#include "Pledge.h"
#include "fs/VFS.h"
#include "fs/ext2/FileSystem.h"
#include "fs/tmpfs/FileSystem.h"
#include "memory/MemoryManager.h"
#include "sys/Syscall.h"
#include "thread/Scheduler.h"

Result<u64> sys_mount(Registers*, SyscallArgs args)
{
    auto target = TRY(MemoryManager::strdup_from_user(args[0]));
    auto fstype = TRY(MemoryManager::strdup_from_user(args[1]));
    auto source = TRY(MemoryManager::strdup_from_user(args[2]));

    auto* current = Scheduler::current();
    TRY(check_pledge(current, Promise::p_mount));
    if (current->auth.euid != 0) return err(EPERM);

    auto get_source = [current, &source]() -> Result<SharedPtr<Device>> {
        auto inode = TRY(VFS::resolve_path(source.chars(), current->auth, current->current_directory));
        if (inode->type() != VFS::InodeType::BlockDevice) return err(ENOTBLK);
        dev_t device_id = inode->metadata().devid;
        return TRY(DeviceRegistry::fetch_special_device(luna_dev_major(device_id), luna_dev_minor(device_id)));
    };

    SharedPtr<VFS::FileSystem> fs;

    if (fstype.view() == "tmpfs") fs = TRY(TmpFS::FileSystem::create());
    else if (fstype.view() == "devfs")
        fs = TRY(DeviceRegistry::create_devfs_instance());
    else if (fstype.view() == "ext2")
    {
        auto source_device = TRY(get_source());
        fs = TRY(Ext2::FileSystem::create(source_device));
    }
    else
        return err(ENODEV);

    TRY(VFS::mount(target.chars(), fs, current->auth, current->current_directory));

    return 0;
}

Result<u64> sys_umount(Registers*, SyscallArgs args)
{
    auto target = TRY(MemoryManager::strdup_from_user(args[0]));

    auto* current = Scheduler::current();
    TRY(check_pledge(current, Promise::p_mount));
    if (current->auth.euid != 0) return err(EPERM);

    TRY(VFS::umount(target.chars(), current->auth, current->current_directory));

    return 0;
}

Result<u64> sys_pivot_root(Registers*, SyscallArgs args)
{
    auto new_root = TRY(MemoryManager::strdup_from_user(args[0]));
    auto put_old = TRY(MemoryManager::strdup_from_user(args[1]));

    auto* current = Scheduler::current();
    TRY(check_pledge(current, Promise::p_mount));
    if (current->auth.euid != 0) return err(EPERM);

    TRY(VFS::pivot_root(new_root.chars(), put_old.chars(), current->current_directory));

    return 0;
}