#pragma once

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

struct PageTable {
    struct flags_t {
        enum class granularity_t : uint8_t {
            page_4KiB,
            page_2MiB,
            page_1GiB,
        };

        bool writeable : 1;            // allow writes
        bool user_accessible : 1;      // allow ring-3 access
        bool write_through : 1;        // write-through instead of write-back
        bool cache_disabled : 1;       // uncached (MMIO)
        bool execute_disabled : 1;     // forbid instruction fetch
        bool global : 1;               // keep in TLB across CR3 switches
        granularity_t granularity : 2; // mapping size
    };
    struct info_t {
        flags_t flags;
        paddr_t address;
    };

    static PageTable fromCurrent();

    void activate();
    bool map(void* vaddress, paddr_t paddress, flags_t flags);
    void unmap(void* vaddress);
    optional<info_t> get(void* vaddress);

private:
    paddr_t l4;
};