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 <libgen.h>

#include "mpd_client.h"

#define MAX_SIZE 1024 * 100

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) || (pss->do_send & DO_SEND_PLAYLIST)) {
                n = mpd_put_playlist(p);
                pss->queue_version = queue_version;
                pss->do_send &= ~DO_SEND_PLAYLIST;
            }
            else if(pss->do_send & DO_SEND_TRACK_INFO) {
                n = mpd_put_current_song(p);
                pss->do_send &= ~DO_SEND_TRACK_INFO;
            }
            else if(pss->do_send & DO_SEND_BROWSE) {
                n = mpd_put_browse(p, pss->browse_path);
                pss->do_send &= ~DO_SEND_BROWSE;
                free(pss->browse_path);
            }
            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:
            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(!strcmp((const char *)in, MPD_API_RM_ALL)) {
                mpd_run_clear(conn);
            }
            else if(!strncmp((const char *)in, MPD_API_RM_TRACK, sizeof(MPD_API_RM_TRACK)-1)) {
                unsigned id;
                if(sscanf(in, "MPD_API_RM_TRACK,%d", &id))
                    mpd_run_delete_id(conn, id);
            }
            else if(!strncmp((const char *)in, MPD_API_PLAY_TRACK, sizeof(MPD_API_PLAY_TRACK)-1)) {
                unsigned id;
                if(sscanf(in, "MPD_API_PLAY_TRACK,%d", &id))
                    mpd_run_play_id(conn, id);
            }
            else if(!strncmp((const char *)in, MPD_API_TOGGLE_RANDOM, sizeof(MPD_API_TOGGLE_RANDOM)-1)) {
                unsigned random;
                if(sscanf(in, "MPD_API_TOGGLE_RANDOM,%d", &random))
                    mpd_run_random(conn, random);
            }
            else if(!strncmp((const char *)in, MPD_API_TOGGLE_REPEAT, sizeof(MPD_API_TOGGLE_REPEAT)-1)) {
                unsigned repeat;
                if(sscanf(in, "MPD_API_TOGGLE_REPEAT,%d", &repeat))
                    mpd_run_repeat(conn, repeat);
            }
            else if(!strncmp((const char *)in, MPD_API_TOGGLE_CONSUME, sizeof(MPD_API_TOGGLE_CONSUME)-1)) {
                unsigned consume;
                if(sscanf(in, "MPD_API_TOGGLE_CONSUME,%d", &consume))
                    mpd_run_consume(conn, consume);
            }
            else if(!strncmp((const char *)in, MPD_API_TOGGLE_SINGLE, sizeof(MPD_API_TOGGLE_SINGLE)-1)) {
                unsigned single;
                if(sscanf(in, "MPD_API_TOGGLE_SINGLE,%d", &single))
                    mpd_run_single(conn, single);
            }
            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);
            }
            else if(!strncmp((const char *)in, MPD_API_GET_BROWSE, sizeof(MPD_API_GET_BROWSE)-1)) {
                char *dir;
                if(sscanf(in, "MPD_API_GET_BROWSE,%m[^\t\n]", &dir) && dir != NULL) {
                    pss->do_send |= DO_SEND_BROWSE;
                    pss->browse_path = dir;
                }
            }
            else if(!strncmp((const char *)in, MPD_API_ADD_TRACK, sizeof(MPD_API_ADD_TRACK)-1)) {
                char *uri;
                if(sscanf(in, "MPD_API_ADD_TRACK,%m[^\t\n]", &uri) && uri != NULL) {
                    mpd_run_add(conn, uri);
                    free(uri);
                }
            }
            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 basename(str);
}

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

    status = mpd_run_status(conn);
    if (!status) {
        lwsl_err("MPD mpd_run_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);
    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)
        return 0;

    len = snprintf(buffer, MAX_SIZE, "{\"type\": \"current_song\", \"data\":"
            "{\"pos\":%d, \"title\":\"%s\", \"artist\":\"%s\", \"album\":\"%s\"}}",
            mpd_song_get_pos(song),
            mpd_get_title(song),
            mpd_song_get_tag(song, MPD_TAG_ARTIST, 0),
            mpd_song_get_tag(song, MPD_TAG_ALBUM, 0)
            );
    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;

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

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

    while((entity = mpd_recv_entity(conn)) != NULL) {
        const struct mpd_song *song;

        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, "] }");
    return cur - buffer;
}

int mpd_put_browse(char *buffer, char *path)
{
    char *cur = buffer;
    const char *end = buffer + MAX_SIZE;
    struct mpd_entity *entity;

    if (!mpd_send_list_meta(conn, path)) {
        lwsl_err("MPD mpd_send_list_meta: %s\n", mpd_connection_get_error_message(conn));
        mpd_conn_state = MPD_FAILURE;
        return 0;
    }
    cur += snprintf(cur, end  - cur, "{\"type\":\"browse\",\"data\":[ ");

    while((entity = mpd_recv_entity(conn)) != NULL) {
        const struct mpd_song *song;
        const struct mpd_directory *dir;
        const struct mpd_playlist *pl;

        switch (mpd_entity_get_type(entity)) {
            case MPD_ENTITY_TYPE_UNKNOWN:
                break;

            case MPD_ENTITY_TYPE_SONG:
                song = mpd_entity_get_song(entity);
                cur += snprintf(cur, end  - cur, 
                        "{\"type\":\"song\",\"uri\":\"%s\",\"duration\":%d,\"title\":\"%s\"},",
                        mpd_song_get_uri(song),
                        mpd_song_get_duration(song),
                        mpd_get_title(song)
                        );
                break;

            case MPD_ENTITY_TYPE_DIRECTORY:
                dir = mpd_entity_get_directory(entity);
                cur += snprintf(cur, end  - cur, 
                        "{\"type\":\"directory\",\"dir\":\"%s\"},",
                        mpd_directory_get_path(dir)
                        );
                break;

            case MPD_ENTITY_TYPE_PLAYLIST:
                pl = mpd_entity_get_playlist(entity);
                cur += snprintf(cur, end  - cur, 
                        "{\"type\":\"playlist\",\"plist\":\"%s\"},",
                        mpd_playlist_get_path(pl)
                        );
                break;
        }
        mpd_entity_free(entity);
    }

    if (mpd_connection_get_error(conn) != MPD_ERROR_SUCCESS || !mpd_response_finish(conn)) {
        lwsl_err("MPD mpd_send_list_meta: %s\n", mpd_connection_get_error_message(conn));
        mpd_conn_state = MPD_FAILURE;
        return 0;
    }

    /* remove last ',' */
    cur--;
    cur += snprintf(cur, end  - cur, "] }");
    return cur - buffer;
}