#include <algorithm>
#include <iostream>
#include <iterator>
#include <sstream>

#include "common.h"

constexpr std::size_t K = 1'000;

std::size_t pfor::ParallelForParameters::nThreads{1};

struct Arguments {
	std::size_t arraySize;
	std::string method;
};

Arguments processCLA(int argc, char **argv) {
	if(argc < 2) {
		std::cerr << "Usage: " << *argv << " N method" << std::endl;
		std::cerr << "  N: array size (1..1000000)" << std::endl;
		std::cerr << "  method: {seq, gen}" << std::endl;
		std::exit(1);
	}

	Arguments args;

	{
		std::istringstream iss{argv[1]};
		iss >> args.arraySize;
	}
	args.method = std::string{argv[2]};

	if(args.arraySize < 1 || args.arraySize > 1000000) {
		std::cerr << "N out of bounds" << std::endl;
		std::exit(1);
	}

	if(args.method != "seq" && args.method != "gen") {
		std::cerr << "method out of bounds" << std::endl;
		std::exit(1);
	}

	return args;
}

using T = int;

int main(int argc, char **argv) {
	Arguments args = processCLA(argc, argv);
	std::size_t const N = args.arraySize;

	OPERAND(T, a0, N, i++);
	OPERAND(T, a1, N, i++);
	OPERAND(T, a2, N, i++);
	OPERAND(T, a3, N, i++);
	OPERAND(T, a4, N, i++);
	OPERAND(T, a5, N, i++);
	OPERAND(T, a6, N, i++);
	OPERAND(T, a7, N, i++);

/*
* Sample 0: sequential
*/
	// arraysPrinter(K, N, a0, a1, a2, a5);

	if(args.method == "seq") {
		BENCH(K)
			for(std::size_t i = 0; i < N-1; ++i) {
				a0_[i] = a0_[i+1] + a1_[i] * a2_[i];
				a1_[i] = a1_[i+1] + a2_[i] * a3_[i];
				a2_[i] = a2_[i+1] + a3_[i] * a4_[i];
				a5_[i] = a5_[i+1] + a6_[i] * a7_[i];
			}
		END_BENCH();
	} else if(args.method == "gen") {
		BENCH(K)
			pfor::parallelFor(pfor::Range{0, static_cast<long>(N-1)}, [&](pfor::Index i) {
				return
					a0[i] = a0[i+_<1>] + a1[i] * a2[i],
					a1[i] = a1[i+_<1>] + a2[i] * a3[i],
					a2[i] = a2[i+_<1>] + a3[i] * a4[i],
					a5[i] = a5[i+_<1>] + a6[i] * a7[i];
			});
		END_BENCH();
	}

	if(rand() == rand()) arraysPrinter(1, N, a0_, a1_, a2_, a3_, a4_, a5_, a6_, a7_);

	END_OPERAND(a0);
	END_OPERAND(a1);
	END_OPERAND(a2);
	END_OPERAND(a3);
	END_OPERAND(a4);
	END_OPERAND(a5);
	END_OPERAND(a6);
	END_OPERAND(a7);
}