#include "mmuContext.h"
#include "alloc.h"
#include "allocArea.h"
#include "errno.h"
#include "klibc.h"
#include "irq.h"
#include "list.h"
#include "paging.h"
#include "stdarg.h"
#include "types.h"

struct mmu_context {
    paddr_t paddr_PD;
    vaddr_t vaddr_PD;
    uint32_t ref;

    struct mmu_context *next, *prev;
};

static struct mmu_context *listContext    = NULL;
static struct mmu_context *currentContext = NULL;

int mmuContextSetup()
{
    struct mmu_context *initialCtx;
    int ret = 0;

    initialCtx = malloc(sizeof(struct mmu_context));

    if (initialCtx == NULL)
        return -ENOMEM;

    initialCtx->paddr_PD = pagingGetCurrentPDPaddr();
    initialCtx->vaddr_PD = areaAlloc(1, 0);

    ret = pageMap(initialCtx->vaddr_PD, initialCtx->paddr_PD,
                  PAGING_MEM_WRITE | PAGING_MEM_READ);

    if (ret)
        return ret;

    list_singleton(listContext, initialCtx);
    currentContext = initialCtx;

    // We create the context and we are using it
    initialCtx->ref = 2;
    return 0;
}

struct mmu_context *mmuContextCreate()
{
    struct mmu_context *ctx;
    uint32_t flags;

    ctx = malloc(sizeof(struct mmu_context));

    if (ctx == NULL)
        return NULL;

    ctx->vaddr_PD = areaAlloc(1, AREA_PHY_MAP);

    if (ctx->vaddr_PD == (vaddr_t)NULL) {
        pr_info("Fail to allocate MMU Context\n");
        free(ctx);

        return NULL;
    }

    ctx->paddr_PD = pagingGetPaddr(ctx->vaddr_PD);

    ctx->ref = 1;

    //TODO copy kernel space
    disable_IRQs(flags);
    list_add_tail(listContext, ctx);
    restore_IRQs(flags);

    return ctx;
}

int mmuContextSyncKernelPDE(int pdEntry, void * pde, size_t pdeSize)
{
    uint32_t flags;
    struct mmu_context *destContext;
    int nbContexts;

    disable_IRQs(flags);
    list_foreach_forward(listContext, destContext, nbContexts)
    {
        void *dest_pd;

        assert(destContext->ref > 0);

        dest_pd          = (void *)destContext->vaddr_PD;
        memcpy(dest_pd + pdEntry *pdeSize, pde, pdeSize);
    }
    restore_IRQs(flags);

    return 0;
}