/*
 * Plan 9 versions of system-specific functions
 *	By convention, exported routines herein have names beginning with an
 *	upper case letter.
 */
#include "rc.h"
#include "exec.h"
#include "io.h"
#include "fns.h"
#include "getflags.h"
char *Signame[]={
	"sigexit",	"sighup",	"sigint",	"sigquit",
	"sigalrm",	"sigkill",	"sigfpe",	"sigterm",
	0
};
char *syssigname[]={
	"exit",		/* can't happen */
	"hangup",
	"interrupt",
	"quit",		/* can't happen */
	"alarm",
	"kill",
	"sys: fp: ",
	"term",
	0
};
char Rcmain[]="/rc/lib/rcmain";
char Fdprefix[]="/fd/";
void execfinit(void);
void execbind(void);
void execmount(void);
void execnewpgrp(void);
builtin Builtin[]={
	"cd",		execcd,
	"whatis",	execwhatis,
	"eval",		execeval,
	"exec",		execexec,	/* but with popword first */
	"exit",		execexit,
	"shift",	execshift,
	"wait",		execwait,
	".",		execdot,
	"finit",	execfinit,
	"flag",		execflag,
	"rfork",	execnewpgrp,
	0
};
void execnewpgrp(void){
	int arg;
	char *s;
	switch(count(runq->argv->words)){
	case 1: arg=RFENVG|RFNAMEG|RFNOTEG; break;
	case 2:
		arg=0;
		for(s=runq->argv->words->next->word;*s;s++) switch(*s){
		default:
			goto Usage;
		case 'n': arg|=RFNAMEG;  break;
		case 'N': arg|=RFCNAMEG; break;
		case 'm': arg|=RFNOMNT;  break;
		case 'e': arg|=RFENVG;   break;
		case 'E': arg|=RFCENVG;  break;
		case 's': arg|=RFNOTEG;  break;
		case 'f': arg|=RFFDG;    break;
		case 'F': arg|=RFCFDG;   break;
		}
		break;
	default:
	Usage:
		pfmt(err, "Usage: %s [fnesFNEm]\n", runq->argv->words->word);
		setstatus("rfork usage");
		poplist();
		return;
	}
	if(rfork(arg)==-1){
		pfmt(err, "rc: %s failed\n", runq->argv->words->word);
		setstatus("rfork failed");
	}
	else
		setstatus("");
	poplist();
}
void Vinit(void){
	int dir, f, len;
	word *val;
	char *buf, *s;
	Dir *ent;
	int i, nent;
	char envname[256];
	dir=open("/env", OREAD);
	if(dir<0){
		pfmt(err, "rc: can't open /env: %r\n");
		return;
	}
	ent = nil;
	for(;;){
		nent = dirread(dir, &ent);
		if(nent <= 0)
			break;
		for(i=0; i<nent; i++){
			len=ent[i].length;
			if(len && strncmp(ent[i].name, "fn#", 3)!=0){
				snprint(envname, sizeof envname, "/env/%s", ent[i].name);
				if((f=open(envname, 0))>=0){
					buf=emalloc((int)len+1);
					read(f, buf, (long)len);
					val=0;
					/* Charitably add a 0 at the end if need be */
					if(buf[len-1]) buf[len++]='\0';
					s=buf+len-1;
					for(;;){
						while(s!=buf && s[-1]!='\0') --s;
						val=newword(s, val);
						if(s==buf) break;
						--s;
					}
					setvar(ent[i].name, val);
					vlook(ent[i].name)->changed=0;
					close(f);
					efree(buf);
				}
			}
		}
		free(ent);
	}
	close(dir);
}
int envdir;
void Xrdfn(void){
	int f, len;
	static Dir *ent, *allocent;
	static int nent;
	Dir *e;
	char envname[256];

