#define MODULE "mem"

#include "interrupts/Context.h"
#include "log/Log.h"
#include "memory/MemoryManager.h"
#include "memory/VMM.h"
#include <stddef.h>

void sys_mmap(Context* context, void* address, size_t size, int flags)
{
    if (size < 4096)
    {
        kdbgln("sys_mmap: size too small");
        context->rax = 0;
        return;
    }
    int real_flags = MAP_USER;
    if (flags & MAP_READ_WRITE) real_flags |= MAP_READ_WRITE;
    if (address)
    {
        kdbgln("sys_mmap: %ld pages at address %lx, %s", size / 4096, (uint64_t)address,
               real_flags & MAP_READ_WRITE ? "rw" : "ro");
        if (kernelVMM.getPhysical((uint64_t)address) != (uint64_t)-1) // Address is already used.
        {
            kdbgln("attempt to mmap an already mapped address");
            context->rax = 0;
            return;
        }
        uint64_t offset = (uint64_t)address % 4096;
        void* result = MemoryManager::get_pages_at((uint64_t)address - offset, size / 4096, real_flags);
        if (result)
        {
            kdbgln("mmap succeeded: %lx", (uint64_t)result);
            context->rax = (uint64_t)result;
            return;
        }
        else
        {
            kdbgln("mmap failed");
            context->rax = 0;
            return;
        }
    }
    kdbgln("sys_mmap: %ld pages at any address, %s", size / 4096, real_flags & MAP_READ_WRITE ? "rw" : "ro");
    void* result = MemoryManager::get_pages(size / 4096, real_flags);
    if (result)
    {
        kdbgln("mmap succeeded: %lx", (uint64_t)result);
        context->rax = (uint64_t)result;
        return;
    }
    else
    {
        kdbgln("mmap failed");
        context->rax = 0;
        return;
    }
}

void sys_munmap(Context* context, void* address, size_t size)
{
    kdbgln("sys_munmap: attempting to unmap %lx", (uint64_t)address);
    if (!address)
    {
        kdbgln("munmap failed: attempted to unmap page 0");
        context->rax = -1;
        return;
    }
    uint64_t flags = kernelVMM.getFlags((uint64_t)address);
    if (!(flags & MAP_USER))
    {
        kdbgln("munmap failed: attempted to unmap a kernel page");
        context->rax = -1;
        return;
    }
    uint64_t offset = (uint64_t)address % 4096;
    MemoryManager::release_pages((void*)((uint64_t)address - offset), size / 4096);
    kdbgln("munmap succeeded");
    context->rax = 0;
    return;
}