/**
 * OpenAL cross platform audio library
 * Copyright (C) 1999-2007 by authors.
 * This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 *  Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the
 *  Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 * Or go to http://www.gnu.org/copyleft/lgpl.html
 */

#include "config.h"

#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include <unistd.h>
#include <errno.h>
#include <math.h>

#include "alMain.h"
#include "alu.h"
#include "alconfig.h"
#include "threads.h"
#include "compat.h"

#include "backends/base.h"

#include <sys/audioio.h>


struct ALCsolarisBackend final : public ALCbackend {
    int fd;

    ALubyte *mix_data;
    int data_size;

    ATOMIC(ALenum) killNow;
    althrd_t thread;
};

static int ALCsolarisBackend_mixerProc(void *ptr);

static void ALCsolarisBackend_Construct(ALCsolarisBackend *self, ALCdevice *device);
static void ALCsolarisBackend_Destruct(ALCsolarisBackend *self);
static ALCenum ALCsolarisBackend_open(ALCsolarisBackend *self, const ALCchar *name);
static ALCboolean ALCsolarisBackend_reset(ALCsolarisBackend *self);
static ALCboolean ALCsolarisBackend_start(ALCsolarisBackend *self);
static void ALCsolarisBackend_stop(ALCsolarisBackend *self);
static DECLARE_FORWARD2(ALCsolarisBackend, ALCbackend, ALCenum, captureSamples, void*, ALCuint)
static DECLARE_FORWARD(ALCsolarisBackend, ALCbackend, ALCuint, availableSamples)
static DECLARE_FORWARD(ALCsolarisBackend, ALCbackend, ClockLatency, getClockLatency)
static DECLARE_FORWARD(ALCsolarisBackend, ALCbackend, void, lock)
static DECLARE_FORWARD(ALCsolarisBackend, ALCbackend, void, unlock)
DECLARE_DEFAULT_ALLOCATORS(ALCsolarisBackend)

DEFINE_ALCBACKEND_VTABLE(ALCsolarisBackend);


static const ALCchar solaris_device[] = "Solaris Default";

static const char *solaris_driver = "/dev/audio";


static void ALCsolarisBackend_Construct(ALCsolarisBackend *self, ALCdevice *device)
{
    new (self) ALCsolarisBackend{};
    ALCbackend_Construct(STATIC_CAST(ALCbackend, self), device);
    SET_VTABLE2(ALCsolarisBackend, ALCbackend, self);

    self->fd = -1;
    self->mix_data = nullptr;
    ATOMIC_INIT(&self->killNow, AL_FALSE);
}

static void ALCsolarisBackend_Destruct(ALCsolarisBackend *self)
{
    if(self->fd != -1)
        close(self->fd);
    self->fd = -1;

    free(self->mix_data);
    self->mix_data = nullptr;
    self->data_size = 0;

    ALCbackend_Destruct(STATIC_CAST(ALCbackend, self));
    self->~ALCsolarisBackend();
}


static int ALCsolarisBackend_mixerProc(void *ptr)
{
    ALCsolarisBackend *self = static_cast<ALCsolarisBackend*>(ptr);
    ALCdevice *device = STATIC_CAST(ALCbackend, self)->mDevice;
    struct timeval timeout;
    ALubyte *write_ptr;
    ALint frame_size;
    ALint to_write;
    ssize_t wrote;
    fd_set wfds;
    int sret;

    SetRTPriority();
    althrd_setname(althrd_current(), MIXER_THREAD_NAME);

    frame_size = FrameSizeFromDevFmt(device->FmtChans, device->FmtType, device->AmbiOrder);

    ALCsolarisBackend_lock(self);
    while(!ATOMIC_LOAD(&self->killNow, almemory_order_acquire) &&
          ATOMIC_LOAD(&device->Connected, almemory_order_acquire))
    {
        FD_ZERO(&wfds);
        FD_SET(self->fd, &wfds);
        timeout.tv_sec = 1;
        timeout.tv_usec = 0;

