/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

//#define USE_ERROR

//#define USE_TRACE

#include "PLATFORM_API_LinuxOS_ALSA_CommonUtils.h"

static void alsaDebugOutput(const char *file, int line, const char *function, int err, const char *fmt, ...) {

#ifdef USE_ERROR

    va_list args;

    va_start(args, fmt);

    printf("%s:%d function %s: error %d: %s\n", file, line, function, err, snd_strerror(err));

    if (strlen(fmt) > 0) {

        vprintf(fmt, args);

    }

    va_end(args);

#endif

}

static int alsa_inited = 0;

static int alsa_enumerate_pcm_subdevices = FALSE; // default: no

static int alsa_enumerate_midi_subdevices = FALSE; // default: no

void initAlsaSupport() {

    char* enumerate;

    if (!alsa_inited) {

        alsa_inited = TRUE;

        snd_lib_error_set_handler(&alsaDebugOutput);

        enumerate = getenv(ENV_ENUMERATE_PCM_SUBDEVICES);

        if (enumerate != NULL && strlen(enumerate) > 0

            && (enumerate[0] != 'f')   // false

            && (enumerate[0] != 'F')   // False

            && (enumerate[0] != 'n')   // no

            && (enumerate[0] != 'N')) { // NO

            alsa_enumerate_pcm_subdevices = TRUE;

        }

#ifdef ALSA_MIDI_ENUMERATE_SUBDEVICES

        alsa_enumerate_midi_subdevices = TRUE;

#endif

    }

}

/* if true (non-zero), ALSA sub devices should be listed as separate devices

 */

int needEnumerateSubdevices(int isMidi) {

    initAlsaSupport();

    return isMidi ? alsa_enumerate_midi_subdevices

                  : alsa_enumerate_pcm_subdevices;

}

/*

 * deviceID contains packed card, device and subdevice numbers

 * each number takes 10 bits

 * "default" device has id == ALSA_DEFAULT_DEVICE_ID

 */

UINT32 encodeDeviceID(int card, int device, int subdevice) {

    return (((card & 0x3FF) << 20) | ((device & 0x3FF) << 10)

           | (subdevice & 0x3FF)) + 1;

}

void decodeDeviceID(UINT32 deviceID, int* card, int* device, int* subdevice,

                    int isMidi) {

    deviceID--;

    *card = (deviceID >> 20) & 0x3FF;

    *device = (deviceID >> 10) & 0x3FF;

    if (needEnumerateSubdevices(isMidi)) {

        *subdevice = deviceID  & 0x3FF;

    } else {

        *subdevice = -1; // ALSA will choose any subdevices

    }

}

void getDeviceString(char* buffer, int card, int device, int subdevice,

                     int usePlugHw, int isMidi) {

    if (needEnumerateSubdevices(isMidi)) {

        sprintf(buffer, "%s:%d,%d,%d",

                        usePlugHw ? ALSA_PLUGHARDWARE : ALSA_HARDWARE,

                        card, device, subdevice);

    } else {

        sprintf(buffer, "%s:%d,%d",

                        usePlugHw ? ALSA_PLUGHARDWARE : ALSA_HARDWARE,

                        card, device);

    }

}

void getDeviceStringFromDeviceID(char* buffer, UINT32 deviceID,

                                 int usePlugHw, int isMidi) {

    int card, device, subdevice;

    if (deviceID == ALSA_DEFAULT_DEVICE_ID) {

        strcpy(buffer, ALSA_DEFAULT_DEVICE_NAME);

    } else {

        decodeDeviceID(deviceID, &card, &device, &subdevice, isMidi);

        getDeviceString(buffer, card, device, subdevice, usePlugHw, isMidi);

    }

}

static int hasGottenALSAVersion = FALSE;

#define ALSAVersionString_LENGTH 200

static char ALSAVersionString[ALSAVersionString_LENGTH];

void getALSAVersion(char* buffer, int len) {

    if (!hasGottenALSAVersion) {

        // get alsa version from proc interface

        FILE* file;

        int curr, len, totalLen, inVersionString;

        file = fopen(ALSA_VERSION_PROC_FILE, "r");

        ALSAVersionString[0] = 0;

        if (file) {

            if (NULL != fgets(ALSAVersionString, ALSAVersionString_LENGTH, file)) {

                // parse for version number

                totalLen = strlen(ALSAVersionString);

                inVersionString = FALSE;

                len = 0;

                curr = 0;

                while (curr < totalLen) {

                    if (!inVersionString) {

                        // is this char the beginning of a version string ?

                        if (ALSAVersionString[curr] >= '0'

                            && ALSAVersionString[curr] <= '9') {

                            inVersionString = TRUE;

                        }

                    }

                    if (inVersionString) {

                        // the version string ends with white space

                        if (ALSAVersionString[curr] <= 32) {

                            break;

                        }

                        if (curr != len) {

                            // copy this char to the beginning of the string

                            ALSAVersionString[len] = ALSAVersionString[curr];

                        }

                        len++;

                    }

                    curr++;

                }

                // remove trailing dots

                while ((len > 0) && (ALSAVersionString[len - 1] == '.')) {

                    len--;

                }

                // null terminate

                ALSAVersionString[len] = 0;

            }

            fclose(file);

            hasGottenALSAVersion = TRUE;

        }

    }

    strncpy(buffer, ALSAVersionString, len);

}

/* end */