/*
 * Copyright (C) 2017 The LineageOS Project
 *
 * 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.
 */

#define LOG_TAG "android.hardware.light@2.0-service.berlna"

#include <log/log.h>

#include "Light.h"

#include <fstream>

namespace android {
namespace hardware {
namespace light {
namespace V2_0 {
namespace implementation {

#define LEDS            "/sys/class/leds/"

#define LCD_LED         LEDS "lcd-backlight/"
#define CHARGING_LED    LEDS "charging/"

#define BRIGHTNESS      "brightness"
#define BREATH          "breath"
#define DELAY_OFF       "delay_off"
#define DELAY_ON        "delay_on"

/*
 * Write value to path and close file.
 */
static void set(std::string path, std::string value) {
    std::ofstream file(path);

    if (!file.is_open()) {
        ALOGE("failed to write %s to %s", value.c_str(), path.c_str());
        return;
    }

    file << value;
}

static void set(std::string path, int value) {
    set(path, std::to_string(value));
}
    
static uint32_t rgbToBrightness(const LightState& state) {
    uint32_t color = state.color & 0x00ffffff;
    return ((77 * ((color >> 16) & 0xff)) + (150 * ((color >> 8) & 0xff)) +
            (29 * (color & 0xff))) >> 8;
}

static void handleBacklight(const LightState& state) {
    uint32_t brightness = rgbToBrightness(state);
    set(LCD_LED BRIGHTNESS, brightness);
}

static void handleNotification(const LightState& state) {
    uint32_t alpha, brightness;

    /*
     * Extract brightness from AARRGGBB.
     */
    alpha = (state.color >> 24) & 0xFF;
    brightness = rgbToBrightness(state);

    /*
     * Scale brightness if the Alpha brightness is not 0xFF.
     */
    if (alpha != 0xFF)
        brightness = (brightness * alpha) / 0xFF;
    
    /* Disable blinking. */
    set(CHARGING_LED BREATH, 0);

    if (state.flashMode == Flash::TIMED) {
        /* Set LED */
        set(CHARGING_LED DELAY_OFF, state.flashOffMs);
        set(CHARGING_LED DELAY_ON, state.flashOnMs);

        /* Enable blinking. */
        set(CHARGING_LED BREATH, 1);
    } else {
        set(CHARGING_LED BRIGHTNESS, brightness);
    }
}

static std::map<Type, std::function<void(const LightState&)>> lights = {
    {Type::BACKLIGHT, handleBacklight},
    {Type::BATTERY, handleNotification},
    {Type::NOTIFICATIONS, handleNotification},
    {Type::ATTENTION, handleNotification},
};

Light::Light() {}

Return<Status> Light::setLight(Type type, const LightState& state) {
    auto it = lights.find(type);

    if (it == lights.end()) {
        return Status::LIGHT_NOT_SUPPORTED;
    }

    /*
     * Lock global mutex until light state is updated.
     */
    std::lock_guard<std::mutex> lock(globalLock);

    it->second(state);

    return Status::SUCCESS;
}

Return<void> Light::getSupportedTypes(getSupportedTypes_cb _hidl_cb) {
    std::vector<Type> types;

    for (auto const& light : lights) types.push_back(light.first);

    _hidl_cb(types);

    return Void();
}

}  // namespace implementation
}  // namespace V2_0
}  // namespace light
}  // namespace hardware
}  // namespace android