/*
 * Copyright (c) 2011, Denis Steckelmacher <steckdenis@yahoo.fr>
 * Copyright (c) 2012-2014, Texas Instruments Incorporated - http://www.ti.com/
 * All rights reserved.
 *
 * 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 copyright holder 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 COPYRIGHT HOLDERS AND CONTRIBUTORS "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.
 */

/**
 * \file context.cpp
 * \brief Context
 */

#include "context.h"
#include "deviceinterface.h"
#include "propertylist.h"
#include "platform.h"

#include <cstring>
#include <cstdlib>

#include <llvm/Support/TargetSelect.h>

using namespace Coal;

static void default_pfn_notify(const char *, const void *, size_t, void *)
{
    return;
}

Context::Context(const cl_context_properties *properties,
                 cl_uint num_devices,
                 const cl_device_id *devices,
                 void (CL_CALLBACK *pfn_notify)(const char *, const void *,
                                                size_t, void *),
                 void *user_data,
                 cl_int *errcode_ret)
: Object(Object::T_Context, 0), p_properties(0), p_pfn_notify(pfn_notify),
  p_user_data(user_data), p_devices(0), p_num_devices(0), p_props_len(0),
  p_platform(&the_platform)
{
    if (!p_pfn_notify)
        p_pfn_notify = &default_pfn_notify;

    // Intialize LLVM, this can be done more than one time per program
    llvm::InitializeNativeTarget();
    llvm::InitializeNativeTargetAsmPrinter();
    llvm::InitializeNativeTargetAsmParser();

    // Explore the properties
    if (properties)
    {
        const unsigned char *props = (const unsigned char *)properties;
        cl_context_properties prop;
        size_t props_len = 0;

#define GET_PROP(type, var)     \
    var = *(const type *)props;       \
    props += sizeof(type);      \
    props_len += sizeof(type);

		int propset = 0;
        while (true)
        {
            GET_PROP(cl_context_properties, prop)

            if (!prop)
                break;

            switch (prop)
            {
                case CL_CONTEXT_PLATFORM:
                    if (!propset)
                    {
                        GET_PROP(cl_platform_id, p_platform);
                        propset = 1;
                    }
                    else
                    {
                        *errcode_ret = CL_INVALID_PROPERTY;
                        return;
                    }
                    break;

                default:
                    *errcode_ret = CL_INVALID_PROPERTY;
                    return;
            }
        }

        // properties may be allocated on the stack of the client application
        // copy it into a real buffer
        p_properties = (cl_context_properties *)std::malloc(props_len);
        p_props_len = props_len;

        if (!p_properties)
        {
            *errcode_ret = CL_OUT_OF_HOST_MEMORY;
            return;
        }

        std::memcpy((void *)p_properties, (const void *)properties, props_len);
    }

    // Verify that the platform is good
    if (p_platform != &the_platform)
    {
        *errcode_ret = CL_INVALID_PLATFORM;
        return;
    }

    // Explore the devices
    p_devices = (DeviceInterface **)std::malloc(num_devices * sizeof(DeviceInterface *));
    p_num_devices = num_devices;

    if (!p_devices)
    {
        *errcode_ret = CL_OUT_OF_HOST_MEMORY;
        return;
    }

    for (cl_uint i=0; i<num_devices; ++i)
    {
        cl_device_id device = devices[i];

        if (device == 0)
        {
            *errcode_ret = CL_INVALID_DEVICE;
            return;
        }

        // Verify that the device is available
        cl_bool device_available;

        *errcode_ret = device->info(CL_DEVICE_AVAILABLE,
                                    sizeof(device_available),
                                    &device_available,
                                    0);

        if (*errcode_ret != CL_SUCCESS)
            return;

        if (!device_available)
        {
            *errcode_ret = CL_DEVICE_NOT_AVAILABLE;
            return;
        }

        // Add the device to the list
        p_devices[i] = (DeviceInterface *)device;
    }
}

Context::~Context()
{
    if (p_properties)
        std::free((void *)p_properties);

    if (p_devices)
        std::free((void *)p_devices);
}

cl_int Context::info(cl_context_info param_name,
                     size_t param_value_size,
                     void *param_value,
                     size_t *param_value_size_ret) const
{
    void *value = 0;
    size_t value_length = 0;

    union {
        cl_uint cl_uint_var;
    };

    switch (param_name)
    {
        case CL_CONTEXT_REFERENCE_COUNT:
            SIMPLE_ASSIGN(cl_uint, references());
            break;

        case CL_CONTEXT_NUM_DEVICES:
            SIMPLE_ASSIGN(cl_uint, p_num_devices);
            break;

        case CL_CONTEXT_DEVICES:
            MEM_ASSIGN(p_num_devices * sizeof(DeviceInterface *), p_devices);
            break;

        case CL_CONTEXT_PROPERTIES:
            MEM_ASSIGN(p_props_len, p_properties);
            break;

        default:
            return CL_INVALID_VALUE;
    }

    if (param_value && param_value_size < value_length)
        return CL_INVALID_VALUE;

    if (param_value_size_ret)
        *param_value_size_ret = value_length;

    if (param_value && value_length /* CONTEXT_PROPERTIES can be of length 0 */)
        std::memcpy(param_value, value, value_length);

    return CL_SUCCESS;
}

bool Context::hasDevice(DeviceInterface *device) const
{
    for (unsigned int i=0; i<p_num_devices; ++i)
        if (p_devices[i] == device)
            return true;

    return false;
}