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

#include "buffer.h"
#include "byte.h"
#include "case.h"
#include "cdbmake.h"
#include "genalloc.h"
#include "getln.h"
#include "logmsg.h"
#include "open.h"
#include "stralloc.h"

#include "control.h"
#include "token822.h"

#ifdef USE_CONFIG
  #include "fehsqm-config.h"
#else
  #include "auto_qmail.h"
#endif

#define WHO "newaliases"

int rename(const char *, const char *);  // stdio.h

void nomem()
{
  logmsg(WHO, 111, FATAL, "out of memory");
}

void nulbyte()
{
  logmsg(WHO, 100, FATAL, "NUL bytes are not permitted");
}

void longaddress()
{
  logmsg(WHO, 100, FATAL, "addresses over 800 bytes are not permitted");
}

void writeerr()
{
  logmsg(WHO, 111, FATAL, "unable to write to /etc/aliases.tmp");
}

void readerr()
{
  logmsg(WHO, 111, FATAL, "unable to read /etc/aliases");
}

void die_control()
{
  logmsg(WHO, 111, FATAL, "unable to read controls");
}

stralloc me = {0};
stralloc defaulthost = {0};
stralloc defaultdomain = {0};
stralloc plusdomain = {0};

void readcontrols()
{
  int r;
  int fddir;

  fddir = open_read(".");
  if (fddir == -1) logmsg(WHO, 111, FATAL, "unable to open current directory");

  if (chdir(auto_qmail) == -1) logmsg(WHO, 111, FATAL, B("unable to chdir to: ", auto_qmail));

  r = control_readline(&me, "control/me");
  if (r == -1) die_control();
  if (!r && !stralloc_copys(&me, "me")) nomem();

  r = control_readline(&defaultdomain, "control/defaultdomain");
  if (r == -1) die_control();
  if (!r && !stralloc_copy(&defaultdomain, &me)) nomem();

  r = control_readline(&defaulthost, "control/defaulthost");
  if (r == -1) die_control();
  if (!r && !stralloc_copy(&defaulthost, &me)) nomem();

  r = control_readline(&plusdomain, "control/plusdomain");
  if (r == -1) die_control();
  if (!r && !stralloc_copy(&plusdomain, &me)) nomem();

  if (fchdir(fddir) == -1) logmsg(WHO, 111, FATAL, "unable to set current directory");
}

stralloc target = {0};
stralloc fulltarget = {0};
stralloc instr = {0};

stralloc cbuf = {0};
token822_alloc toks = {0};
token822_alloc tokaddr = {0};
stralloc address = {0};

void gotincl()
{
  token822_reverse(&tokaddr);
  if (token822_unquote(&address, &tokaddr) != 1) nomem();
  tokaddr.len = 0;

  if (!address.len) logmsg(WHO, 111, FATAL, "empty :include: filenames not permitted");
  if (byte_chr(address.s, address.len, '\0') < address.len)
    logmsg(WHO, 111, FATAL, "NUL not permitted in :include: filenames");

  if ((address.s[0] != '.') && (address.s[0] != '/'))
    if (!stralloc_cats(&instr, "./")) nomem();
  if (!stralloc_cat(&instr, &address)) nomem();
  if (!stralloc_cats(&instr, ".bin")) nomem();
  if (!stralloc_0(&instr)) nomem();
}

void gotaddr()
{
  int i;
  int j;
  int flaghasat;

  token822_reverse(&tokaddr);
  if (token822_unquote(&address, &tokaddr) != 1) nomem();

  if (!address.len) logmsg(WHO, 111, FATAL, "empty recipient addresses not permitted");

  flaghasat = 0;
  for (i = 0; i < tokaddr.len; ++i)
    if (tokaddr.t[i].type == TOKEN822_AT) flaghasat = 1;

  tokaddr.len = 0;

  if (!address.len) return;

  if (!flaghasat) {
    if (address.s[0] == '/') {
      if (!stralloc_0(&address)) nomem();
      logmsg(WHO, 111, FATAL, B("file delivery for ", address.s, " not supported"));
    }
  }
  if (!flaghasat && address.s[0] == '|') {
    if (byte_chr(address.s, address.len, '\0') < address.len)
      logmsg(WHO, 111, FATAL, "NUL not permitted in program names");
    if (!stralloc_cats(&instr, "!")) nomem();
    if (!stralloc_catb(&instr, address.s + 1, address.len - 1)) nomem();
    if (!stralloc_0(&instr)) nomem();
    return;
  }

  if (target.len) {
    if (!stralloc_cats(&instr, "&")) nomem();
    if (!stralloc_cat(&instr, &fulltarget)) nomem();
    if (!stralloc_0(&instr)) nomem();
  }

  if (!flaghasat)
    if (!stralloc_cats(&address, "@")) nomem();

  if (!stralloc_copy(&target, &address)) nomem();
  if (!stralloc_copy(&fulltarget, &address)) nomem();

  if (fulltarget.s[fulltarget.len - 1] == '@')
    if (!stralloc_cat(&fulltarget, &defaulthost)) nomem();
  if (fulltarget.s[fulltarget.len - 1] == '+') {
    fulltarget.s[fulltarget.len - 1] = '.';
    if (!stralloc_cat(&fulltarget, &plusdomain)) nomem();
  }

