#region License
//
// LinuxKeyboardTTY.cs
//
// Author:
//       thefiddler <stapostol@gmail.com>
//
// Copyright (c) 2006-2014 
//
// 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.
//
#endregion

using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using OpenTK.Input;

namespace OpenTK.Platform.Linux
{
    class LinuxKeyboardTTY : IKeyboardDriver2, IDisposable
    {
        const int stdin = 0; // STDIN_FILENO
        readonly object sync = new object();
        Thread input_thread;
        long exit;
        KeyboardState state;

        TerminalState original_state;
        TerminalState current_state;

        IntPtr original_mode = new IntPtr(-1);

        public LinuxKeyboardTTY()
        {
            if (!SetupTTY(stdin))
            {
                throw new NotSupportedException();
            }

            input_thread = new Thread(ProcessEvents);
            input_thread.IsBackground = true;
            input_thread.Start();
        }

        #region Private Members

        bool SetupTTY(int stdin)
        {
            int ret = Terminal.GetAttributes(stdin, out original_state);
            if (ret < 0)
            {
                Debug.Print("[Linux] Terminal.GetAttributes({0}) failed. Error: {1}",
                    stdin, ret);
                return false;
            }

            // Retrieve current keyboard mode
            ret = Libc.ioctl(stdin, KeyboardIoctlCode.GetMode, ref original_mode);
            if (ret != 0)
            {
                Debug.Print("[Linux] Libc.ioctl({0}, KeyboardIoctlCode.GetMode) failed. Error: {1}",
                    stdin, ret);
                return false;
            }

            // Update terminal state
            current_state = original_state;
            current_state.LocalMode &= ~(LocalFlags.ECHO | LocalFlags.ICANON | LocalFlags.ISIG);
            current_state.InputMode &= ~(
                InputFlags.ISTRIP | InputFlags.IGNCR | InputFlags.ICRNL |
                InputFlags.INLCR | InputFlags.IXOFF | InputFlags.IXON);
            current_state.ControlCharacters.VMIN = 0;
            current_state.ControlCharacters.VTIME = 0;
            Terminal.SetAttributes(stdin, OptionalActions.FLUSH, ref current_state);

            // Request keycodes
            int mode = 0x02; // K_MEDIUMRAW
            ret = Libc.ioctl(stdin, KeyboardIoctlCode.SetMode, mode);
            if (ret != 0)
            {
                Debug.Print("[Linux] Libc.ioctl({0}, KeyboardIoctlCode.SetMode, {1}) failed. Error: {2}",
                    stdin, mode, ret);
                ExitTTY(this, EventArgs.Empty);
                return false;
            }

            // Ensure we reset the original keyboard/terminal state on exit,
            // even if we crash.
            HookEvents();

            return true;
        }

        void ExitTTY(object sender, EventArgs e)
        {
            if (original_mode != new IntPtr(-1))
            {
                Libc.ioctl(stdin, KeyboardIoctlCode.SetMode, ref original_mode);
                Terminal.SetAttributes(stdin, OptionalActions.FLUSH, ref original_state);
                original_mode = new IntPtr(-1);

                UnhookEvents();
            }
        }

        void HookEvents()
        {
            Process.GetCurrentProcess().Exited += ExitTTY;
            Console.CancelKeyPress += ExitTTY;
        }

        void UnhookEvents()
        {
            Process.GetCurrentProcess().Exited -= ExitTTY;
            Console.CancelKeyPress -= ExitTTY;
        }

        void ProcessEvents()
        {
            state.SetIsConnected(true);

            while (Interlocked.Read(ref exit) == 0)
            {
                byte scancode;
                short extended;

                while (Libc.read(stdin, out scancode) > 0)
                {
                    bool pressed = (scancode & 0x80) == 0;
                    int key = scancode & ~0x80;
                    KeyModifiers mods;
                    Debug.Print("{0}:{1} is {2}", key, (int)TranslateKey(key, out mods), pressed);

                    if (key == 0)
                    {
                        // This is an extended scancode, ignore
                        Libc.read(stdin, out extended);
                    }
                    else
                    {
                        lock (sync)
                        {
                            state[(Key)key] = pressed;
                        }
                    }

                }
            }

            input_thread = null;
        }

        Key TranslateKey(int key, out KeyModifiers mods)
        {
            int k = MathHelper.Clamp((int)key, 0, KeyMap.Length);
            Key result = KeyMap[k];
            mods = 0;
            mods |= (result == Key.AltLeft || result == Key.AltRight) ? KeyModifiers.Alt : 0;
            mods |= (result == Key.ControlLeft || result == Key.ControlRight) ? KeyModifiers.Control : 0;
            mods |= (result == Key.ShiftLeft || result == Key.ShiftRight) ? KeyModifiers.Shift : 0;
            return KeyMap[k];
        }

