//
// ConstructFixer.cs
//
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
//
// Copyright (c) 2014 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 System.Text;
using System.Reflection;
using System.Linq;

namespace ICSharpCode.NRefactory.CSharp
{
	abstract class ConstructCompleter
	{
		public abstract bool TryFix (ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset);

		protected AstNode GetLastNonErrorChild (AstNode node)
		{
			var lastNode = node.LastChild;

			while (lastNode is ErrorNode) {
				lastNode = lastNode.GetPrevNode(FormattingVisitor.NoWhitespacePredicate);
			}
			return lastNode;
		}
	}

	class TypeDeclarationCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var typeDeclaration = syntaxTree.GetNodeAt<TypeDeclaration>(location); 
			if (typeDeclaration != null) {
				if (typeDeclaration.LBraceToken.IsNull && typeDeclaration.RBraceToken.IsNull) {
					if (typeDeclaration.Members.Any())
						return false;
					var lastNode = GetLastNonErrorChild (typeDeclaration);
					if (lastNode == null)
						return false;
					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (typeDeclaration, fixer.Options.ClassBraceStyle, false, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class DelegateDeclarationCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var typeDeclaration = syntaxTree.GetNodeAt<DelegateDeclaration>(location); 
			if (typeDeclaration != null) {
				if (typeDeclaration.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (typeDeclaration);
					if (lastNode == null)
						return false;
					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, ");\n");
					newOffset += ");\n".Length;
					return true;
				}
			}
			return false;
		}
	}

	class MethodDeclarationCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var methodDeclaration = syntaxTree.GetNodeAt<MethodDeclaration>(location); 
			if (methodDeclaration != null) {
				if (!methodDeclaration.LParToken.IsNull && methodDeclaration.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (methodDeclaration);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, ")\n\t{\t\t\n\t}");
					newOffset += ")\n\t{\t\t".Length;
					return true;
				}
			}
			return false;
		}
	}

	class IfStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var ifStatement = syntaxTree.GetNodeAt<IfElseStatement>(location); 
			if (ifStatement != null) {
				if (!ifStatement.LParToken.IsNull && ifStatement.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (ifStatement);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (ifStatement, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class ForeachStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var ifStatement = syntaxTree.GetNodeAt<ForeachStatement>(location); 
			if (ifStatement != null) {
				if (!ifStatement.LParToken.IsNull && ifStatement.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (ifStatement);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (ifStatement, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class WhileStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var ifStatement = syntaxTree.GetNodeAt<WhileStatement>(location); 
			if (ifStatement != null) {
				if (!ifStatement.LParToken.IsNull && ifStatement.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (ifStatement);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (ifStatement, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class DoWhileStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<DoWhileStatement>(location); 
			if (stmt != null) {
				if (!stmt.LParToken.IsNull && stmt.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (stmt);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, ");");
					newOffset = insertionOffset + 2;
					return true;
				}
			}
			return false;
		}
	}

	class FixedStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<FixedStatement>(location); 
			if (stmt != null) {
				if (!stmt.LParToken.IsNull && stmt.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (stmt);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (stmt, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class SwitchStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var switchStatement = syntaxTree.GetNodeAt<SwitchStatement>(location); 
			if (switchStatement != null) {
				if (!switchStatement.LParToken.IsNull && switchStatement.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (switchStatement);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (switchStatement, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class InvocationCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var invocationExpression = syntaxTree.GetNodeAt<InvocationExpression>(location); 

			if (invocationExpression != null) {
				if (!invocationExpression.LParToken.IsNull && invocationExpression.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (invocationExpression);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);

					newOffset = insertionOffset;


					var text = ")";
					newOffset++;
					var expressionStatement = invocationExpression.Parent as ExpressionStatement;
					if (expressionStatement != null) {
						if (expressionStatement.SemicolonToken.IsNull)
							text = ");";
						newOffset ++;
					}
					document.Insert(insertionOffset, text);


					return true;
				}

			}
			return false;
		}
	}

	class BreakStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<BreakStatement>(location); 

			if (stmt != null && stmt.SemicolonToken.IsNull) {
				// TODO !!!!
				return true;
			}
			return false;
		}
	}

	class CheckedStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<CheckedExpression>(location); 

			if (stmt != null && stmt.Parent is ExpressionStatement) {
				var insertionOffset = document.GetOffset(stmt.EndLocation);
				document.Insert(insertionOffset, fixer.GenerateBody (stmt, fixer.Options.StatementBraceStyle, false, ref newOffset));
				return true;
			}
			return false;
		}
	}

	class UncheckedStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<UncheckedExpression>(location); 

			if (stmt != null && stmt.Parent is ExpressionStatement) {
				var insertionOffset = document.GetOffset(stmt.EndLocation);
				document.Insert(insertionOffset, fixer.GenerateBody (stmt, fixer.Options.StatementBraceStyle, false, ref newOffset));
				return true;
			}
			return false;
		}
	}

	class ExpressionStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var expressionStatement = syntaxTree.GetNodeAt<ExpressionStatement>(location); 

