/*
 * Copyright (C) 2018 "IoT.bzh"
 * Author Fulup Ar Foll <fulup@iot.bzh>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#define _GNU_SOURCE  // needed for vasprintf

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/ioctl.h>

#include "alsa-softmixer.h"

// extracted IOCTLs from <alsa/asoundlib.h>
#define _IOR_HACKED(type,nr,size)       _IOC(_IOC_READ,(type),(nr),size)
#define SNDRV_CTL_IOCTL_CARD_INFO(size) _IOR_HACKED('U', 0x01, size)


// Clone of AlsaLib snd_card_load2 static function
PUBLIC snd_ctl_card_info_t *AlsaByPathInfo (CtlSourceT *source, const char *devpath) {
    int open_dev;
    snd_ctl_card_info_t *cardInfo = malloc(snd_ctl_card_info_sizeof());

    if (!devpath) goto OnErrorExit;
    
    open_dev = open(devpath, O_RDONLY);
    if (open_dev < 0) goto OnErrorExit;
    
    int rc = ioctl(open_dev, SNDRV_CTL_IOCTL_CARD_INFO(snd_ctl_card_info_sizeof()), cardInfo);
    if (rc < 0) {
        close(open_dev);
        goto OnErrorExit;
    }
        
    close(open_dev);
    return cardInfo;
    
OnErrorExit:
    AFB_ApiError(source->api,"AlsaCardInfoByPath: fail to find sndcard by path= %s", devpath);
    return NULL;
}

PUBLIC snd_pcm_t* AlsaByPathOpenPcm(CtlSourceT *source, AlsaDevByPathT *dev, snd_pcm_stream_t direction) {
    char pcmName[32];
    int error;
    snd_pcm_t *pcmHandle;

    // get card info from /dev/snd/xxx if not use hw:x,x,x
    snd_ctl_card_info_t *cardInfo=NULL;
    if (dev->devpath) cardInfo = AlsaByPathInfo(source, dev->devpath);
    else if (dev->devid) cardInfo = AlsaCtlGetInfo (source, dev->devid);

    if (!cardInfo) {
        AFB_ApiError(source->api, "AlsaByPathOpenPcm: fail to find sndcard by path=%s id=%s", dev->devpath, dev->devid);
        goto OnErrorExit;
    }

    // extract useful info from cardInfo handle
    int cardIdx = snd_ctl_card_info_get_card(cardInfo);
    const char *cardName = snd_ctl_card_info_get_name(cardInfo);

    // build a valid name and open sndcard
    snprintf(pcmName, sizeof (pcmName), "hw:%i,%i,%i", cardIdx, dev->device, dev->subdev);
    error = snd_pcm_open(&pcmHandle, pcmName, direction, SND_PCM_NONBLOCK);
    if (error) {
        AFB_ApiError(source->api, "AlsaByPathOpenPcm: fail openpcm (hw:%d -> %s name=%i subdev=%d): %s"
                , cardIdx, cardName, dev->device, dev->subdev, snd_strerror(error));
        goto OnErrorExit;
    }
       
    return (pcmHandle);

OnErrorExit:
    return NULL;
}

PUBLIC snd_ctl_t *AlsaByPathOpenCtl (CtlSourceT *source, AlsaDevByPathT *dev) {
    int err;
    char devid[32];
    snd_ctl_t *handle;
    
    // get card info from /dev/snd/xxx if not use hw:x,x,x
    snd_ctl_card_info_t *cardInfo=NULL;
    if (dev->devpath) cardInfo = AlsaByPathInfo(source, dev->devpath);
    else if (dev->devid) cardInfo = AlsaCtlGetInfo (source, dev->devid);

    if (!cardInfo) {
        AFB_ApiError(source->api, "AlsaByPathOpenCtl: fail to find sndcard by path=%s id=%s", dev->devpath, dev->devid);
        goto OnErrorExit;
    }
    
    // extract useful info from cardInfo handle
    int cardIndex = snd_ctl_card_info_get_card(cardInfo);
    const char *cardId = snd_ctl_card_info_get_id(cardInfo);
    const char *cardName = snd_ctl_card_info_get_name(cardInfo);

    // build a valid name and open sndcard
    snprintf(devid, sizeof (devid), "hw:%i", cardIndex);
    if ((err = snd_ctl_open(&handle, devid, 0)) < 0) {
        AFB_ApiError(source->api,"control open (hw:%d -> %s): %s", cardIndex, cardName, snd_strerror(err));
        goto OnErrorExit;
    }

    AFB_ApiNotice(source->api, "AlsaCtlOpenByPath: sndcard hw:%d id=%s name=%s", cardIndex, cardId, cardName);
    free (cardInfo);
    return handle;
    
OnErrorExit:
    return NULL;
}