/*
 * Copyright (C) 2018 "IoT.bzh"
 * Author Loïc Collignon <loic.collignon@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.
 */

#include <algorithm>
#include "role.hpp"
#include "jsonc_utils.hpp"
#include "ahl-binding.hpp"

using session_t = std::vector<role_t*>;

inline restype_t fromstring(const std::string& str)
{
    if (str == "" || str == "stream") return restype_t::stream;
    if (str == "playback") return restype_t::playback;
    if (str == "control") return restype_t::control;

    std::stringstream ss;
    ss << "Unknown resource type: " << str;
    throw std::runtime_error(ss.str());
}

role_t::role_t(json_object* j)
{
    rtype_ = restype_t::stream;

    jcast(uid_, j, "uid");
    jcast(description_, j, "description");
    jcast(priority_, j, "priority");
    jcast(resource_, j, "resource");
    jcast_array(interrupts_, j, "interrupts");

    std::string type;
    jcast(type, j, "type");
    rtype_ = fromstring(type);

    // device_uri_ = (rtype_ == restype_t::stream) ? "" : resource_;
    if (rtype_ == restype_t::control)
    {
        device_uri_ = resource_;
        hal_ = "4a-hal-csl-cm106-8ch-usb";
    }
    opened_ = false;
}

role_t& role_t::operator<<(json_object* j)
{
    rtype_ = restype_t::stream;

    jcast(uid_, j, "uid");
    jcast(description_, j, "description");
    jcast(priority_, j, "priority");
    jcast(resource_, j, "resource");
    jcast_array(interrupts_, j, "interrupts");

    std::string type;
    jcast(type, j, "type");
    rtype_ = fromstring(type);

    // device_uri_ = (rtype_ == restype_t::stream) ? "" : resource_;
    return *this;
}

std::string role_t::uid() const
{
    return uid_;
}

std::string role_t::description() const
{
    return description_;
}

std::string role_t::hal() const
{
    return hal_;
}

std::string role_t::resource() const
{
    return resource_;
}

restype_t role_t::rtype() const
{
    return rtype_;
}

int role_t::priority() const
{
    return priority_;
}

const std::vector<interrupt_t>& role_t::interrupts() const
{
    return interrupts_;
}

std::string role_t::device_uri() const
{
    return device_uri_;
}

bool role_t::opened() const
{
    return opened_;
}

void role_t::uid(std::string v)
{
    uid_ = v;
}

void role_t::description(std::string v)
{
    description_ = v;
}

void role_t::hal(std::string v)
{
    hal_ = v;
}

void role_t::resource(std::string v)
{
    resource_ = v;
}

void role_t::rtype(restype_t v)
{
    rtype_ = v;
}

void role_t::priority(int v)
{
    priority_ = v;
}

void role_t::device_uri(std::string v)
{
    device_uri_ = v;
}

int role_t::apply_policy(afb_req_t req)
{
    return interrupts_.size() ? interrupts_[0].apply(req, *this) : 0;
}

void role_t::invoke(afb_req_t req)
{
    json_object* arg = afb_req_json(req);
    if (arg == nullptr)
    {
        afb_req_fail(req, "No valid argument!", nullptr);
        return;
    }

    json_object* jaction;
    json_bool ret = json_object_object_get_ex(arg, "action", &jaction);
    if (!ret)
    {
        afb_req_fail(req, "No valid action!", nullptr);
        return;
    }

    std::string action = json_object_get_string(jaction);
    if (action.size() == 0)
    {
        afb_req_fail(req, "No valid action!", nullptr);
        return;
    }

         if (action == "open")      open(req, arg);
    else if (action == "close")     close(req, arg);
    else if (action == "volume")    volume(req, arg);
    else if (action == "interrupt") interrupt(req, arg);
    else if (action == "mute")      mute(req, arg);
    else if (action == "unmute")    unmute(req, arg);
    else afb_req_fail(req, "Unknown action!", nullptr);
}

void role_t::open(afb_req_t r, json_object* o)
{
    if (opened_)
    {
        afb_req_fail(r, "Already opened!", nullptr);
        return;
    }

    if (rtype_ != restype_t::stream)
    {
        afb_req_fail(r, "Only stream resources can be opened!", nullptr);
    }
    else if (!apply_policy(r))
    {
        afb_req_context(r,
            0, // Do not replace previous context if any
            [](void* arg) -> void* { return new session_t(); },
            [](void* arg) {
                afb_api_t api = ahl_binding_t::instance().handle();
                session_t* opened_roles = reinterpret_cast<session_t*>(arg);
                for(role_t* role : *opened_roles)
                {
                    AFB_API_DEBUG(api, "Released role %s\n", role->uid_.c_str());
                    role->opened_ = false;
                    if(role->interrupts_.size()) role->interrupts_[0].clear();

                    // send a mute command to the HAL. We cannot reuse the do_mute function,
                    // because in the context here, the afb_request is no longer valid.
                    json_object* a = json_object_new_object();
                    json_object_object_add(a, "mute", json_object_new_boolean(true));

                    afb_api_call(
                        api,
                        role->hal_.c_str(),
                        role->resource_.c_str(),
                        a,
                        NULL,
                        NULL);
                }
                delete opened_roles;
            },
            nullptr
        );

        opened_ = true;

