/******************************************************************************
*                            recordMyDesktop                                  *
*******************************************************************************
*                                                                             *
*            Copyright (C) 2006,2007,2008 John Varouhakis                     *
*                                                                             *
*                                                                             *
*   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 2 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, write to the Free Software               *
*   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA  *
*                                                                             *
*                                                                             *
*                                                                             *
*   For further information contact me at johnvarouhakis@gmail.com            *
******************************************************************************/


#include <recordmydesktop.h>

#ifdef HAVE_JACK_H


#define CHECK_DLERRORS_FATAL(__error_p)\
    if((__error_p=dlerror())!=NULL){\
        fprintf(stderr,"%s\n",__error_p);\
        return 1;\
    }

#define DLSYM_AND_CHECK(lib_handle,__call_name__,__error_p)\
    __call_name__##_p=dlsym(lib_handle,#__call_name__);\
    CHECK_DLERRORS_FATAL(__error_p)


/**
*
*   Fuction Pointers To Jack API Calls (shouldn't a jack header provide these?)
*
*/
jack_client_t *(*jack_client_new_p)(const char *client_name);
jack_nframes_t (*jack_get_sample_rate_p)(jack_client_t * client);
int (*jack_set_buffer_size_p)(jack_client_t *client, jack_nframes_t nframes);
jack_nframes_t (*jack_get_buffer_size_p)(jack_client_t *client);
int (*jack_set_process_callback_p)(jack_client_t *client,
                                   JackProcessCallback process_callback,
                                   void *arg);
void (*jack_on_shutdown_p)(jack_client_t *client,
                           void(*function)(void *arg),
                           void *arg);
int (*jack_activate_p)(jack_client_t *client);
int (*jack_client_close_p)(jack_client_t *client);
void *(*jack_port_get_buffer_p)(jack_port_t *port,jack_nframes_t);
jack_port_t *(*jack_port_register_p)(jack_client_t *client,
                                     const char *port_name,
                                     const char *port_type,
                                     unsigned long flags,
                                     unsigned long buffer_size);
int (*jack_connect_p)(jack_client_t *client,
                      const char *source_port,
                      const char *destination_port);
const char *(*jack_port_name_p)(const jack_port_t *port);
int (*jack_port_name_size_p)(void);
jack_ringbuffer_t *(*jack_ringbuffer_create_p)(size_t sz);
void (*jack_ringbuffer_free_p)(jack_ringbuffer_t *rb);
size_t (*jack_ringbuffer_write_p)(jack_ringbuffer_t *rb,
                                  const char *src,
                                  size_t cnt);


/**
*   Callback for capture through jack
*
*   \param  nframes Number of frames captured
*
*   \param jdata_t  Pointer to JackData struct containing port
*                   and client information
*
*   \returns Zero always
*/
static int JackCapture(jack_nframes_t nframes,void *jdata_t) {
    int i=0;
    JackData *jdata=(JackData *)jdata_t;

    if((!*Running)||(Paused) || (!jdata->capture_started))
        return 0;
    for(i= 0;i<jdata->nports;i++)
        jdata->portbuf[i]=jack_port_get_buffer_p(jdata->ports[i],nframes);
//vorbis analysis buffer wants uninterleaved data
//so we are simply placing the buffers for every channel
//sequentially on the ringbuffer
    for(i=0;i<jdata->nports;i++)
        (*jack_ringbuffer_write_p)(jdata->sound_buffer,
                                   (void *)(jdata->portbuf[i]),
                                   nframes*
                                   sizeof(jack_default_audio_sample_t));
/*FIXME */
//This is not safe.
//cond_var signaling must move away from signal handlers
//alltogether (JackCapture, SetExpired, SetPaused).
//Better would be a set of pipes for each of these.
//The callback should write on the pipe and the main thread
//should perform a select over the fd's, signaling afterwards the
//appropriate cond_var.
    pthread_mutex_lock(jdata->snd_buff_ready_mutex);
    pthread_cond_signal(jdata->sound_data_read);
    pthread_mutex_unlock(jdata->snd_buff_ready_mutex);

    return 0;
}

/**
*   Register and Activate specified ports
*
*   \param jdata_t  Pointer to JackData struct containing port
*                   and client information
*
*   \returns 0 on Success, 1 on failure
*/
static int SetupPorts(JackData *jdata) {
    int i=0;
    jdata->ports=malloc(sizeof(jack_port_t *)*
                               jdata->nports);
    jdata->portbuf=malloc(sizeof(jack_default_audio_sample_t*)*
                          jdata->nports);
    memset(jdata->portbuf,0,sizeof(jack_default_audio_sample_t*)*
                            jdata->nports);

    for(i=0;i<jdata->nports;i++){
        char name[64];//recordMyDesktop:input_n<64 is enough for full name
        char num[8];
        strcpy(name,"input_");
        I16TOA((i+1),num);
        strcat(name,num);
        if((jdata->ports[i]=jack_port_register_p(jdata->client,
                                                 name,
                                                 JACK_DEFAULT_AUDIO_TYPE,
                                                 JackPortIsInput,
                                                 0))==0){
            fprintf(stderr,"Cannot register input port \"%s\"!\n",name);
            return 1;
        }
        if(jack_connect_p(jdata->client,
                          jdata->port_names[i],
                          jack_port_name_p(jdata->ports[i]))){
            fprintf(stderr,"Cannot connect input port %s to %s\n",
                           jack_port_name_p(jdata->ports[i]),
                           jdata->port_names[i]);
            return 1;
        }
    }
    return 0;
}

