/////////////////////////////////////////////////////////////////////////
 //
 //     www.ultima.smoce.net
 //     Name: Podpora UOAM
 //
 /////////////////////////////////////////////////////////////////////////
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Windows.Forms;
using Phoenix.Communication;
using Phoenix.Communication.Packets;
using Phoenix.Runtime;
using Phoenix.WorldData;
using System.Linq;

namespace Phoenix.Scripts {
    [RuntimeObject]
    public class AssistApi : IDisposable {
        private const string ApiKey = "UOASSIST-TP-MSG-WND";

        public AssistApi() {
            alive = true;
            finished = new ManualResetEvent( false );

            RuntimeCore.UnregisteringAssembly += new UnregisteringAssemblyEventHandler( RuntimeCore_UnregisteringAssembly );
            Core.LoginComplete += new EventHandler( Core_LoginComplete );

            applications = new Dictionary<IntPtr, uint>();
            commands = new Dictionary<string, CommandInfo>();

            apiThread = new Thread( new ThreadStart( Work ) );
            apiThread.IsBackground = true;
            apiThread.Start();
        }
        ~AssistApi() {
            Dispose();
        }

        private Thread apiThread;
        private bool alive;
        private ManualResetEvent finished;

        private Dictionary<IntPtr, uint> applications;
        private Dictionary<string, CommandInfo> commands;

        private void Work() {
            try {
                Message message;
                NativeMethods.PeekMessage( out message, IntPtr.Zero, 0, 0, 0 );

                WndProcDelegate wndProc = new WndProcDelegate( WndProc );

                WNDCLASS windowClass = new WNDCLASS();
                windowClass.lpszClassName = ApiKey;
                windowClass.lpfnWndProc = Marshal.GetFunctionPointerForDelegate( wndProc );

                Debug.WriteLine( "Registering window", "AssistApi" );
                ushort windowClassAtom = NativeMethods.RegisterClass( ref windowClass );
                if ( windowClassAtom == 0 && Marshal.GetLastWin32Error() != 1410 )
                    throw new Win32Exception();

                Debug.WriteLine( "Creating window", "AssistApi" );
                IntPtr windowHandle = NativeMethods.CreateWindowEx( 0, ApiKey, ApiKey, 0, 0, 0, 0, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero );
                if ( windowHandle == IntPtr.Zero )
                    throw new Win32Exception();

                Debug.WriteLine( "Entering main loop", "AssistApi" );

                while ( alive ) {
                    while ( NativeMethods.PeekMessage( out message, IntPtr.Zero, 0, 0, 0 ) ) {
                        if ( NativeMethods.GetMessage( out message, IntPtr.Zero, 0, 0 ) == -1 )
                            throw new Win32Exception();

                        NativeMethods.TranslateMessage( ref message );
                        NativeMethods.DispatchMessage( ref message );
                    }
                    Thread.Sleep( 100 );
                }

                Debug.WriteLine( "Destroying window", "AssistApi" );
                if ( !NativeMethods.DestroyWindow( windowHandle ) )
                    throw new Win32Exception();

                Debug.WriteLine( "Unregistering window", "AssistApi" );
                if ( !NativeMethods.UnregisterClass( ApiKey, IntPtr.Zero ) )
                    throw new Win32Exception();
            }
            catch ( Exception e1 ) {
                Debug.WriteLine( e1.Message, "Error" );
                Debug.WriteLine( e1.StackTrace, "Error" );
            }
            finally {
                finished.Set();
            }
        }

        private string ReadAtomAndDelete( ushort atom ) {
            StringBuilder result = new StringBuilder( 255 );

            if ( NativeMethods.GlobalGetAtomName( atom, result, result.Capacity ) == 0 )
                throw new Win32Exception();

