System notification via event notification system

Introduces `devel_new_mail_command` config option. When used instead of
`new_mail_command`, Neomutt's event notification system will be used for
new mail notifications. This is part of a bigger refactoring of the
legacy notification approach. The initial implementation uses only very
limited set of expandos.

Makefile.autosetup

@@ -563,7 +563,7 @@ LIBMUTTOBJS=	mutt/atoi.o mutt/base64.o mutt/buffer.o mutt/charset.o \
 		mutt/date.o mutt/envlist.o mutt/exit.o mutt/file.o \
 		mutt/filter.o mutt/hash.o mutt/list.o mutt/logging.o \
 		mutt/mapping.o mutt/mbyte.o mutt/md5.o mutt/memory.o \
-		mutt/notify.o mutt/path.o mutt/pool.o mutt/prex.o \
+		mutt/new_mail.o mutt/notify.o mutt/path.o mutt/pool.o mutt/prex.o \
 		mutt/qsort_r.o mutt/random.o mutt/regex.o mutt/signal.o \
 		mutt/slist.o mutt/state.o mutt/string.o
 

core/mailbox.h

@@ -178,6 +178,8 @@ enum NotifyMailbox
   NT_MAILBOX_RESORT,     ///< Email list needs resorting
   NT_MAILBOX_UPDATE,     ///< Update internal tables
   NT_MAILBOX_UNTAG,      ///< Clear the 'last-tagged' pointer
+
+  NT_MAILBOX_NEW_MAIL,   ///< New messages have been added
 };
 
 /**

docs/config.c

@@ -986,6 +986,17 @@
 ** or when you save it to another folder.
 */
 
+{ "devel_new_mail_command", DT_COMMAND, 0 },
+/*
+** .pp
+** If \fIset\fP, NeoMutt will call this command after a new message is received.
+** The following \fCprintf(3)\fP-like sequences are supported: 
+** .dl 
+** .dt %n  .dd Mailbox name
+** .dt %f  .dd Mailbox folder path
+** .de
+*/
+
 { "digest_collapse", DT_BOOL, true },
 /*
 ** .pp

main.c

@@ -944,6 +944,7 @@ main
   notify_observer_add(NeoMutt->notify, NT_CONFIG, main_hist_observer, NULL);
   notify_observer_add(NeoMutt->notify, NT_CONFIG, main_log_observer, NULL);
   notify_observer_add(NeoMutt->notify, NT_CONFIG, main_config_observer, NULL);
+  notify_observer_add(NeoMutt->notify, NT_MAILBOX, new_mail_observer, NULL);
 
   if (sendflags & SEND_POSTPONED)
   {

mutt/lib.h

@@ -46,6 +46,7 @@
  * | mutt/mbyte.c     | @subpage mutt_mbyte     |
  * | mutt/md5.c       | @subpage mutt_md5       |
  * | mutt/memory.c    | @subpage mutt_memory    |
+ * | mutt/new_mail.c  | @subpage mutt_new_mail  |
  * | mutt/notify.c    | @subpage mutt_notify    |
  * | mutt/path.c      | @subpage mutt_path      |
  * | mutt/pool.c      | @subpage mutt_pool      |
@@ -86,6 +87,7 @@
 #include "md5.h"
 #include "memory.h"
 #include "message.h"
+#include "new_mail.h"
 #include "notify.h"
 #include "notify_type.h"
 #include "observer.h"

