ResolveExpression(invoke);
          if (tExpr == null || tExpr.Result == null || tExpr.Result.IsError) {
            return null;
          }

          return factory.CreateTypeParameterDataProvider(document.GetOffset(invoke.Node.StartLocation), CollectAllTypes(tExpr.Result.Type));
        case '[':
          invoke = GetIndexerBeforeCursor();
          if (invoke == null) {
            return null;
          }
          if (invoke.Node is ArrayCreateExpression) {
            return null;
          }
          var indexerExpression = ResolveExpression(invoke);
          if (indexerExpression == null || indexerExpression.Result == null || indexerExpression.Result.IsError) {
            return null;
          }
          return factory.CreateIndexerParameterDataProvider(document.GetOffset(invoke.Node.StartLocation), indexerExpression.Result.Type, GetAccessibleIndexers (indexerExpression.Result.Type), invoke.Node);
      }
      return null;
    }
    
    IEnumerable<IType> CollectAllTypes(IType baseType)
    {
      var state = GetState();
      for (var n = state.CurrentUsingScope; n != null; n = n.Parent) {
        foreach (var u in n.Usings) {
          foreach (var type in u.Types) {
            if (type.TypeParameterCount > 0 && type.Name == baseType.Name) {
              yield return type;
            }
          }
        }
        
        foreach (var type in n.Namespace.Types) {
          if (type.TypeParameterCount > 0 && type.Name == baseType.Name) {
            yield return type;
          }
        }
      }
    }
    
    List<string> GetUsedNamespaces()
    {
      var scope = ctx.CurrentUsingScope;
      var result = new List<string>();
      while (scope != null) {
        result.Add(scope.Namespace.FullName);
        
        foreach (var ns in scope.Usings) {
          result.Add(ns.FullName);
        }
        scope = scope.Parent;
      }
      return result;
    }
    
    
  }
}