ympd/src/mpd_client.c

#include <mpd/client.h>
#include <mpd/status.h>
#include <mpd/song.h>
#include <mpd/entity.h>
#include <mpd/search.h>
#include <mpd/tag.h>

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

#include "mpd_client.h"

#define MAX_SIZE 9000*10

struct mpd_connection *conn = NULL;
enum mpd_conn_states mpd_conn_state = MPD_DISCONNECTED;
enum mpd_state mpd_play_state = MPD_STATE_UNKNOWN;
unsigned queue_version;

int callback_ympd(struct libwebsocket_context *context,
	struct libwebsocket *wsi,
	enum libwebsocket_callback_reasons reason,
	void *user, void *in, size_t len)
{
	size_t n;
	int m;
	char *buf = NULL, *p;
	struct per_session_data__ympd *pss = (struct per_session_data__ympd *)user;

	switch (reason) {
		case LWS_CALLBACK_ESTABLISHED:
			lwsl_info("mpd_client: "
				"LWS_CALLBACK_ESTABLISHED\n");
			break;

		case LWS_CALLBACK_SERVER_WRITEABLE:
			buf = (char *)malloc(MAX_SIZE + LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING);
			if(buf == NULL) {
				lwsl_err("ERROR Failed allocating memory\n");
				return -1;
			}
			p = &buf[LWS_SEND_BUFFER_PRE_PADDING];

			if(mpd_conn_state != MPD_CONNECTED) {
				n = snprintf(p, MAX_SIZE, "{\"type\":\"disconnected\"}");
			}
			else if(pss->queue_version != queue_version) {
				n = mpd_put_playlist(p);
				pss->queue_version = queue_version;
			}
			else if(pss->do_send & DO_SEND_STATE) {
				n = mpd_put_state(p);
				pss->do_send &= ~DO_SEND_STATE;
			}
			else if(pss->do_send & DO_SEND_PLAYLIST) {
				n = mpd_put_playlist(p);
				pss->do_send &= ~DO_SEND_PLAYLIST;
			}
			else if(pss->do_send & DO_SEND_TRACK_INFO)
				n = mpd_put_current_song(p);
			else {
				n = mpd_put_state(p);
			}

			if(n > 0)
				m = libwebsocket_write(wsi, (unsigned char*)p, n, LWS_WRITE_TEXT);

			if (m < n) {
				lwsl_err("ERROR %d writing to socket\n", n, m);
				free(buf);
				return -1;
			}
			free(buf);
			break;

		case LWS_CALLBACK_RECEIVE:
			printf("Got %s\n", (char *)in);

			if(!strcmp((const char *)in, MPD_API_GET_STATE))
				pss->do_send |= DO_SEND_STATE;
			else if(!strcmp((const char *)in, MPD_API_GET_PLAYLIST))
				pss->do_send |= DO_SEND_PLAYLIST;
			else if(!strcmp((const char *)in, MPD_API_GET_TRACK_INFO))
				pss->do_send |= DO_SEND_TRACK_INFO;
			else if(!strcmp((const char *)in, MPD_API_UPDATE_DB)) {
				mpd_send_update(conn, NULL);
				mpd_response_finish(conn);
			}
			else if(!strcmp((const char *)in, MPD_API_SET_PAUSE)) {
				mpd_send_toggle_pause(conn);
				mpd_response_finish(conn);
			}
			else if(!strcmp((const char *)in, MPD_API_SET_PREV)) {
				mpd_send_previous(conn);
				mpd_response_finish(conn);
			}
			else if(!strcmp((const char *)in, MPD_API_SET_NEXT)) {
				mpd_send_next(conn);
				mpd_response_finish(conn);
			}
			else if(!strncmp((const char *)in, MPD_API_SET_VOLUME, sizeof(MPD_API_SET_VOLUME)-1)) {
				unsigned int volume;
				if(sscanf(in, "MPD_API_SET_VOLUME,%ud", &volume) && volume < 100)
					mpd_run_set_volume(conn, volume);
			}
			break;

		default:
			break;
	}

	return 0;
}

void mpd_loop()
{
	switch (mpd_conn_state) {
		case MPD_DISCONNECTED:
			/* Try to connect */
			conn = mpd_connection_new("127.0.0.1", 6600, 3000);
			if (conn == NULL) {
				lwsl_err("Out of memory.");
				mpd_conn_state = MPD_FAILURE;
				return;
			}

