#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <stdint.h>
#include "cachelab.h"

#define mprintf(...) if (VERBOSE) printf(__VA_ARGS__)

void print_usage();
size_t parse_int_arg(char *arg, char opt);

/**
   If VERBOSE is non-zero, mprintf will not print. Otherwise, it will.
   Set in main().
 */
int8_t VERBOSE = 0;

/* USURE. As defined in conference. */
struct line_s {
	int8_t validity;
	int tag;
};
typedef struct line_s line;


int main(int argc, char* argv[])
{
	size_t set_index_bits = 0, lines = 0, block_bits = 0; // Useful variables.
	char *filename = NULL;
	int opt = 0;
	while ((opt=getopt(argc, argv, "hvs:E:b:t:")) != -1) {
		switch (opt) {
			/* TODO: maybe add checking for optarg swallowing actual arguments. */
		case 'v':
			VERBOSE = 1;
			break;
		case 's': // 2^s = number of sets
			set_index_bits = parse_int_arg(optarg, 's');
			break;
		case 'E': // associativity - lines per set
			lines = parse_int_arg(optarg, 'E');
			break;
		case 'b': // 2^b = block size
			block_bits = parse_int_arg(optarg, 'b');
			break;
		case 't':
			filename = optarg;
			break;
		case 'h':
			print_usage();
			return 0;
		default:
			printf("Usage: ./csim [-hv] -s <number> -E <number> -b <number> -t <file>\n");
			return 1;
		}
	}
	/* If any required arguments were not provided. (argflags != 0b1111) */
	if (!set_index_bits || !lines || !block_bits || !filename) {
		printf("Usage: ./csim [-hv] -s <number> -E <number> -b <number> -t <file>\n");
		return 1;
	}
	/* End of argument parsing. */
	printf("Arguments: %zd, %zd, %zd, %hd, %s\n", set_index_bits, lines, block_bits, VERBOSE, filename);

	char buffer[20];
	FILE* f = fopen(filename, "r");
	if(!f)
	{
		printf("Invalid file name: %s", filename);
		exit(-1);
	}

	while (fgets(buffer, 20, f))
	{
		if (buffer[0] == 'I')
			continue;

		char* end;
		char op = buffer[1];
		long address = strtol(buffer+3, &end, 16);
		if (*end != ',' || !(op == 'S' || op == 'L' || op == 'M'))
		{
			printf("Invalid input file, last line:\n%s\n", buffer);
			return -1;
		}
		printf("%c %ld\n", op, address);
	}

	printSummary(0, 0, 0);
	return 0;
}


void print_usage()
{
	printf("Usage: ./csim [-hv] -s <number> -E <number> -b <number> -t <file>\n"
		   "Options:\n"
		   "  -h  Print this help.\n"
		   "  -v  Display trace info.\n"
		   "  -s <number> The number of set index bits. Must be a positive integer.\n"
		   "  -E <number> Associativity (lines per set). Must be a positive integer.\n"
		   "  -b <number> The number of block bits. Must be a positive integer.\n"
		   "  -t <file>   Name of the file to read a valgrind trace from.");
}

/**
   Parses a string
   @param arg The string to parse.
   @param opt The option being parsed.
   @return The parsed integer if the argument was an integer.
   @note Exits if argument is invalid
 */
size_t parse_int_arg(char* arg, char opt)
{
	char* end;
	long i = strtol(arg, &end, 0);

	if (!i || *end != '\0') {
		printf("Invalid argument \"%s\" for option -%c\n", arg, opt);
		printf("Usage: ./csim [-hv] -s <number> -E <number> -b <number> -t <file>\n");
		exit(1);
	}
	else if (i < 0) {
		printf("Argument %ld for option %c too small (must be greater than 0)", i, opt);
		exit(1);
	}
	else {
	return (size_t)i;
	}
}