// CSharp Editor Example with Code Completion
// Copyright (c) 2006, 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.Collections;
using System.Collections.Generic;
using System.Windows.Forms;
using ICSharpCode.TextEditor;
using ICSharpCode.TextEditor.Gui.CompletionWindow;

using Dom = ICSharpCode.SharpDevelop.Dom;
using NRefactoryResolver = ICSharpCode.SharpDevelop.Dom.NRefactoryResolver.NRefactoryResolver;

namespace HeuristicLab.CodeEditor {
  class CodeCompletionProvider : ICompletionDataProvider {
    CodeEditor codeEditor;

    public CodeCompletionProvider(CodeEditor codeEditor) {
      this.codeEditor = codeEditor;
    }

    public ImageList ImageList {
      get {
        return codeEditor.imageList1;
      }
    }

    public string PreSelection {
      get {
        return null;
      }
    }

    public int DefaultIndex {
      get {
        return -1;
      }
    }

    public CompletionDataProviderKeyResult ProcessKey(char key) {
      if (char.IsLetterOrDigit(key) || key == '_') {
        return CompletionDataProviderKeyResult.NormalKey;
      } else {
        // key triggers insertion of selected items
        return CompletionDataProviderKeyResult.InsertionKey;
      }
    }

    /// <summary>
    /// Called when entry should be inserted. Forward to the insertion action of the completion data.
    /// </summary>
    public bool InsertAction(ICompletionData data, TextArea textArea, int insertionOffset, char key) {
      textArea.Caret.Position = textArea.Document.OffsetToPosition(insertionOffset);
      return data.InsertAction(textArea, key);
    }

    public ICompletionData[] GenerateCompletionData(string fileName, TextArea textArea, char charTyped) {
      // We can return code-completion items like this:

      //return new ICompletionData[] {
      //	new DefaultCompletionData("Text", "Description", 1)
      //};

      NRefactoryResolver resolver = new NRefactoryResolver(codeEditor.projectContent.Language);
      Dom.ResolveResult rr = resolver.Resolve(FindExpression(textArea),
                                              codeEditor.parseInformation,
                                              textArea.MotherTextEditorControl.Text);
      List<ICompletionData> resultList = new List<ICompletionData>();
      if (rr != null) {
        try {
          ArrayList completionData = rr.GetCompletionData(codeEditor.projectContent);
          if (completionData != null) {
            AddCompletionData(resultList, completionData);
          }
        }
        catch (NullReferenceException) { }
      }
      return resultList.ToArray();
    }

    /// <summary>
    /// Find the expression the cursor is at.
    /// Also determines the context (using statement, "new"-expression etc.) the
    /// cursor is at.
    /// </summary>
    Dom.ExpressionResult FindExpression(TextArea textArea) {
      Dom.IExpressionFinder finder;
      finder = new Dom.CSharp.CSharpExpressionFinder(codeEditor.parseInformation);
      Dom.ExpressionResult expression = finder.FindExpression(textArea.Document.TextContent, textArea.Caret.Offset);
      if (expression.Region.IsEmpty) {
        expression.Region = new Dom.DomRegion(textArea.Caret.Line + 1, textArea.Caret.Column + 1);
      }
      return expression;
    }

    void AddCompletionData(List<ICompletionData> resultList, ArrayList completionData) {
      // used to store the method names for grouping overloads
      Dictionary<string, CodeCompletionData> nameDictionary = new Dictionary<string, CodeCompletionData>();

      // Add the completion data as returned by SharpDevelop.Dom to the
      // list for the text editor
      foreach (object obj in completionData) {
        if (obj is string) {
          // namespace names are returned as string
          resultList.Add(new DefaultCompletionData((string)obj, "namespace " + obj, 5));
        } else if (obj is Dom.IClass) {
          Dom.IClass c = (Dom.IClass)obj;
          resultList.Add(new CodeCompletionData(c));
        } else if (obj is Dom.IMember) {
          Dom.IMember m = (Dom.IMember)obj;
          if (m is Dom.IMethod && ((m as Dom.IMethod).IsConstructor)) {
            // Skip constructors
            continue;
          }
          // Group results by name and add "(x Overloads)" to the
          // description if there are multiple results with the same name.

          CodeCompletionData data;
          if (nameDictionary.TryGetValue(m.Name, out data)) {
            data.AddOverload(m);
          } else {
            nameDictionary[m.Name] = data = new CodeCompletionData(m);
            resultList.Add(data);
          }
        } else {
          // Current ICSharpCode.SharpDevelop.Dom should never return anything else
          throw new NotSupportedException();
        }
      }
    }
  }
}