            NativeMethods.GlobalDeleteAtom( atom );
            if ( Marshal.GetLastWin32Error() != 0 )
                throw new Win32Exception();

            return result.ToString();
        }

        private void CleanDead() {
            foreach ( IntPtr application in ( from a in applications.Keys
                                              where !NativeMethods.IsWindow( a )
                                              select a ).ToList() )
                applications.Remove( application );

            foreach ( string command in ( from c in commands.Values
                                          where !NativeMethods.IsWindow( c.Handle )
                                          select c.Name ).ToList() )
                commands.Remove( command );
        }

        private IntPtr WndProc( IntPtr hwnd, uint uMsg, IntPtr wParam, IntPtr lParam ) {

            CleanDead();

            switch ( uMsg ) {

                case 0x400 + 200:
                    if ( applications.ContainsKey( wParam ) ) {
                        foreach ( string command in ( from c in commands.Values
                                                      where c.Handle == wParam
                                                      select c.Name ).ToList() )
                            commands.Remove( command );

                        Debug.WriteLine( "Unregistered application", "AssistApi" );
                        applications.Remove( wParam );
                        return new IntPtr( 2 );
                    }

                    Debug.WriteLine( "Registered new application", "AssistApi" );
                    applications.Add( wParam, ( uint )lParam );

                    return new IntPtr( 1 );

                case 0x400 + 202:
                    return new IntPtr( World.Player.X | ( World.Player.Y << 16 ) );

                case 0x400 + 207:
                    ushort messageColor = ( ushort )wParam.ToInt32();
                    bool messageSystem = ( ( wParam.ToInt32() >> 16 ) & 1 ) == 1;
                    string message = ReadAtomAndDelete( ( ushort )lParam );

                    Core.SendToClient( PacketBuilder.CharacterSpeechUnicode( messageSystem ? Serial.Invalid : ( uint )World.Player.Serial, World.Player.Model, "UOAM", SpeechType.Regular, SpeechFont.Normal, messageColor, message ) );
                    break;

                case 0x400 + 209:
                    string commandName = ReadAtomAndDelete( ( ushort )lParam );

                    if ( wParam == IntPtr.Zero ) {
                        commands.Remove( commandName );
                        Debug.WriteLine( string.Format( "Unregistered command '{0}'", commandName ), "AssistApi" );
                        return IntPtr.Zero;
                    }

                    CommandInfo commandInfo = new CommandInfo( wParam, commandName );
                    commands.Add( commandName, commandInfo );
                    Debug.WriteLine( string.Format( "Registered command '{0}' (slot {1})", commandName, commandInfo.Offset ), "AssistApi" );
                    return new IntPtr( 0x400 + 0x400 + commandInfo.Offset );

                default:
                    if ( uMsg > 0x400 )
                        Debug.WriteLine( string.Format( "Unknown message 0x{0:x4} w: 0x{1:x4} l: 0x{2:x4}", uMsg, wParam, lParam ), "AssistApi" );
                    break;

            }

            return NativeMethods.DefWindowProc( hwnd, uMsg, wParam, lParam );
        }

        #region Event handlers

        [ClientMessageHandler( 0x03, Priority = CallbackPriority.Highest )]
        [ClientMessageHandler( 0xad, Priority = CallbackPriority.Highest )]
        public CallbackResult OnSpeechRequest( byte[] data, CallbackResult prevResult ) {
            string text;

            text = data[ 0 ] == 0x03 ? new AsciiSpeechRequest( data ).Text : new UnicodeSpeechRequest( data ).Text;

            if ( text.StartsWith( "-" ) ) {
                string commandName = text.Substring( 1 );
                foreach ( CommandInfo command in commands.Values ) {
                    if ( commandName.StartsWith( command.Name.ToLower() ) ) {
                        command.Invoke( commandName.Substring( command.Name.Length ) );
                        return CallbackResult.Eat;
                    }
                }

                UO.PrintError( "Unknown assist api command" );
                return CallbackResult.Eat;
            }

            return prevResult;
        }

        private void RuntimeCore_UnregisteringAssembly( object sender, Runtime.UnregisteringAssemblyEventArgs e ) {
            Dispose();
        }

        private void Core_LoginComplete( object sender, EventArgs e ) {
            foreach ( IntPtr handle in applications.Keys ) {
                Debug.WriteLine( string.Format( "Sending login notification to 0x{0:x8}", handle ), "AssistApi" );
                NativeMethods.SendMessage( handle, 0x400 + 303, new IntPtr( World.Player.Serial ), IntPtr.Zero );
            }
        }

