#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using Irony.Interpreter;
using Irony.Interpreter.Ast;
using Irony.Parsing;

namespace HeuristicLab.BenchmarkGenerator {
  public class ExpressionGrammar : InterpretedLanguageGrammar {
    public ExpressionGrammar() : this(caseSensitive: false) { }

    public ExpressionGrammar(bool caseSensitive)
      : base(caseSensitive) {

      var comma = ToTerm(",");
      // Define terminals
      var number = new NumberLiteral("Number") {
        DefaultIntTypes = new[] { TypeCode.Double },
        //        DefaultIntTypes = new[] { TypeCode.Int32, TypeCode.Int64 },
        DefaultFloatType = TypeCode.Double
      };
      var identifier = new IdentifierTerminal("Identifier");

      // Define non-terminals
      var term = new NonTerminal("Term");
      var binExpr = new NonTerminal("BinExpr", typeof(BinaryOperationNode));
      var binOp = new NonTerminal("BinOp", "operator");
      var unExpr = new NonTerminal("UnExpr", typeof(UnaryOperationNode));
      var unOp = new NonTerminal("UnOp", "operator");
      var expr = new NonTerminal("Expr");
      var argList = new NonTerminal("ArgList", typeof(ExpressionListNode));
      var functionCall = new NonTerminal("FunctionCall", typeof(FunctionCallNode));
      var parExpr = new NonTerminal("ParExpr");
      var statement = new NonTerminal("Statement");
      var assignmentStmt = new NonTerminal("AssignmentStmt", typeof(AssignmentNode));
      var assignmentOp = new NonTerminal("AssignmentOp", "assignment operator");
      var program = new NonTerminal("Program", typeof(StatementListNode));

      // BNF rules
      expr.Rule = term | unExpr | binExpr;
      term.Rule = number | parExpr | identifier | functionCall;
      parExpr.Rule = "(" + expr + ")";
      unExpr.Rule = unOp + term;
      unOp.Rule = ToTerm("+") | "-";
      binExpr.Rule = expr + binOp + expr;
      binOp.Rule = ToTerm("+") | "-" | "*" | "/" | "^"; // add, sub, mul, div, pow
      argList.Rule = MakeStarRule(argList, comma, expr);
      functionCall.Rule = identifier + PreferShiftHere() + "(" + argList + ")";
      assignmentStmt.Rule = identifier + assignmentOp + expr;
      assignmentOp.Rule = ToTerm("=");
      statement.Rule = assignmentStmt | expr | Empty;
      program.Rule = MakePlusRule(program, NewLine, statement);
      this.Root = program;

      // Caption templates
      functionCall.NodeCaptionTemplate = "call #{0}(...)";

      // Operators precedence
      RegisterOperators(1, "+", "-");
      RegisterOperators(2, "*", "/");
      RegisterOperators(3, Associativity.Right, "^");

      // Punctuation and braces
      MarkPunctuation("(", ")", "[", "]");
      RegisterBracePair("(", ")");
      RegisterBracePair("[", "]");
      // Mark transient because these don't have corresponding AST nodes
      MarkTransient(term, expr, statement, binOp, unOp, assignmentOp, parExpr);
      // Language flags                         
      LanguageFlags = LanguageFlags.NewLineBeforeEOF | LanguageFlags.CreateAst;
    }

    public override LanguageRuntime CreateRuntime(LanguageData data) {
      return new CustomLanguageRuntime(data);
    }
  }
}