        #region KeyMap

        static readonly Key[] KeyMap = new Key[]
        {
            // 0-7
            Key.Unknown,
            Key.Escape,
            Key.Number1,
            Key.Number2,
            Key.Number3,
            Key.Number4,
            Key.Number5,
            Key.Number6,
            // 8-15
            Key.Number7,
            Key.Number8,
            Key.Number9,
            Key.Number0,
            Key.Minus,
            Key.Plus,
            Key.BackSpace,
            Key.Tab,
            // 16-23
            Key.Q,
            Key.W,
            Key.E,
            Key.R,
            Key.T,
            Key.Y,
            Key.U,
            Key.I,
            // 24-31
            Key.O,
            Key.P,
            Key.BracketLeft,
            Key.BracketRight,
            Key.Enter,
            Key.ControlLeft,
            Key.A,
            Key.S,
            // 32-39
            Key.D,
            Key.F,
            Key.G,
            Key.H,
            Key.J,
            Key.K,
            Key.L,
            Key.Semicolon,
            // 40-47
            Key.Quote,
            Key.Tilde,
            Key.ShiftLeft,
            Key.BackSlash, //Key.Execute,
            Key.Z,
            Key.X,
            Key.C,
            Key.V, //Key.Help,
            // 48-55
            Key.B,
            Key.N,
            Key.M,
            Key.Comma,
            Key.Period,
            Key.Slash,
            Key.ShiftRight,
            Key.KeypadMultiply,
            // 56-63
            Key.AltLeft,
            Key.Space,
            Key.CapsLock,
            Key.F1,
            Key.F2,
            Key.F3,
            Key.F4,
            Key.F5,
            // 64-71
            Key.F6,
            Key.F7,
            Key.F8,
            Key.F9,
            Key.F10,
            Key.NumLock,
            Key.ScrollLock,
            Key.Keypad7,
            // 72-79
            Key.Keypad8,
            Key.Keypad9,
            Key.KeypadSubtract,
            Key.Keypad4,
            Key.Keypad5,
            Key.Keypad6,
            Key.KeypadPlus,
            Key.Keypad1,
            // 80-87
            Key.Keypad2,
            Key.Keypad3,
            Key.Keypad0,
            Key.KeypadPeriod,
            Key.Unknown,
            Key.Unknown, // Zzenkakuhankaku
            Key.Unknown, // 102ND
            Key.F11,
            // 88-95
            Key.F12,
            Key.Unknown, // ro
            Key.Unknown, // katakana
            Key.Unknown, // hiragana
            Key.Unknown, // henkan
            Key.Unknown, // katakanahiragana
            Key.Unknown, // muhenkan
            Key.Unknown, // kpjpcomma
            // 96-103
            Key.KeypadEnter,
            Key.ControlRight,
            Key.KeypadDivide,
            Key.Unknown, // sysrq
            Key.AltRight,
            Key.Unknown, // linefeed
            Key.Home,
            Key.Up,
            // 104-111
            Key.PageUp,
            Key.Left,
            Key.Right,
            Key.End,
            Key.Down,
            Key.PageDown,
            Key.Insert,
            Key.Delete,
            // 112-119
            Key.Unknown, // macro
            Key.Unknown, // mute
            Key.Unknown, // volumedown
            Key.Unknown, // volumeup
            Key.Unknown, // power
            Key.Unknown, // kpequal
            Key.Unknown, // kpplusminus
            Key.Pause,
            // 120-127
            Key.Unknown, // scale
            Key.Unknown, // kpcomma
            Key.Unknown, // hangeul / hanguel
            Key.Unknown, // hanja
            Key.Unknown, // yen
            Key.WinLeft,
            Key.WinRight,
            Key.Unknown, // compose
            // 128-135
            Key.Unknown, // stop
            Key.Unknown, // again
            Key.Unknown, // props
            Key.Unknown, // undo
            Key.Unknown, // front
            Key.Unknown, // copy
            Key.Unknown, // open
            Key.Unknown, // paste
            // 136-143
            Key.Unknown, // find
            Key.Unknown, // cut
            Key.Unknown, // help
            Key.Unknown, // menu
            Key.Unknown, // calc
            Key.Unknown, // setup
            Key.Unknown, // sleep
            Key.Unknown, // wakeup
            // 144-151
            Key.Unknown, // file
            Key.Unknown, // send file
            Key.Unknown, // delete file
            Key.Unknown, // xfer
            Key.Unknown, // prog1
            Key.Unknown, // prog2
            Key.Unknown, // www
            Key.Unknown, // msdos
            // 152-159
            Key.Unknown, // coffee / screenlock
            Key.Unknown, // direction
            Key.Unknown, // cycle windows
