#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "alloc.h"
#include "auto_qmail.h"
#include "auto_queue.h"
#include "byte.h"
#include "constmap.h"
#include "control.h"
#include "direntry.h"
#include "error.h"
#include "exit.h"
#include "fmt.h"
#include "fmtqfn.h"
#include "getln.h"
#include "open.h"
#include "ndelay.h"
#include "now.h"
#include "readsubdir.h"
#include "buffer.h"
#include "scan.h"
#include "select.h"
#include "str.h"
#include "sig.h"
#include "stralloc.h"
#include "trigger.h"
#include "qsutil.h"
#include "sendtodo.h"
#include "qmail.h"

stralloc queuedir = {0};

stralloc percenthack = {0};
struct constmap mappercenthack;
stralloc locals = {0};
struct constmap maplocals;
stralloc vdoms = {0};
struct constmap mapvdoms;
stralloc envnoathost = {0};

char strnum[FMT_ULONG];

/* XXX not good, if qmail-send.c changes this has to be updated */
#define CHANNELS 2
#define BUF_CHANNELS 1024
char *chanaddr[CHANNELS] = { "local/", "remote/" };

datetime_sec recent;
int flagquitasap = 0;

void sendlog1(char *x);
void sendlog3(char *x,char *y,char *z);

void sigterm(void)
{
  if (flagquitasap == 0)
    sendlog1("status: qmail-todo stop processing asap\n");
  flagquitasap = 1;
}

int flagreadasap = 0; void sighup(void) { flagreadasap = 1; }
int flagsendalive = 1; void senddied(void) { flagsendalive = 0; }

void cleandied()
{ 
  sendlog1("alert: qmail-todo lost connection to qmail-clean ... exiting\n");
  flagquitasap = 1;
}


/* this file is not so long ------------------------------------- FILENAMES */

stralloc fn = {0};

void fnmake_init(void)
{
  while (!stralloc_ready(&fn,FMTQFN)) nomem();
}

void fnmake_info(unsigned long id) { fn.len = fmtqfn(fn.s,"info/",id,1); }
void fnmake_todo(unsigned long id) { fn.len = fmtqfn(fn.s,"todo/",id,1); }
void fnmake_mess(unsigned long id) { fn.len = fmtqfn(fn.s,"mess/",id,1); }
void fnmake_chanaddr(unsigned long id,int c) { fn.len = fmtqfn(fn.s,chanaddr[c],id,1); }


/* this file is not so long ------------------------------------- REWRITING */

stralloc rwline = {0};

/* 1 if by land, 2 if by sea, 0 if out of memory. not allowed to barf. */
/* may trash recip. must set up rwline, between a T and a \0. */

int rewrite(char *recip)
{
  int i;
  int j;
  char *x;
  static stralloc addr = {0};
  int at;

  if (!stralloc_copys(&rwline,"T")) return 0;
  if (!stralloc_copys(&addr,recip)) return 0;

  i = byte_rchr(addr.s,addr.len,'@');
  if (i == addr.len) {
    if (!stralloc_cats(&addr,"@")) return 0;
    if (!stralloc_cat(&addr,&envnoathost)) return 0;
  }

  while (constmap(&mappercenthack,addr.s + i + 1,addr.len - i - 1)) {
    j = byte_rchr(addr.s,i,'%');
    if (j == i) break;
    addr.len = i;
    i = j;
    addr.s[i] = '@';
  }

  at = byte_rchr(addr.s,addr.len,'@');

  if (constmap(&maplocals,addr.s + at + 1,addr.len - at - 1)) {
    if (!stralloc_cat(&rwline,&addr)) return 0;
    if (!stralloc_0(&rwline)) return 0;
    return 1;
  }

  for (i = 0; i <= addr.len; ++i)
    if (!i || (i == at + 1) || (i == addr.len) || ((i > at) && (addr.s[i] == '.')))
      if ((x = constmap(&mapvdoms,addr.s + i,addr.len - i))) {
        if (!*x) break;
        if (!stralloc_cats(&rwline,x)) return 0;
        if (!stralloc_cats(&rwline,"-")) return 0;
        if (!stralloc_cat(&rwline,&addr)) return 0;
        if (!stralloc_0(&rwline)) return 0;
        return 1;
      }
 
  if (!stralloc_cat(&rwline,&addr)) return 0;
  if (!stralloc_0(&rwline)) return 0;
  return 2;
}

