/*
 
  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
  Copyright (C) 2009-2012 Michael Möller <mmoeller@openhardwaremonitor.org>
	
*/

using System;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;

namespace OpenHardwareMonitor.Hardware.ATI {
  
  [StructLayout(LayoutKind.Sequential)]
  internal struct ADLAdapterInfo {
    public int Size;
    public int AdapterIndex;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string UDID;
    public int BusNumber;
    public int DeviceNumber;
    public int FunctionNumber;
    public int VendorID;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string AdapterName;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string DisplayName;
    public int Present;
    public int Exist;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string DriverPath;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string DriverPathExt;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = ADL.ADL_MAX_PATH)]
    public string PNPString;
    public int OSDisplayIndex;
  }

  [StructLayout(LayoutKind.Sequential)]
  internal struct ADLPMActivity {
    public int Size;
    public int EngineClock;
    public int MemoryClock;
    public int Vddc;
    public int ActivityPercent;
    public int CurrentPerformanceLevel;
    public int CurrentBusSpeed;
    public int CurrentBusLanes;
    public int MaximumBusLanes;
    public int Reserved;
  }

  [StructLayout(LayoutKind.Sequential)]
  internal struct ADLTemperature {
    public int Size;
    public int Temperature;
  }

  [StructLayout(LayoutKind.Sequential)]
  internal struct ADLFanSpeedValue {
    public int Size;
    public int SpeedType;
    public int FanSpeed;
    public int Flags;
  }

  [StructLayout(LayoutKind.Sequential)]
  internal struct ADLFanSpeedInfo {
    public int Size;
    public int Flags;
    public int MinPercent;
    public int MaxPercent;
    public int MinRPM;
    public int MaxRPM;
  }

  internal class ADL {
    public const int ADL_MAX_PATH = 256;
    public const int ADL_MAX_ADAPTERS = 40;
    public const int ADL_MAX_DISPLAYS = 40;
    public const int ADL_MAX_DEVICENAME = 32;
    public const int ADL_OK = 0;
    public const int ADL_ERR = -1;
    public const int ADL_DRIVER_OK = 0;
    public const int ADL_MAX_GLSYNC_PORTS = 8;
    public const int ADL_MAX_GLSYNC_PORT_LEDS = 8;
    public const int ADL_MAX_NUM_DISPLAYMODES = 1024;

    public const int ADL_DL_FANCTRL_SPEED_TYPE_PERCENT = 1;
    public const int ADL_DL_FANCTRL_SPEED_TYPE_RPM = 2;

    public const int ADL_DL_FANCTRL_SUPPORTS_PERCENT_READ = 1;
    public const int ADL_DL_FANCTRL_SUPPORTS_PERCENT_WRITE = 2;
    public const int ADL_DL_FANCTRL_SUPPORTS_RPM_READ = 4;
    public const int ADL_DL_FANCTRL_SUPPORTS_RPM_WRITE = 8;
    public const int ADL_DL_FANCTRL_FLAG_USER_DEFINED_SPEED = 1;

    public const int ATI_VENDOR_ID = 0x1002;

    private delegate int ADL_Main_Control_CreateDelegate(
      ADL_Main_Memory_AllocDelegate callback, int enumConnectedAdapters);
    private delegate int ADL_Adapter_AdapterInfo_GetDelegate(IntPtr info,
      int size);

