/*
 * Copyright (C) 2022 The Android Open Source 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.
 */

#include <android-base/logging.h>
#include <android-base/macros.h>
#include <net/if.h>
#include <private/android_filesystem_config.h>

#include <cstddef>
#include <iostream>
#include <limits>
#include <random>

#include "wifi_iface_util.h"

namespace {
// Constants to set the local bit & clear the multicast bit.
constexpr uint8_t kMacAddressMulticastMask = 0x01;
constexpr uint8_t kMacAddressLocallyAssignedMask = 0x02;

}  // namespace

namespace aidl {
namespace android {
namespace hardware {
namespace wifi {
namespace iface_util {

WifiIfaceUtil::WifiIfaceUtil(const std::weak_ptr<::android::wifi_system::InterfaceTool> iface_tool,
                             const std::weak_ptr<legacy_hal::WifiLegacyHal> legacy_hal)
    : iface_tool_(iface_tool),
      legacy_hal_(legacy_hal),
      random_mac_address_(nullptr),
      event_handlers_map_() {}

std::array<uint8_t, 6> WifiIfaceUtil::getFactoryMacAddress(const std::string& iface_name) {
    return iface_tool_.lock()->GetFactoryMacAddress(iface_name.c_str());
}

bool WifiIfaceUtil::setMacAddress(const std::string& iface_name,
                                  const std::array<uint8_t, 6>& mac) {
#ifndef WIFI_AVOID_IFACE_RESET_MAC_CHANGE
    legacy_hal::wifi_error legacy_status;
    uint64_t legacy_feature_set;
    std::tie(legacy_status, legacy_feature_set) =
            legacy_hal_.lock()->getSupportedFeatureSet(iface_name);

    if (!(legacy_feature_set & WIFI_FEATURE_DYNAMIC_SET_MAC) &&
        !iface_tool_.lock()->SetUpState(iface_name.c_str(), false)) {
        LOG(ERROR) << "SetUpState(false) failed.";
        return false;
    }
#endif
    bool success = iface_tool_.lock()->SetMacAddress(iface_name.c_str(), mac);
#ifndef WIFI_AVOID_IFACE_RESET_MAC_CHANGE
    if (!(legacy_feature_set & WIFI_FEATURE_DYNAMIC_SET_MAC) &&
        !iface_tool_.lock()->SetUpState(iface_name.c_str(), true)) {
        LOG(ERROR) << "SetUpState(true) failed. Wait for driver ready.";
        // Wait for driver ready and try to set iface UP again
        if (legacy_hal_.lock()->waitForDriverReady() != legacy_hal::WIFI_SUCCESS) {
            LOG(ERROR) << "SetUpState(true) wait for driver ready failed.";
            return false;
        }
        if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), true)) {
            LOG(ERROR) << "SetUpState(true) failed after retry.";
            return false;
        }
    }
#endif
    IfaceEventHandlers event_handlers = {};
    const auto it = event_handlers_map_.find(iface_name);
    if (it != event_handlers_map_.end()) {
        event_handlers = it->second;
    }
    if (event_handlers.on_state_toggle_off_on != nullptr) {
        event_handlers.on_state_toggle_off_on(iface_name);
    }
    if (!success) {
        LOG(ERROR) << "SetMacAddress failed on " << iface_name;
    } else {
        LOG(DEBUG) << "SetMacAddress succeeded on " << iface_name;
    }
    return success;
}

std::array<uint8_t, 6> WifiIfaceUtil::getOrCreateRandomMacAddress() {
    if (random_mac_address_) {
        return *random_mac_address_.get();
    }
    random_mac_address_ = std::make_unique<std::array<uint8_t, 6>>(createRandomMacAddress());
    return *random_mac_address_.get();
}

void WifiIfaceUtil::registerIfaceEventHandlers(const std::string& iface_name,
                                               IfaceEventHandlers handlers) {
    event_handlers_map_[iface_name] = handlers;
}

void WifiIfaceUtil::unregisterIfaceEventHandlers(const std::string& iface_name) {
    event_handlers_map_.erase(iface_name);
}

std::array<uint8_t, 6> WifiIfaceUtil::createRandomMacAddress() {
    std::array<uint8_t, 6> address = {};
    std::random_device rd;
    std::default_random_engine engine(rd());
    std::uniform_int_distribution<uint8_t> dist(std::numeric_limits<uint8_t>::min(),
                                                std::numeric_limits<uint8_t>::max());
    for (size_t i = 0; i < address.size(); i++) {
        address[i] = dist(engine);
    }
    // Set the local bit and clear the multicast bit.
    address[0] |= kMacAddressLocallyAssignedMask;
    address[0] &= ~kMacAddressMulticastMask;
    return address;
}

bool WifiIfaceUtil::setUpState(const std::string& iface_name, bool request_up) {
    if (!iface_tool_.lock()->SetUpState(iface_name.c_str(), request_up)) {
        LOG(ERROR) << "SetUpState to " << request_up << " failed";
        return false;
    }
    return true;
}

unsigned WifiIfaceUtil::ifNameToIndex(const std::string& iface_name) {
    return if_nametoindex(iface_name.c_str());
}

bool WifiIfaceUtil::createBridge(const std::string& br_name) {
    if (!iface_tool_.lock()->createBridge(br_name)) {
        return false;
    }

    if (!iface_tool_.lock()->SetUpState(br_name.c_str(), true)) {
        LOG(ERROR) << "bridge SetUpState(true) failed.";
    }
    return true;
}

bool WifiIfaceUtil::deleteBridge(const std::string& br_name) {
    if (!iface_tool_.lock()->SetUpState(br_name.c_str(), false)) {
        LOG(INFO) << "SetUpState(false) failed for bridge=" << br_name.c_str();
    }

    return iface_tool_.lock()->deleteBridge(br_name);
}

bool WifiIfaceUtil::addIfaceToBridge(const std::string& br_name, const std::string& if_name) {
    return iface_tool_.lock()->addIfaceToBridge(br_name, if_name);
}

bool WifiIfaceUtil::removeIfaceFromBridge(const std::string& br_name, const std::string& if_name) {
    return iface_tool_.lock()->removeIfaceFromBridge(br_name, if_name);
}

}  // namespace iface_util
}  // namespace wifi
}  // namespace hardware
}  // namespace android
}  // namespace aidl