/*
 * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <AK/UUID.h>
#include <Kernel/Devices/BlockDevice.h>
#include <Kernel/FileSystem/Ext2FileSystem.h>
#include <Kernel/PCI/Access.h>
#include <Kernel/Storage/IDEController.h>
#include <Kernel/Storage/Partition/EBRPartitionTable.h>
#include <Kernel/Storage/Partition/GUIDPartitionTable.h>
#include <Kernel/Storage/Partition/MBRPartitionTable.h>
#include <Kernel/Storage/StorageManagement.h>

namespace Kernel {

static StorageManagement* s_the;

StorageManagement::StorageManagement(String boot_argument, bool force_pio)
    : m_boot_argument(boot_argument)
    , m_controllers(enumerate_controllers(force_pio))
    , m_storage_devices(enumerate_storage_devices())
    , m_disk_partitions(enumerate_disk_partitions())
{
    if (!boot_argument_contains_partition_uuid()) {
        determine_boot_device();
        return;
    }
    determine_boot_device_with_partition_uuid();
}

bool StorageManagement::boot_argument_contains_partition_uuid()
{
    return m_boot_argument.starts_with("PARTUUID=");
}

NonnullRefPtrVector<StorageController> StorageManagement::enumerate_controllers(bool force_pio) const
{
    NonnullRefPtrVector<StorageController> controllers;
    PCI::enumerate([&](const PCI::Address& address, PCI::ID) {
        if (PCI::get_class(address) == 0x1 && PCI::get_subclass(address) == 0x1) {
            controllers.append(IDEController::initialize(address, force_pio));
        }
    });
    return controllers;
}

NonnullRefPtrVector<StorageDevice> StorageManagement::enumerate_storage_devices() const
{
    ASSERT(!m_controllers.is_empty());
    NonnullRefPtrVector<StorageDevice> devices;
    for (auto& controller : m_controllers) {
        for (size_t device_index = 0; device_index < controller.devices_count(); device_index++) {
            auto device = controller.device(device_index);
            if (device.is_null())
                continue;
            devices.append(device.release_nonnull());
        }
    }
    return devices;
}

OwnPtr<PartitionTable> StorageManagement::try_to_initialize_partition_table(const StorageDevice& device) const
{
    auto mbr_table_or_result = MBRPartitionTable::try_to_initialize(device);
    if (!mbr_table_or_result.is_error())
        return move(mbr_table_or_result.value());
    if (mbr_table_or_result.error() == PartitionTable::Error::MBRProtective) {
        auto gpt_table_or_result = GUIDPartitionTable::try_to_initialize(device);
        if (gpt_table_or_result.is_error())
            return nullptr;
        return move(gpt_table_or_result.value());
    }
    if (mbr_table_or_result.error() == PartitionTable::Error::ConatinsEBR) {
        auto ebr_table_or_result = EBRPartitionTable::try_to_initialize(device);
        if (ebr_table_or_result.is_error())
            return nullptr;
        return move(ebr_table_or_result.value());
    }
    return nullptr;
}

NonnullRefPtrVector<DiskPartition> StorageManagement::enumerate_disk_partitions() const
{
    ASSERT(!m_storage_devices.is_empty());
    NonnullRefPtrVector<DiskPartition> partitions;
    size_t device_index = 0;
    for (auto& device : m_storage_devices) {
        auto partition_table = try_to_initialize_partition_table(device);
        if (!partition_table)
            continue;
        for (size_t partition_index = 0; partition_index < partition_table->partitions_count(); partition_index++) {
            auto partition_metadata = partition_table->partition(partition_index);
            if (!partition_metadata.has_value())
                continue;
            // FIXME: Try to not hardcode a maximum of 16 partitions per drive!
            auto disk_partition = DiskPartition::create(const_cast<StorageDevice&>(device), (partition_index + (16 * device_index)), partition_metadata.value());
            partitions.append(disk_partition);
            const_cast<StorageDevice&>(device).m_partitions.append(disk_partition);
        }
        device_index++;
    }
    return partitions;
}

void StorageManagement::determine_boot_device()
{
    ASSERT(!m_controllers.is_empty());
    if (!m_boot_argument.starts_with("/dev/hd")) {
        klog() << "init_stage2: root filesystem must be on an hard drive";
        Processor::halt();
    }

    auto drive_letter = m_boot_argument.substring(strlen("/dev/hd"), m_boot_argument.length() - strlen("/dev/hd"))[0];

    if (drive_letter < 'a' || drive_letter > 'z') {
        klog() << "init_stage2: root filesystem must be on an hard drive name";
        Processor::halt();
    }

    size_t drive_index = (u8)drive_letter - (u8)'a';
    if (drive_index >= m_storage_devices.size()) {
        klog() << "init_stage2: invalid selection of hard drive.";
        Processor::halt();
    }

    auto& determined_boot_device = m_storage_devices[drive_index];
    auto root_device = m_boot_argument.substring(strlen("/dev/hda"), m_boot_argument.length() - strlen("/dev/hda"));
    if (!root_device.length()) {
        m_boot_block_device = determined_boot_device;
        return;
    }

    auto partition_number = root_device.to_uint();
    if (!partition_number.has_value()) {
        klog() << "init_stage2: couldn't parse partition number from root kernel parameter";
        Processor::halt();
    }

    if (partition_number.value() > determined_boot_device.m_partitions.size()) {
        klog() << "init_stage2: invalid partition number!";
        Processor::halt();
    }

    m_boot_block_device = determined_boot_device.m_partitions[partition_number.value() - 1];
}

void StorageManagement::determine_boot_device_with_partition_uuid()
{
    ASSERT(!m_disk_partitions.is_empty());
    ASSERT(m_boot_argument.starts_with("PARTUUID="));

    auto partition_uuid = UUID(m_boot_argument.substring_view(strlen("PARTUUID=")));

    if (partition_uuid.to_string().length() != 36) {
        klog() << "init_stage2: specified partition UUID is not valid";
        Processor::halt();
    }

    for (auto& partition : m_disk_partitions) {
        if (partition.metadata().unique_guid().is_zero())
            continue;
        if (partition.metadata().unique_guid() == partition_uuid) {
            m_boot_block_device = partition;
            break;
        }
    }
}

RefPtr<BlockDevice> StorageManagement::boot_block_device() const
{
    return m_boot_block_device;
}

NonnullRefPtr<FS> StorageManagement::root_filesystem() const
{
    auto boot_device_description = boot_block_device();
    if (!boot_device_description) {
        klog() << "init_stage2: couldn't find a suitable device to boot from";
        Processor::halt();
    }
    auto e2fs = Ext2FS::create(FileDescription::create(boot_device_description.release_nonnull()).value());
    if (!e2fs->initialize()) {
        klog() << "init_stage2: couldn't open root filesystem";
        Processor::halt();
    }
    return e2fs;
}

bool StorageManagement::initialized()
{
    return (s_the != nullptr);
}

void StorageManagement::initialize(String root_device, bool force_pio)
{
    ASSERT(!StorageManagement::initialized());
    s_the = new StorageManagement(root_device, force_pio);
}

StorageManagement& StorageManagement::the()
{
    return *s_the;
}

NonnullRefPtrVector<StorageController> StorageManagement::ide_controllers() const
{
    NonnullRefPtrVector<StorageController> ide_controllers;
    for (auto& controller : m_controllers) {
        if (controller.type() == StorageController::Type::IDE)
            ide_controllers.append(controller);
    }
    return ide_controllers;
}
}