/***
  This file is part of PulseAudio.

  Copyright 2006 Lennart Poettering
  Copyright 2017 BenjMIn Berg

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

#include <pulsecore/core.h>
#include <pulsecore/core-util.h>
#include <pulsecore/sink-input.h>
#include <pulsecore/source-output.h>
#include <pulsecore/modargs.h>
#include <pulsecore/log.h>

#include "module-prevent-dpms-off-symdef.h"

PA_MODULE_AUTHOR("Benjamin Berg");
PA_MODULE_DESCRIPTION("Signal to graphical session that displays should not be suspended using DPMS");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(true);

/*
 * This module signals that DPMS should not happen if a sink is not suspended
 * and device.requires.no_dpms_off is set on the active port (prefered) or on
 * the sink/source itself.
 *
 * Note that the sink might not be suspended for short periods of time even
 * though no playback is happening. This module does not special case these
 * corner cases for the sake of simplicity.
 *
 * As such the following events are relevant:
 *  - SINK/SOURCE state change
 *  - SINK/SOURCE unlinking
 *  - SINK/SOURCE port changes
 *  - SINK/SOURCE proplist changes
 *
 * The device.requires.no_dpms_off property is only checked when a sink/source
 * becomes active.
 */

static const char* const valid_modargs[] = {
    NULL,
};

struct userdata {
    pa_core *core;
    pa_hashmap *inhibit_infos;
};

struct dpms_inhibit_info {
    struct userdata *userdata;
    pa_sink *sink;
    pa_source *source;

    /* also store e.g. cookie or similar to uninhibit */
};

static void inhibit_dpms(struct userdata *u, pa_sink *sink, pa_source *source)
{
    struct dpms_inhibit_info *d;

    if (sink && !pa_hashmap_get(u->inhibit_infos, sink)) {
        d = pa_xnew(struct dpms_inhibit_info, 1);

        d->userdata = u;
        d->source = NULL;
        d->sink = pa_sink_ref(sink);

        pa_hashmap_put(u->inhibit_infos, sink, d);

        pa_log_info("Sink %s is now inhibiting DPMS power management of monitors.", d->sink->name);
    }
    if (source && (d = pa_hashmap_get(u->inhibit_infos, source))) {
        d = pa_xnew(struct dpms_inhibit_info, 1);

        d->userdata = u;
        d->source = pa_source_ref(source);
        d->sink = NULL;

        pa_hashmap_remove_and_free(u->inhibit_infos, sink);

        pa_log_info("Source %s is now inhibiting DPMS power management of monitors.", d->source->name);
    }
}

static void uninhibit_dpms(struct userdata *u, pa_sink *sink, pa_source *source)
{
    struct dpms_inhibit_info *d;

    if (sink && (d = pa_hashmap_get(u->inhibit_infos, sink))) {
        pa_log_info("Sink %s is no longer inhibiting DPMS power management of monitors.", d->sink->name);

        pa_hashmap_remove_and_free(u->inhibit_infos, sink);
    }
    if (source && (d = pa_hashmap_get(u->inhibit_infos, source))) {
        pa_log_info("Source %s is no longer inhibiting DPMS power management of monitors.", d->source->name);

        pa_hashmap_remove_and_free(u->inhibit_infos, sink);
    }
}

static void sync_dpms_inhibit_state(struct userdata *u, bool active, pa_sink *sink, pa_source *source)
{
    bool inhibit;

    pa_assert(source || sink);

    if (active) {
        const char *prop_str = NULL;
        pa_device_port *port;
        inhibit = true;

        port = sink ? sink->active_port : source->active_port;
        if (port)
            prop_str = pa_proplist_gets(port->proplist, PA_PROP_DEVICE_REQUIRES_NO_DPMS_OFF);
        if (!prop_str)
            prop_str = pa_proplist_gets(sink ? sink->proplist : source->proplist, PA_PROP_DEVICE_REQUIRES_NO_DPMS_OFF);

