/***
  This file is part of PulseAudio.

  Copyright 2004-2008 Lennart Poettering

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2.1 of the License,
  or (at your option) any later version.

  PulseAudio 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 Lesser General Public License
  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

#include <pulse/rtclock.h>
#include <pulse/timeval.h>
#include <pulse/xmalloc.h>

#include <pulsecore/i18n.h>
#include <pulsecore/macro.h>
#include <pulsecore/sink.h>
#include <pulsecore/module.h>
#include <pulsecore/core-util.h>
#include <pulsecore/modargs.h>
#include <pulsecore/log.h>
#include <pulsecore/thread.h>
#include <pulsecore/thread-mq.h>
#include <pulsecore/rtpoll.h>

#include <aaudio/AAudio.h>

PA_MODULE_AUTHOR("Tom Yan");
PA_MODULE_DESCRIPTION("Android AAudio sink");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(false);
PA_MODULE_USAGE(
    "sink_name=<name for the sink> "
    "sink_properties=<properties for the sink> "
    "rate=<sampling rate> "
    "latency=<buffer length> "
    "no_close_hack=<avoid segfault caused by AAudioStream_close()> "
);

#define DEFAULT_SINK_NAME "AAudio sink"

struct userdata {
    pa_core *core;
    pa_module *module;
    pa_sink *sink;

    pa_thread *thread;
    pa_thread_mq thread_mq;
    pa_rtpoll *rtpoll;

    uint32_t latency;
    uint32_t rate;
    bool no_close;

    pa_memchunk memchunk;
    size_t frame_size;

    AAudioStreamBuilder *builder;
    AAudioStream *stream;
    pa_sample_spec ss;
};

static const char* const valid_modargs[] = {
    "sink_name",
    "sink_properties",
    "rate",
    "latency",
    "no_close_hack",
    NULL
};

static void update_latency(struct userdata *u) {
    pa_usec_t block_usec;

    if(!u->latency) {
        block_usec = PA_USEC_PER_SEC * AAudioStream_getBufferSizeInFrames(u->stream) / u->sink->sample_spec.rate / 2;
        if(!pa_thread_mq_get())
            pa_sink_set_fixed_latency(u->sink, block_usec);
        else
            pa_sink_set_fixed_latency_within_thread(u->sink, block_usec);
    }
}

static aaudio_data_callback_result_t buffer_callback(AAudioStream *stream, void *userdata, void *audioData, int32_t numFrames) {
    struct userdata* u = userdata;

    pa_assert(u);

    if (!pa_thread_mq_get()) {
        pa_log_debug("Thread starting up");
        pa_thread_mq_install(&u->thread_mq);
    }

    u->memchunk.memblock = pa_memblock_new_fixed(u->core->mempool, audioData, numFrames * u->frame_size, false);
    u->memchunk.length = numFrames * u->frame_size;
    pa_sink_render_into_full(u->sink, &u->memchunk);
    pa_memblock_unref_fixed(u->memchunk.memblock);

    return AAUDIO_CALLBACK_RESULT_CONTINUE;
}

static void error_callback(AAudioStream *stream, void *userdata, aaudio_result_t error) {
    struct userdata* u = userdata;

    pa_assert(u);

    if (error == AAUDIO_ERROR_DISCONNECTED) {
        if (!pa_thread_mq_get()) {
            pa_sink_suspend(u->sink, true, PA_SUSPEND_UNAVAILABLE);
            pa_sink_suspend(u->sink, false, PA_SUSPEND_UNAVAILABLE);
        } else {
            AAudioStream_requestStop(u->stream);
            AAudioStream_requestStart(u->stream);
            update_latency(u);
            pa_log("Failed to reconfigure sink for new device.\n");
        }
    }
}

#define CHK(stmt) { \
    aaudio_result_t res = stmt; \
    if (res != AAUDIO_OK) { \
        fprintf(stderr, "error %d at %s:%d\n", res, __FILE__, __LINE__); \
        goto fail; \
    } \
}

static int pa_open_aaudio_stream(struct userdata *u)
{
    bool want_float;
    aaudio_format_t format;
    pa_sample_spec *ss = &u->ss;

    CHK(AAudio_createStreamBuilder(&u->builder));
    AAudioStreamBuilder_setPerformanceMode(u->builder, AAUDIO_PERFORMANCE_MODE_LOW_LATENCY);
    AAudioStreamBuilder_setDataCallback(u->builder, buffer_callback, u);
    AAudioStreamBuilder_setErrorCallback(u->builder, error_callback, u);

    want_float = ss->format > PA_SAMPLE_S16BE;
    ss->format = want_float ? PA_SAMPLE_FLOAT32LE : PA_SAMPLE_S16LE;
    format = want_float ? AAUDIO_FORMAT_PCM_FLOAT : AAUDIO_FORMAT_PCM_I16;
    AAudioStreamBuilder_setFormat(u->builder, format);

    if (u->rate)
        AAudioStreamBuilder_setSampleRate(u->builder, u->rate);

    AAudioStreamBuilder_setChannelCount(u->builder, ss->channels);

    CHK(AAudioStreamBuilder_openStream(u->builder, &u->stream));
    CHK(AAudioStreamBuilder_delete(u->builder));

    ss->rate = AAudioStream_getSampleRate(u->stream);
    u->frame_size = pa_frame_size(ss);

    return 0;

fail:
    return -1;
}

#undef CHK

static void thread_func(void *userdata) {
    struct userdata *u = userdata;

    pa_assert(u);

    pa_log_debug("Thread starting up");
    pa_thread_mq_install(&u->thread_mq);

    for (;;) {
        int ret;

        if (PA_SINK_IS_LINKED(u->sink->thread_info.state)) {
            AAudioStream_requestStart(u->stream);
            update_latency(u);
            break;
        }

