#include "uaddrspace.h"
#include "alloc.h"
#include "kernel.h"
#include "mem.h"
#include "mmuContext.h"
#include "process.h"
#include "stdarg.h"
#include "thread.h"
#include "types.h"
#include <assert.h>
#include <stddef.h>
#include <stdint.h>

struct uAddrVirtualReg {
    uaddr_t addr;
    size_t size;
    int right;       // PAGING_MEM_*
    uint32_t offset; // in the mappedRessource
    uint flags;

    struct mappedRessource *res;
    struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
    struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
};

struct uAddrSpace {
    struct process *process; // The process that is represented by this AS
    struct mmu_context *ctx; // The corresponding MMU configuration

    struct uAddrVirtualReg *listVirtualReg; // List of Virtual Region used by this process

    uaddr_t heapStart; // Start of the Head
    size_t heapSize;   // Hep size -> modified by brk()
};

struct mappedRessourceOps {
    int (*open)(struct uAddrVirtualReg *vreg);
    int (*close)(struct uAddrVirtualReg *vreg);
    int (*unmap)(struct uAddrVirtualReg *vregi, uaddr_t addr, size_t size);
    int (*nopage)(struct uAddrVirtualReg *vregi, uaddr_t addr,
                  int right); // Called by the pageflt handler when the page is missing
};

struct mappedRessource {
    int right; // PAGING_MEM_*
    struct mappedRessourceOps *ops;
    struct uAddrVirtualReg *listVirtualReg;
};

struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
{
    struct uAddrSpace *addr = (struct uAddrSpace *)malloc(sizeof(struct uAddrSpace));

    if (addr == NULL)
        return NULL;

    addr->ctx = mmuContextCreate();

    if (addr->ctx == NULL) {
        free(addr);

        return NULL;
    }

    addr->process = proc;

    return addr;
}

int uAddrSpaceDelete(struct uAddrSpace *addr)
{
    // TODO Work on Virtual Region
    return mmuContextUnref(addr->ctx);
}

struct mmu_context *uAddrSpaceGetMMUContext(struct uAddrSpace *addr)
{
    return addr->ctx;
}

int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size)
{
    as->heapStart = addr;
    as->heapSize  = size;

    return 0;
}

uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
{
    int incSize;
    assert(as->heapStart);
    if (!newHeapTop || newHeapTop < as->heapStart)
        return as->heapStart + as->heapSize;

    newHeapTop = ALIGN(newHeapTop, PAGE_SIZE);

    if (newHeapTop == as->heapStart + as->heapSize)
        return newHeapTop;

    incSize = ALIGN(newHeapTop - (as->heapStart + as->heapSize), PAGE_SIZE);

    if (incSize < 0){
        //FIXME
        return as->heapStart + as->heapSize;
    }

    //WIP do it manually
    for (uaddr_t begin = ALIGN(as->heapStart + as->heapSize, PAGE_SIZE); begin < newHeapTop; begin += PAGE_SIZE) {
        paddr_t ppage = allocPhyPage(1);
        if (0 != pageMap(begin, ppage,
                         PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ))
            return (uaddr_t)NULL;

        unrefPhyPage(ppage);
    }

    return 0;
}