        /* Not set or set to boolean FALSE (or invalid). */
        if (!prop_str || pa_parse_boolean(prop_str) <= 0)
           inhibit = false;
    } else {
        inhibit = false;
    }

    if (inhibit)
        inhibit_dpms(u, sink, source);
    else
        uninhibit_dpms(u, sink, source);
}

static pa_hook_result_t device_unlink_hook_cb(pa_core *c, pa_object *o, struct userdata *u) {
    pa_assert(c);
    pa_object_assert_ref(o);
    pa_assert(u);

    if (pa_sink_isinstance(o)) {
        pa_sink *s = PA_SINK(o);

        uninhibit_dpms(u, s, NULL);
    } else if (pa_source_isinstance(o)) {
        pa_source *s = PA_SOURCE(o);

        uninhibit_dpms(u, NULL, s);
    }

    return PA_HOOK_OK;
}

static pa_hook_result_t device_recheck_dpms_inhibit_state(pa_core *c, pa_object *o, struct userdata *u) {
    pa_assert(c);
    pa_object_assert_ref(o);
    pa_assert(u);

    if (pa_sink_isinstance(o)) {
        pa_sink *s = PA_SINK(o);
        pa_sink_state_t state = pa_sink_get_state(s);

        sync_dpms_inhibit_state(u, PA_SINK_IS_OPENED(state), s, NULL);

    } else if (pa_source_isinstance(o)) {
        pa_source *s = PA_SOURCE(o);
        pa_source_state_t state = pa_source_get_state(s);

        sync_dpms_inhibit_state(u, PA_SOURCE_IS_OPENED(state), NULL, s);
    }

    return PA_HOOK_OK;
}

static void dpms_inhibit_info_free(struct dpms_inhibit_info *d) {
    pa_assert(d);

    if (d->source)
        pa_source_unref(d->source);
    if (d->sink)
        pa_sink_unref(d->sink);

    pa_xfree(d);
}

int pa__init(pa_module*m) {
    pa_modargs *ma = NULL;
    struct userdata *u;
    uint32_t idx;
    pa_sink *sink;
    pa_source *source;

    pa_assert(m);

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

    m->userdata = u = pa_xnew(struct userdata, 1);
    u->core = m->core;
    u->inhibit_infos = pa_hashmap_new_full(pa_idxset_trivial_hash_func, pa_idxset_trivial_compare_func, NULL, (pa_free_cb_t) dpms_inhibit_info_free);

    PA_IDXSET_FOREACH(sink, m->core->sinks, idx)
        device_recheck_dpms_inhibit_state(m->core, PA_OBJECT(sink), u);

    PA_IDXSET_FOREACH(source, m->core->sources, idx)
        device_recheck_dpms_inhibit_state(m->core, PA_OBJECT(source), u);

    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SINK_UNLINK_POST], PA_HOOK_NORMAL, (pa_hook_cb_t) device_unlink_hook_cb, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_UNLINK_POST], PA_HOOK_NORMAL, (pa_hook_cb_t) device_unlink_hook_cb, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SINK_STATE_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_STATE_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SINK_PORT_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_PORT_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SINK_PROPLIST_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_PROPLIST_CHANGED], PA_HOOK_NORMAL, (pa_hook_cb_t) device_recheck_dpms_inhibit_state, u);
    /* There is no PA_CORE_HOOK_PORT_PROPLIST_CHANGED */

    pa_modargs_free(ma);
    return 0;

fail:

    if (ma)
        pa_modargs_free(ma);

    return -1;
}

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

    pa_assert(m);

    if (!m->userdata)
        return;

    u = m->userdata;

    PA_HASHMAP_FOREACH(d, u->inhibit_infos, state) {
        if (d->sink) {
            pa_log_info("Uninhibiting DPMS off for sink %s on module unload.", d->sink->name);
        }

        if (d->source) {
            pa_log_info("Uninhibiting DPMS off for source %s on module unload.", d->source->name);
        }
    }

    pa_hashmap_free(u->inhibit_infos);

    pa_xfree(u);
}