app_randomplayback: add RandomPlayback application

Author: InterLinked1

apps/app_randomplayback.c

@@ -0,0 +1,248 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2022, Naveen Albert
+ *
+ * Naveen Albert <[email protected]>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Trivial application to randomly play a sound file
+ *
+ * \author Naveen Albert <[email protected]>
+ *
+ * \ingroup applications
+ */
+
+/*** MODULEINFO
+	<support_level>extended</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include <dirent.h>
+#include <sys/stat.h>
+#include <libgen.h>
+
+#include "asterisk/file.h"
+#include "asterisk/pbx.h"
+#include "asterisk/module.h"
+#include "asterisk/app.h"
+#include "asterisk/paths.h"	/* use ast_config_AST_DATA_DIR */
+
+/*** DOCUMENTATION
+	<application name="RandomPlayback" language="en_US">
+		<synopsis>
+			Plays a random file with a particular directory and/or file prefix
+		</synopsis>
+		<syntax>
+			<parameter name="prefix">
+				<para>Directory/file prefix that must match.</para>
+			</parameter>
+		</syntax>
+		<description>
+			<para>Plays back a random file with the provided prefix which contains
+			a specific directory, optionally followed by a file prefix. If there
+			is no file prefix, be sure to end with a trailing slash to search
+			in a directory of the given name as opposed to a trailing file prefix.</para>
+			<para>Knowledge of actual specific file candidates is not necessary.</para>
+			<para>A random file matching this full prefix will be played.</para>
+			<para>This application does not automatically answer the channel and should
+			be preceded by <literal>Progress</literal> or <literal>Answer</literal> as
+			appropriate.</para>
+		</description>
+		<see-also>
+			<ref type="application">Playback</ref>
+			<ref type="application">ControlPlayback</ref>
+		</see-also>
+	</application>
+ ***/
+
+static char *app = "RandomPlayback";
+
+/*!
+ * \brief Traverses a directory and returns number of files or a specific file with specified prefix
+ *
+ * \param chan Channel
+ * \param directoryprefix Directory name and file prefix (optional)
+ * \param filename 0 if getting the file count, otherwise positive 1-indexed file number to retrieve
+ * \param buffer Buffer to fill. Do not allocate beforehand.
+ *
+ * \retval -1 Failure
+ * \retval 0 No files in directory (file count)
+ * \retval non-zero Number of files in directory (file count) or file number that matched (retrieval)
+ */
+static int traverse_directory(struct ast_channel *chan, char *directoryprefix, int filenum, char **buffer)
+{
+	char *fullpath;
+	char *dir, *base;
+	struct dirent* dent;
+	DIR* srcdir;
+	int files = 0, baselen = 0;
+	RAII_VAR(struct ast_str *, media_dir, ast_str_create(64), ast_free);
+	RAII_VAR(struct ast_str *, variant_dir, ast_str_create(64), ast_free);
+
+	if (!media_dir || !variant_dir) {
+		return -1;
+	}
+
+	if (directoryprefix[0] == '/') { /* absolute path */
+		ast_str_set(&media_dir, 0, "%s", directoryprefix);
+	} else if (directoryprefix[0]) {
+		ast_str_set(&media_dir, 0, "%s/sounds/%s/%s", ast_config_AST_DATA_DIR, chan ? ast_channel_language(chan) : "en", directoryprefix);
+	} else {
+		ast_str_set(&media_dir, 0, "%s/sounds/%s", ast_config_AST_DATA_DIR, chan ? ast_channel_language(chan) : "en");
+	}
+
+	fullpath = ast_str_buffer(media_dir);
+	baselen = strlen(fullpath);
+	if (!fullpath[0]) {
+		return -1;
+	}