/* this file is not so long --------------------------------- COMMUNICATION */

buffer toqc; 
char toqcbuf[BUFSIZE_LINE];
buffer fromqc; 
char fromqcbuf[BUFSIZE_LINE];
stralloc comm_buf = {0};
int comm_pos;
int fdout = -1;
int fdin = -1;

void sendlog1(char* x)
{
  int pos;

  pos = comm_buf.len;
  if (!stralloc_cats(&comm_buf,"L")) goto FAIL;
  if (!stralloc_cats(&comm_buf,x)) goto FAIL;
  if (!stralloc_0(&comm_buf)) goto FAIL;
  return;

  FAIL:
  /* either all or nothing */
  comm_buf.len = pos;
}

void sendlog3(char* x, char *y, char *z)
{
  int pos;

  pos = comm_buf.len;
  if (!stralloc_cats(&comm_buf,"L")) goto FAIL;
  if (!stralloc_cats(&comm_buf,x)) goto FAIL;
  if (!stralloc_cats(&comm_buf,y)) goto FAIL;
  if (!stralloc_cats(&comm_buf,z)) goto FAIL;
  if (!stralloc_0(&comm_buf)) goto FAIL;
  return;

  FAIL:
  /* either all or nothing */
  comm_buf.len = pos;
}

void comm_init(void)
{
  buffer_init(&toqc,write,2,toqcbuf,sizeof(toqcbuf));
  buffer_init(&fromqc,read,3,fromqcbuf,sizeof(fromqcbuf));

  fdout = 1; /* stdout */
  fdin = 0;  /* stdin */
  if (ndelay_on(fdout) == -1)
 /* this is so stupid: NDELAY semantics should be default on write */
    senddied(); /* drastic, but better than risking deadlock */

  while (!stralloc_ready(&comm_buf,BUF_CHANNELS)) nomem();
}

int comm_canwrite(void)
{
  /* XXX: could allow a bigger buffer; say 10 recipients */
  /* XXX: returns true if there is something in the buffer */
  if (!flagsendalive) return 0;
  if (comm_buf.s && comm_buf.len) return 1;
  return 0;
}

void comm_write(unsigned long id,int local,int remote)
{
  int pos;
  char *s;
  
  if (local && remote) s="B";
  else if (local) s="L";
  else if (remote) s="R";
  else s="X";
  
  pos = comm_buf.len;
  strnum[fmt_ulong(strnum,id)] = 0;
  if (!stralloc_cats(&comm_buf,"D")) goto FAIL;
  if (!stralloc_cats(&comm_buf,s)) goto FAIL;
  if (!stralloc_cats(&comm_buf,strnum)) goto FAIL;
  if (!stralloc_0(&comm_buf)) goto FAIL;
  return;
  
  FAIL:
  /* either all or nothing */
  comm_buf.len = pos;
}

void comm_info(unsigned long id,unsigned long size,char* from,unsigned long pid,unsigned long uid)
{
  int pos;
  int i;

  pos = comm_buf.len;
  if (!stralloc_cats(&comm_buf,"Linfo msg ")) goto FAIL;
  strnum[fmt_ulong(strnum,id)] = 0;
  if (!stralloc_cats(&comm_buf,strnum)) goto FAIL;
  if (!stralloc_cats(&comm_buf,": bytes ")) goto FAIL;
  strnum[fmt_ulong(strnum,size)] = 0;
  if (!stralloc_cats(&comm_buf,strnum)) goto FAIL;
  if (!stralloc_cats(&comm_buf," from <")) goto FAIL;
  i = comm_buf.len;
  if (!stralloc_cats(&comm_buf,from)) goto FAIL;
  
  for (; i < comm_buf.len; ++i)
    if (comm_buf.s[i] == '\n')
      comm_buf.s[i] = '/';
    else
      if (!issafe(comm_buf.s[i]))
        comm_buf.s[i] = '_';

  if (!stralloc_cats(&comm_buf,"> qp ")) goto FAIL;
  strnum[fmt_ulong(strnum,pid)] = 0;
  if (!stralloc_cats(&comm_buf,strnum)) goto FAIL;
  if (!stralloc_cats(&comm_buf," uid ")) goto FAIL;
  strnum[fmt_ulong(strnum,uid)] = 0;
  if (!stralloc_cats(&comm_buf,strnum)) goto FAIL;
  if (!stralloc_cats(&comm_buf,"\n")) goto FAIL;
  if (!stralloc_0(&comm_buf)) goto FAIL;
  return;