        // Add the current role to the session
        session_t* context = reinterpret_cast<session_t*>(afb_req_context_get(r));
        if(context) context->push_back(this);

        json_object* result = json_object_new_object();
        json_object_object_add(result, "device_uri", json_object_new_string(device_uri_.c_str()));

        afb_req_success(r, result, nullptr);
    }
}

void role_t::close(afb_req_t r, json_object* o)
{
    if (!opened_)
    {
        afb_req_success(r, nullptr, "Already closed!");
        return;
    }

    session_t* context = reinterpret_cast<session_t*>(afb_req_context_get(r));
    if(!context)
    {
        afb_req_fail(r, "Stream is opened by another client!", nullptr);
        return;
    }

    // Remove the current role from the session.
    std::string uid = uid_;
    std::remove_if(context->begin(), context->end(), [uid](role_t* r) { return r->uid_ == uid; });
    context->push_back(this);

    opened_ = false;
    if(interrupts_.size()) interrupts_[0].clear();
    afb_req_success(r, nullptr, "Stream closed!");
}

void role_t::mute(afb_req_t r, json_object* o) {
    if (rtype_ != restype_t::stream) afb_req_fail(r, "Only stream resource can be muted!", nullptr);
    else do_mute(r, true);
}

void role_t::unmute(afb_req_t r, json_object  *o) {
    if (rtype_ != restype_t::stream) afb_req_fail(r, "Only stream resource can be unmuted!", nullptr);
    else do_mute(r, false);
}

void role_t::do_mute(afb_req_t r, bool v) {

    json_object* a = json_object_new_object();
    json_object_object_add(a, "mute", json_object_new_boolean(v));
    afb_api_t api = ahl_binding_t::instance().handle();

    afb_api_call(
        api,
        hal_.c_str(),
        resource_.c_str(),
        a,
        [](void* closure, json_object* result, const char* error, const char* info, afb_api_t handle)
        {
            AFB_API_DEBUG(handle, "Got the following answer: %s", json_object_to_json_string(result));
            afb_req_t r = (afb_req_t)closure;

            json_object_get(result);
            if (error) afb_req_fail(r, json_object_to_json_string(result), nullptr);
            else afb_req_success(r, result, nullptr);
            afb_req_unref(r);
        },
        afb_req_addref(r));
}

struct volumeclosure
{
    role_t* role;
    afb_req_t req;
};

void role_t::volume(afb_req_t r, json_object* o)
{
    afb_api_t api = ahl_binding_t::instance().handle();

    if(!afb_req_has_permission(r, "urn:AGL:permission::public:4a-audio-mixer"))
    {
        if (!opened_)
        {
            afb_req_fail(r, "You have to open the stream first!", nullptr);
            return;
        }

        if(!afb_req_context_get(r))
        {
            afb_req_fail(r, "Stream is opened by another client!", nullptr);
            return;
        }
    }
    else
    {
        AFB_API_DEBUG(api, "Granted special audio-mixer permission to change volume");
    }

    json_object* value;
    json_bool ret = json_object_object_get_ex(o, "value", &value);
    if (!ret)
    {
        afb_req_fail(r, "No value given!", nullptr);
        return;
    }

    json_object_get(value);

    json_object* a = json_object_new_object();
    json_object_object_add(a, (rtype_ == restype_t::control ? "value" : "volume"), value);

    AFB_API_DEBUG(api, "VOLUME QUERY: %s", json_object_to_json_string(a));

    volumeclosure* userdata = new volumeclosure();
    userdata->role = this;
    userdata->req = afb_req_addref(r);

    afb_api_call(
        api,
        hal_.c_str(),
        resource_.c_str(),
        a,
        [](void* closure, json_object* result, const char* error, const char* info, afb_api_t handle)
        {
            AFB_API_DEBUG(handle, "Got the following answer: %s", json_object_to_json_string(result));
            volumeclosure* r = reinterpret_cast<volumeclosure*>(closure);

            if (error)
            {
                json_object_get(result);
                afb_req_fail(r->req, json_object_to_json_string(result), nullptr);
            }
            else
            {
                if (r->role->rtype() == restype_t::control)
                {
                    int average = 0;
                    size_t arraylen = json_object_array_length(result);
                    for (size_t i = 0; i < arraylen; ++i)
                    {
                        average += json_object_get_int(json_object_array_get_idx(result, i));
                    }
                    average = average / (int)arraylen;

                    json_object* response = json_object_new_object();
                    json_object* newvol = json_object_new_int(average);
                    json_object_object_add(response, "newvol", newvol);
                    ahl_binding_t::instance().emit_volume_changed(r->role->uid(), average);
                    afb_req_success(r->req, response, nullptr);
                }
                else
                {
                    json_object* volnew;
                    if (json_object_object_get_ex(result, "volnew", &volnew))
                    {
                        ahl_binding_t::instance().emit_volume_changed(r->role->uid(), json_object_get_int(volnew));
                    }
                    json_object_get(result);
                    afb_req_success(r->req, result, nullptr);
                }
            }
            afb_req_unref(r->req);
            delete r;
        },
        userdata
    );
}

void role_t::interrupt(afb_req_t r, json_object* o)
{
}