			if (expressionStatement != null) {
				int offset = document.GetOffset(expressionStatement.Expression.EndLocation);
				if (expressionStatement.SemicolonToken.IsNull) {
					document.Insert(offset, ";");
					newOffset = offset + 1;
				}
				return true;
			}
			return false;
		}
	}

	class LockStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<LockStatement>(location); 
			if (stmt != null) {
				if (!stmt.LParToken.IsNull && stmt.RParToken.IsNull) {
					var lastNode = GetLastNonErrorChild (stmt);
					if (lastNode == null)
						return false;

					var insertionOffset = document.GetOffset(lastNode.EndLocation);
					document.Insert(insertionOffset, fixer.GenerateBody (stmt, fixer.Options.StatementBraceStyle, true, ref newOffset));
					return true;
				}
			}
			return false;
		}
	}

	class ReturnStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<ReturnStatement>(location); 

			if (stmt != null && stmt.SemicolonToken.IsNull) {
				var insertionOffset = document.GetOffset(stmt.EndLocation);
				document.Insert(insertionOffset, ";");
				newOffset = insertionOffset + 1;
				return true;
			}
			return false;
		}
	}

	class YieldReturnStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<YieldReturnStatement>(location); 

			if (stmt != null && stmt.SemicolonToken.IsNull) {
				var insertionOffset = document.GetOffset(stmt.EndLocation);
				document.Insert(insertionOffset, ";");
				newOffset = insertionOffset + 1;
				return true;
			}
			return false;
		}
	}

	class ThrowStatementCompleter : ConstructCompleter
	{
		public override bool TryFix(ConstructFixer fixer, SyntaxTree syntaxTree, IDocument document, TextLocation location, ref int newOffset)
		{
			var stmt = syntaxTree.GetNodeAt<ThrowStatement>(location); 

			if (stmt != null && stmt.SemicolonToken.IsNull) {
				var insertionOffset = document.GetOffset(stmt.EndLocation);
				document.Insert(insertionOffset, ";");
				newOffset = insertionOffset + 1;
				return true;
			}
			return false;
		}
	}


	public class ConstructFixer
	{
		static readonly ConstructCompleter[] completer = {
			new TypeDeclarationCompleter(),
			new DelegateDeclarationCompleter (),
			new MethodDeclarationCompleter (),
			new IfStatementCompleter (),
			new ForeachStatementCompleter (),
			new WhileStatementCompleter (),
			new LockStatementCompleter (),
			new FixedStatementCompleter (),
			new DoWhileStatementCompleter (),
			new SwitchStatementCompleter (),
			new BreakStatementCompleter (),
			new ThrowStatementCompleter (),
			new ReturnStatementCompleter (),
			new YieldReturnStatementCompleter (),
			new CheckedStatementCompleter (),
			new UncheckedStatementCompleter (),

			new InvocationCompleter (),
			new ExpressionStatementCompleter ()
		};

		readonly CSharpFormattingOptions options;
		readonly TextEditorOptions textEditorOptions;

		public CSharpFormattingOptions Options {
			get {
				return options;
			}
		}

		public ConstructFixer(CSharpFormattingOptions options, TextEditorOptions textEditorOptions)
		{
			this.options = options;
			this.textEditorOptions = textEditorOptions;
		}
		

		string GetIndent(AstNode node)
		{
			if (node == null || node is SyntaxTree)
				return "";
			if (node is BlockStatement || node is TypeDeclaration || node is NamespaceDeclaration)
				return "\t" + GetIndent(node.Parent);
			return GetIndent(node.Parent);
		}

		internal string GenerateBody(AstNode node, BraceStyle braceStyle, bool addClosingBracket, ref int newOffset)
		{
			StringBuilder result = new StringBuilder();
			if (addClosingBracket)
				result.Append(")");
			var nodeIndent = GetIndent(node.Parent);
			switch (braceStyle) {
				case BraceStyle.DoNotChange:
				case BraceStyle.BannerStyle:
				case BraceStyle.EndOfLine:
					result.Append(" ");
					result.Append("{");
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					break;
				case BraceStyle.EndOfLineWithoutSpace:
					result.Append("{");
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					break;
				case BraceStyle.NextLine:
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent);
					result.Append("{");
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					break;
				case BraceStyle.NextLineShifted:
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					result.Append("{");
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					break;
				case BraceStyle.NextLineShifted2:
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t");
					result.Append("{");
					result.Append(textEditorOptions.EolMarker);
					result.Append(nodeIndent + "\t" + "\t");
					break;
			}

			newOffset += result.Length;
			result.Append(textEditorOptions.EolMarker);
			result.Append(nodeIndent);
			result.Append("}");

			return result.ToString();
		}

		public bool TryFix (IDocument document, int offset, out int newOffset)
		{
			newOffset = offset;

			var syntaxTree = SyntaxTree.Parse(document, "a.cs"); 
			var location = document.GetLocation(offset - 1);
			foreach (var c in completer) {
				if (c.TryFix(this, syntaxTree, document, location, ref newOffset)) {
					return true;
				}
			}
			return false;
		}
	}
}