  j = 0;
  for (i = 0; i < fulltarget.len; ++i)
    if (fulltarget.s[i] == '@') j = i;
  for (i = j; i < fulltarget.len; ++i)
    if (fulltarget.s[i] == '.') break;
  if (i == fulltarget.len) {
    if (!stralloc_cats(&fulltarget, ".")) nomem();
    if (!stralloc_cat(&fulltarget, &defaultdomain)) nomem();
  }

  if (fulltarget.len > 800) longaddress();
  if (byte_chr(fulltarget.s, fulltarget.len, '\0') < fulltarget.len)
    logmsg(WHO, 111, FATAL, "NUL not permitted in recipient addresses");
}

stralloc line = {0};
stralloc newline = {0};
int match;

void parseerr()
{
  if (!stralloc_0(&line)) nomem();
  logmsg(WHO, 111, FATAL, B("unable to parse this line: ", line.s));
}

void parseline()
{
  int wordok;
  struct token822 *t;
  struct token822 *beginning;

  switch (token822_parse(&toks, &line, &cbuf)) {
    case -1: nomem();
    case 0:  parseerr();
  }

  beginning = toks.t;
  t = toks.t + toks.len;
  wordok = 1;

  if (!token822_readyplus(&tokaddr, 1)) nomem();
  tokaddr.len = 0;

  while (t > beginning) {
    switch ((--t)->type) {
      case TOKEN822_SEMI: break; /*XXX*/
      case TOKEN822_COLON:
        if (t >= beginning + 2 && t[-2].type == TOKEN822_COLON && t[-1].type == TOKEN822_ATOM
            && t[-1].slen == 7 && !byte_diff(t[-1].s, 7, "include"))
        {
          gotincl();
          t -= 2;
        }
        break; /*XXX*/
      case TOKEN822_RIGHT:
        if (tokaddr.len) gotaddr();
        while ((t > beginning) && (t[-1].type != TOKEN822_LEFT))
          if (!token822_append(&tokaddr, --t)) nomem();
        gotaddr();
        if (t <= beginning) parseerr();
        --t;
        while ((t > beginning)
               && ((t[-1].type == TOKEN822_COMMENT) || (t[-1].type == TOKEN822_ATOM)
                   || (t[-1].type == TOKEN822_QUOTE) || (t[-1].type == TOKEN822_AT)
                   || (t[-1].type == TOKEN822_DOT)))
        {
          --t;
        }
        wordok = 0;
        continue;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:
      case TOKEN822_LITERAL:
        if (!wordok && tokaddr.len) gotaddr();
        wordok = 0;
        if (!token822_append(&tokaddr, t)) nomem();
        continue;
      case TOKEN822_COMMENT:
        /* comment is lexically a space; shouldn't affect wordok */
        break;
      case TOKEN822_COMMA:
        if (tokaddr.len) gotaddr();
        wordok = 1;
        break;
      default:
        wordok = 1;
        if (!token822_append(&tokaddr, t)) nomem();
        continue;
    }
  }
  if (tokaddr.len) gotaddr();
}

char inbuf[1024];
buffer bi;
struct cdb_make cdb;
stralloc key = {0};

void doit()
{
  if (!instr.len) {
    if (target.len) parseerr();
    return;
  }

  if (!target.len) parseerr();

  if (stralloc_starts(&target, "owner-")) {
    if (!stralloc_copys(&key, "?")) nomem();
    if (!stralloc_catb(&key, target.s + 6, target.len - 6)) nomem();
    case_lowerb(key.s, key.len);
    if (cdb_make_add(&cdb, key.s, key.len, fulltarget.s, fulltarget.len) == -1) writeerr();
  }

  if (!stralloc_copys(&key, ":")) nomem();
  if (!stralloc_cat(&key, &target)) nomem();
  case_lowerb(key.s, key.len);
  if (cdb_make_add(&cdb, key.s, key.len, instr.s, instr.len) == -1) writeerr();
}

int main()
{
  int fd;

  umask(033);
  readcontrols();

  fd = open_read("/etc/aliases");
  if (fd == -1) readerr();
  buffer_init(&bi, read, fd, inbuf, sizeof(inbuf));

  fd = open_trunc("/etc/aliases.tmp");
  if (fd == -1) logmsg(WHO, 111, FATAL, "unable to create /etc/aliases.tmp");
  if (cdb_make_start(&cdb, fd) == -1) writeerr();

  if (!stralloc_copys(&line, "")) nomem();

  for (;;) {
    if (getln(&bi, &newline, &match, '\n') != 0) readerr();

    if (match && (newline.s[0] == '\n')) continue;

    if (match && ((newline.s[0] == ' ') || (newline.s[0] == '\t'))) {
      if (!stralloc_cat(&line, &newline)) nomem();
      continue;
    }

    if (line.len && line.s[0] != '#') {
      if (!stralloc_copys(&target, "")) nomem();
      if (!stralloc_copys(&fulltarget, "")) nomem();
      if (!stralloc_copys(&instr, "")) nomem();
      parseline();
      doit();
    }

    if (!match) break;
    if (!stralloc_copy(&line, &newline)) nomem();
  }

  if (cdb_make_finish(&cdb) == -1) writeerr();
  if (fsync(fd) == -1) writeerr();
  if (close(fd) == -1) writeerr(); /* NFS stupidity */

  if (rename("/etc/aliases.tmp", "/etc/aliases.cdb") == -1)
    logmsg(WHO, 111, FATAL, "unable to move /etc/aliases.tmp to /etc/aliases.cdb");

  _exit(0);
}