        ALCsolarisBackend_unlock(self);
        sret = select(self->fd+1, nullptr, &wfds, nullptr, &timeout);
        ALCsolarisBackend_lock(self);
        if(sret < 0)
        {
            if(errno == EINTR)
                continue;
            ERR("select failed: %s\n", strerror(errno));
            aluHandleDisconnect(device, "Failed to wait for playback buffer: %s", strerror(errno));
            break;
        }
        else if(sret == 0)
        {
            WARN("select timeout\n");
            continue;
        }

        write_ptr = self->mix_data;
        to_write = self->data_size;
        aluMixData(device, write_ptr, to_write/frame_size);
        while(to_write > 0 && !ATOMIC_LOAD_SEQ(&self->killNow))
        {
            wrote = write(self->fd, write_ptr, to_write);
            if(wrote < 0)
            {
                if(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
                    continue;
                ERR("write failed: %s\n", strerror(errno));
                aluHandleDisconnect(device, "Failed to write playback samples: %s",
                                    strerror(errno));
                break;
            }

            to_write -= wrote;
            write_ptr += wrote;
        }
    }
    ALCsolarisBackend_unlock(self);

    return 0;
}


static ALCenum ALCsolarisBackend_open(ALCsolarisBackend *self, const ALCchar *name)
{
    ALCdevice *device;

    if(!name)
        name = solaris_device;
    else if(strcmp(name, solaris_device) != 0)
        return ALC_INVALID_VALUE;

    self->fd = open(solaris_driver, O_WRONLY);
    if(self->fd == -1)
    {
        ERR("Could not open %s: %s\n", solaris_driver, strerror(errno));
        return ALC_INVALID_VALUE;
    }

    device = STATIC_CAST(ALCbackend,self)->mDevice;
    alstr_copy_cstr(&device->DeviceName, name);

    return ALC_NO_ERROR;
}

static ALCboolean ALCsolarisBackend_reset(ALCsolarisBackend *self)
{
    ALCdevice *device = STATIC_CAST(ALCbackend,self)->mDevice;
    audio_info_t info;
    ALsizei frameSize;
    ALsizei numChannels;

    AUDIO_INITINFO(&info);

    info.play.sample_rate = device->Frequency;

    if(device->FmtChans != DevFmtMono)
        device->FmtChans = DevFmtStereo;
    numChannels = ChannelsFromDevFmt(device->FmtChans, device->AmbiOrder);
    info.play.channels = numChannels;

    switch(device->FmtType)
    {
        case DevFmtByte:
            info.play.precision = 8;
            info.play.encoding = AUDIO_ENCODING_LINEAR;
            break;
        case DevFmtUByte:
            info.play.precision = 8;
            info.play.encoding = AUDIO_ENCODING_LINEAR8;
            break;
        case DevFmtUShort:
        case DevFmtInt:
        case DevFmtUInt:
        case DevFmtFloat:
            device->FmtType = DevFmtShort;
            /* fall-through */
        case DevFmtShort:
            info.play.precision = 16;
            info.play.encoding = AUDIO_ENCODING_LINEAR;
            break;
    }

    frameSize = numChannels * BytesFromDevFmt(device->FmtType);
    info.play.buffer_size = device->UpdateSize*device->NumUpdates * frameSize;

    if(ioctl(self->fd, AUDIO_SETINFO, &info) < 0)
    {
        ERR("ioctl failed: %s\n", strerror(errno));
        return ALC_FALSE;
    }

    if(ChannelsFromDevFmt(device->FmtChans, device->AmbiOrder) != (ALsizei)info.play.channels)
    {
        ERR("Failed to set %s, got %u channels instead\n", DevFmtChannelsString(device->FmtChans), info.play.channels);
        return ALC_FALSE;
    }

    if(!((info.play.precision == 8 && info.play.encoding == AUDIO_ENCODING_LINEAR8 && device->FmtType == DevFmtUByte) ||
         (info.play.precision == 8 && info.play.encoding == AUDIO_ENCODING_LINEAR && device->FmtType == DevFmtByte) ||
         (info.play.precision == 16 && info.play.encoding == AUDIO_ENCODING_LINEAR && device->FmtType == DevFmtShort) ||
         (info.play.precision == 32 && info.play.encoding == AUDIO_ENCODING_LINEAR && device->FmtType == DevFmtInt)))
    {
        ERR("Could not set %s samples, got %d (0x%x)\n", DevFmtTypeString(device->FmtType),
            info.play.precision, info.play.encoding);
        return ALC_FALSE;
    }

    device->Frequency = info.play.sample_rate;
    device->UpdateSize = (info.play.buffer_size/device->NumUpdates) + 1;

