#include <unistd.h>
#include <sys/types.h>
#include "control.h"
#include "sig.h"
#include "constmap.h"
#include "readwrite.h"
#include "exit.h"
#include "env.h"
#include "qmail.h"
#include "auto_qmail.h"
#include "auto_break.h"
#include "buffer.h"
#include "case.h"
#include "str.h"
#include "fmt.h"
#include "stralloc.h"
#include "logmsg.h"
#include "srs2.h"

#define WHO "srsreverse"

void die_nomem() { logmsg(WHO,111,FATAL,"out of memory"); } 
void die_control() { logmsg(WHO,110,FATAL,"Unable to read control files"); }

struct qmail qqt;
char *vdomainuser = 0;
stralloc vdomains = {0};
struct constmap mapvdomains;
char *srsdomaininfo = 0;
stralloc srsdomains = {0};
struct constmap mapsrsdomains;
stralloc srserror = {0};
stralloc srshost = {0};

/** @file  srsreverse.c
    @brief forwarding bounces with SRS enhanced addresss
    @return   0 on success (forwarded or not)
             -3 SRS error with error output
            111 no memory / processing error
            110 control file not readable
*/

static int srserror_str(int code) {
  if (!stralloc_copys(&srserror,"SRS: ")) die_nomem();
  if (!stralloc_cats(&srserror,srs_strerror(code))) die_nomem();
  if (!stralloc_0(&srserror)) die_nomem();
  return -3;
}

ssize_t mywrite(int fd,char *buf,int len)
{
  qmail_put(&qqt,buf,len);
  return len;
}

char inbuf[BUFFER_INSIZE];
char outbuf[1];
buffer bi = BUFFER_INIT(read,0,inbuf,sizeof(inbuf));
buffer bo = BUFFER_INIT(mywrite,-1,outbuf,sizeof(outbuf));

char num[FMT_ULONG];

int main()
{
  int i, j, r;
  char *recipient;
  char *dtline;
  char *qqx;
  srs_t *srs;
  stralloc cookie = {0};
  char separator = '=';
  char srsrecipient[512];
  char *host = 0;

  sig_pipeignore();
 
  recipient = env_get("RECIPIENT");
  if (!recipient)
    logmsg(WHO,100,FATAL,"RECIPIENT not set");
  dtline = env_get("DTLINE");
  if (!dtline)
    logmsg(WHO,100,FATAL,"DTLINE not set");
  host = env_get("HOST");
  if (!host)
    logmsg(WHO,100,FATAL,"HOST not set");
    
  if (chdir(auto_qmail) == -1)
      logmsg(WHO,111,FATAL,B("unable to chdir to: ",auto_qmail));

  /* Check for particular virtual SRS domain user */

  switch (control_readfile(&vdomains,"control/virtualdomains",0)) {
    case -1: die_control();
    case  0: if (!constmap_init(&mapvdomains,"",0,1)) die_nomem(); break;
    case  1: if (!constmap_init(&mapvdomains,vdomains.s,vdomains.len,1)) die_nomem(); break;
  }

  j = str_len(host);
  for (i = 0; i <= j; ++i) 
    if ((i == 0) || (host[i] == '.')) {
      if (!stralloc_copys(&srshost,"")) die_nomem();
      if (!stralloc_catb(&srshost,host + i,j - i)) die_nomem();
      if ((srsdomaininfo = constmap(&mapvdomains,srshost.s,srshost.len)) != 0) goto SRSDOMAINS;
    }
  if (!stralloc_copys(&srshost,host)) die_nomem();

  SRSDOMAINS:

  switch (control_readfile(&srsdomains,"control/srsdomains",0)) {
    case -1: die_control();
    case  0: if (!constmap_init(&mapsrsdomains,"",0,1)) die_nomem(); break;
    case  1: if (!constmap_init(&mapsrsdomains,srsdomains.s,srsdomains.len,1)) die_nomem(); break;
  }
  if ((srsdomaininfo = constmap(&mapsrsdomains,srshost.s,srshost.len)) == 0)
    if ((srsdomaininfo = constmap(&mapsrsdomains,"*",1)) == 0) return 0;

  if (*srsdomaininfo) {
    i = str_chr(srsdomaininfo,'|');                  // multiple cookies; separated by  ' '
    if (srsdomaininfo[i] == '|') {
        srsdomaininfo[i] = 0;
        separator = srsdomaininfo[i+1];
    }
    if (!stralloc_copys(&cookie,srsdomaininfo)) die_nomem();
    if (!stralloc_0(&cookie)) die_nomem();
  }

  /* strip virtual user from recipient */

  if ((vdomainuser = constmap(&mapvdomains,host,j))) {
    i = str_chr(recipient,*auto_break);
    if (!case_diffb(recipient,i - 1,vdomainuser)) recipient += i + 1;
  }
 
  /* Let's go SRS reverse */

  srs = srs_new();

  if (separator == '-' || separator == '+' || separator == '=') {    // '=' is default
    r = srs_set_separator(srs,separator);
    if (r != SRS_SUCCESS) return srserror_str(r);
  }

  for (j = 0, i = 0; j < cookie.len; j++) {
    if (cookie.s[j] == ' ' || cookie.s[j] == '\0' ) { 
      cookie.s[j] = '\0'; 
      r = srs_add_secret(srs,cookie.s + i);
      if (r != SRS_SUCCESS) return srserror_str(r);
      i = j + 1; 
      if (cookie.s[i] == ' ') { j++; continue; }
    }
  }

  if ((r = srs_reverse(srs,srsrecipient,sizeof(srsrecipient),recipient)) != SRS_SUCCESS) {
    logmsg(WHO,100,FATAL,B("unable to reverse: ",recipient," ",srs_strerror(r)));
  }

  if (qmail_open(&qqt) == -1)
    logmsg(WHO,111,FATAL,"unable to fork: ");
  qmail_puts(&qqt,dtline);
  if (buffer_copy(&bo,&bi) != 0)
    logmsg(WHO,111,FATAL,"unable to read message: ");
  buffer_flush(&bo);

  num[fmt_ulong(num,qmail_qp(&qqt))] = 0;
 
  qmail_from(&qqt,"");
  qmail_to(&qqt,srsrecipient);
  qqx = qmail_close(&qqt);
  if (*qqx) logmsg(WHO,*qqx == 'D' ? 100 : 111,FATAL,qqx + 1);
  logmsg(WHO,0,LOG,B(srsrecipient,": qp ",num));

}