  FAIL:
  /* either all or nothing */
  comm_buf.len = pos;
}

void comm_exit(void)
{
  /* if it FAILs exit, we have already stoped */
  if (!stralloc_cats(&comm_buf,"X")) _exit(1);
  if (!stralloc_0(&comm_buf)) _exit(1);
}

void comm_selprep(int *nfds, fd_set *wfds, fd_set *rfds)
{
  if (flagsendalive) {
    if (flagquitasap && comm_canwrite() == 0)
      comm_exit();
    if (comm_canwrite()) {
      FD_SET(fdout,wfds);
      if (*nfds <= fdout)
	*nfds = fdout + 1;
    }
    FD_SET(fdin,rfds);
    if (*nfds <= fdin)
      *nfds = fdin + 1;
  }
}

void comm_do(fd_set *wfds, fd_set *rfds)
{
  /* first write then read */
  if (flagsendalive)
    if (comm_canwrite())
      if (FD_ISSET(fdout,wfds)) {
	int w;
	int len;
	len = comm_buf.len;
	w = write(fdout,comm_buf.s + comm_pos,len - comm_pos);
	if (w <= 0) {
	  if ((w == -1) && (errno == EPIPE))
	    senddied();
	} else {
	  comm_pos += w;
	  if (comm_pos == len) {
	    comm_buf.len = 0;
	    comm_pos = 0;
	  }
	}
      }
  if (flagsendalive)
    if (FD_ISSET(fdin,rfds)) {
      /* there are only two messages 'H' and 'X' */
      char c;
      int r;
      r = read(fdin, &c, 1);
      if (r <= 0) {
	if ((r == -1) && (errno != EINTR))
	  senddied();
      } else {
	switch (c) {
	  case 'H':
	    sighup();
	    break;
	  case 'X':
	    sigterm();
	    break;
	  default:
	    sendlog1("warning: qmail-todo: qmail-send speaks an obscure dialect\n");
	    break;
	}
      }
    }
}

/* this file is not so long ------------------------------------------ TODO */

datetime_sec nexttodorun;
int flagtododir; /* if 0, have to opendir again */
readsubdir todosubdir;
stralloc todoline = {0};
char todobuf[BUFSIZE_MESS];
char todobufinfo[BUFSIZE_OUT];
char todobufchan[CHANNELS][BUF_CHANNELS];

void todo_init(void)
{
  flagtododir = 0;
  nexttodorun = now();
  trigger_set();
}

void todo_selprep(int *nfds, fd_set *rfds, datetime_sec *wakeup)
{
  if (flagquitasap) return;
  trigger_selprep(nfds,rfds);
  if (flagtododir) *wakeup = 0;
  if (*wakeup > nexttodorun) *wakeup = nexttodorun;
}

void todo_do(fd_set *rfds)
{
  struct stat st;
  buffer bi; 
  int fd;
  buffer bo; 
  int fdnumber;
  buffer bchan[CHANNELS];
  int fdchan[CHANNELS];
  int flagchan[CHANNELS];
  char ch;
  int match;
  unsigned long id;
  int c;
  unsigned long uid;
  unsigned long pid;

  fd = -1;
  fdnumber = -1;
  for (c = 0; c < CHANNELS; ++c) 
    fdchan[c] = -1;

  if (flagquitasap) return;

  if (!flagtododir) {
    if (!trigger_pulled(rfds)) {
      if (recent < nexttodorun) return;
    }
    trigger_set();
    readsubdir_init(&todosubdir,"todo",pausedir);
    flagtododir = 1;
    nexttodorun = recent + SLEEP_TODO;
  }

  switch (readsubdir_next(&todosubdir,&id)) {
    case 1:  break;
    case 0:  flagtododir = 0;
    default: return;
  }

  fnmake_todo(id);

  fd = open_read(fn.s);
  if (fd == -1) { sendlog3("warning: qmail-todo is unable to open ",fn.s,"\n"); return; }

  fnmake_mess(id);
  /* just for the statistics */
  if (stat(fn.s,&st) == -1)
    { sendlog3("warning: qmail-todo is unable to stat ",fn.s," for mess\n"); goto FAIL; }

  for (c = 0; c < CHANNELS; ++c) {
    fnmake_chanaddr(id,c);
    if (unlink(fn.s) == -1) if (errno != ENOENT)
      { sendlog3("warning: qmail-todo is unable to unlink ",fn.s," for mess\n"); goto FAIL; }
  }

  fnmake_info(id);
  if (unlink(fn.s) == -1) if (errno != ENOENT)
    { sendlog3("warning: qmail-todo is unable to unlink ",fn.s," for info\n"); goto FAIL; }