mutt/new_mail.c

@@ -0,0 +1,99 @@
+/**
+ * @file
+ * New mail notification observer implementation.
+ *
+ * @authors
+ * Copyright (C) 2022 Michal Siedlaczek <michal@siedlaczek.me>
+ *
+ * @copyright
+ * This program 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 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program 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
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @page new_mail Notify about new incoming mail
+ *
+ * Use an external command to send a system notification when new mail arrives.
+ */
+
+#include "config/lib.h"
+#include "new_mail.h"
+#include "mutt_mailbox.h"
+#include "muttlib.h"
+#include "protos.h"
+
+/**
+ * new_mail_format_str - Format a string for the new mail notification.
+ * @param[out] buf      Buffer in which to save string
+ * @param[in]  buflen   Buffer length
+ * @param[in]  col      Starting column
+ * @param[in]  cols     Number of screen columns
+ * @param[in]  src      Printf-like format string
+ * @param[in]  prec     Field precision, e.g. "-3.4"
+ * ############# TODO #############
+ *
+ * | Expando | Description
+ * | :------ | :-------------------------------------------------------
+ * | \%n     | Folder name
+ * | \%f     | Folder path
+ */
+const char *new_mail_format_str(char *buf, size_t buflen, size_t col, int cols,
+                                char op, const char *src, const char *prec,
+                                const char *if_str, const char *else_str,
+                                intptr_t data, MuttFormatFlags flags)
+{
+  struct Mailbox *mailbox = (struct Mailbox *) data;
+
+  switch (op)
+  {
+    case 'n':
+      snprintf(buf, buflen, "%s", NONULL(mailbox->name));
+      break;
+    case 'f':
+      snprintf(buf, buflen, "%s", NONULL(mailbox_path(mailbox)));
+      break;
+  }
+  return src;
+}
+
+int handle_new_mail_event(const char *cmd, struct NotifyCallback *nc, Execute *execute)
+{
+  if (nc->event_subtype != NT_MAILBOX_NEW_MAIL)
+    return 0;
+
+  struct EventMailbox *ev_m = nc->event_data;
+  if (!ev_m || !ev_m->mailbox)
+    return 0;
+
+  struct Mailbox *mailbox = ev_m->mailbox;
+  char expanded_cmd[1024];
+  mutt_expando_format(expanded_cmd, 1024, 0, 1024, cmd, new_mail_format_str,
+                      (intptr_t) mailbox, MUTT_FORMAT_NO_FLAGS);
+  execute(expanded_cmd);
+  return 0;
+}
+
+int execute_cmd(const char *cmd)
+{
+  if (mutt_system(cmd) != 0)
+    mutt_error(_("Error running \"%s\""), cmd);
+  return 0;
+}
+
+int new_mail_observer(struct NotifyCallback *nc)
+{
+  const char *c_devel_new_mail_command = cs_subset_string(NeoMutt->sub, "devel_new_mail_command");
+  if (!c_devel_new_mail_command)
+    return 0;
+  return handle_new_mail_event(c_devel_new_mail_command, nc, execute_cmd);
+}

mutt/new_mail.h

@@ -0,0 +1,40 @@
+/**
+ * @file
+ * New mail notification observer.
+ *
+ * @authors
+ * Copyright (C) 2022 Michal Siedlaczek <michal@siedlaczek.me>
+ *
+ * @copyright
+ * This program 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 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program 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
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MUTT_NEW_MAIL_H
+#define MUTT_NEW_MAIL_H
+
+#include <stdint.h>
+#include <stdio.h>
+#include "mutt/notify.h"
+#include "format_flags.h"
+
+typedef int(Execute)(const char *cmd);
+
+const char *new_mail_format_str(char *buf, size_t buflen, size_t col, int cols,
+                                char op, const char *src, const char *prec,
+                                const char *if_str, const char *else_str,
+                                intptr_t data, MuttFormatFlags flags);
+int handle_new_mail_event(const char *cmd, struct NotifyCallback *nc, Execute *execute);
+int new_mail_observer(struct NotifyCallback *nc);
+
+#endif

mutt_config.c

@@ -407,6 +407,9 @@ static struct ConfigDef MainVars[] = {
   { "new_mail_command", DT_STRING|DT_COMMAND, 0, 0, NULL,
     "External command to run when new mail arrives"
   },
+  { "devel_new_mail_command", DT_STRING|DT_COMMAND, 0, 0, NULL,
+    "External command to run when new mail arrives (in development, clashes with new_mail_command)"
+  },
   { "pager", DT_STRING|DT_COMMAND, IP "builtin", 0, NULL,
     "External command for viewing messages, or 'builtin' to use NeoMutt's"
   },

mx.c

@@ -1808,6 +1808,12 @@ enum MxStatus mx_mbox_check_stats(struct Mailbox *m, uint8_t flags)
     struct EventMailbox ev_m = { m };
     notify_send(m->notify, NT_MAILBOX, NT_MAILBOX_CHANGE, &ev_m);
   }
+  if (rc == MX_STATUS_NEW_MAIL && !m->notified)
+  {
+    struct EventMailbox ev_m = { m };
+    notify_send(m->notify, NT_MAILBOX, NT_MAILBOX_NEW_MAIL, &ev_m);
+    m->notified = true;
+  }
 
   return rc;
 }

test/Makefile.autosetup

@@ -355,6 +355,9 @@ NEOMUTT_OBJS	= test/neo/neomutt_account_add.o \
 		  test/neo/neomutt_mailboxlist_get_all.o \
 		  test/neo/neomutt_new.o
 