    public delegate int ADL_Main_Control_DestroyDelegate();
    public delegate int ADL_Adapter_NumberOfAdapters_GetDelegate(
      ref int numAdapters);    
    public delegate int ADL_Adapter_ID_GetDelegate(int adapterIndex,
      out int adapterID);
    public delegate int ADL_Display_AdapterID_GetDelegate(int adapterIndex,
      out int adapterID);      	
    public delegate int ADL_Adapter_Active_GetDelegate(int adapterIndex,
      out int status);
    public delegate int ADL_Overdrive5_CurrentActivity_GetDelegate(
      int iAdapterIndex, ref ADLPMActivity activity);
    public delegate int ADL_Overdrive5_Temperature_GetDelegate(int adapterIndex,
        int thermalControllerIndex, ref ADLTemperature temperature);
    public delegate int ADL_Overdrive5_FanSpeed_GetDelegate(int adapterIndex,
        int thermalControllerIndex, ref	ADLFanSpeedValue fanSpeedValue);
    public delegate int ADL_Overdrive5_FanSpeedInfo_GetDelegate(
      int adapterIndex, int thermalControllerIndex,
      ref ADLFanSpeedInfo fanSpeedInfo);
    public delegate int ADL_Overdrive5_FanSpeedToDefault_SetDelegate(
      int adapterIndex, int thermalControllerIndex);
    public delegate int ADL_Overdrive5_FanSpeed_SetDelegate(int adapterIndex,
      int thermalControllerIndex, ref	ADLFanSpeedValue fanSpeedValue);

    private static ADL_Main_Control_CreateDelegate
      _ADL_Main_Control_Create;
    private static ADL_Adapter_AdapterInfo_GetDelegate
      _ADL_Adapter_AdapterInfo_Get;

    public static ADL_Main_Control_DestroyDelegate
      ADL_Main_Control_Destroy;
    public static ADL_Adapter_NumberOfAdapters_GetDelegate
      ADL_Adapter_NumberOfAdapters_Get;
    public static ADL_Adapter_ID_GetDelegate 
      _ADL_Adapter_ID_Get;
    public static ADL_Display_AdapterID_GetDelegate 
      _ADL_Display_AdapterID_Get;
    public static ADL_Adapter_Active_GetDelegate 
      ADL_Adapter_Active_Get;
    public static ADL_Overdrive5_CurrentActivity_GetDelegate
      ADL_Overdrive5_CurrentActivity_Get;
    public static ADL_Overdrive5_Temperature_GetDelegate
      ADL_Overdrive5_Temperature_Get;
    public static ADL_Overdrive5_FanSpeed_GetDelegate
      ADL_Overdrive5_FanSpeed_Get;
    public static ADL_Overdrive5_FanSpeedInfo_GetDelegate
      ADL_Overdrive5_FanSpeedInfo_Get;
    public static ADL_Overdrive5_FanSpeedToDefault_SetDelegate
      ADL_Overdrive5_FanSpeedToDefault_Set;
    public static ADL_Overdrive5_FanSpeed_SetDelegate
      ADL_Overdrive5_FanSpeed_Set;

    private static string dllName;

    private static void GetDelegate<T>(string entryPoint, out T newDelegate)
      where T : class 
    {
      DllImportAttribute attribute = new DllImportAttribute(dllName);
      attribute.CallingConvention = CallingConvention.Cdecl;
      attribute.PreserveSig = true;
      attribute.EntryPoint = entryPoint;
      PInvokeDelegateFactory.CreateDelegate(attribute, out newDelegate);
    }

    private static void CreateDelegates(string name) {
      int p = (int)Environment.OSVersion.Platform;
      if ((p == 4) || (p == 128))
        dllName = name + ".so";
      else
        dllName = name + ".dll";

