#include <sys/types.h>
#include <unistd.h>

#include "buffer.h"
#include "case.h"
#include "constmap.h"
#include "env.h"
#include "exit.h"
#include "fmt.h"
#include "logmsg.h"
#include "readwrite.h"
#include "sig.h"
#include "str.h"
#include "stralloc.h"

#include "auto_break.h"
#include "auto_qmail.h"
#include "control.h"
#include "qmail.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));
}