	for(;;){
		if(nent == 0){
			free(allocent);
			nent = dirread(envdir, &allocent);
			ent = allocent;
		}
		if(nent <= 0)
			break;
		while(nent){
			e = ent++;
			nent--;
			len=e->length;
			if(len && strncmp(e->name, "fn#", 3)==0){
				snprint(envname, sizeof envname, "/env/%s", e->name);
				if((f=open(envname, 0))>=0){
					execcmds(openfd(f));
					return;
				}
			}
		}
	}
	close(envdir);
	Xreturn();
}
union code rdfns[4];
void execfinit(void){
	static int first=1;
	if(first){
		rdfns[0].i=1;
		rdfns[1].f=Xrdfn;
		rdfns[2].f=Xjump;
		rdfns[3].i=1;
		first=0;
	}
	Xpopm();
	envdir=open("/env", 0);
	if(envdir<0){
		pfmt(err, "rc: can't open /env: %r\n");
		return;
	}
	start(rdfns, 1, runq->local);
}
int Waitfor(int pid, int){
	thread *p;
	Waitmsg *w;
	char errbuf[ERRMAX];

	while((w = wait()) != nil){
		if(w->pid==pid){
			setstatus(w->msg);
			free(w);
			return 0;
		}
		for(p=runq->ret;p;p=p->ret)
			if(p->pid==w->pid){
				p->pid=-1;
				strcpy(p->status, w->msg);
			}
		free(w);
	}

	errstr(errbuf, sizeof errbuf);
	if(strcmp(errbuf, "interrupted")==0) return -1;
	return 0;
}
char **mkargv(word *a)
{
	char **argv=(char **)emalloc((count(a)+2)*sizeof(char *));
	char **argp=argv+1;	/* leave one at front for runcoms */
	for(;a;a=a->next) *argp++=a->word;
	*argp=0;
	return argv;
}
void addenv(var *v)
{
	char envname[256];
	word *w;
	int f;
	io *fd;
	if(v->changed){
		v->changed=0;
		snprint(envname, sizeof envname, "/env/%s", v->name);
		if((f=Creat(envname))<0)
			pfmt(err, "rc: can't open %s: %r\n", envname);
		else{
			for(w=v->val;w;w=w->next)
				write(f, w->word, strlen(w->word)+1L);
			close(f);
		}
	}
	if(v->fnchanged){
		v->fnchanged=0;
		snprint(envname, sizeof envname, "/env/fn#%s", v->name);
		if((f=Creat(envname))<0)
			pfmt(err, "rc: can't open %s: %r\n", envname);
		else{
			if(v->fn){
				fd=openfd(f);
				pfmt(fd, "fn %s %s\n", v->name, v->fn[v->pc-1].s);
				closeio(fd);
			}
			close(f);
		}
	}
}
void updenvlocal(var *v)
{
	if(v){
		updenvlocal(v->next);
		addenv(v);
	}
}
void Updenv(void){
	var *v, **h;
	for(h=gvar;h!=&gvar[NVAR];h++)
		for(v=*h;v;v=v->next)
			addenv(v);
	if(runq) updenvlocal(runq->local);
}
void Execute(word *args, word *path)
{
	char **argv=mkargv(args);
	char file[1024];
	int nc;
	Updenv();
	for(;path;path=path->next){
		nc=strlen(path->word);
		if(nc<1024){
			strcpy(file, path->word);
			if(file[0]){
				strcat(file, "/");
				nc++;
			}
			if(nc+strlen(argv[1])<1024){
				strcat(file, argv[1]);
				exec(file, argv+1);
			}
			else werrstr("command name too long");
		}
	}
	rerrstr(file, sizeof file);
	pfmt(err, "%s: %s\n", argv[1], file);
	efree((char *)argv);
}
#define	NDIR	256		/* shoud be a better way */
int Globsize(char *p)
{
	ulong isglob=0, globlen=NDIR+1;
	for(;*p;p++){
		if(*p==GLOB){
			p++;
			if(*p!=GLOB) isglob++;
			globlen+=*p=='*'?NDIR:1;
		}
		else
			globlen++;
	}
	return isglob?globlen:0;
}
#define	NFD	50
#define	NDBUF	32
struct{
	Dir	*dbuf;
	int	i;
	int	n;
}dir[NFD];
int Opendir(char *name)
{
	Dir *db;
	int f;
	f=open(name, 0);
	if(f==-1)
		return f;
	db = dirfstat(f);
	if(db!=nil && (db->mode&DMDIR)){
		if(f<NFD){
			dir[f].i=0;
			dir[f].n=0;
		}
		free(db);
		return f;
	}
	free(db);
	close(f);
	return -1;
}