        #endregion

        #region IDisposable

        public void Dispose() {
            alive = false;
            finished.WaitOne();
            finished.Close();

            GC.SuppressFinalize( this );
        }

        #endregion

        #region Delegates

        [UnmanagedFunctionPointer( CallingConvention.Winapi )]
        private delegate IntPtr WndProcDelegate( IntPtr hwnd, uint uMsg, IntPtr wParam, IntPtr lParam );

        #endregion

        #region Nested type: CommandInfo

        private class CommandInfo {
            public CommandInfo( IntPtr handle, string name ) {
                Handle = handle;
                Name = name;

                Offset = offset++;
            }

            private static int offset;

            public void Invoke( string args ) {
                ushort atom = NativeMethods.GlobalAddAtom( args );

                NativeMethods.PostMessage( Handle, ( uint )( 0x400 + 0x400 + Offset ), new IntPtr( atom ), IntPtr.Zero );
            }

            public IntPtr Handle {
                get;
                private set;
            }

            public int Offset {
                get;
                private set;
            }

            public string Name {
                get;
                private set;
            }
        }

        #endregion

        #region Nested type: WNDCLASS

        private struct WNDCLASS {
            public uint style;
            public IntPtr lpfnWndProc;
            public int cbClsExtra;
            public int cbWndExtra;
            public IntPtr hInstance;
            public IntPtr hIcon;
            public IntPtr hCursor;
            public IntPtr hbrBackground;
            [MarshalAs( UnmanagedType.LPStr )]
            public string lpszMenuName;
            [MarshalAs( UnmanagedType.LPStr )]
            public string lpszClassName;
        }

        #endregion

        #region Native methods

        private class NativeMethods {

            [DllImport( "kernel32", SetLastError = true )]
            public static extern uint GlobalGetAtomName( ushort nAtom, [MarshalAs( UnmanagedType.LPStr )] StringBuilder lpBuffer, int nSize );

            [DllImport( "kernel32", SetLastError = true )]
            public static extern ushort GlobalAddAtom( [MarshalAs( UnmanagedType.LPStr )] string lpString );

            [DllImport( "kernel32", SetLastError = true )]
            public static extern ushort GlobalDeleteAtom( ushort nAtom );

            [DllImport( "user32", SetLastError = true )]
            public static extern IntPtr CreateWindowEx(
                uint dwExStyle,
                [MarshalAs( UnmanagedType.LPStr )] string lpClassName,
                [MarshalAs( UnmanagedType.LPStr )] string lpWindowName,
                uint dwStyle,
                int x,
                int y,
                int nWidth,
                int nHeight,
                IntPtr hWndParent,
                IntPtr hMenu,
                IntPtr hInstance,
                IntPtr lpParam
            );

            [DllImport( "user32", SetLastError = true )]
            public static extern bool DestroyWindow( IntPtr hWnd );

            [DllImport( "user32" )]
            public static extern IntPtr DefWindowProc( IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam );

            [DllImport( "user32", SetLastError = true )]
            public static extern ushort RegisterClass( ref WNDCLASS lpWndClass );

            [DllImport( "user32", SetLastError = true )]
            public static extern bool UnregisterClass( [MarshalAs( UnmanagedType.LPStr )] string lpClassName, IntPtr hInstance );

            [DllImport( "user32" )]
            public static extern bool PeekMessage( out Message lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax, uint wRemoveMsg );

            [DllImport( "user32", SetLastError = true )]
            public static extern int GetMessage( out Message lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax );

            [DllImport( "user32" )]
            public static extern bool TranslateMessage( ref Message lpMsg );

            [DllImport( "user32" )]
            public static extern bool DispatchMessage( ref Message lpMsg );

            [DllImport( "user32" )]
            public static extern IntPtr SendMessage( IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam );

            [DllImport( "user32" )]
            public static extern IntPtr PostMessage( IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam );

            [DllImport( "user32" )]
            public static extern IntPtr FindWindow( [MarshalAs( UnmanagedType.LPStr )] string lpClassName, [MarshalAs( UnmanagedType.LPStr )] string lpWindowName );

            [DllImport( "user32" )]
            public static extern bool IsWindow( IntPtr hWnd );

        }

        #endregion
    }
}