#include "commands.h"

#include "fd.h"

#include "sig.h"

#include "stralloc.h"

#include "substdio.h"

#include "alloc.h"

#include "wait.h"

#include "str.h"

#include "byte.h"

#include "now.h"

#include "fmt.h"

#include "exit.h"

#include "readwrite.h"

#include "timeoutread.h"

#include "timeoutwrite.h"

void die() { _exit(1); }

int saferead(fd,buf,len) int fd; char *buf; int len;

{

  int r;

  r = timeoutread(1200,fd,buf,len);

  if (r <= 0) die();

  return r;

}

int safewrite(fd,buf,len) int fd; char *buf; int len;

{

  int r;

  r = timeoutwrite(1200,fd,buf,len);

  if (r <= 0) die();

  return r;

}

char ssoutbuf[128];

substdio ssout = SUBSTDIO_FDBUF(safewrite,1,ssoutbuf,sizeof ssoutbuf);

char ssinbuf[128];

substdio ssin = SUBSTDIO_FDBUF(saferead,0,ssinbuf,sizeof ssinbuf);

void puts(s) char *s;

{

  substdio_puts(&ssout,s);

}

void flush()

{

  substdio_flush(&ssout);

}

void err(s) char *s;

{

  puts("-ERR ");

  puts(s);

  puts("\r\n");

  flush();

}

void die_usage() { err("usage: popup hostname subprogram"); die(); }

void die_nomem() { err("out of memory"); die(); }

void die_pipe() { err("unable to open pipe"); die(); }

void die_write() { err("unable to write pipe"); die(); }

void die_fork() { err("unable to fork"); die(); }

void die_childcrashed() { err("aack, child crashed"); }

void die_badauth() { err("authorization failed"); }

void err_syntax() { err("syntax error"); }

void err_wantuser() { err("USER first"); }

void err_authoriz() { err("authorization first"); }

void okay() { puts("+OK \r\n"); flush(); }

void pop3_quit() { okay(); die(); }

char unique[FMT_ULONG + FMT_ULONG + 3];

char *hostname;

stralloc username = {0};

int seenuser = 0;

char **childargs;

substdio ssup;

char upbuf[128];

void doanddie(user,userlen,pass)

char *user;

unsigned int userlen; /* including 0 byte */

char *pass;

{

  int child;

  int wstat;

  int pi[2];

  if (fd_copy(2,1) == -1) die_pipe();

  close(3);

  if (pipe(pi) == -1) die_pipe();

  if (pi[0] != 3) die_pipe();

  switch(child = fork()) {

    case -1:

      die_fork();

    case 0:

      close(pi[1]);

      sig_pipedefault();

      execvp(*childargs,childargs);

      _exit(1);

  }

  close(pi[0]);

  substdio_fdbuf(&ssup,write,pi[1],upbuf,sizeof upbuf);

  if (substdio_put(&ssup,user,userlen) == -1) die_write();

  if (substdio_put(&ssup,pass,str_len(pass) + 1) == -1) die_write();

  if (substdio_puts(&ssup,"<") == -1) die_write();

  if (substdio_puts(&ssup,unique) == -1) die_write();

  if (substdio_puts(&ssup,hostname) == -1) die_write();

  if (substdio_put(&ssup,">",2) == -1) die_write();

  if (substdio_flush(&ssup) == -1) die_write();

  close(pi[1]);

  byte_zero(pass,str_len(pass));

  byte_zero(upbuf,sizeof upbuf);

  if (wait_pid(&wstat,child) == -1) die();

  if (wait_crashed(wstat)) die_childcrashed();

  if (wait_exitcode(wstat)) die_badauth();

  die();

}

void pop3_greet()

{

  char *s;

  s = unique;

  s += fmt_uint(s,getpid());

  *s++ = '.';

  s += fmt_ulong(s,(unsigned long) now());

  *s++ = '@';

  *s++ = 0;

  puts("+OK <");

  puts(unique);

  puts(hostname);

  puts(">\r\n");

  flush();

}

void pop3_user(arg) char *arg;

{

  if (!*arg) { err_syntax(); return; }

  okay();

  seenuser = 1;

  if (!stralloc_copys(&username,arg)) die_nomem(); 

  if (!stralloc_0(&username)) die_nomem(); 

}

void pop3_pass(arg) char *arg;

{

  if (!seenuser) { err_wantuser(); return; }

  if (!*arg) { err_syntax(); return; }

  doanddie(username.s,username.len,arg);

}

void pop3_apop(arg) char *arg;

{

  char *space;

  space = arg + str_chr(arg,' ');

  if (!*space) { err_syntax(); return; }

  *space++ = 0;

  doanddie(arg,space - arg,space);

}

struct commands pop3commands[] = {

  { "user", pop3_user, 0 }

, { "pass", pop3_pass, 0 }

, { "apop", pop3_apop, 0 }

, { "quit", pop3_quit, 0 }

, { "noop", okay, 0 }

, { 0, err_authoriz, 0 }

} ;

void main(argc,argv)

int argc;

char **argv;

{

  sig_alarmcatch(die);

  sig_pipeignore();

  hostname = argv[1];

  if (!hostname) die_usage();

  childargs = argv + 2;

  if (!*childargs) die_usage();

  pop3_greet();

  commands(&ssin,pop3commands);

  die();

}