/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * 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 OpenSim Project 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 DEVELOPERS ``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 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 OpenSim.Region.ExtensionsScriptModule.JVMEngine.Types;
using OpenSim.Region.ExtensionsScriptModule.JVMEngine.Types.PrimitiveTypes;

namespace OpenSim.Region.ExtensionsScriptModule.JVMEngine.JVM
{
    partial class Thread
    {
        private partial class Interpreter
        {
            private Thread m_thread;

            public Interpreter(Thread parentThread)
            {
                m_thread = parentThread;
            }

            public bool Excute()
            {
                bool run = true;
                byte currentOpCode = GlobalMemory.MethodArea.MethodBuffer[m_thread.PC++];
                // Console.WriteLine("opCode is: " + currentOpCode);
                bool handled = false;

                handled = IsLogicOpCode(currentOpCode);
                if (!handled)
                {
                    handled = IsMethodOpCode(currentOpCode);
                }
                if (!handled)
                {
                    if (currentOpCode == 172)
                    {
                        if (m_thread.stack.StackFrames.Count > 1)
                        {
                            Console.WriteLine("returning int from function");
                            int retPC1 = m_thread.m_currentFrame.ReturnPC;
                            BaseType bas1 = m_thread.m_currentFrame.OpStack.Pop();
                            m_thread.stack.StackFrames.Pop();
                            m_thread.m_currentFrame = m_thread.stack.StackFrames.Peek();
                            m_thread.PC = retPC1;
                            if (bas1 is Int)
                            {
                                m_thread.m_currentFrame.OpStack.Push((Int) bas1);
                            }
                        }
                        else
                        {
                            //  Console.WriteLine("No parent function so ending program");
                            m_thread.stack.StackFrames.Pop();
                            run = false;
                        }
                        handled = true;
                    }
                    if (currentOpCode == 174)
                    {
                        if (m_thread.stack.StackFrames.Count > 1)
                        {
                            Console.WriteLine("returning float from function");
                            int retPC1 = m_thread.m_currentFrame.ReturnPC;
                            BaseType bas1 = m_thread.m_currentFrame.OpStack.Pop();
                            m_thread.stack.StackFrames.Pop();
                            m_thread.m_currentFrame = m_thread.stack.StackFrames.Peek();
                            m_thread.PC = retPC1;
                            if (bas1 is Float)
                            {
                                m_thread.m_currentFrame.OpStack.Push((Float) bas1);
                            }
                        }
                        else
                        {
                            // Console.WriteLine("No parent function so ending program");
                            m_thread.stack.StackFrames.Pop();
                            run = false;
                        }
                        handled = true;
                    }
                    if (currentOpCode == 177)
                    {
                        if (m_thread.stack.StackFrames.Count > 1)
                        {
                            Console.WriteLine("returning from function");
                            int retPC = m_thread.m_currentFrame.ReturnPC;
                            m_thread.stack.StackFrames.Pop();
                            m_thread.m_currentFrame = m_thread.stack.StackFrames.Peek();
                            m_thread.PC = retPC;
                        }
                        else
                        {
                            // Console.WriteLine("No parent function so ending program");
                            m_thread.stack.StackFrames.Pop();
                            run = false;
                        }
                        handled = true;
                    }
                }
                if (!handled)
                {
                    Console.WriteLine("opcode " + currentOpCode + " not been handled ");
                }
                return run;
            }
        }
    }
}
