/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 2007, 2008 Free Software Foundation, Inc.

   GNU Mailutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GNU Mailutils is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GNU Mailutils; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301 USA */

#include "maidag.h"

int multiple_delivery;     /* Don't return errors when delivering to multiple
			      recipients */
int ex_quota_tempfail;     /* Return temporary failure if mailbox quota is
			      exceeded. If this variable is not set, maidag
			      will return "service unavailable" */
int exit_code = EX_OK;     /* Exit code to be used */
uid_t current_uid;         /* Current user id */

char *quotadbname = NULL;  /* Name of mailbox quota database */
char *quota_query = NULL;  /* SQL query to retrieve mailbox quota */

char *sender_address = NULL;       
char *progfile_pattern = NULL;
char *sieve_pattern = NULL;

int log_to_stderr = -1;

/* Debuggig options */
int debug_level;           /* General debugging level */ 
int sieve_debug_flags;     /* Sieve debugging flags */
int sieve_enable_log;      /* Enables logging of executed Sieve actions */
char *message_id_header;   /* Use the value of this header as message
			      identifier when logging Sieve actions */

/* For LMTP mode */
mu_m_server_t server;
int lmtp_mode;
int url_option;
char *lmtp_url_string;
int reuse_lmtp_address = 1;

const char *program_version = "maidag (" PACKAGE_STRING ")";
static char doc[] =
N_("GNU maildag -- the mail delivery agent")
"\v"
N_("Debug flags are:\n\
  g - guimb stack traces\n\
  t - sieve trace (MU_SIEVE_DEBUG_TRACE)\n\
  i - sieve instructions trace (MU_SIEVE_DEBUG_INSTR)\n\
  l - sieve action logs\n\
  0-9 - Set maidag debugging level\n");

static char args_doc[] = N_("[recipient...]");

#define STDERR_OPTION 256
#define MESSAGE_ID_HEADER_OPTION 257
#define LMTP_OPTION 258
#define FOREGROUND_OPTION 260
#define URL_OPTION 261

static struct argp_option options[] = 
{
  { "foreground", FOREGROUND_OPTION, 0, 0, N_("Remain in foreground."), 0 },
  { "inetd",  'i', 0, 0, N_("Run in inetd mode"), 0 },
  { "daemon", 'd', N_("NUMBER"), OPTION_ARG_OPTIONAL,
    N_("Runs in daemon mode with a maximum of NUMBER children"), 0 },
  { "url", URL_OPTION, 0, 0, N_("Deliver to given URLs"), 0 },
  { "from", 'f', N_("EMAIL"), 0,
    N_("Specify the sender's name") },
  { NULL, 'r', NULL, OPTION_ALIAS, NULL },
  { "sieve", 'S', N_("PATTERN"), 0,
    N_("Set name pattern for user-defined Sieve mail filters"), 0 },
  { "message-id-header", MESSAGE_ID_HEADER_OPTION, N_("STRING"), 0,
    N_("Identify messages by the value of this header when logging Sieve actions"), 0 },
#ifdef WITH_GUILE
  { "source", 's', N_("PATTERN"), 0,
    N_("Set name pattern for user-defined Scheme mail filters"), 0 },
#endif
  { "lmtp", LMTP_OPTION, N_("URL"), OPTION_ARG_OPTIONAL,
    N_("Operate in LMTP mode"), 0 },
  { "debug", 'x', N_("FLAGS"), 0,
    N_("Enable debugging"), 0 },
  { "stderr", STDERR_OPTION, NULL, 0,
    N_("Log to standard error"), 0 },
  { NULL,      0, NULL, 0, NULL, 0 }
};

static error_t parse_opt (int key, char *arg, struct argp_state *state);

static struct argp argp = {
  options,
  parse_opt,
  args_doc, 
  doc,
  NULL,
  NULL, NULL
};

static const char *maidag_argp_capa[] = {
  "auth",
  "common",
  "debug",
  "license",
  "logging",
  "mailbox",
  "locking",
  "mailer",
  NULL
};

