/*
 * 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 "Apex.h"

#include <format>

#include <android-base/logging.h>
#include <android-base/strings.h>
#ifdef LIBVINTF_TARGET
#include "com_android_apex_flags.h"
#endif
#include "com_android_apex.h"
#include "constants-private.h"

using android::base::StartsWith;

namespace android::vintf::apex {

namespace {
// Partition tags used in apex-info-list.xml
constexpr const char* SYSTEM = "SYSTEM";
constexpr const char* SYSTEM_EXT = "SYSTEM_EXT";
constexpr const char* PRODUCT = "PRODUCT";
constexpr const char* VENDOR = "VENDOR";
constexpr const char* ODM = "ODM";
}  // namespace

static bool isApexReady(PropertyFetcher* propertyFetcher) {
#ifdef LIBVINTF_TARGET
    if constexpr (com::android::apex::flags::mount_before_data()) {
        // "APEX ready" here means that the APEXes in the default mount
        // namespace are ready to use. If init started with a single mount
        // namespace, no need to wait for "APEX ready" because all APEXes are
        // activated early.
        if (propertyFetcher->getUintProperty("ro.init.mnt_ns.count", 2) == 1) {
            return true;
        }
    }
    return propertyFetcher->getBoolProperty("apex.all.ready", false);
#else
    // When running on host, it assumes that /apex is ready.
    // Reason for still relying on PropertyFetcher API is for host-side tests.
    return propertyFetcher->getBoolProperty("apex.all.ready", true);
#endif
}

static status_t GetVintfDirs(FileSystem* fileSystem, PropertyFetcher* propertyFetcher,
                             std::vector<std::string>* dirs, std::string* error,
                             std::function<bool(const std::string&)> filter) {
    std::string apexInfoFile = details::kApexInfoFile;
    std::string apexDir = "/apex";
    if (!isApexReady(propertyFetcher)) {
        apexInfoFile = details::kBootstrapApexInfoFile;
        apexDir = "/bootstrap-apex";
    }

    // Load apex-info-list
    std::string xml;
    auto status = fileSystem->fetch(apexInfoFile, &xml, error);
    if (status == NAME_NOT_FOUND) {
        if (error) {
            error->clear();
        }
        return OK;
    }
    if (status != OK) return status;

    auto apexInfoList = com::android::apex::parseApexInfoList(xml.c_str());
    if (!apexInfoList.has_value()) {
        if (error) {
            *error = std::string("Not a valid XML: ") + apexInfoFile;
        }
        return UNKNOWN_ERROR;
    }

    // Get vendor apex vintf dirs
    for (const auto& apexInfo : apexInfoList->getApexInfo()) {
        // Skip non-active apexes
        if (!apexInfo.getIsActive()) continue;

        if (filter(apexInfo.getPartition())) {
            dirs->push_back(std::format("{}/{}/" VINTF_SUB_DIR, apexDir, apexInfo.getModuleName()));
        }
    }
    LOG(INFO) << "Loaded APEX Infos from " << apexInfoFile;
    return OK;
}

std::optional<timespec> GetModifiedTime(FileSystem* fileSystem, PropertyFetcher* propertyFetcher) {
    std::string apexInfoFile = details::kApexInfoFile;
    if (!isApexReady(propertyFetcher)) {
        apexInfoFile = details::kBootstrapApexInfoFile;
    }

    timespec mtime{};
    std::string error;
    status_t status = fileSystem->modifiedTime(apexInfoFile, &mtime, &error);
    if (status == NAME_NOT_FOUND) {
        return std::nullopt;
    }
    if (status != OK) {
        LOG(ERROR) << error;
        return std::nullopt;
    }
    return mtime;
}

status_t GetVendorVintfDirs(FileSystem* fileSystem, PropertyFetcher* propertyFetcher,
                            std::vector<std::string>* dirs, std::string* error) {
    return GetVintfDirs(fileSystem, propertyFetcher, dirs, error, [](const std::string& partition) {
        return partition.compare(VENDOR) == 0;
    });
}

status_t GetOdmVintfDirs(FileSystem* fileSystem, PropertyFetcher* propertyFetcher,
                         std::vector<std::string>* dirs, std::string* error) {
    return GetVintfDirs(fileSystem, propertyFetcher, dirs, error,
                        [](const std::string& partition) { return partition.compare(ODM) == 0; });
}

status_t GetFrameworkVintfDirs(FileSystem* fileSystem, PropertyFetcher* propertyFetcher,
                               std::vector<std::string>* dirs, std::string* error) {
    return GetVintfDirs(fileSystem, propertyFetcher, dirs, error, [](const std::string& partition) {
        return partition.compare(SYSTEM) == 0 || partition.compare(SYSTEM_EXT) == 0 ||
               partition.compare(PRODUCT) == 0;
    });
}

}  // namespace android::vintf::apex