using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HeuristicLab.Core;
using System.Threading;

namespace HeuristicLab.Operators.MPISupport {
  class MPIHelper {
    public static IScope ShallowCopy(IScope scope) {
      IScope copy = new Scope(scope.Name, scope.Description);

      copy.Parent = null;

      foreach (IVariable variable in scope.Variables) {
        Variable copyVar = new Variable();
        copyVar.Name = variable.Name;
        copyVar.Value = variable.Value;
        copy.Variables.Add(copyVar);
      }

      foreach (IScope subscope in scope.SubScopes) {
        copy.SubScopes.Add(ShallowCopy(subscope));
      }

      return copy;
    }

    public static void Execute(IAtomicOperation op) {
      IOperation next;
      OperationCollection coll;
      IAtomicOperation operation;

      Stack<IOperation> executionStack = new Stack<IOperation>();
      executionStack.Push(op);

      while (executionStack.Count > 0) {
        next = executionStack.Pop();
        if (next is OperationCollection) {
          coll = (OperationCollection)next;
          for (int i = coll.Count - 1; i >= 0; i--)
            if (coll[i] != null) executionStack.Push(coll[i]);
        } else if (next is IAtomicOperation) {
          operation = (IAtomicOperation)next;
          try {
            next = operation.Operator.Execute((IExecutionContext)operation, new CancellationToken());
          }
          catch (Exception ex) {
            executionStack.Push(operation);
            if (ex is OperationCanceledException) throw ex;
            else throw new OperatorExecutionException(operation.Operator, ex);
          }
          if (next != null) executionStack.Push(next);
        }
      }
    }
  }
}