#define D_DEFAULT "9,s"

static void
set_debug_flags (mu_debug_t debug, const char *arg)
{
  while (*arg)
    {
      if (isdigit (*arg))
	debug_level = strtoul (arg, (char**)&arg, 10);
      else
	for (; *arg && *arg != ','; arg++)
	  {
	    switch (*arg)
	      {
	      case 'g':
#ifdef WITH_GUILE
		debug_guile = 1;
#endif
		break;

	      case 't':
		sieve_debug_flags |= MU_SIEVE_DEBUG_TRACE;
		break;
	  
	      case 'i':
		sieve_debug_flags |= MU_SIEVE_DEBUG_INSTR;
		break;
	  
	      case 'l':
		sieve_enable_log = 1;
		break;
	  
	      default:
		mu_cfg_format_error (debug, MU_DEBUG_ERROR,
				     _("%c is not a valid debug flag"), *arg);
		break;
	      }
	  }
      if (*arg == ',')
	arg++;
      else if (*arg)
	mu_cfg_format_error (debug, MU_DEBUG_ERROR,
			     _("expected comma, but found %c"), *arg);
    }
}

static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  static struct mu_argp_node_list lst;

  switch (key)
    {
    case 'd':
      mu_argp_node_list_new (&lst, "mode", "daemon");
      if (arg)
	mu_argp_node_list_new (&lst, "max-children", arg);
      break;

    case 'i':
      mu_argp_node_list_new (&lst, "mode", "inetd");
      break;

    case FOREGROUND_OPTION:
      mu_argp_node_list_new (&lst, "foreground", "yes");
      break;
      
    case MESSAGE_ID_HEADER_OPTION:
      mu_argp_node_list_new (&lst, "message-id-header", arg);
      break;

    case LMTP_OPTION:
      mu_argp_node_list_new (&lst, "lmtp", "yes");
      if (arg)
	mu_argp_node_list_new (&lst, "listen", arg);
      break;

    case 'r':
    case 'f':
      if (sender_address != NULL)
	{
	  argp_error (state, _("Multiple --from options"));
	  return EX_USAGE;
	}
      sender_address = arg;
      break;
      
#ifdef WITH_GUILE	
    case 's':
      mu_argp_node_list_new (&lst, "guile-filter", arg);
      break;
#endif

    case 'S':
      mu_argp_node_list_new (&lst, "sieve-filter", arg);
      break;
      
    case 'x':
      mu_argp_node_list_new (&lst, "debug", arg ? arg : D_DEFAULT);
      break;

    case STDERR_OPTION:
      mu_argp_node_list_new (&lst, "stderr", "yes");
      break;

    case URL_OPTION:
      url_option = 1;
      break;
      
    case ARGP_KEY_INIT:
      mu_argp_node_list_init (&lst);
      break;
      
    case ARGP_KEY_FINI:
      mu_argp_node_list_finish (&lst, NULL, NULL);
      break;
      
    case ARGP_KEY_ERROR:
      exit (EX_USAGE);

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}



static int
cb_debug (mu_debug_t debug, void *data, mu_config_value_t *val)
{
  if (mu_cfg_assert_value_type (val, MU_CFG_STRING, debug))
    return 1;
  set_debug_flags (debug, val->v.string);
  return 0;
}

static int
cb2_group (mu_debug_t debug, const char *gname, void *data)
{
  mu_list_t *plist = data;
  struct group *group;

  if (!*plist)
    mu_list_create (plist);
  group = getgrnam (gname);
  if (!group)
    mu_cfg_format_error (debug, MU_DEBUG_ERROR, _("Unknown group: %s"), gname);
  else
    mu_list_append (*plist, (void*)group->gr_gid);
  return 0;
}
  
static int
cb_group (mu_debug_t debug, void *data, mu_config_value_t *arg)
{
  return mu_cfg_string_value_cb (debug, arg, cb2_group, data);
}