            Key.Unknown, // mail
            Key.Unknown, // bookmarks
            Key.Unknown, // computer
            Key.Back,
            Key.Unknown, // forward
            // 160-167
            Key.Unknown, // close cd
            Key.Unknown, // eject cd
            Key.Unknown, // eject/close cd
            Key.Unknown, // next song
            Key.Unknown, // play/pause
            Key.Unknown, // previous song
            Key.Unknown, // stop cd
            Key.Unknown, // record
            // 168-175
            Key.Unknown, // rewind
            Key.Unknown, // phone
            Key.Unknown, // iso
            Key.Unknown, // config
            Key.Unknown, // homepage
            Key.Unknown, // refresh
            Key.Unknown, // exit
            Key.Unknown, // move,
            // 176-183
            Key.Unknown, // edit,
            Key.Unknown, // scroll up,
            Key.Unknown, // scroll down,
            Key.Unknown, // kp left paren,
            Key.Unknown, // kp right paren,
            Key.Unknown, // new,
            Key.Unknown, // redo,
            Key.F13,
            // 184-191
            Key.F14,
            Key.F15,
            Key.F16,
            Key.F17,
            Key.F18,
            Key.F19,
            Key.F20,
            Key.F21,
            // 192-199
            Key.F22,
            Key.F23,
            Key.F24,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            // 200-207
            Key.Unknown, // play cd
            Key.Unknown, // pause cd
            Key.Unknown, // prog3
            Key.Unknown, // prog4
            Key.Unknown, // dashboard
            Key.Unknown, // suspend
            Key.Unknown, // close
            Key.Unknown, // play
            // 208-215
            Key.Unknown, // fast forward
            Key.Unknown, // bass boost
            Key.Unknown, // print
            Key.Unknown, // hp
            Key.Unknown, // camera
            Key.Unknown, // sound
            Key.Unknown, // question
            Key.Unknown, // email
            // 216-223
            Key.Unknown, // chat
            Key.Unknown, // search
            Key.Unknown, // connect
            Key.Unknown, // finance
            Key.Unknown, // sport
            Key.Unknown, // shop
            Key.Unknown, // alt erase
            Key.Unknown, // cancel
            // 224-231
            Key.Unknown, // brightness down
            Key.Unknown, // brightness up
            Key.Unknown, // media
            Key.Unknown, // switch video mode
            Key.Unknown, // dillum toggle
            Key.Unknown, // dillum down
            Key.Unknown, // dillum up
            Key.Unknown, // send
            // 232-239
            Key.Unknown, // reply
            Key.Unknown, // forward email
            Key.Unknown, // save
            Key.Unknown, // documents
            Key.Unknown, // battery
            Key.Unknown, // bluetooth
            Key.Unknown, // wlan
            Key.Unknown, // uwb
            // 240-247
            Key.Unknown,
            Key.Unknown, // video next
            Key.Unknown, // video prev
            Key.Unknown, // brightness cycle
            Key.Unknown, // brightness zero
            Key.Unknown, // display off
            Key.Unknown, // wwan / wimax
            Key.Unknown, // rfkill
            // 248-255
            Key.Unknown, // mic mute
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown,
            Key.Unknown, // reserved
        };

        #endregion

        #endregion

        #region IKeyboardDriver2 implementation

        public KeyboardState GetState()
        {
            lock (this)
            {
                return state;
            }
        }

        public KeyboardState GetState(int index)
        {
            lock (this)
            {
                if (index == 0)
                    return state;
                else
                    return new KeyboardState();
            }
        }

        public string GetDeviceName(int index)
        {
            if (index == 0)
                return "Standard Input";
            else
                return String.Empty;
        }

        #endregion

        #region IDisposable Implementation

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        void Dispose(bool disposing)
        {
            Interlocked.Increment(ref exit);

            if (disposing)
            {
                ExitTTY(this, EventArgs.Empty);
            }
            else
            {
                Debug.Print("{0} leaked, did you forget to call Dispose()?", typeof(LinuxKeyboardTTY).FullName);
            }
        }

        ~LinuxKeyboardTTY()
        {
            Dispose(false);
        }

        #endregion
    }
}