/*
 * Copyright (C) 2018 The Android Open Source Project
 * Copyright (C) 2020 The LineageOS Project
 *
 * SPDX-License-Identifier: Apache-2.0
 */

// Author := dev_harsh1998, Isaac Chen

#define LOG_TAG "android.hardware.lights-service.xiaomi_sdm660"
/* #define LOG_NDEBUG 0 */

#include "Lights.h"

#include <android-base/file.h>
#include <android-base/logging.h>
#include <unistd.h>

namespace {

#define PPCAT_NX(A, B) A/B
#define PPCAT(A, B) PPCAT_NX(A, B)
#define STRINGIFY_INNER(x) #x
#define STRINGIFY(x) STRINGIFY_INNER(x)

#define LEDS(x) PPCAT(/sys/class/leds, x)
#define LCD_ATTR(x) STRINGIFY(PPCAT(LEDS(lcd-backlight), x))
#define WHITE_ATTR(x) STRINGIFY(PPCAT(LEDS(white), x))
#define BUTTON_ATTR(x) STRINGIFY(PPCAT(LEDS(button-backlight), x))
#define BUTTON1_ATTR(x) STRINGIFY(PPCAT(LEDS(button-backlight1), x))

using ::android::base::ReadFileToString;
using ::android::base::WriteStringToFile;

// Default max brightness
constexpr auto kDefaultMaxLedBrightness = 255;
constexpr auto kDefaultMaxScreenBrightness = 4095;

// Each step will stay on for 50ms by default.
constexpr auto kRampStepDurationDefault = 50;

// Write value to path and close file.
bool WriteToFile(const std::string& path, uint32_t content) {
    return WriteStringToFile(std::to_string(content), path);
}

bool WriteToFile(const std::string& path, const std::string& content) {
    return WriteStringToFile(content, path);
}

uint32_t RgbaToBrightness(uint32_t color) {
    // Extract brightness from AARRGGBB.
    uint32_t alpha = (color >> 24) & 0xFF;

    // Retrieve each of the RGB colors
    uint32_t red = (color >> 16) & 0xFF;
    uint32_t green = (color >> 8) & 0xFF;
    uint32_t blue = color & 0xFF;

    // Scale RGB colors if a brightness has been applied by the user
    if (alpha != 0xFF) {
        red = red * alpha / 0xFF;
        green = green * alpha / 0xFF;
        blue = blue * alpha / 0xFF;
    }

    return (77 * red + 150 * green + 29 * blue) >> 8;
}

inline uint32_t RgbaToBrightness(uint32_t color, uint32_t max_brightness) {
    return RgbaToBrightness(color) * max_brightness / 0xFF;
}

inline bool IsLit(uint32_t color) {
    return color & 0x00ffffff;
}

}  // anonymous namespace

namespace aidl {
namespace android {
namespace hardware {
namespace light {

Lights::Lights() {
std::map<int, std::function<void(int id, const HwLightState&)>> lights_{
            {(int)LightType::NOTIFICATIONS,
             [this](auto&&... args) { setLightNotification(args...); }},
            {(int)LightType::BATTERY, [this](auto&&... args) { setLightNotification(args...); }},
            {(int)LightType::BACKLIGHT, [this](auto&&... args) { setLightBacklight(args...); }}};

    std::vector<HwLight> availableLights;
    for (auto const& pair : lights_) {
        int id = pair.first;
        HwLight hwLight{};
        hwLight.id = id;
        availableLights.emplace_back(hwLight);
    }
    mAvailableLights = availableLights;
    mLights = lights_;

    std::string buf;

    if (ReadFileToString(LCD_ATTR(max_brightness), &buf)) {
        max_screen_brightness_ = std::stoi(buf);
    } else {
        max_screen_brightness_ = kDefaultMaxScreenBrightness;
        LOG(ERROR) << "Failed to read max screen brightness, fallback to "
                   << kDefaultMaxScreenBrightness;
    }

    if (ReadFileToString(WHITE_ATTR(max_brightness), &buf)) {
        max_led_brightness_ = std::stoi(buf);
    } else {
        max_led_brightness_ = kDefaultMaxLedBrightness;
        LOG(ERROR) << "Failed to read max LED brightness, fallback to " << kDefaultMaxLedBrightness;
    }

    if (!access(BUTTON_ATTR(brightness), W_OK)) {
        lights_.emplace(std::make_pair((int)LightType::BUTTONS,
                                       [this](auto&&... args) { setLightButtons(args...); }));
        buttons_.emplace_back(BUTTON_ATTR(brightness));

        if (!access(BUTTON1_ATTR(brightness), W_OK)) {
            buttons_.emplace_back(BUTTON1_ATTR(brightness));
        }

        if (ReadFileToString(BUTTON_ATTR(max_brightness), &buf)) {
            max_button_brightness_ = std::stoi(buf);
        } else {
            max_button_brightness_ = kDefaultMaxLedBrightness;
            LOG(ERROR) << "Failed to read max button brightness, fallback to "
                       << kDefaultMaxLedBrightness;
        }
    }
}

ndk::ScopedAStatus Lights::setLightState(int id, const HwLightState& state) {
    auto it = mLights.find(id);
    if (it == mLights.end()) {
        LOG(ERROR) << "Light not supported";
        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
    }

    it->second(id, state);

    return ndk::ScopedAStatus::ok();
}

ndk::ScopedAStatus Lights::getLights(std::vector<HwLight>* lights) {
    for (auto i = mAvailableLights.begin(); i != mAvailableLights.end(); i++) {
        lights->push_back(*i);
    }
    return ndk::ScopedAStatus::ok();
}

void Lights::setLightBacklight(int /*id*/, const HwLightState& state) {
    uint32_t brightness = RgbaToBrightness(state.color, max_screen_brightness_);
    WriteToFile(LCD_ATTR(brightness), brightness);
}

void Lights::setLightButtons(int /*id*/, const HwLightState& state) {
    uint32_t brightness = RgbaToBrightness(state.color, max_button_brightness_);
    for (auto&& button : buttons_) {
        WriteToFile(button, brightness);
    }
}

void Lights::setLightNotification(int id, const HwLightState& state) {
    bool found = false;
    for (auto&& [cur_id, cur_state] : notif_states_) {
        if (cur_id == id) {
            cur_state = state;
        }

        // Fallback to battery light
        if (!found && (cur_id == (int)LightType::BATTERY || IsLit(cur_state.color))) {
            found = true;
            LOG(DEBUG) << __func__ << ": id=" << id;
            applyNotificationState(cur_state);
        }
    }
}

void Lights::applyNotificationState(const HwLightState& state) {
    uint32_t white_brightness = RgbaToBrightness(state.color, max_led_brightness_);

    // Turn off the leds (initially)
    WriteToFile(WHITE_ATTR(blink), 0);

    if (state.flashMode == FlashMode::TIMED && state.flashOnMs > 0 && state.flashOffMs > 0) {
        WriteToFile(WHITE_ATTR(ramp_step_ms),
                    static_cast<uint32_t>(kRampStepDurationDefault)),
        // White
        WriteToFile(WHITE_ATTR(start_idx), 0);
        WriteToFile(WHITE_ATTR(pause_lo), static_cast<uint32_t>(state.flashOffMs));
        WriteToFile(WHITE_ATTR(blink), 1);
    } else {
        WriteToFile(WHITE_ATTR(brightness), white_brightness);
    }
}

}  // namespace light
}  // namespace hardware
}  // namespace android
}  // namespace aidl