    SetDefaultChannelOrder(device);

    free(self->mix_data);
    self->data_size = device->UpdateSize * FrameSizeFromDevFmt(
        device->FmtChans, device->FmtType, device->AmbiOrder
    );
    self->mix_data = static_cast<ALubyte*>(calloc(1, self->data_size));

    return ALC_TRUE;
}

static ALCboolean ALCsolarisBackend_start(ALCsolarisBackend *self)
{
    ATOMIC_STORE_SEQ(&self->killNow, AL_FALSE);
    if(althrd_create(&self->thread, ALCsolarisBackend_mixerProc, self) != althrd_success)
        return ALC_FALSE;
    return ALC_TRUE;
}

static void ALCsolarisBackend_stop(ALCsolarisBackend *self)
{
    int res;

    if(ATOMIC_EXCHANGE_SEQ(&self->killNow, AL_TRUE))
        return;

    althrd_join(self->thread, &res);

    if(ioctl(self->fd, AUDIO_DRAIN) < 0)
        ERR("Error draining device: %s\n", strerror(errno));
}


struct ALCsolarisBackendFactory final : public ALCbackendFactory {
    ALCsolarisBackendFactory() noexcept;
};

ALCbackendFactory *ALCsolarisBackendFactory_getFactory(void);

static ALCboolean ALCsolarisBackendFactory_init(ALCsolarisBackendFactory *self);
static DECLARE_FORWARD(ALCsolarisBackendFactory, ALCbackendFactory, void, deinit)
static ALCboolean ALCsolarisBackendFactory_querySupport(ALCsolarisBackendFactory *self, ALCbackend_Type type);
static void ALCsolarisBackendFactory_probe(ALCsolarisBackendFactory *self, enum DevProbe type, al_string *outnames);
static ALCbackend* ALCsolarisBackendFactory_createBackend(ALCsolarisBackendFactory *self, ALCdevice *device, ALCbackend_Type type);
DEFINE_ALCBACKENDFACTORY_VTABLE(ALCsolarisBackendFactory);


ALCsolarisBackendFactory::ALCsolarisBackendFactory() noexcept
  : ALCbackendFactory{GET_VTABLE2(ALCsolarisBackendFactory, ALCbackendFactory)}
{ }

ALCbackendFactory *ALCsolarisBackendFactory_getFactory(void)
{
    static ALCsolarisBackendFactory factory{};
    return STATIC_CAST(ALCbackendFactory, &factory);
}


static ALCboolean ALCsolarisBackendFactory_init(ALCsolarisBackendFactory* UNUSED(self))
{
    ConfigValueStr(nullptr, "solaris", "device", &solaris_driver);
    return ALC_TRUE;
}

static ALCboolean ALCsolarisBackendFactory_querySupport(ALCsolarisBackendFactory* UNUSED(self), ALCbackend_Type type)
{
    if(type == ALCbackend_Playback)
        return ALC_TRUE;
    return ALC_FALSE;
}

static void ALCsolarisBackendFactory_probe(ALCsolarisBackendFactory* UNUSED(self), enum DevProbe type, al_string *outnames)
{
    switch(type)
    {
        case ALL_DEVICE_PROBE:
        {
#ifdef HAVE_STAT
            struct stat buf;
            if(stat(solaris_driver, &buf) == 0)
#endif
                alstr_append_range(outnames, solaris_device, solaris_device+sizeof(solaris_device));
        }
        break;

        case CAPTURE_DEVICE_PROBE:
            break;
    }
}

ALCbackend* ALCsolarisBackendFactory_createBackend(ALCsolarisBackendFactory* UNUSED(self), ALCdevice *device, ALCbackend_Type type)
{
    if(type == ALCbackend_Playback)
    {
        ALCsolarisBackend *backend;
        NEW_OBJ(backend, ALCsolarisBackend)(device);
        if(!backend) return nullptr;
        return STATIC_CAST(ALCbackend, backend);
    }

    return nullptr;
}