static int
trimdirs(Dir *d, int nd)
{
	int r, w;

	for(r=w=0; r<nd; r++)
		if(d[r].mode&DMDIR)
			d[w++] = d[r];
	return w;
}

/*
 * onlydirs is advisory -- it means you only
 * need to return the directories.  it's okay to
 * return files too (e.g., on unix where you can't
 * tell during the readdir), but that just makes 
 * the globber work harder.
 */
int Readdir(int f, char *p, int onlydirs)
{
	int n;
	if(f<0 || f>=NFD)
		return 0;
Again:
	if(dir[f].i==dir[f].n){	/* read */
		free(dir[f].dbuf);
		dir[f].dbuf=0;
		n=dirread(f, &dir[f].dbuf);
		if(n>0){
			if(onlydirs){
				n=trimdirs(dir[f].dbuf, n);
				if(n==0)
					goto Again;
			}	
			dir[f].n=n;
		}else
			dir[f].n=0;
		dir[f].i=0;
	}
	if(dir[f].i==dir[f].n)
		return 0;
	strcpy(p, dir[f].dbuf[dir[f].i].name);
	dir[f].i++;
	return 1;
}
void Closedir(int f){
	if(f>=0 && f<NFD){
		free(dir[f].dbuf);
		dir[f].i=0;
		dir[f].n=0;
		dir[f].dbuf=0;
	}
	close(f);
}
int interrupted = 0;
void
notifyf(void*, char *s)
{
	int i;
	for(i=0;syssigname[i];i++) if(strncmp(s, syssigname[i], strlen(syssigname[i]))==0){
		if(strncmp(s, "sys: ", 5)!=0) interrupted=1;
		goto Out;
	}
	pfmt(err, "rc: note: %s\n", s);
	noted(NDFLT);
	return;
Out:
	if(strcmp(s, "interrupt")!=0 || trap[i]==0){
		trap[i]++;
		ntrap++;
	}
	if(ntrap>=32){	/* rc is probably in a trap loop */
		pfmt(err, "rc: Too many traps (trap %s), aborting\n", s);
		abort();
	}
	noted(NCONT);
}
void Trapinit(void){
	notify(notifyf);
}
void Unlink(char *name)
{
	remove(name);
}
long Write(int fd, char *buf, long cnt)
{
	return write(fd, buf, (long)cnt);
}
long Read(int fd, char *buf, long cnt)
{
	return read(fd, buf, cnt);
}
long Seek(int fd, long cnt, long whence)
{
	return seek(fd, cnt, whence);
}
int Executable(char *file)
{
	Dir *statbuf;
	int ret;

	statbuf = dirstat(file);
	if(statbuf == nil) return 0;
	ret = ((statbuf->mode&0111)!=0 && (statbuf->mode&DMDIR)==0);
	free(statbuf);
	return ret;
}
int Creat(char *file)
{
	return create(file, 1, 0666L);
}
int Dup(int a, int b){
	return dup(a, b);
}
int Dup1(int){
	return -1;
}
void Exit(char *stat)
{
	Updenv();
	setstatus(stat);
	exits(truestatus()?"":getstatus());
}
int Eintr(void){
	return interrupted;
}
void Noerror(void){
	interrupted=0;
}
int Isatty(int fd){
	Dir *d1, *d2;
	int ret;

	d1 = dirfstat(fd);
	if(d1 == nil) return 0;
	if(strncmp(d1->name, "ptty", 4)==0){	/* fwd complaints to philw */
		free(d1);
		return 1;
	}
	d2 = dirstat("/dev/cons");
	if(d2 == nil){
		free(d1);
		return 0;
	}
	ret = (d1->type==d2->type&&d1->dev==d2->dev&&d1->qid.path==d2->qid.path);
	free(d1);
	free(d2);
	return ret;
}
void Abort(void){
	pfmt(err, "aborting\n");
	flush(err);
	Exit("aborting");
}
void Memcpy(char *a, char *b, long n)
{
	memmove(a, b, (long)n);
}
void *Malloc(ulong n){
	return malloc(n);
}