#include "fluid_buffer.h"

#include <fstream>

FluidBuffer::FluidBuffer(std::size_t dimX, std::size_t dimY):
	dim_x_(dimX),
	dim_y_(dimY),
	density_(new Density[dimX*dimY]),
	velocity_(new Velocity[dimX*dimY]) { }

std::size_t FluidBuffer::dimX() const {
	return dim_x_;
}

std::size_t FluidBuffer::dimY() const {
	return dim_y_;
}

Density& FluidBuffer::density(std::size_t x, std::size_t y) {
	return density_[y*dim_x_ + x];
}

Density& FluidBuffer::density(Vector<std::size_t> pos) {
	return density(pos[0], pos[1]);
}

Velocity& FluidBuffer::velocity(std::size_t x, std::size_t y) {
	return velocity_[y*dim_x_ + x];
}

Velocity& FluidBuffer::velocity(Vector<std::size_t> pos) {
	return velocity(pos[0], pos[1]);
}

void FluidBuffer::writeAsVTK(const std::filesystem::path& path) {
	std::filesystem::create_directories(path.parent_path());

	std::ofstream fout;
	fout.open(path.c_str());

	fout << "# vtk DataFile Version 3.0\n";
	fout << "lbm_output\n";
	fout << "ASCII\n";
	fout << "DATASET RECTILINEAR_GRID\n";
	fout << "DIMENSIONS " << dimX() << " " << dimY() << " 1" << "\n";

	fout << "X_COORDINATES " << dimX() << " float\n";
	for( std::size_t x = 0; x < dimX(); ++x ) {
		fout << x << " ";
	}

	fout << "\nY_COORDINATES " << dimY() << " float\n";
	for( std::size_t y = 0; y < dimY(); ++y ) {
		fout << y << " ";
	}

	fout << "\nZ_COORDINATES " << 1 << " float\n";
	fout << 0 << "\n";
	fout << "POINT_DATA " << dimX() * dimY() << "\n";

	fout << "VECTORS velocity float\n";
	for ( std::size_t y = 0; y < dimY(); ++y ) {
		for ( std::size_t x = 0; x < dimX(); ++x ) {
			fout << velocity(x,y)[0] << " " << velocity(x,y)[1] << " 0\n";
		}
	}

	fout << "SCALARS density float 1\n";
	fout << "LOOKUP_TABLE default\n";
	for ( std::size_t y = 0; y < dimY(); ++y ) {
		for ( std::size_t x = 0; x < dimX(); ++x ) {
			fout << density(x,y) << "\n";
		}
	}

	fout.close();
}