/**
*   dlopen libjack and dlsym all needed functions
*
*   \param jack_lib_handle  Pointer to handle for jack library
*
*   \returns 0 on Success, 1 on failure
*/
static int LoadJackLib(void *jack_lib_handle) {
    char *error;
    jack_lib_handle=dlopen("libjack.so",RTLD_LAZY);
    if(!jack_lib_handle){
        fprintf(stderr,"%s\n",dlerror());
        return 1;
    }
    if((error=dlerror())!=NULL){
        fprintf(stderr,"%s\n",dlerror());
    }
//this macro will call return with status 1 on failure
    DLSYM_AND_CHECK(jack_lib_handle,jack_client_new,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_get_sample_rate,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_set_buffer_size,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_get_buffer_size,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_set_process_callback,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_on_shutdown,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_activate,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_client_close,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_port_get_buffer,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_port_register,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_connect,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_port_name,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_port_name_size,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_ringbuffer_create,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_ringbuffer_free,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_ringbuffer_read,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_ringbuffer_read_space,error)
    DLSYM_AND_CHECK(jack_lib_handle,jack_ringbuffer_write,error)

    return 0;
}

//in case the jack server shuts down
//the program should stop recording,
//encode the result(if not on the fly)
//an exit cleanly.
void JackShutdown(void *jdata_t){
    fprintf (stderr, "JACK shutdown\n");
    *Running=0;
}

int StartJackClient(JackData *jdata){
    float ring_buffer_size=0.0;
    int pid;
    char pidbuf[8];
    char rmd_client_name[32];

    //construct the jack client name
    //which is recordMyDesktop-pid
    //in order to allow multiple
    //instances of recordMyDesktop
    //to connetc to a Jack Server
    strcpy(rmd_client_name,"recordMyDesktop-");
    pid=getpid();
    I16TOA(pid,pidbuf)
    strcat(rmd_client_name,pidbuf);

    if(LoadJackLib(jdata->jack_lib_handle)){
        fprintf (stderr,"Couldn't load the Jack library (libjack.so)!\n");
        return 14;
    }
    if ((jdata->client=(*jack_client_new_p)(rmd_client_name))==0){
        fprintf(stderr,"Could not create new client!\n"
                       "Make sure that Jack server is running!\n");
        return 15;
    }
//in contrast to ALSA and OSS, Jack dictates frequency
//and buffersize to the values it was launched with.
//Supposedly jack_set_buffer_size can set the buffersize
//but that causes some kind of halt and keeps giving me
//zero buffers.
//recordMyDesktop cannot handle buffer size changes.
//FIXME
//There is a callback for buffer size changes that I should use.
//It will provide clean exits, instead of ?segfaults? .
//Continuing though is not possible, with the current layout
//(it might be in some cases, but it will certainly be the cause
//of unpredicted problems). A clean exit is preferable
//and any recording up to that point will be encoded and saved.
    jdata->frequency=jack_get_sample_rate_p(jdata->client);
    jdata->buffersize=jack_get_buffer_size_p(jdata->client);
    ring_buffer_size=(jdata->ringbuffer_secs*
                      jdata->frequency*
                      sizeof(jack_default_audio_sample_t)*
                      jdata->nports);
    jdata->sound_buffer=
        (*jack_ringbuffer_create_p)((int)(ring_buffer_size+0.5));//round up
    jack_set_process_callback_p(jdata->client,JackCapture,jdata);
    jack_on_shutdown_p(jdata->client,JackShutdown,jdata);

    if (jack_activate_p(jdata->client)) {
        fprintf(stderr,"cannot activate client!\n");
        return 16;
    }
    if(SetupPorts(jdata)){
        jack_client_close_p(jdata->client);
        return 17;
    }

    return 0;
}

int StopJackClient(JackData *jdata){
    int ret=0;

    (*jack_ringbuffer_free_p)(jdata->sound_buffer);
    if(jack_client_close_p(jdata->client)){
        fprintf(stderr,"Cannot close Jack client!\n");
        ret=1;
    }

/*TODO*/
//I need to make some kind of program/thread
//flow diagram to see where it's safe to dlclose
//because here it causes a segfault.

//     if(dlclose(jdata->jack_lib_handle)){
//         fprintf(stderr,"Cannot unload Jack library!\n");
//         ret=1;
//     }
//     else fprintf(stderr,"Unloaded Jack library.\n");

    return ret;
}

#endif