      GetDelegate("ADL_Main_Control_Create",
        out _ADL_Main_Control_Create);
      GetDelegate("ADL_Adapter_AdapterInfo_Get",
        out _ADL_Adapter_AdapterInfo_Get);
      GetDelegate("ADL_Main_Control_Destroy",
        out ADL_Main_Control_Destroy);
      GetDelegate("ADL_Adapter_NumberOfAdapters_Get",
        out ADL_Adapter_NumberOfAdapters_Get);
      GetDelegate("ADL_Adapter_ID_Get",
        out _ADL_Adapter_ID_Get);
      GetDelegate("ADL_Display_AdapterID_Get", 
        out _ADL_Display_AdapterID_Get);
      GetDelegate("ADL_Adapter_Active_Get",
        out ADL_Adapter_Active_Get);
      GetDelegate("ADL_Overdrive5_CurrentActivity_Get",
        out ADL_Overdrive5_CurrentActivity_Get);
      GetDelegate("ADL_Overdrive5_Temperature_Get",
        out ADL_Overdrive5_Temperature_Get);
      GetDelegate("ADL_Overdrive5_FanSpeed_Get",
        out ADL_Overdrive5_FanSpeed_Get);
      GetDelegate("ADL_Overdrive5_FanSpeedInfo_Get",
        out ADL_Overdrive5_FanSpeedInfo_Get);
      GetDelegate("ADL_Overdrive5_FanSpeedToDefault_Set",
        out ADL_Overdrive5_FanSpeedToDefault_Set);
      GetDelegate("ADL_Overdrive5_FanSpeed_Set",
        out ADL_Overdrive5_FanSpeed_Set);
    }

    static ADL() {
      CreateDelegates("atiadlxx");
    }

    private ADL() { }

    public static int ADL_Main_Control_Create(int enumConnectedAdapters) {
      try {
        try {
          return _ADL_Main_Control_Create(Main_Memory_Alloc,
            enumConnectedAdapters);
        } catch {
          CreateDelegates("atiadlxy");
          return _ADL_Main_Control_Create(Main_Memory_Alloc,
            enumConnectedAdapters);
        }
      } catch {
        return ADL_ERR;
      }
    }

    public static int ADL_Adapter_AdapterInfo_Get(ADLAdapterInfo[] info) {
      int elementSize = Marshal.SizeOf(typeof(ADLAdapterInfo));
      int size = info.Length * elementSize;
      IntPtr ptr = Marshal.AllocHGlobal(size);
      int result = _ADL_Adapter_AdapterInfo_Get(ptr, size);
      for (int i = 0; i < info.Length; i++)
        info[i] = (ADLAdapterInfo)
          Marshal.PtrToStructure((IntPtr)((long)ptr + i * elementSize),
          typeof(ADLAdapterInfo));
      Marshal.FreeHGlobal(ptr);

      // the ADLAdapterInfo.VendorID field reported by ADL is wrong on 
      // Windows systems (parse error), so we fix this here
      for (int i = 0; i < info.Length; i++) {
        // try Windows UDID format
        Match m = Regex.Match(info[i].UDID, "PCI_VEN_([A-Fa-f0-9]{1,4})&.*");
        if (m.Success && m.Groups.Count == 2) {
          info[i].VendorID = Convert.ToInt32(m.Groups[1].Value, 16);
          continue;
        }
        // if above failed, try Unix UDID format
        m = Regex.Match(info[i].UDID, "[0-9]+:[0-9]+:([0-9]+):[0-9]+:[0-9]+");
        if (m.Success && m.Groups.Count == 2) {
          info[i].VendorID = Convert.ToInt32(m.Groups[1].Value, 10);
        }
      }

      return result;
    }

    public static int ADL_Adapter_ID_Get(int adapterIndex,
      out int adapterID) {
      try {
        return _ADL_Adapter_ID_Get(adapterIndex, out adapterID);
      } catch (EntryPointNotFoundException) {
        try {
          return _ADL_Display_AdapterID_Get(adapterIndex, out adapterID);
        } catch (EntryPointNotFoundException) {
          adapterID = 1;
          return ADL_OK;
        }
      }
    }

    private delegate IntPtr ADL_Main_Memory_AllocDelegate(int size);

    // create a Main_Memory_Alloc delegate and keep it alive
    private static ADL_Main_Memory_AllocDelegate Main_Memory_Alloc =
      delegate(int size) {
        return Marshal.AllocHGlobal(size);
      };

    private static void Main_Memory_Free(IntPtr buffer) {
      if (IntPtr.Zero != buffer)
        Marshal.FreeHGlobal(buffer);
    }
  }
}