#include <unistd.h>
#include <merror.h>
#include <string.h>
#include <stdio.h>

#include "gen.h"
#include "masm.h"
#include "asm/elf32.h"

void help(void) {
	printf(
"usage: masm [options] source.asm\n"
"\n"
"options: \n"
"	-h		print the help message \n"
"	-g		assume undefined symbols are external\n"
"	-o <output>	specify the object file output name \n"
"	-a <abi>	specify mips abi used [none, o32] \n"
"			default: o32 \n"
"	-i <isa>	mips machine isa to assemble for [mips1, mips32r2, mips32r6] \n"
"			default: mips32r6\n"
"	-f <format>	specify the object file format [elf32] \n"
"			defualt: elf32\n"
	);
}

static int read_isa(enum isa *isa, const char *str)
{
	#define __ISA_CHK(name) \
		if (strcasecmp(#name, str) == 0) { \
			*isa = ISA_ ##name; \
			return M_SUCCESS; \
		} \

	__ISA_CHK(MIPS1);
	__ISA_CHK(MIPS32R2);
	__ISA_CHK(MIPS32R6);

	ERROR("invalid isa '%s'", str);
	return M_ERROR;
}

static int read_abi(enum abi *abi, const char *str)
{
	#define __ABI_CHK(name) \
		if (strcasecmp(#name, str) == 0) { \
			*abi = ABI_ ##name; \
			return M_SUCCESS; \
		} \


	__ABI_CHK(O32);
	__ABI_CHK(NONE);

	ERROR("invalid abi '%s'", str);
	return M_ERROR;
}

static int read_format(enum format *format, const char *str)
{
	#define __FORMAT_CHK(name) \
		if (strcasecmp(#name, str) == 0) { \
			*format = FORMAT_ ##name; \
			return M_SUCCESS; \
		} \


	__FORMAT_CHK(ELF32);

	ERROR("invalid format '%s'", str);
	return M_ERROR;
}

static int generate(struct generator *gen, struct arguments *args)
{
	if (generator_init(args->in_file, gen))
		return M_ERROR;

	switch (args->isa) {
        case ISA_MIPS1:
		return generate_mips1(gen);
        case ISA_MIPS32R2:
		return generate_mips32r2(gen);
        case ISA_MIPS32R6:
		return generate_mips32r6(gen);
        }

	return M_ERROR;
}

static int assemble(struct arguments *args)
{
	struct generator gen;
	int res = M_SUCCESS;

	if (generate(&gen, args))
		return M_ERROR;

	switch (args->format) {
        case FORMAT_ELF32:
		res = assemble_elf32(&gen, args);
		break;
	default:
		res = M_ERROR;
		break;
        }

	generator_free(&gen);

	return res;
}

int main(int argc, char **argv) {

	struct arguments args = {
		.in_file = NULL,
		.out_file = "out.o",
		.extern_undefined = false,
		.isa = ISA_MIPS32R6,
		.abi = ABI_O32,
		.format = FORMAT_ELF32
	};

	int c;

	while ((c = getopt(argc, argv, "hgo:a:i:f:")) != 1) {
		switch(c) {
		case 'h':
			help();
			return M_SUCCESS;
		case 'g':
			args.extern_undefined = true;
			break;
		case 'o':
			args.out_file = optarg;
			break;
		case 'a':
			if (read_abi(&args.abi, optarg))
				return M_ERROR;
			break;
		case 'i':
			if (read_isa(&args.isa, optarg))
				return M_ERROR;
			break;
		case 'f':
			if (read_format(&args.format, optarg))
				return M_ERROR;
			break;
		case '?':
			return M_ERROR;
		default:
			goto next;
		}
	}

next:
	if (optind < argc - 1) {
		ERROR("too many source files passed");
		return M_ERROR;
	}

	if (optind >= argc) {
		ERROR("no source files passed");
		return M_ERROR;
	}

	args.in_file = argv[optind];

	return assemble(&args);
}