struct mu_cfg_param maidag_cfg_param[] = {
  { "exit-multiple-delivery-success", mu_cfg_bool, &multiple_delivery, 0, NULL,
    N_("In case of multiple delivery, exit with code 0 if at least one "
       "delivery succeeded.") },
  { "exit-quota-tempfail", mu_cfg_bool, &ex_quota_tempfail, 0, NULL,
    N_("Indicate temporary failure if the recipient is over his mail quota.")
  },
#ifdef USE_DBM
  { "quota-db", mu_cfg_string, &quotadbname, 0, NULL,
    N_("Name of DBM quota database file."),
    N_("file") },
#endif
#ifdef USE_SQL
  { "quota-query", mu_cfg_string, &quota_query, 0, NULL,
    N_("SQL query to retrieve mailbox quota.  This is deprecated, use "
       "sql { ... } instead."),
    N_("query") },
#endif
  { "sieve-filter", mu_cfg_string, &sieve_pattern, 0, NULL,
    N_("File name or name pattern for Sieve filter file."),
    N_("file-or-pattern") },
  { "message-id-header", mu_cfg_string, &message_id_header, 0, NULL,
    N_("When logging Sieve actions, identify messages by the value of "
       "this header."),
    N_("name") },
#ifdef WITH_GUILE
  { "guile-filter", mu_cfg_string, &progfile_pattern, 0, NULL,
    N_("File name or name pattern for Guile filter file."),
    N_("file-or-pattern") },
#endif
  { "debug", mu_cfg_callback, NULL, 0, cb_debug,
    N_("Set maidag debug level.  Debug level consists of one or more "
       "of the following letters:\n"
       "  g - guimb stack traces\n"
       "  t - sieve trace (MU_SIEVE_DEBUG_TRACE)\n"
       "  i - sieve instructions trace (MU_SIEVE_DEBUG_INSTR)\n"
       "  l - sieve action logs\n") },
  { "stderr", mu_cfg_bool, &log_to_stderr, 0, NULL,
    N_("Log to stderr instead of syslog.") },
/* LMTP support */
  { "lmtp", mu_cfg_bool, &lmtp_mode, 0, NULL,
    N_("Run in LMTP mode.") },
  { "group", mu_cfg_callback, &lmtp_groups, 0, cb_group,
    N_("In LMTP mode, retain these supplementary groups."),
    N_("groups: list of string") },
  { "listen", mu_cfg_string, &lmtp_url_string, 0, NULL,
    N_("In LMTP mode, listen on the given URL.  Valid URLs are:\n"
       "   tcp://<address: string>:<port: number> (note that port is "
       "mandatory)\n"
       "   file://<socket-file-name>\n"
       "or socket://<socket-file-name>"),
    N_("url") },
  { "reuse-address", mu_cfg_bool, &reuse_lmtp_address, 0, NULL,
    N_("Reuse existing address (LMTP mode).  Default is \"yes\".") },
  { ".server", mu_cfg_section, NULL, 0, NULL,
    N_("LMTP server configuration.") },
  TCP_WRAPPERS_CONFIG
  { NULL }
};


/* Logging */

static int
_sieve_debug_printer (void *unused, const char *fmt, va_list ap)
{
  mu_diag_vprintf (MU_DIAG_DEBUG, fmt, ap);
  return 0;
}

static void
_sieve_action_log (void *user_name,
		   const mu_sieve_locus_t *locus, size_t msgno,
		   mu_message_t msg,
		   const char *action, const char *fmt, va_list ap)
{
  int pfx = 0;
  mu_debug_t debug;

  mu_diag_get_debug (&debug);
  mu_debug_set_locus (debug, locus->source_file, locus->source_line);
  
  mu_diag_printf (MU_DIAG_NOTICE, _("(user %s) "), (char*) user_name);
  if (message_id_header)
    {
      mu_header_t hdr = NULL;
      char *val = NULL;
      mu_message_get_header (msg, &hdr);
      if (mu_header_aget_value (hdr, message_id_header, &val) == 0
	  || mu_header_aget_value (hdr, MU_HEADER_MESSAGE_ID, &val) == 0)
	{
	  pfx = 1;
	  mu_diag_printf (MU_DIAG_NOTICE, _("%s on msg %s"), action, val);
	  free (val);
	}
    }
  
  if (!pfx)
    {
      size_t uid = 0;
      mu_message_get_uid (msg, &uid);
      mu_diag_printf (MU_DIAG_NOTICE, _("%s on msg uid %d"), action, uid);
    }
  
  if (fmt && strlen (fmt))
    {
      mu_diag_printf (MU_DIAG_NOTICE, "; ");
      mu_diag_vprintf (MU_DIAG_NOTICE, fmt, ap);
    }
  mu_diag_printf (MU_DIAG_NOTICE, "\n");
  mu_debug_set_locus (debug, NULL, 0);
}

static int
_sieve_parse_error (void *user_name, const char *filename, int lineno,
		    const char *fmt, va_list ap)
{
  mu_debug_t debug;

  mu_diag_get_debug (&debug);
  if (filename)
    mu_debug_set_locus (debug, filename, lineno);

  mu_diag_printf (MU_DIAG_ERROR, _("(user %s) "), (char*) user_name);
  mu_diag_vprintf (MU_DIAG_ERROR, fmt, ap);
  mu_diag_printf (MU_DIAG_ERROR, "\n");
  mu_debug_set_locus (debug, NULL, 0);
  return 0;
}

int
sieve_test (struct mu_auth_data *auth, mu_message_t msg)
{
  int rc = 1;
  char *progfile;
    
  if (!sieve_pattern)
    return 1;

