#include <cuda.h>

#include "GPU_MagneticField.h"



//------------------------------------
// MakeGPUResidentBfieldSectionList
//------------------------------------
BfieldSectionList* MakeGPUResidentBfieldSectionList(BfieldSectionList *host_BfieldSectionList)
{
	/// Allocate memory on the GPU to hold a BfieldSectionList
	/// structure and copy the host-resident one into it. The
	/// sections arrays should contain pointers to *host* resident
	/// structures. Each of those will be copied into gpu resident
	/// structures as the BfieldSectionList is made.

	// Copy host_BfieldSectionList to temporary structure so we can
	// replace the BfieldSection pointers with device resident ones
	BfieldSectionList tmp_BfieldSectionList;
	tmp_BfieldSectionList = *host_BfieldSectionList;
	
	// Allocate memory on device for BfieldSectionList
	int size = sizeof(BfieldSectionList);
	BfieldSectionList *device_BfieldSectionList;
	cudaMalloc(&device_BfieldSectionList, size);
	
	// Loop over Bx sections, copying them to GPU memory
	for(int i=0; i<tmp_BfieldSectionList.Nx; i++){
		tmp_BfieldSectionList.sections_Bx[i] = MakeGPUResidentBfieldSection(host_BfieldSectionList->sections_Bx[i]);
	}

	// Loop over Bz sections, copying them to GPU memory
	for(int i=0; i<tmp_BfieldSectionList.Nz; i++){
		tmp_BfieldSectionList.sections_Bz[i] = MakeGPUResidentBfieldSection(host_BfieldSectionList->sections_Bz[i]);
	}

	// Copy temporary BfieldSectionList into GPU memory
	cudaMemcpy(device_BfieldSectionList, &tmp_BfieldSectionList, size, cudaMemcpyHostToDevice);

	return device_BfieldSectionList;
}

//------------------------------------
// MakeGPUResidentBfieldSection
//------------------------------------
BfieldSection* MakeGPUResidentBfieldSection(BfieldSection *host_BfieldSection)
{
	/// Allocate memory on the GPU to hold a BfieldSection structure
	/// and copy the contents of the given host resident structure to
	/// it. Returns a pointer to the GPU resident copy.
	
	int size = sizeof(BfieldSection);
	BfieldSection *device_BfieldSection;
	cudaMalloc(&device_BfieldSection, size);
	cudaMemcpy(device_BfieldSection, host_BfieldSection, size, cudaMemcpyHostToDevice);

	return device_BfieldSection;
}

//------------------------------------
// BfieldSectionIsInRange
//------------------------------------
__device__ int BfieldSectionIsInRange(BfieldSection *bfs, double z)
{
	return z<=bfs->zmax && z>=bfs->zmin;
}