/*
 * General note:  Error checking is kind of a circus in this file
 */

#include<CL/cl.h>
#include<stdio.h>
#include<ctype.h>
#include "scolor.h"

cl_device_info query_items[] = {CL_DEVICE_TYPE, CL_DEVICE_VENDOR_ID, CL_DEVICE_MAX_COMPUTE_UNITS, CL_DEVICE_GLOBAL_MEM_SIZE, CL_DEVICE_LOCAL_MEM_SIZE, CL_DEVICE_NAME, CL_DRIVER_VERSION, CL_DEVICE_VENDOR, CL_DEVICE_EXTENSIONS};

char* query_names[] = {"CL_DEVICE_TYPE", "CL_DEVICE_VENDOR_ID", "CL_DEVICE_MAX_COMPUTE_UNITS", "CL_DEVICE_GLOBAL_MEM_SIZE", "CL_DEVICE_LOCAL_MEM_SIZE", "CL_DEVICE_NAME", "CL_DRIVER_VERSION", "CL_DEVICE_VENDOR", "CL_DEVICE_EXTENSIONS"};

#define check(m) if(errcode != CL_SUCCESS){ puts(m); goto err; }

int main(){
	cl_platform_id plt_ids[10];
	cl_uint plt_count;
	cl_device_id dev_ids[10];
	cl_uint dev_count;
	char pname[1024];

	cl_int retval = clGetPlatformIDs(10, plt_ids, &plt_count);
	if(retval != CL_SUCCESS){
		printf(RED("clGetPlatformIDs failed with error %d\n"), retval);
		goto err;
	}
	for(int i = 0; i < plt_count; i++){
		printf(PURPLE("Platform %d (ID %lu):\n"), i, (size_t)plt_ids[i]);
		cl_int retval = clGetDeviceIDs(plt_ids[i], CL_DEVICE_TYPE_ALL, 10, dev_ids, &dev_count);
		if(retval != CL_SUCCESS){
			printf(RED("clGetPlatformIDs failed with error %d\n"), retval);
			goto err;
		}
		for(int j = 0; j < dev_count; j++){
			printf(GREEN("Device %d (ID %lu):\n"), j, (size_t)dev_ids[j]);	
			for(int q = 0; q < sizeof(query_items)/sizeof(cl_device_info); q++){
				size_t psize;
				retval = clGetDeviceInfo(dev_ids[j], query_items[q], 1024, pname, &psize);
				if(retval != CL_SUCCESS){
					printf(RED("Query Failed:  %s\n"), query_names[q]);
					continue;
				}
				if(isalnum(pname[0]) || (psize != 4 && psize != 8)){ // Not bulletproof
					pname[psize] = 0;
					printf("%s : "BBLUE("%s")" (%ld)\n", query_names[q], pname, psize);
				} else if(psize == 4) {
					printf("%s : "BBLUE("%u")" (%ld)\n", query_names[q], *((cl_uint*)pname), psize);
				} else {
					printf("%s : "BBLUE("%lu")" (%ld)\n", query_names[q], *((size_t*)pname), psize);
				}
			}
		}
	}
	/* We'll assume platform 0, device 0 from this point on */
	cl_int errcode;
	cl_context context = clCreateContext(0, 1, dev_ids, 0, 0, &errcode);
	if(errcode != CL_SUCCESS) goto err;

	/* Note here:  You won't find a manpage for clCreateCommandQueueWithProperties on Debian Linux, and probably others
	 * The deprecated version is just called clCreateCommandQueue, and they take the same parameters.
	 * On Debian at least, the compiler will warn that clCreateCommandQueue is deprecated, and accept this version
	 * nVidia has been slow with OpenCL support and clCreateCommandQueueWithProperties is OpenCL 2.0+, but it works
	 */
	cl_command_queue queue = clCreateCommandQueueWithProperties(context, dev_ids[0], 0, &errcode);
	check("clCreateCommandQueue");

	int input[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
	cl_mem input_buffer = clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, sizeof(input), input, &errcode);
	if(errcode != CL_SUCCESS) goto err;
	
	cl_mem output_buffer = clCreateBuffer(context, CL_MEM_WRITE_ONLY, sizeof(input), 0, &errcode);
	if(errcode != CL_SUCCESS) goto err;

	const char* kernel_code = " \
		__kernel void squares(__global int* in, __global int* out){ \
			const int i = get_global_id(0); \
			out[i] = in[i] * in[i]; \
		}";
	cl_program program = clCreateProgramWithSource(context, 1, &kernel_code, 0, &errcode);
	check("clCreateProgramWithSource");

	if(clBuildProgram(program, 1, dev_ids, 0, 0, 0) != CL_SUCCESS){
		puts("clBuildProgram");
		goto err;
	}

	cl_kernel kernel = clCreateKernel(program, "squares", &errcode);
	check("clCreateKernel");

	errcode = clSetKernelArg(kernel, 0, sizeof(cl_mem), &input_buffer);
	check("clSetKernelArg");

	if(CL_SUCCESS != (errcode = clSetKernelArg(kernel, 1, sizeof(cl_mem), &output_buffer))){
		printf("clSetKernelArg #2\n");
		goto err;
	}

	const size_t worklen = sizeof(input) / sizeof(float);
	if(CL_SUCCESS != (errcode = clEnqueueNDRangeKernel(queue, kernel, 1, 0, &worklen, 0, 0, 0, 0))){
		perror("clEnqueueNDRangeKernel");
		goto err;
	}

	errcode = clEnqueueReadBuffer(queue, output_buffer, CL_TRUE, 0, sizeof(input), input, 0, 0, 0);
	check("clEnqueueReadBuffer");
	printf(BGREEN("Results: ")PURPLE("["));
	for(int i = 0; i < sizeof(input) / sizeof(float); i++){
		printf(PURPLE("%d, "), input[i]);
	}
	printf(PURPLE("\b\b]\n"));

	return 0;
err:
	printf(RED("We have failed to discover the wonders of OpenCL, errcode = %d\n"), errcode);
	return 1;
}