  fdnumber = open_excl(fn.s);
  if (fdnumber == -1)
    { sendlog3("warning: qmail-todo unable to create ",fn.s," for info\n"); goto FAIL; }

  strnum[fmt_ulong(strnum,id)] = 0;
  sendlog3("new msg ",strnum,"\n");

  for (c = 0; c < CHANNELS; ++c) 
    flagchan[c] = 0;

  buffer_init(&bi,read,fd,todobuf,sizeof(todobuf));
  buffer_init(&bo,write,fdnumber,todobufinfo,sizeof(todobufinfo));

  uid = 0;
  pid = 0;

  for (;;) {
    if (getln(&bi,&todoline,&match,'\0') == -1) {
      /* perhaps we're out of memory, perhaps an I/O error */
      fnmake_todo(id);
      sendlog3("warning: qmail-todo has trouble reading ",fn.s,"\n"); goto FAIL;
    }
    if (!match) break;

    switch (todoline.s[0]) {
     case 'u':
       scan_ulong(todoline.s + 1,&uid); break;
     case 'p':
       scan_ulong(todoline.s + 1,&pid); break;
     case 'F':
       if (buffer_putflush(&bo,todoline.s,todoline.len) == -1) {
         fnmake_info(id);
         sendlog3("warning: qmail-todo has trouble writing to ",fn.s," for todo\n"); goto FAIL;
       }
       comm_info(id,(unsigned long) st.st_size,todoline.s + 1,pid,uid);
       break;
     case 'T':
       switch (rewrite(todoline.s + 1)) {
         case 0: nomem(); goto FAIL;
         case 2: c = 1; break;
         default: c = 0; break;
       }
       if (fdchan[c] == -1) {
         fnmake_chanaddr(id,c);
         fdchan[c] = open_excl(fn.s);
         if (fdchan[c] == -1)
           { sendlog3("warning: qmail-todo is unable to create ",fn.s," for delivery\n"); goto FAIL; }
         buffer_init(&bchan[c],write,fdchan[c],todobufchan[c],sizeof(todobufchan[c]));
         flagchan[c] = 1;
       }
       if (buffer_put(&bchan[c],rwline.s,rwline.len) == -1) {
         fnmake_chanaddr(id,c);
         sendlog3("warning: qmail-todo has trouble writing to ",fn.s," for delivery\n"); goto FAIL;
       }
       break;
     default:
       fnmake_todo(id);
       sendlog3("warning: qmail-todo recognizes unknown record type in ",fn.s,"\n"); goto FAIL;
    }
  }

  close(fd); fd = -1;

  fnmake_info(id);
  if (buffer_flush(&bo) == -1)
    { sendlog3("warning: qmail-todo has trouble writing to ",fn.s," for info\n"); goto FAIL; }
  if (fsync(fdnumber) == -1)
    { sendlog3("warning: qmail-todo has trouble fsyncing ",fn.s," for info\n"); goto FAIL; }
  close(fdnumber); fdnumber = -1;

  for (c = 0; c < CHANNELS; ++c)
    if (fdchan[c] != -1) {
      fnmake_chanaddr(id,c);
      if (buffer_flush(&bchan[c]) == -1) { sendlog3("warning: qmail-todo has trouble writing to ",fn.s," in channel\n"); goto FAIL; }
      if (fsync(fdchan[c]) == -1) { sendlog3("warning: qmail-todo has trouble fsyncing ",fn.s," in channel\n"); goto FAIL; }
      close(fdchan[c]); fdchan[c] = -1;
    }

  fnmake_todo(id);
  if (buffer_putflush(&toqc,fn.s,fn.len) == -1) { cleandied(); return; }
  if (buffer_get(&fromqc,&ch,1) != 1) { cleandied(); return; }

  if (ch != '+') {
    sendlog3("warning: qmail-clean unable to clean up ",fn.s,"\n");
    return;
  }

  comm_write(id,flagchan[0],flagchan[1]);
  return;
 
  FAIL:
  if (fd != -1) close(fd);
  if (fdnumber != -1) close(fdnumber);
  for (c = 0; c < CHANNELS; ++c)
    if (fdchan[c] != -1) close(fdchan[c]);
}

