notmuch: Add a configuration system.

This will allow for things like the database path to be specified
without any cheesy NOTMUCH_BASE environment variable. It also will
allow "notmuch reply" to recognize the user's email address when
constructing a reply in order to do the right thing, (that is, to use
the user's address to which mail was sent as From:, and not to reply
to the user's own addresses).

With this change, the "notmuch setup" command is now strictly for
changing the configuration of notmuch. It no longer creates the
database, but instead instructs the user to call "notmuch new" to do
that.

1 files changed, 374 insertions, 0 deletions

diff --git a/notmuch-config.c b/notmuch-config.c
new file mode 100644
index 00000000..0dc2b133
--- /dev/null
+++ b/notmuch-config.c
@@ -0,0 +1,374 @@
+/* notmuch - Not much of an email program, (just index and search)
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * 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 3 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/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
+
+#include "notmuch-client.h"
+
+#include <pwd.h>
+#include <netdb.h>
+
+struct _notmuch_config {
+    char *filename;
+    GKeyFile *key_file;
+
+    char *database_path;
+    char *user_name;
+    char *user_primary_email;
+    char **user_other_email;
+    size_t user_other_email_length;
+};
+
+static int
+notmuch_config_destructor (notmuch_config_t *config)
+{
+    if (config->key_file)
+	g_key_file_free (config->key_file);
+
+    return 0;
+}
+
+static char *
+get_name_from_passwd_file (void *ctx)
+{
+    long pw_buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
+    char *pw_buf = talloc_zero_size (ctx, pw_buf_size);
+    struct passwd passwd, *ignored;
+    char *name;
+
+    if (getpwuid_r (getuid (), &passwd, pw_buf, pw_buf_size, &ignored) == 0) {
+	char *comma = strchr (passwd.pw_gecos, ',');
+	if (comma)
+	    name = talloc_strndup (ctx, passwd.pw_gecos,
+				   comma - passwd.pw_gecos);
+	else
+	    name = talloc_strdup (ctx, passwd.pw_gecos);
+    } else {
+	name = talloc_strdup (ctx, "");
+    }
+
+    talloc_free (pw_buf);
+
+    return name;
+}
+
+static char *
+get_username_from_passwd_file (void *ctx)
+{
+    long pw_buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
+    char *pw_buf = talloc_zero_size (ctx, pw_buf_size);
+    struct passwd passwd, *ignored;
+    char *name;
+
+    if (getpwuid_r (getuid (), &passwd, pw_buf, pw_buf_size, &ignored) == 0)
+	name = talloc_strdup (ctx, passwd.pw_name);
+    else
+	name = talloc_strdup (ctx, "");
+
+    talloc_free (pw_buf);
+
+    return name;
+}
+
+/* Open the named notmuch configuration file. A filename of NULL will
+ * be interpreted as the default configuration file
+ * ($HOME/.notmuch-config).
+ *
+ * If any error occurs, (out of memory, or a permission-denied error,
+ * etc.), this function will print a message to stderr and return
+ * NULL.
+ *
+ * Note: It is *not* an error if the specified configuration file does
+ * not exist. In this case, a default configuration will be created
+ * and returned. Subsequently calling notmuch_config_save will cause
+ * the configuration to be written to the filename specified at the
+ * time of notmuch_config_open.
+ *
+ * The default configuration settings are determined as follows:
+ *
+ *	database_path:		$HOME/mail
+ *
+ *	user_name:		From /etc/passwd
+ *
+ *	user_primary_mail: 	$EMAIL variable if set, otherwise
+ *				constructed from the username and
+ *				hostname of the current machine.
+ *
+ *	user_other_email:	Not set.
+ *
+ * The default configuration also contains comments to guide the user
+ * in editing the file directly.
+ */
+notmuch_config_t *
+notmuch_config_open (void *ctx, const char *filename)
+{
+    GError *error = NULL;
+
+    notmuch_config_t *config = talloc (ctx, notmuch_config_t);
+    if (config == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	return NULL;
+    }
+    
+    talloc_set_destructor (config, notmuch_config_destructor);
+
+    if (filename)
+	config->filename = talloc_strdup (config, filename);
+    else
+	config->filename = talloc_asprintf (config, "%s/.notmuch-config",
+					    getenv ("HOME"));
+
+    config->key_file = g_key_file_new ();
+
+    config->database_path = NULL;
+    config->user_name = NULL;
+    config->user_primary_email = NULL;
+    config->user_other_email = NULL;
+    config->user_other_email_length = 0;
+
+    if (! g_key_file_load_from_file (config->key_file,
+				     config->filename,
+				     G_KEY_FILE_KEEP_COMMENTS,
+				     &error))
+    {
+	/* We are capable of dealing with a non-existent configuration
+	 * file, so be silent about that. */
+	if (!(error->domain == G_FILE_ERROR &&
+	      error->code == G_FILE_ERROR_NOENT))
+	{
+	    fprintf (stderr, "Error reading configuration file %s: %s\n",
+		     config->filename, error->message);
+	    talloc_free (config);
+	    return NULL;
+	}
+    }
+
+    if (notmuch_config_get_database_path (config) == NULL) {
+	char *path = talloc_asprintf (config, "%s/mail",
+				      getenv ("HOME"));
+	notmuch_config_set_database_path (config, path);
+	talloc_free (path);
+    }
+
