/* A simple, two-pass gameboy assembler */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "gbasm/emitter.h"
#include "gbasm/assemble.h"

#define GBASM_FILE_BUFFER_SIZE (1024 * 1024)

static char file_buffer[GBASM_FILE_BUFFER_SIZE];

static void usage()
{
	printf("gbasm -i <file> -o <file>\n"
	       " -h                 Print this usage \n"
	       " -i   <input file>  The file to assemble\n"
	       " -o   <output file> The file to write the assembled program to\n");
}

int main(int argc, char **argv)
{
	struct emitter emitter;
	struct fd_emitter fd_emitter;
	char opt;
	int in_fd = -1;
	int out_fd = -1;
	
	while ((opt = getopt(argc, argv, "i:o:h")) != -1) {

		switch (opt) {
		case 'o':
			if (out_fd >= 0) {
				close(out_fd);
			}

			out_fd = open(optarg,
				      O_WRONLY | O_CREAT | O_TRUNC,
				      S_IRUSR | S_IWUSR);
			if (out_fd < 0) {
				fprintf(stderr, "failed to open output file %s\n", optarg);
				exit(1);
			}
			break;
		case 'i':
			if (in_fd >= 0) {
				close(in_fd);
			}

			in_fd = open(optarg, O_RDONLY);
			if (in_fd < 0) {
				fprintf(stderr, "failed to open input file %s\n", optarg);
				exit(1);
			}
			break;
		case 'h':
			usage();
			exit(1);
		case ':':
			fprintf(stderr, "Option -%c requires argument\n", optopt);
			usage();
			exit(1);
		case '?':
			fprintf(stderr, "Unrecognized option -%c\n", optopt);
			usage();
			exit(1);
		}
	}

	if (in_fd < 0) {
		exit(1);
	} else {
		pread(in_fd, file_buffer, GBASM_FILE_BUFFER_SIZE - 1, 0);
		file_buffer[GBASM_FILE_BUFFER_SIZE - 1] = '\0';
	}

	if (out_fd < 0) {
		exit(1);
	}

	fd_emitter_init(&emitter, &fd_emitter, out_fd);

	return gbasm_assemble(file_buffer, &emitter);	
}