        /* Hmm, nothing to do. Let's sleep */
        if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
            goto fail;

        if (ret == 0)
            goto finish;
    }

    for (;;) {
        int ret;

        /* Hmm, nothing to do. Let's sleep */
        if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
            goto fail;

        if (ret == 0)
            goto finish;
    }

fail:
    /* If this was no regular exit from the loop we have to continue
     * processing messages until we received PA_MESSAGE_SHUTDOWN */
    pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
    pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);

finish:
    pa_log_debug("Thread shutting down");
}

static int state_func(pa_sink *s, pa_sink_state_t state, pa_suspend_cause_t suspend_cause) {
    struct userdata *u = s->userdata;
    int r = 0;
    uint32_t idx;
    pa_sink_input *i;
    pa_idxset *inputs;

    if ((PA_SINK_IS_OPENED(s->state) && state == PA_SINK_SUSPENDED) ||
        (PA_SINK_IS_LINKED(s->state) && state == PA_SINK_UNLINKED)) {
        if (u->no_close) {
            AAudioStream_requestStop(u->stream);
        } else {
            AAudioStream_close(u->stream);
        }
    } else if (s->state == PA_SINK_SUSPENDED && PA_SINK_IS_OPENED(state)) {
        pa_open_aaudio_stream(u);

        inputs = pa_idxset_copy(s->inputs, NULL);
        PA_IDXSET_FOREACH(i, inputs, idx) {
            if (i->state == PA_SINK_INPUT_RUNNING) {
                pa_sink_input_cork(i, true);
            } else {
                pa_idxset_remove_by_index(inputs, idx);
            }
        }

        s->alternate_sample_rate = u->ss.rate;
        pa_sink_reconfigure(s, &u->ss, false);
        s->default_sample_rate = u->ss.rate;

        /* Avoid infinite loop triggered if uncork in this case */
        if (s->suspend_cause == PA_SUSPEND_IDLE)
            pa_sink_suspend(u->sink, true, PA_SUSPEND_UNAVAILABLE);

        PA_IDXSET_FOREACH(i, inputs, idx) pa_sink_input_cork(i, false);
        pa_idxset_free(inputs, NULL);

        AAudioStream_requestStart(u->stream);
        update_latency(u);
    }
    return r;
}

static int reconfigure_func(pa_sink *s, pa_sample_spec *ss, bool passthrough) {
    s->sample_spec.rate = ss->rate;
    return 0;
}

static void process_rewind(pa_sink *s) {
    pa_sink_process_rewind(s, 0);
}

int pa__init(pa_module*m) {
    struct userdata *u = NULL;
    pa_channel_map map;
    pa_modargs *ma = NULL;
    pa_sink_new_data data;
    pa_usec_t block_usec;

    pa_assert(m);

    m->userdata = u = pa_xnew0(struct userdata, 1);

    u->core = m->core;
    u->module = m;
    u->rtpoll = pa_rtpoll_new();
    pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);

    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
        pa_log("Failed to parse module arguments.");
        goto fail;
    }

    u->ss = m->core->default_sample_spec;
    map = m->core->default_channel_map;
    pa_modargs_get_sample_rate(ma, &u->rate);

    pa_modargs_get_value_boolean(ma, "no_close_hack", &u->no_close);

    if (pa_open_aaudio_stream(u) < 0)
        goto fail;

    pa_sink_new_data_init(&data);
    data.driver = __FILE__;
    data.module = m;
    pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
    pa_sink_new_data_set_sample_spec(&data, &u->ss);
    pa_sink_new_data_set_alternate_sample_rate(&data, u->ss.rate);
    pa_sink_new_data_set_channel_map(&data, &map);
    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, _("AAudio Output"));
    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");

    if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
        pa_log("Invalid properties");
        pa_sink_new_data_done(&data);
        goto fail;
    }

    u->sink = pa_sink_new(m->core, &data, 0);
    pa_sink_new_data_done(&data);

    if (!u->sink) {
        pa_log("Failed to create sink object.");
        goto fail;
    }

    u->sink->parent.process_msg = pa_sink_process_msg;
    u->sink->set_state_in_main_thread = state_func;
    u->sink->reconfigure = reconfigure_func;
    u->sink->request_rewind = process_rewind;
    u->sink->userdata = u;

    pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
    pa_sink_set_rtpoll(u->sink, u->rtpoll);

    pa_modargs_get_value_u32(ma, "latency", &u->latency);
    if (u->latency) {
        block_usec = PA_USEC_PER_MSEC * u->latency;
        pa_sink_set_fixed_latency(u->sink, block_usec);
    }

    if (!(u->thread = pa_thread_new("aaudio-sink", thread_func, u))) {
        pa_log("Failed to create thread.");
        goto fail;
    }

    pa_sink_put(u->sink);

    pa_modargs_free(ma);

    return 0;

fail:
    if (ma)
        pa_modargs_free(ma);

    pa__done(m);

    return -1;
}

int pa__get_n_used(pa_module *m) {
    struct userdata *u;

    pa_assert(m);
    pa_assert_se(u = m->userdata);

    return pa_sink_linked_by(u->sink);
}

void pa__done(pa_module*m) {
    struct userdata *u;

    pa_assert(m);

    if (!(u = m->userdata))
        return;

    if (u->sink)
        pa_sink_unlink(u->sink);

    if (u->thread) {
        pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
        pa_thread_free(u->thread);
    }

    pa_thread_mq_done(&u->thread_mq);

    if (u->sink)
        pa_sink_unref(u->sink);

    if (u->rtpoll)
        pa_rtpoll_free(u->rtpoll);

    pa_xfree(u);
}