/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * 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 Digital Milliwatt Test
 *
 * \author Mark Spencer <markster@digium.com>
 * 
 * \ingroup applications
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/utils.h"

static char *app = "Milliwatt";

static char *synopsis = "Generate a Constant 1000Hz tone at 0dbm (mu-law)";

static char *descrip = 
"Milliwatt(): Generate a Constant 1000Hz tone at 0dbm (mu-law)\n";

static char digital_milliwatt[] = {0x1e,0x0b,0x0b,0x1e,0x9e,0x8b,0x8b,0x9e} ;

static void *milliwatt_alloc(struct ast_channel *chan, void *params)
{
	return ast_calloc(1, sizeof(int));
}

static void milliwatt_release(struct ast_channel *chan, void *data)
{
	free(data);
	return;
}

static int milliwatt_generate(struct ast_channel *chan, void *data, int len, int samples)
{
	unsigned char buf[AST_FRIENDLY_OFFSET + 640];
	const int maxsamples = sizeof (buf) / sizeof (buf[0]);
	int i, *indexp = (int *) data;
	struct ast_frame wf = {
		.frametype = AST_FRAME_VOICE,
		.subclass = AST_FORMAT_ULAW,
		.offset = AST_FRIENDLY_OFFSET,
		.data = buf + AST_FRIENDLY_OFFSET,
		.src = __FUNCTION__,
	};

	/* Instead of len, use samples, because channel.c generator_force
	* generate(chan, tmp, 0, 160) ignores len. In any case, len is
	* a multiple of samples, given by number of samples times bytes per
	* sample. In the case of ulaw, len = samples. for signed linear
	* len = 2 * samples */
	if (samples > maxsamples) {
		ast_log(LOG_WARNING, "Only doing %d samples (%d requested)\n", maxsamples, samples);
		samples = maxsamples;
	}
	len = samples * sizeof (buf[0]);
	wf.datalen = len;
	wf.samples = samples;

	/* create a buffer containing the digital milliwatt pattern */
	for (i = 0; i < len; i++) {
		buf[AST_FRIENDLY_OFFSET + i] = digital_milliwatt[(*indexp)++];
		*indexp &= 7;
	}

	if (ast_write(chan,&wf) < 0) {
		ast_log(LOG_WARNING,"Failed to write frame to '%s': %s\n",chan->name,strerror(errno));
		return -1;
	}

	return 0;
}

static struct ast_generator milliwattgen = 
{
	alloc: milliwatt_alloc,
	release: milliwatt_release,
	generate: milliwatt_generate,
};

static int milliwatt_exec(struct ast_channel *chan, void *data)
{

	struct ast_module_user *u;
	u = ast_module_user_add(chan);

	ast_set_write_format(chan, AST_FORMAT_ULAW);
	ast_set_read_format(chan, AST_FORMAT_ULAW);


	if (chan->_state != AST_STATE_UP)
		ast_answer(chan);

	if (ast_activate_generator(chan,&milliwattgen,"milliwatt") < 0) {
		ast_log(LOG_WARNING,"Failed to activate generator on '%s'\n",chan->name);
		ast_module_user_remove(u);
		return -1;
	}

	while(!ast_safe_sleep(chan, 10000));

	ast_deactivate_generator(chan);

	ast_module_user_remove(u);

	return -1;
}

static int unload_module(void)
{
	int res;

	res = ast_unregister_application(app);

	ast_module_user_hangup_all();

	return res;
}

static int load_module(void)
{
	return ast_register_application(app, milliwatt_exec, synopsis, descrip);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Digital Milliwatt (mu-law) Test Application");