#pragma once

#include "init/multiboot2.h"
#include "memory/pointer.h"
#include "util/optional.h"

constexpr const size_t page_size = 4096;

struct PhysicalAllocator {
    struct allocation_t {
        paddr_t ptr;
        size_t page_count;
    };

    enum class address_range_t : uint8_t {
        any,
        below_4gib,
    };

    static void init(const multiboot::tag_mmap* multiboot_info);
    static PhysicalAllocator& getInstance();

    optional<allocation_t> allocPages(
        size_t page_count, size_t alignment_pages = 1, address_range_t range = address_range_t::any
    );
    void free(allocation_t ptr);
    bool force(allocation_t ptr, bool free);

private:
    struct page_t {
        page_t* next;
        page_t* prev;
        uint64_t count[510];
    };
    static_assert(sizeof(page_t) == page_size);

    page_t* storage;

    friend struct PhysicalAllocatorImpl;
};