+    if (notmuch_config_get_user_name (config) == NULL) {
+	char *name = get_name_from_passwd_file (config);
+	notmuch_config_set_user_name (config, name);
+	talloc_free (name);
+    }
+
+    if (notmuch_config_get_user_primary_email (config) == NULL) {
+	char *email = getenv ("EMAIL");
+	if (email) {
+	    notmuch_config_set_user_primary_email (config, email);
+	} else {
+	    char hostname[256];
+	    struct hostent *hostent;
+	    const char *domainname;
+
+	    char *username = get_username_from_passwd_file (config);
+
+	    gethostname (hostname, 256);
+	    hostname[255] = '\0';
+
+	    hostent = gethostbyname (hostname);
+	    if (hostent && (domainname = strchr (hostent->h_name, '.')))
+		domainname += 1;
+	    else
+		domainname = "(none)";
+
+	    email = talloc_asprintf (config, "%s@%s.%s",
+				     username, hostname, domainname);
+
+	    notmuch_config_set_user_primary_email (config, email);
+
+	    talloc_free (username);
+	    talloc_free (email);
+	}
+    }
+
+    return config;
+}
+
+/* Close the given notmuch_config_t object, freeing all resources.
+ * 
+ * Note: Any changes made to the configuration are *not* saved by this
+ * function. To save changes, call notmuch_config_save before
+ * notmuch_config_close.
+*/
+void
+notmuch_config_close (notmuch_config_t *config)
+{
+    talloc_free (config);
+}
+
+/* Save any changes made to the notmuch configuration.
+ *
+ * Any comments originally in the file will be preserved.
+ *
+ * Returns 0 if successful, and 1 in case of any error, (after
+ * printing a description of the error to stderr).
+ */
+int
+notmuch_config_save (notmuch_config_t *config)
+{
+    size_t length;
+    char *data;
+    GError *error = NULL;
+
+    data = g_key_file_to_data (config->key_file, &length, NULL);
+    if (data == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	return 1;
+    }
+
+    if (! g_file_set_contents (config->filename, data, length, &error)) {
+	fprintf (stderr, "Error saving configuration to %s: %s\n",
+		 config->filename, error->message);
+	return 1;
+    }
+
+    return 0;
+}
+
+const char *
+notmuch_config_get_database_path (notmuch_config_t *config)
+{
+    char *path;
+
+    if (config->database_path == NULL) {
+	path = g_key_file_get_string (config->key_file,
+				      "database", "path", NULL);
+	if (path) {
+	    config->database_path = talloc_strdup (config, path);
+	    free (path);
+	}
+    }
+
+    return config->database_path;
+}
+
+void
+notmuch_config_set_database_path (notmuch_config_t *config,
+				  const char *database_path)
+{
+    g_key_file_set_string (config->key_file,
+			   "database", "path", database_path);
+
+    talloc_free (config->database_path);
+    config->database_path = NULL;
+}
+
+const char *
+notmuch_config_get_user_name (notmuch_config_t *config)
+{
+    char *name;
+
+    if (config->user_name == NULL) {
+	name = g_key_file_get_string (config->key_file,
+				      "user", "name", NULL);
+	if (name) {
+	    config->user_name = talloc_strdup (config, name);
+	    free (name);
+	}
+    }
+
+    return config->user_name;
+}
+
+void
+notmuch_config_set_user_name (notmuch_config_t *config,
+			      const char *user_name)
+{
+    g_key_file_set_string (config->key_file,
+			   "user", "name", user_name);
+
+    talloc_free (config->user_name);
+    config->user_name = NULL;
+}
+
+const char *
+notmuch_config_get_user_primary_email (notmuch_config_t *config)
+{
+    char *email;
+
+    if (config->user_primary_email == NULL) {
+	email = g_key_file_get_string (config->key_file,
+				       "user", "primary_email", NULL);
+	if (email) {
+	    config->user_primary_email = talloc_strdup (config, email);
+	    free (email);
+	}
+    }
+
+    return config->user_primary_email;
+}
+
+void
+notmuch_config_set_user_primary_email (notmuch_config_t *config,
+				       const char *primary_email)
+{
+    g_key_file_set_string (config->key_file,
+			   "user", "primary_email", primary_email);
+
+    talloc_free (config->user_primary_email);
+    config->user_primary_email = NULL;
+}
+
+char **
+notmuch_config_get_user_other_email (notmuch_config_t *config,
+				     size_t *length)
+{
+    char **emails;
+    size_t emails_length;
+    unsigned int i;
+
+    if (config->user_other_email == NULL) {
+	emails = g_key_file_get_string_list (config->key_file,
+					     "user", "other_email",
+					     &emails_length, NULL);
+	if (emails) {
+	    config->user_other_email = talloc_size (config,
+						    sizeof (char *) *
+						    (emails_length + 1));
+	    for (i = 0; i < emails_length; i++)
+		config->user_other_email[i] = talloc_strdup (config->user_other_email,
+							     emails[i]);
+	    config->user_other_email[i] = NULL;
+
+	    g_strfreev (emails);
+
+	    config->user_other_email_length = emails_length;
+	}
+    }
+
+    *length = config->user_other_email_length;
+    return config->user_other_email;
+}
+
+void
+notmuch_config_set_user_other_email (notmuch_config_t *config,
+				     const char *other_email[],
+				     size_t length)
+{
+    g_key_file_set_string_list (config->key_file,
+				"user", "other_email",
+				other_email, length);
+
+    talloc_free (config->user_other_email);
+    config->user_other_email = NULL;
+}