// CSharp Editor Example with Code Completion
// Copyright (c) 2007, Daniel Grunwald
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
// 
// - Redistributions of source code must retain the above copyright notice, this list
//   of conditions and the following disclaimer.
// 
// - Redistributions in binary form must reproduce the above copyright notice, this list
//   of conditions and the following disclaimer in the documentation and/or other materials
//   provided with the distribution.
// 
// - Neither the name of the ICSharpCode team nor the names of its contributors may be used to
//   endorse or promote products derived from this software without specific prior written
//   permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS &AS IS& AND ANY EXPRESS
// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
// IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

using System;
using System.Text;
using ICSharpCode.SharpDevelop.Dom;
using ICSharpCode.SharpDevelop.Dom.CSharp;
using ICSharpCode.SharpDevelop.Dom.VBNet;
using TextEditor = ICSharpCode.TextEditor;
using NRefactoryResolver = ICSharpCode.SharpDevelop.Dom.NRefactoryResolver.NRefactoryResolver;

namespace HeuristicLab.CodeEditor {
  sealed class ToolTipProvider {
    CodeEditor codeEditor;
    TextEditor.TextEditorControl editor;

    private ToolTipProvider(CodeEditor codeEditor, TextEditor.TextEditorControl editor) {
      this.codeEditor = codeEditor;
      this.editor = editor;
    }

    public static void Attach(CodeEditor codeEditor, TextEditor.TextEditorControl editor) {
      ToolTipProvider tp = new ToolTipProvider(codeEditor, editor);
      editor.ActiveTextAreaControl.TextArea.ToolTipRequest += tp.OnToolTipRequest;
    }

    void OnToolTipRequest(object sender, TextEditor.ToolTipRequestEventArgs e) {
      if (e.InDocument && !e.ToolTipShown) {
        IExpressionFinder expressionFinder;
        expressionFinder = new CSharpExpressionFinder(codeEditor.parseInformation);        
        ExpressionResult expression = expressionFinder.FindFullExpression(
          editor.Text,
          editor.Document.PositionToOffset(e.LogicalPosition));
        if (expression.Region.IsEmpty) {
          expression.Region = new DomRegion(e.LogicalPosition.Line + 1, e.LogicalPosition.Column + 1);
        }

        TextEditor.TextArea textArea = editor.ActiveTextAreaControl.TextArea;
        NRefactoryResolver resolver = new NRefactoryResolver(codeEditor.projectContent.Language);
        ResolveResult rr = resolver.Resolve(expression,
                                            codeEditor.parseInformation,
                                            textArea.MotherTextEditorControl.Text);
        string toolTipText = GetText(rr);
        if (toolTipText != null) {
          e.ShowToolTip(toolTipText);
        }
      }
    }

    static string GetText(ResolveResult result) {
      if (result == null) {
        return null;
      }
      if (result is MixedResolveResult)
        return GetText(((MixedResolveResult)result).PrimaryResult);
      IAmbience ambience = new CSharpAmbience();
      ambience.ConversionFlags = ConversionFlags.StandardConversionFlags | ConversionFlags.ShowAccessibility;
      if (result is MemberResolveResult) {
        return GetMemberText(ambience, ((MemberResolveResult)result).ResolvedMember);
      } else if (result is LocalResolveResult) {
        LocalResolveResult rr = (LocalResolveResult)result;
        ambience.ConversionFlags = ConversionFlags.UseFullyQualifiedTypeNames
          | ConversionFlags.ShowReturnType;
        StringBuilder b = new StringBuilder();
        if (rr.IsParameter)
          b.Append("parameter ");
        else
          b.Append("local variable ");
        b.Append(ambience.Convert(rr.Field));
        return b.ToString();
      } else if (result is NamespaceResolveResult) {
        return "namespace " + ((NamespaceResolveResult)result).Name;
      } else if (result is TypeResolveResult) {
        IClass c = ((TypeResolveResult)result).ResolvedClass;
        if (c != null)
          return GetMemberText(ambience, c);
        else
          return ambience.Convert(result.ResolvedType);
      } else if (result is MethodGroupResolveResult) {
        MethodGroupResolveResult mrr = result as MethodGroupResolveResult;
        IMethod m = mrr.GetMethodIfSingleOverload();
        if (m != null)
          return GetMemberText(ambience, m);
        else
          return "Overload of " + ambience.Convert(mrr.ContainingType) + "." + mrr.Name;
      } else {
        return null;
      }
    }

    static string GetMemberText(IAmbience ambience, IEntity member) {
      StringBuilder text = new StringBuilder();
      if (member is IField) {
        text.Append(ambience.Convert(member as IField));
      } else if (member is IProperty) {
        text.Append(ambience.Convert(member as IProperty));
      } else if (member is IEvent) {
        text.Append(ambience.Convert(member as IEvent));
      } else if (member is IMethod) {
        text.Append(ambience.Convert(member as IMethod));
      } else if (member is IClass) {
        text.Append(ambience.Convert(member as IClass));
      } else {
        text.Append("unknown member ");
        text.Append(member.ToString());
      }
      string documentation = member.Documentation;
      if (documentation != null && documentation.Length > 0) {
        text.Append('\n');
        text.Append(CodeCompletionData.XmlDocumentationToText(documentation));
      }
      return text.ToString();
    }
  }
}