#include <ctype.h> /* isspace(3) */
#include <stddef.h> /* NULL */
#include <stdio.h> /* getc(3) */
#include <stdlib.h> /* getenv(3), rand(3), srand(3) */
#include <string.h> /* strcmp(3) */
#include <sys/wait.h> /* wait(2) */
#include <time.h> /* time(3) */
#include <unistd.h> /* fork(2), write(2) */
#include "libio.h"
#include "usefulmacros.h"

#include "nutshell.h"
#include "nutshell_builtins.c"

static int
parse_argv(char *buffer, char **argv, int argc_max){
	int i;
	int j;
	int s;

	for(i = 0, j = 0, s = 1; buffer[i] != '\0' && j < argc_max; ++i){
		while(isspace(buffer[i])){
			s = 1;
			buffer[i++] = '\0';
		}
		if(s)
			argv[j++] = buffer + i;
	}

	return j;
}

static char *
read_buffer(char *buf, size_t buf_s){
	int i;

	for(i = 0; ; ++i){
		/* ..., '\0', buf_s */
		/* This isn't perfect but is simple and doesn't matter for
		 * longer buffers that much. */
		if(i == buf_s - 1 - 1){
			buf[i] = '\0';
			break;
		}

		buf[i] = getc(stdin);

		if(buf[i] == EOF)
			return NULL;

		else if(buf[i] == '\n'){
			buf[i + 1] = '\0';
			break;
		}
	}

	return buf;
}

static int
run(char *buf){
	int argc;
	static char *argv[ARGV_MAX];
	int i;

	/* get argv and argc */
	for(i = 0; i < ARRAYLEN(argv); ++i){
		if(argv[i] == NULL)
			break;
		argv[i] = NULL;
	}

	argc = parse_argv(buf, argv, ARRAYLEN(argv));

	/* builtins get priority */
	if((i = isbuiltin(argv[0])) != 0)
		return builtins[i - 1].f(argc, argv);

	if(state.jailed)
		goto runerr;

runerr:
	/* This is what busybox ash(1) does. */
	return 127;
}

int main(int argc, char *argv[]){
	static char buf[BUF_MAX];
	static char prompt[] = DEFAULT_PROMPT;

	builtin_init(0, empty_argv);

	for(;;){
		write(1, prompt, ARRAYLEN(prompt));
		if(read_buffer(buf, ARRAYLEN(buf)) == NULL){
			write(1, "EOF\n", 4);
			state.status = 0;
			break;
		}

		state.status = run(buf);
	}

	return state.status;
}