+NEW_MAIL_OBJS	= test/new_mail/new_mail_observer.o \
+		  test/new_mail/new_mail_format_str.o
+
 NOTIFY_OBJS	= test/notify/notify_free.o \
 		  test/notify/notify_new.o \
 		  test/notify/notify_observer_add.o \
@@ -610,6 +613,7 @@ TEST_OBJS	= test/main.o test/common.o \
 		  $(MD5_OBJS) \
 		  $(MEMORY_OBJS) \
 		  $(NEOMUTT_OBJS) \
+		  $(NEW_MAIL_OBJS) \
 		  $(NOTIFY_OBJS) \
 		  $(NOTMUCH_OBJS) \
 		  $(PARAMETER_OBJS) \

test/main.c

@@ -396,6 +396,10 @@
   NEOMUTT_TEST_ITEM(test_neomutt_mailboxlist_get_all)                          \
   NEOMUTT_TEST_ITEM(test_neomutt_new)                                          \
                                                                                \
+  /* new_mail */                                                               \
+  NEOMUTT_TEST_ITEM(test_new_mail_observer)                                    \
+  NEOMUTT_TEST_ITEM(test_new_mail_format_str)                                  \
+                                                                               \
   /* notify */                                                                 \
   NEOMUTT_TEST_ITEM(test_notify_free)                                          \
   NEOMUTT_TEST_ITEM(test_notify_new)                                           \

test/new_mail/new_mail_format_str.c

@@ -0,0 +1,55 @@
+/**
+ * @file
+ * Test code for new_mail_format_str()
+ *
+ * @authors
+ * Copyright (C) 2022 Michal Siedlaczek <michal@siedlaczek.me>
+ *
+ * @copyright
+ * This program 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 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program 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
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mutt/string2.h"
+#define TEST_NO_MAIN
+#include "config.h"
+#include "acutest.h"
+#include "mutt/lib.h"
+#include "core/lib.h"
+
+void test_new_mail_format_str(void)
+{
+  // const char *new_mail_format_str(char *buf, size_t buflen, size_t col, int cols,
+  //                                 char op, const char *src, const char *prec,
+  //                                 const char *if_str, const char *else_str,
+  //                                 intptr_t data, MuttFormatFlags flags);
+
+  char buf[64];
+  size_t col = 0;
+  int cols = 64;
+  struct Mailbox *mailbox = mailbox_new();
+  mailbox->name = mutt_str_dup("MailBox");
+  mailbox->pathbuf = mutt_buffer_make(16);
+  mutt_buffer_strcpy(&mailbox->pathbuf, "/path");
+  intptr_t data = (intptr_t) mailbox;
+
+  new_mail_format_str((char *) buf, 64, col, cols, 'n', NULL, NULL, NULL, NULL, data, 0);
+  TEST_CHECK(mutt_str_equal(buf, "MailBox"));
+  TEST_MSG("Check failed: %s != MailBox", buf);
+
+  new_mail_format_str((char *) buf, 64, col, cols, 'f', NULL, NULL, NULL, NULL, data, 0);
+  TEST_CHECK(mutt_str_equal(buf, "/path"));
+  TEST_MSG("Check failed: %s != /path", buf);
+
+  mailbox_free(&mailbox);
+}

test/new_mail/new_mail_observer.c

@@ -0,0 +1,65 @@
+/**
+ * @file
+ * Test code for new_mail_observer()
+ *
+ * @authors
+ * Copyright (C) 2022 Michal Siedlaczek <michal@siedlaczek.me>
+ *
+ * @copyright
+ * This program 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 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program 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
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mutt/notify.h"
+#include "mutt/observer.h"
+#include "mutt/string2.h"
+#define TEST_NO_MAIN
+#include "config.h"
+#include "acutest.h"
+#include "mutt/lib.h"
+#include "core/lib.h"
+
+static char *message = NULL;
+
+int dummy_execute_cmd(const char *cmd)
+{
+  message = mutt_str_dup(cmd);
+  return 0;
+}
+
+int dummy_new_mail_observer(struct NotifyCallback *nc)
+{
+  return handle_new_mail_event("New messages", nc, dummy_execute_cmd);
+}
+
+void test_new_mail_observer(void)
+{
+  struct Notify *notify = notify_new();
+  notify_observer_add(notify, NT_MAILBOX, dummy_new_mail_observer, NULL);
+  struct Mailbox *mailbox = mailbox_new();
+  mailbox->name = mutt_str_dup("Mailbox");
+  struct EventMailbox event;
+  event.mailbox = mailbox;
+
+  notify_send(notify, NT_MAILBOX, NT_MAILBOX_NEW_MAIL, NULL);
+  TEST_CHECK(message == NULL);
+
+  notify_send(notify, NT_MAILBOX, NT_MAILBOX_NEW_MAIL, &event);
+  TEST_CHECK(message != NULL);
+  TEST_CHECK(mutt_str_equal(message, "New messages"));
+  TEST_MSG("Check failed: \"%s\" != \"New messages\"", message);
+
+  notify_free(&notify);
+  mailbox_free(&mailbox);
+  FREE(&message);
+}