#include "flags.h"
#include "lib.h"
#include "stream.h"

#include <string.h>
#include <strings.h>

static format_t get_file_extension(char *path) {
	char *filename = strrchr(path, '/');
	if (filename == NULL)
		return NBT;
	char *extension = strrchr(filename, '.');
	if (extension == NULL)
		return NBT;
	else if (strcasecmp(extension, "json") == 0)
		return JSON;
	else if (strcasecmp(extension, "snbt") == 0)
		return SNBT;
	return NBT;
}

void parse_long_arg(flags_t *flags, char *arg) {

	char *key = arg + 2;
	char *value = strchr(key, '=');
	if (value != NULL) {
		*value = '\0';
		value++;
	}

	if (strcmp(key, "help") == 0) {
		flags->help = true;
		return;
	}

	else if (strcmp(key, "version") == 0) {
		flags->version = true;
		return;
	}

	else if (strcmp(key, "in") == 0) {
		if (value == NULL)
			error_and_die("--in requires a value\n");
		flags->in = stream_open(value, "r");
		if (flags->__set_fin == false)
			flags->fin = get_file_extension(value);
	}
	
	else if (strcmp(key, "out") == 0) {
		if (value == NULL)
			error_and_die("--out requires a value\n");
		flags->out = stream_open(value, "w");
		if (flags->__set_fout == false)
			flags->fout = get_file_extension(value);
	}

	else {
		error_and_die("invalid argument '--%s'\n", key);
	}

}

void parse_short_args(flags_t *flags, char *arg, int len) {
	for (int i = 1; i < len; i++) {
		char c = arg[i];
		switch(c) {
			case 'j':
				flags->fin = JSON;
				flags->__set_fin = true;
				break;
			case 'J':
				flags->fout = JSON;
				flags->__set_fout = true;
				break;
			case 's':
				flags->fin = SNBT;
				flags->__set_fin = true;
				break;
			case 'S':
				flags->fout = SNBT;
				flags->__set_fout = true;
				break;
			case 'n':
				flags->fin = NBT;
				flags->__set_fin = true;
				break;
			case 'N':
				flags->fout = NBT;
				flags->__set_fout = true;
				break;
			case 'h':
				flags->help = true;
				break;
			case 'v':
				flags->version = true;
				break;
			default:
				error_and_die("invalid argument: '-%c'\n", c);
		}
	}
}

void parse_arg(flags_t *flags, char *arg, int len) {
	if (len < 2) {
		error_and_die("invalid argument: '%s'\n", arg);
	} else if (arg[1] == '-') {
		parse_long_arg(flags, arg);
	} else {
		parse_short_args(flags, arg, len);
	}
}

void parse_flags(flags_t *flags, int argc, char **argv) {

	flags->__set_fin = false;
	flags->__set_fout = false;
	flags->help = false;
	flags->version = false;
	flags->in.__file = stdin;
	flags->in.__alloc = false;
	flags->out.__file = stdout;
	flags->out.__alloc = false;
	flags->fin = NBT;
	flags->fout = NBT;

	int i;

	for (i = 1; i < argc; i++) {
		char *arg = argv[i];
		int len = strlen(arg);
	
		if (len == 2 && arg[0] == '-' && arg[1] == '-') {
			break;
		} else if (arg[0] != '-') {
			i--;
			break;
		} else {
			parse_arg(flags, arg, len);
		}
	}

	if (i + 1 < argc) {
		char *arg = argv[i + 1];
		flags->in = stream_open(arg, "r");
		if (flags->__set_fin == false)
			flags->fin = get_file_extension(arg);
	}
	
	if (i + 2 < argc) {
		char *arg = argv[i + 2];
		flags->out = stream_open(arg, "w");
		if (flags->__set_fout == false)
			flags->fout = get_file_extension(arg);
	}

	if (i + 3 < argc) {
		error_and_die("too many arguments passed\n");
	}

}