#include "api.h"
#include "lib.h"
// this one is going to be supporting multiple command lines etc.

#define ALWAYS_REPORT_EXIT_CODE 0
#define PROMPT "+>"
#define PROMPT_LAST_CHAR '>'
#define BUF_LEN 256
#define ARG_LEN 80
#define ARG_MAX 20
char curr_line[BUF_LEN];
int line_len;

typedef struct {
	int len;
	char buf[ARG_LEN];
} argument;
void append_arg(argument*arg,char c) {
	arg->buf[arg->len++]=c;
}
void reset_arg(argument*arg) {
	memset(arg,0,sizeof(*arg));
}
argument args[ARG_MAX];
int arg_count=0;
void split_args() {
	argument *curr_arg=args;
	reset_arg(curr_arg);
	arg_count=0;
	char *curr=curr_line;
	char *end=curr_line+line_len;
	while(curr!=end) {
		switch(*curr) {
			case 0: break;
			case ';': case '&': // command seperators
				if(curr_arg->len) {
					curr_arg++;
					reset_arg(curr_arg);
					arg_count++;
				}
				append_arg(curr_arg,*curr);
				++curr_arg;
				reset_arg(curr_arg);
				arg_count++;
				break;
			case ' ':
				if(curr_arg->len) {
					curr_arg++;
					reset_arg(curr_arg);
					arg_count++;
				}
				break;
			default:
				append_arg(curr_arg,*curr);
				break;
		}
		++curr;
	}
	if(curr_arg->len)
		arg_count++;
}



typedef struct {
	int background;
	int count;
	char* args[ARG_MAX];
} execution_info;
execution_info execinfo;
int set_exec(int index,execution_info* info) {
	int curr=0;
	memset(info,0,sizeof(execution_info));
	while(index<arg_count) {
		argument *arg=args+index;
		if(arg->len) {
			if(arg->len==1) {
				if(arg->buf[0]==';') {
					++index;
// 					if(info->args[curr])
						break;
// 					else
// 						continue;
				} else if(arg->buf[0]=='&') {
					info->background=1;
					++index;
					break;
				}
			}
			info->args[curr++]=arg->buf;
			info->count++;
			index++;
		} else break;
	}
	return index;
}
__attribute__((unused)) static void dump_execinfo(execution_info* info) {
	printf("Command: %s\n",
		   execinfo.background?"Run in background":"Run in forground");
	for(int i=0;i<execinfo.count;++i)
		printf("Arg[%d]:%s\n",i,execinfo.args[i]);
}
void run_program(execution_info* info) {
	int program_fd=-1;
	if(!info->args[0]) return; // if it was a null command.
	if(info->args[0][0]=='/')
		program_fd =sys_open(info->args[0]+1,0);
	else
		program_fd =sys_open(info->args[0],0);
	if(program_fd==-1) {
		printf("No such program: %s - errno=%d\n",curr_line,errno);
		return;
	}
	int retval=0;
	int childpid=sys_fork();
	switch(childpid) {
		case -1: printf("Error forking: %d\n",childpid);
				break;
		case 0:
			sys_execve(program_fd,info->args);
// 			sys_exec(program_fd);
			print("Could not execute program\n");
			sys_exit(1);
			// doesn't return...
		default:
			sys_close(program_fd);
			if(info->background) {
				printf("Running %d in background.\n",childpid);
			}else{
				sys_wait(&retval);
				if(retval || ALWAYS_REPORT_EXIT_CODE) {
					char **argg=info->args;
					while(*argg){
						print(*argg++);
						putch(' ');
					}
					printf(" returned %d\n",curr_line,retval);
				}
			}
			break;
	}
}

int main(void) {
	print("!rsh version 2. (C) Richard Whitty 2009\n");
	for(;;) {
		print(PROMPT);
		flush();
		line_len=fgets(stdin,curr_line,BUF_LEN);
		if(line_len==-1) {
			printf("\nLine too long!\n");
			continue;
		}
// 		printf("Got line: '%s' len: %d\n",curr_line,line_len);
		if(line_len==0)
			continue;
		if(strncmp(curr_line,"exit",5)==0) return 0;
		split_args();
		int x=0;
		while(x<arg_count) {
			x=set_exec(x,&execinfo);
// 			 dump_execinfo(&execinfo);
			run_program(&execinfo);
		}
	}
	return 0;
}