/* asgoldsmith-jikomissar */
/**
   @file csim.c
   @author Adam Goldsmith
   @author Jacob Komissar
   @date 2016-04-25, 2016-04-26, 2016-04-27

   @TODO ADD CORRECT NAME COMMENT AT TOP OF FILE

Exit statuses:
 0 - success
 1 - usage error
-1 - file error

 */
/* Headers */
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include "cachelab.h"

/* Typedefs and structs */
typedef unsigned char uint8_t;
/* UNSURE. As defined in conference. */
struct line_s {
	uint8_t validity;
	int tag;
};
typedef struct line_s line;

/* Macros */
#define mprintf(...) if (VERBOSE) printf(__VA_ARGS__)

/* Prototypes */
void print_usage(void);
void bad_usage_error(void);
size_t parse_int_arg(char *arg, char opt);
size_t bits_to_size(uint8_t bits);
line** make_cache(size_t set_indices, size_t lines);
void free_cache(line** cache, size_t lines);

/* Global variables */
uint8_t VERBOSE = 0; /**< If nonzero, mprintf will not print. Set in main() if -v flag is given. */



int main(int argc, char* argv[])
{
	int hits, misses, evictions;

	uint8_t set_index_bits = 0, block_bits = 0; // Not-useful input variables.
	size_t set_indices = 0, num_lines = 0, block_size = 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 = (uint8_t)parse_int_arg(optarg, 's');
			set_indices = bits_to_size(set_index_bits);
			break;
		case 'E': // associativity - lines per set
			num_lines = parse_int_arg(optarg, 'E');
			break;
		case 'b': // 2^b = block size
			block_bits = (uint8_t)parse_int_arg(optarg, 'b');
			block_size = bits_to_size(block_bits);
			break;
		case 't':
			filename = optarg;
			break;
		case 'h':
			print_usage();
			return 0;
		default:
			bad_usage_error();
		}
	}
	/* If any required arguments were not provided. (argflags != 0b1111) */
	if (!set_indices || !num_lines || !block_size || !filename) {
		bad_usage_error();
	}
	/* End of argument parsing. */
	//printf("Arguments: s=%hhu, E=%zu, b=%hhu, t=%s, v=%hhu, 2^s=%zd, 2^b=%zu\n", set_index_bits, num_lines, block_bits, filename, VERBOSE, set_indices, block_size);

	line** cache = make_cache(set_indices, num_lines);


	/* FILE READING */
	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];
		void* 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);

	fclose(f);
	free_cache(cache, num_lines);

	return 0;
}

line** make_cache(size_t set_indices, size_t lines)
{
	line** cache = calloc(set_indices, sizeof(line*));
	int ii;
	for (ii = 0; ii < lines; ii++)
		cache[ii] = calloc(lines, sizeof(line));
	return cache;
}

void free_cache(line** cache, size_t lines)
{
	int ii;
	for (ii = 0; ii < lines; ii++)
		free(cache[ii]);
	free(cache);
}

void print_usage(void)
{
	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.");
}

/**
   Prints the summarized usage and exits with status 1.
*/
void bad_usage_error(void)
{
	printf("Usage: ./csim [-hv] -s <number> -E <number> -b <number> -t <file>\n");
	exit(1);
}

/**
   Parses a string into a size_t.
   @param arg The string to parse.
   @param opt The option being parsed. If 'E', the output can not be 0.
   @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 (*end != '\0' || (!i && opt=='E')) { // associativity can not be zero
		printf("Invalid argument \"%s\" for option -%c\n", arg, opt);
		bad_usage_error();
	}
	else if (i < 0) {
		printf("Argument %ld for option %c too small (must be greater than 0)", i, opt);
		exit(1);
	}
	return (size_t)i;
}

/**
   Calculates a size using a given number of bits.
   @param bits The power of 2 to use.
   @note Exits if number of bits is larger than a size_t.
 */
size_t bits_to_size(uint8_t bits)
{
	size_t max_shift = 8*sizeof(size_t);
	if (bits > max_shift-1) {
		printf("Argument %hhu too large (-s and -b must be less than %zu)", bits, max_shift);
		exit(1);
	}
	return (size_t)1 << bits;
}