/*
 * Copyright (c) Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once
#include <stratosphere.hpp>
#include "os_address_space_allocator_forbidden_region.hpp"

namespace ams::os::impl {

    enum AddressAllocationResult {
        AddressAllocationResult_Success,
        AddressAllocationResult_OutOfMemory,
        AddressAllocationResult_OutOfSpace,
    };

    template<std::unsigned_integral AddressType_, std::unsigned_integral SizeType_>
    class AddressSpaceAllocatorBase {
        NON_COPYABLE(AddressSpaceAllocatorBase);
        NON_MOVEABLE(AddressSpaceAllocatorBase);
        public:
            using AddressType = AddressType_;
            using SizeType    = SizeType_;
        private:
            static constexpr size_t MaxForbiddenRegions = 2;
        private:
            InternalCriticalSection m_critical_section;
            AddressType m_start_page;
            AddressType m_end_page;
            SizeType m_guard_page_count;
            AddressType m_forbidden_region_start_pages[MaxForbiddenRegions];
            AddressType m_forbidden_region_end_pages[MaxForbiddenRegions];
            size_t m_forbidden_region_count;
        public:
            AddressSpaceAllocatorBase(u64 start_address, u64 end_address, SizeType guard_size, const AddressSpaceAllocatorForbiddenRegion *forbidden_regions, size_t num_forbidden_regions);

            AddressType AllocateSpace(SizeType size, SizeType align, SizeType align_offset, AddressSpaceGenerateRandomFunction generate_random);

            bool CheckGuardSpace(AddressType address, SizeType size, SizeType guard_size);
        private:
            bool GetNextNonOverlappedNodeUnsafe(AddressType page, SizeType page_count);
        public:
            virtual bool CheckFreeSpace(AddressType address, SizeType size) = 0;
    };

    u64 AddressSpaceAllocatorDefaultGenerateRandom(u64 max);

}

#if defined(ATMOSPHERE_OS_HORIZON)
    #include "os_address_space_allocator_impl.os.horizon.hpp"
#else
    #include "os_address_space_allocator_impl.generic.hpp"
#endif