  progfile = mu_expand_path_pattern (sieve_pattern, auth->name);
  if (access (progfile, R_OK))
    {
      if (debug_level > 2)
	mu_diag_output (MU_DIAG_DEBUG, _("Access to %s failed: %m"), progfile);
    }
  else
    {
      mu_sieve_machine_t mach;
      rc = mu_sieve_machine_init (&mach, auth->name);
      if (rc)
	{
	  mu_error (_("Cannot initialize sieve machine: %s"),
		    mu_strerror (rc));
	}
      else
	{
	  mu_sieve_set_debug (mach, _sieve_debug_printer);
	  mu_sieve_set_debug_level (mach, sieve_debug_flags);
	  mu_sieve_set_parse_error (mach, _sieve_parse_error);
	  if (sieve_enable_log)
	    mu_sieve_set_logger (mach, _sieve_action_log);
	  
	  rc = mu_sieve_compile (mach, progfile);
	  if (rc == 0)
	    {
	      mu_attribute_t attr;

	      mu_message_get_attribute (msg, &attr);
	      mu_attribute_unset_deleted (attr);
	      if (switch_user_id (auth, 1) == 0)
		{
		  chdir (auth->dir);
		
		  rc = mu_sieve_message (mach, msg);
		  if (rc == 0)
		    rc = mu_attribute_is_deleted (attr) == 0;

		  switch_user_id (auth, 0);
		  chdir ("/");
		}
	      mu_sieve_machine_destroy (&mach);
	    }
	}
    }
  free (progfile);
  return rc;
}


int
main (int argc, char *argv[])
{
  int arg_index;

  /* Preparative work: close inherited fds, force a reasonable umask
     and prepare a logging. */
  close_fds ();
  umask (0077);

  /* Native Language Support */
  MU_APP_INIT_NLS ();

  /* Default locker settings */
  mu_locker_set_default_flags (MU_LOCKER_PID|MU_LOCKER_RETRY,
			    mu_locker_assign);
  mu_locker_set_default_retry_timeout (1);
  mu_locker_set_default_retry_count (300);

  /* Register needed modules */
  MU_AUTH_REGISTER_ALL_MODULES ();

  /* Register all supported mailbox and mailer formats */
  mu_register_all_formats ();
  mu_registrar_record (mu_smtp_record);

  /* Register a special mailbox */
  mu_registrar_record (mu_remote_mbox_record);
  
  mu_gocs_register ("sieve", mu_sieve_module_init);

  mu_tcpwrapper_cfg_init ();
  mu_acl_cfg_init ();
  mu_m_server_cfg_init ();
  
  /* Parse command line */
  mu_argp_init (program_version, NULL);

  mu_m_server_create (&server, program_version);
  mu_m_server_set_conn (server, lmtp_connection);
  mu_m_server_set_prefork (server, mu_tcp_wrapper_prefork);
  mu_m_server_set_mode (server, MODE_INTERACTIVE);
  mu_m_server_set_max_children (server, 20);
  mu_m_server_set_timeout (server, 600);
  
  if (mu_app_init (&argp, maidag_argp_capa, maidag_cfg_param, 
		   argc, argv, 0, &arg_index, server))
    exit (EX_CONFIG);

  current_uid = getuid ();

  if (log_to_stderr == -1)
    log_to_stderr = url_option || (!lmtp_mode && (current_uid != 0));
  
  if (!log_to_stderr)
    {
      mu_debug_t debug;

      openlog (MU_LOG_TAG (), LOG_PID, mu_log_facility);
      mu_diag_get_debug (&debug);
      mu_debug_set_print (debug, mu_diag_syslog_printer, NULL);

      mu_debug_default_printer = mu_debug_syslog_printer;
    }

  argc -= arg_index;
  argv += arg_index;

  if (lmtp_mode && !url_option)
    {
      if (argc)
	{
	  mu_error (_("Too many arguments"));
	  return EX_USAGE;
	}
      return maidag_lmtp_server ();
    }
  else 
    {
      if (current_uid)
	{
	  if (url_option)
	    {
	      /* FIXME: Verify if the urls are deliverable? */
	    }
	  else
	    {
	      static char *s_argv[2];
	      struct mu_auth_data *auth = mu_get_auth_by_uid (current_uid);
	      
	      if (!current_uid)
		{
		  mu_error (_("Cannot get username"));
		  return EX_UNAVAILABLE;
		}
	      
	      if (argc > 0 && strcmp (auth->name, argv[0]))
		{
		  mu_error (_("Recipients given when running as non-root"));
		  return EX_USAGE;
		}
	      s_argv[0] = auth->name;
	      argv = s_argv;
	      argc = 1;
	    }
	}
      return maidag_stdio_delivery (argc, argv);
    }
}