#include <sys/types.h>

#include <sys/stat.h>

#include "commands.h"

#include "sig.h"

#include "getln.h"

#include "stralloc.h"

#include "substdio.h"

#include "alloc.h"

#include "open.h"

#include "prioq.h"

#include "scan.h"

#include "fmt.h"

#include "str.h"

#include "exit.h"

#include "maildir.h"

#include "readwrite.h"

#include "timeoutread.h"

#include "timeoutwrite.h"

void die() { _exit(0); }

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[1024];

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

char ssinbuf[128];

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

void put(buf,len) char *buf; int len;

{

  substdio_put(&ssout,buf,len);

}

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_nomem() { err("out of memory"); die(); }

void die_nomaildir() { err("this user has no $HOME/Maildir"); die(); }

void die_scan() { err("unable to scan $HOME/Maildir"); die(); }

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

void err_unimpl() { err("unimplemented"); }

void err_deleted() { err("already deleted"); }

void err_nozero() { err("messages are counted from 1"); }

void err_toobig() { err("not that many messages"); }

void err_nosuch() { err("unable to open that message"); }

void err_nounlink() { err("unable to unlink all deleted messages"); }

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

void printfn(fn) char *fn;

{

  fn += 4;

  put(fn,str_chr(fn,':'));

}

char strnum[FMT_ULONG];

stralloc line = {0};

void blast(ssfrom,limit)

substdio *ssfrom;

unsigned long limit;

{

  int match;

  int inheaders = 1;

  for (;;) {

    if (getln(ssfrom,&line,&match,'\n') != 0) die();

    if (!match && !line.len) break;

    if (match) --line.len; /* no way to pass this info over POP */

    if (limit) if (!inheaders) if (!--limit) break;

    if (!line.len)

      inheaders = 0;

    else

      if (line.s[0] == '.')

        put(".",1);

    put(line.s,line.len);

    put("\r\n",2);

    if (!match) break;

  }

  put("\r\n.\r\n",5);

  flush();

}

stralloc filenames = {0};

prioq pq = {0};

struct message {

  int flagdeleted;

  unsigned long size;

  char *fn;

} *m;

int numm;

int last = 0;

void getlist()

{

  struct prioq_elt pe;

  struct stat st;

  int i;

  maildir_clean(&line);

  if (maildir_scan(&pq,&filenames,1,1) == -1) die_scan();

  numm = pq.p ? pq.len : 0;

  m = (struct message *) alloc(numm * sizeof(struct message));

  if (!m) die_nomem();

  for (i = 0;i < numm;++i) {

    if (!prioq_min(&pq,&pe)) { numm = i; break; }

    prioq_delmin(&pq);

    m[i].fn = filenames.s + pe.id;

    m[i].flagdeleted = 0;

    if (stat(m[i].fn,&st) == -1)

      m[i].size = 0;

    else

      m[i].size = st.st_size;

  }

}

void pop3_stat()

{

  int i;

  unsigned long total;

  total = 0;

  for (i = 0;i < numm;++i) if (!m[i].flagdeleted) total += m[i].size;

  puts("+OK ");

  put(strnum,fmt_uint(strnum,numm));

  puts(" ");

  put(strnum,fmt_ulong(strnum,total));

  puts("\r\n");

  flush();

}

void pop3_rset()

{

  int i;

  for (i = 0;i < numm;++i) m[i].flagdeleted = 0;

  last = 0;

  okay();

}

void pop3_last()

{

  puts("+OK ");

  put(strnum,fmt_uint(strnum,last));

  puts("\r\n");

  flush();

}

void pop3_quit()

{

  int i;

  for (i = 0;i < numm;++i)

    if (m[i].flagdeleted) {

      if (unlink(m[i].fn) == -1) err_nounlink();

    }

    else

      if (str_start(m[i].fn,"new/")) {

	if (!stralloc_copys(&line,"cur/")) die_nomem();

	if (!stralloc_cats(&line,m[i].fn + 4)) die_nomem();

	if (!stralloc_cats(&line,":2,")) die_nomem();

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

	rename(m[i].fn,line.s); /* if it fails, bummer */

      }

  okay();

  die();

}

int msgno(arg) char *arg;

{

  unsigned long u;

  if (!scan_ulong(arg,&u)) { err_syntax(); return -1; }

  if (!u) { err_nozero(); return -1; }

  --u;

  if (u >= numm) { err_toobig(); return -1; }

  if (m[u].flagdeleted) { err_deleted(); return -1; }

  return u;

}

void pop3_dele(arg) char *arg;

{

  int i;

  i = msgno(arg);

  if (i == -1) return;

  m[i].flagdeleted = 1;

  if (i + 1 > last) last = i + 1;

  okay();

}

void list(i,flaguidl)

int i;

int flaguidl;

{

  put(strnum,fmt_uint(strnum,i + 1));

  puts(" ");

  if (flaguidl) printfn(m[i].fn);

  else put(strnum,fmt_ulong(strnum,m[i].size));

  puts("\r\n");

}

void dolisting(arg,flaguidl) char *arg; int flaguidl;

{

  unsigned int i;

  if (*arg) {

    i = msgno(arg);

    if (i == -1) return;

    puts("+OK ");

    list(i,flaguidl);

  }

  else {

    okay();

    for (i = 0;i < numm;++i)

      if (!m[i].flagdeleted)

	list(i,flaguidl);

    puts(".\r\n");

  }

  flush();

}

void pop3_uidl(arg) char *arg; { dolisting(arg,1); }

void pop3_list(arg) char *arg; { dolisting(arg,0); }

substdio ssmsg; char ssmsgbuf[1024];

void pop3_top(arg) char *arg;

{

  int i;

  unsigned long limit;

  int fd;

  i = msgno(arg);

  if (i == -1) return;

  arg += scan_ulong(arg,&limit);

  while (*arg == ' ') ++arg;

  if (scan_ulong(arg,&limit)) ++limit; else limit = 0;

  fd = open_read(m[i].fn);

  if (fd == -1) { err_nosuch(); return; }

  okay();

  substdio_fdbuf(&ssmsg,read,fd,ssmsgbuf,sizeof(ssmsgbuf));

  blast(&ssmsg,limit);

  close(fd);

}

struct commands pop3commands[] = {

  { "quit", pop3_quit, 0 }

, { "stat", pop3_stat, 0 }

, { "list", pop3_list, 0 }

, { "uidl", pop3_uidl, 0 }

, { "dele", pop3_dele, 0 }

, { "retr", pop3_top, 0 }

, { "rset", pop3_rset, 0 }

, { "last", pop3_last, 0 }

, { "top", pop3_top, 0 }

, { "noop", okay, 0 }

, { 0, err_unimpl, 0 }

} ;

void main(argc,argv)

int argc;

char **argv;

{

  sig_alarmcatch(die);

  sig_pipeignore();

  if (!argv[1]) die_nomaildir();

  if (chdir(argv[1]) == -1) die_nomaildir();

  getlist();

  okay();

  commands(&ssin,pop3commands);

  die();

}