/* this file is too long ---------------------------------------------- MAIN */

int getcontrols(void)
{
  if (control_init() == -1) return 0;
  if (control_rldef(&envnoathost,"control/envnoathost",1,"envnoathost") != 1) return 0;
  if (control_readfile(&locals,"control/locals",1) != 1) return 0;
  if (!constmap_init(&maplocals,locals.s,locals.len,0)) return 0;
  switch (control_readfile(&percenthack,"control/percenthack",0)) {
    case -1: return 0;
    case 0: if (!constmap_init(&mappercenthack,"",0,0)) return 0; break;
    case 1: if (!constmap_init(&mappercenthack,percenthack.s,percenthack.len,0)) return 0; break;
  }
  switch (control_readfile(&vdoms,"control/virtualdomains",0)) {
    case -1: return 0;
    case 0: if (!constmap_init(&mapvdoms,"",0,1)) return 0; break;
    case 1: if (!constmap_init(&mapvdoms,vdoms.s,vdoms.len,1)) return 0; break;
  }
  return 1;
}

stralloc newlocals = {0};
stralloc newvdoms = {0};

void regetcontrols(void)
{
  int r;

  if (control_readfile(&newlocals,"control/locals",1) != 1)
    { sendlog1("alert: qmail-todo is unable to reread control/locals\n"); return; }
  r = control_readfile(&newvdoms,"control/virtualdomains",0);
  if (r == -1)
    { sendlog1("alert: qmail-todo is unable to reread control/virtualdomains\n"); return; }

  constmap_free(&maplocals);
  constmap_free(&mapvdoms);

  while (!stralloc_copy(&locals,&newlocals)) nomem();
  while (!constmap_init(&maplocals,locals.s,locals.len,0)) nomem();

  if (r) {
    while (!stralloc_copy(&vdoms,&newvdoms)) nomem();
    while (!constmap_init(&mapvdoms,vdoms.s,vdoms.len,1)) nomem();
  }
  else
    while (!constmap_init(&mapvdoms,"",0,1)) nomem();
}

void reread(void)
{
  if (chdir(auto_qmail) == -1) {
    sendlog1("alert: qmail-todo is unable to reread controls: unable to switch to home directory\n");
    return;
  }

  regetcontrols();

  while (chdir(queuedir.s) == -1) {
    sendlog1("alert: qmail-todo is unable to switch back to queue directory; HELP! sleeping...\n");
    sleep(10);
  }
}

int main()
{
  datetime_sec wakeup;
  fd_set rfds;
  fd_set wfds;
  int nfds;
  struct timeval tv;
  int r;
  char c;

  if (!stralloc_copys(&queuedir,auto_queue)) _exit(110);
  if (!stralloc_cats(&queuedir,"/queue")) _exit(110);
  if (!stralloc_0(&queuedir)) _exit(110);

  if (chdir(auto_qmail) == -1)
    { sendlog1("alert: qmail-todo cannot start and switch to home directory\n"); _exit(110); }
  if (!getcontrols())
    { sendlog1("alert: qmail-todo cannot start and read controls\n"); _exit(112); }
  if (chdir(queuedir.s) == -1)
    { sendlog1("alert: qmail-todo cannot start and switch to queue directory\n"); _exit(110); }
  sig_pipeignore();
  umask(077);

  fnmake_init();
  todo_init();
  comm_init();
 
  do {
    r = read(fdin, &c, 1);
    if ((r == -1) && (errno != EINTR))
      _exit(100); /* read failed probably qmail-send died */
  } while ((r =! 1)); /* we assume it is a 'S' */
 
  for (;;) {
    recent = now();
    if (flagreadasap) { flagreadasap = 0; reread(); }
    if (!flagsendalive) {
      /* qmail-send finaly exited, so do the same. */
      if (flagquitasap) _exit(0);
      /* qmail-send died. We can not log and we can not work therefor _exit(1). */
      _exit(1);
    }

    wakeup = recent + SLEEP_FOREVER;
    FD_ZERO(&rfds);
    FD_ZERO(&wfds);
    nfds = 1;

    todo_selprep(&nfds,&rfds,&wakeup);
    comm_selprep(&nfds,&wfds,&rfds);

    if (wakeup <= recent) tv.tv_sec = 0;
    else tv.tv_sec = wakeup - recent + SLEEP_FUZZ;
    tv.tv_usec = 0;

    if (select(nfds,&rfds,&wfds,(fd_set *) 0,&tv) == -1)
      if (errno == EINTR)
        ;
      else
        sendlog1("warning: qmail-todo has trouble in select\n");
    else {
      recent = now();

      todo_do(&rfds);
      comm_do(&wfds, &rfds);
    }
  }
  /* NOTREACHED */
  _exit(1);
}