			if (mpd_connection_get_error(conn) != MPD_ERROR_SUCCESS) {
				lwsl_notice("MPD connection: %s\n", mpd_connection_get_error_message(conn));
				mpd_conn_state = MPD_FAILURE;
				return;
			}

			lwsl_notice("MPD connected.\n");
			mpd_conn_state = MPD_CONNECTED;
			break;

		case MPD_FAILURE:
			lwsl_notice("MPD connection failed.\n");

			if(conn != NULL)
				mpd_connection_free(conn);
			conn = NULL;
			mpd_conn_state = MPD_DISCONNECTED;
			break;

		case MPD_CONNECTED:
			/* Nothing to do */
			break;
	}
}

char* mpd_get_title(struct mpd_song const *song)
{
	char *str, *ptr;

	str = (char *)mpd_song_get_tag(song, MPD_TAG_TITLE, 0);
	if(str == NULL)
		str = (char *)mpd_song_get_uri(song);

	if(str == NULL)
		return NULL;

	ptr = str;
	while(*ptr++ != '\0')
		if(*ptr=='"')
			*ptr=' ';

	return str;
}

int mpd_put_state(char* buffer)
{
	struct mpd_status *status;
	int len;

	status = mpd_run_status(conn);
	if (!status) {
		lwsl_err("MPD status: %s\n", mpd_connection_get_error_message(conn));
		mpd_conn_state = MPD_FAILURE;
		return 0;
	}

	len = snprintf(buffer, MAX_SIZE,
		"{\"type\":\"state\", \"data\":{"
		" \"state\":%d, \"volume\":%d, \"repeat\":%d,"
        " \"single\":%d, \"consume\":%d, \"random\":%d, "
        " \"songpos\": %d, \"elapsedTime\": %d, \"totalTime\":%d, "
        " \"currentsongid\": %d"
	    "}}", 
		mpd_status_get_state(status),
		mpd_status_get_volume(status), 
		mpd_status_get_repeat(status),
		mpd_status_get_single(status),
		mpd_status_get_consume(status),
		mpd_status_get_random(status),
		mpd_status_get_song_pos(status),
		mpd_status_get_elapsed_time(status),
		mpd_status_get_total_time(status),
		mpd_status_get_song_id(status));

	queue_version = mpd_status_get_queue_version(status);
	printf("buffer: %s\n", buffer);
	mpd_status_free(status);
	return len;
}

int mpd_put_current_song(char* buffer)
{
	struct mpd_song *song;
    int len;

	song = mpd_run_current_song(conn);
	if (song != NULL) {
		len = snprintf(buffer, MAX_SIZE, "{\"type\": \"current_song\", \"data\": {"
			"{\"id\":%d, \"duration\":%d, \"title\":\"%s\"},",
			mpd_song_get_id(song),
			mpd_song_get_duration(song),
			mpd_get_title(song)
		);
		mpd_song_free(song);
	}
	mpd_response_finish(conn);

	return len;
}

int mpd_put_playlist(char* buffer)
{
	char *cur = buffer;
	const char *end = buffer + MAX_SIZE;
	struct mpd_entity *entity;
	struct mpd_song const *song;

	mpd_send_list_queue_meta(conn);

	cur += snprintf(cur, end  - cur, "{\"type\": \"playlist\", \"data\": [ ");

	for(entity = mpd_recv_entity(conn); entity; entity = mpd_recv_entity(conn)) {

		if(mpd_entity_get_type(entity) == MPD_ENTITY_TYPE_SONG) {
			song = mpd_entity_get_song(entity);
			cur += snprintf(cur, end  - cur, 
				"{\"id\":%d, \"pos\":%d, \"duration\":%d, \"title\":\"%s\"},",
				mpd_song_get_id(song),
				mpd_song_get_pos(song),
				mpd_song_get_duration(song),
				mpd_get_title(song)
			);
		}

		mpd_entity_free(entity);
	}

	/* remove last ',' */
	cur--;
	cur += snprintf(cur, end  - cur, "] }");
	printf("buffer: %s\n", buffer);
	return cur - buffer;
}