+	if (fullpath[baselen - 1] == '/') { /* ends in trailing slash... but dirname ignores trailing slash */
+		dir = fullpath;
+		dir[baselen - 1] = '\0';
+		base = "";
+	} else {
+		dir = dirname(ast_strdupa(fullpath));
+		base = basename(ast_strdupa(fullpath));
+	}
+	
+	ast_debug(1, "'%s' -> '%s' -> dirname '%s', basename '%s'\n", directoryprefix, fullpath, dir, base);
+
+	baselen = strlen(base);
+	srcdir = opendir(dir);
+	if (!srcdir) {
+		ast_debug(1, "Failed to open '%s'\n", dir);
+		return -1;
+	}
+
+	while((dent = readdir(srcdir)) != NULL) {
+		struct stat st;
+
+		if(!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, "..")) {
+			continue; /* parent directory */
+		}
+		if (*base && strncmp(dent->d_name, base, baselen)) {
+			continue; /* doesn't match required file prefix */
+		}
+
+		ast_str_reset(variant_dir);
+		ast_str_set(&variant_dir, 0, "%s/%s", dir, dent->d_name);
+
+		if (stat(ast_str_buffer(variant_dir), &st) < 0) {
+			ast_log(LOG_ERROR, "Failed to stat %s\n", ast_str_buffer(variant_dir));
+			continue;
+		}
+		if (S_ISDIR(st.st_mode)) {
+			continue; /* don't care about subdirectories */
+		}
+		files++;
+		if (filenum && filenum == files) {
+			int slen = ast_str_strlen(variant_dir) + 1;
+			*buffer = ast_malloc(slen);
+			if (!*buffer) {
+				files = -1;
+				break;
+			}
+			ast_copy_string(*buffer, ast_str_buffer(variant_dir), slen);
+			break;
+		}
+	}
+
+	closedir(srcdir);
+	return files;
+}
+
+static int dir_file_count(struct ast_channel *chan, char *directoryprefix)
+{
+	return traverse_directory(chan, directoryprefix, 0, NULL);
+}
+
+static char *dir_file_match(struct ast_channel *chan, char *directoryprefix, int filenum)
+{
+	char *buf = NULL;
+	traverse_directory(chan, directoryprefix, filenum, &buf);
+	return buf;
+}
+
+static int playback_exec(struct ast_channel *chan, const char *data)
+{
+	int numfiles, rand;
+	int res = 0;
+	char *tmp, *buf;
+
+	AST_DECLARE_APP_ARGS(args,
+		AST_APP_ARG(dirprefix);
+	);
+
+	if (ast_strlen_zero(data)) {
+		ast_log(LOG_WARNING, "RandomPlayback requires an argument (filename)\n");
+		return -1;
+	}
+
+	tmp = ast_strdupa(data);
+	AST_STANDARD_APP_ARGS(args, tmp);
+	/* do not auto-answer channel */
+
+	numfiles = dir_file_count(chan, args.dirprefix);
+	if (numfiles == -1) {
+		ast_log(LOG_WARNING, "Failed to calculate number of files prefixed with '%s'\n", args.dirprefix);
+		return -1;
+	}
+	if (!numfiles) {
+		ast_log(LOG_WARNING, "No files prefixed with '%s'\n", args.dirprefix);
+		return 0;
+	}
+	rand = 1 + (ast_random() % numfiles);
+	buf = dir_file_match(chan, args.dirprefix, rand);
+	if (!buf) {
+		ast_log(LOG_WARNING, "Failed to find random file # %d prefixed with '%s'\n", rand, args.dirprefix);
+		return -1;
+	}
+
+	ast_debug(1, "Lucky file was #%d/%d: '%s'\n", rand, numfiles, buf);
+
+	tmp = buf + strlen(buf) - 1;
+	while (tmp != buf && tmp[0] != '.') {
+		tmp--;
+	}
+	tmp[0] = '\0'; /* get rid of the file extension, for ast_streamfile */
+
+	ast_stopstream(chan);
+	res = ast_streamfile(chan, buf, ast_channel_language(chan));
+	if (!res) {
+		res = ast_waitstream(chan, "");
+		ast_stopstream(chan);
+	}
+
+	ast_free(buf);
+	return res;
+}
+
+static int unload_module(void)
+{
+	int res;
+
+	res = ast_unregister_application(app);
+
+	return res;
+}
+
+static int load_module(void)
+{
+	return ast_register_application_xml(app, playback_exec);
+}
+
+AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Random Playback Application");