#include "link.h"
#include "arch/x86_64/hal/obj.h"
#include "hal/memory.h"
#include "lib/printf.h"
#include "jove.h"

uint8_t 
link_gettype(jove_owned_obj_t *obj)
{
    return obj_gettype(link_deref(obj));
}

uint8_t 
link_getperm(jove_owned_obj_t *link)
{
    struct obj_link *linkval = obj_deref(link);
    return linkval->permissions;
}

uint64_t 
link_getvalue(jove_owned_obj_t *obj)
{
    return obj_getvalue(link_deref(obj));
}

jove_owned_obj_t*
link_deref(jove_owned_obj_t *link)
{
    struct obj_link *linkval = obj_deref(link);
    return obj_take(&linkval->obj);
}

jove_owned_obj_t*
link_try_deref(jove_owned_obj_t *link)
{
    struct obj_link *linkval = obj_deref(link);
    return obj_trytake(&linkval->obj);
}

jove_perm_obj_t 
link_traverse(jove_owned_obj_t *link, lockstack_t *lockstack)
{
    jove_perm_obj_t perm_obj = { .obj = link, .permissions = JOVE_PERM_ALL };
    while(obj_gettype(perm_obj.obj) == JOVE_OBJ_LINK) {
        perm_obj.permissions &= link_getperm(perm_obj.obj);
        perm_obj.obj = lockstack_push(lockstack, link_deref(perm_obj.obj));
    }
    return perm_obj;
}

jove_perm_obj_t 
link_try_traverse(jove_owned_obj_t *link, lockstack_t *lockstack)
{
    jove_perm_obj_t perm_obj = { .obj = link, .permissions = JOVE_PERM_ALL };
    while(perm_obj.obj != NULL && obj_gettype(perm_obj.obj) == JOVE_OBJ_LINK) {
        perm_obj.permissions &= link_getperm(perm_obj.obj);
        perm_obj.obj = lockstack_push(lockstack, link_deref(perm_obj.obj));
    }
    return perm_obj;
}

jove_perm_obj_t
link_try_traverse_objdir(jove_owned_obj_t *objdir, lockstack_t *lockstack,
        size_t pathlen, objpath_part_t *path)
{
    /*Do a traversal through the passed objdir to get objdir permissions.*/
    jove_perm_obj_t perm_obj = link_try_traverse(objdir, lockstack);
    if(perm_obj.obj == 0) return perm_obj;
    if(pathlen == 0) return perm_obj;
    
    /*Get the object pointed to by the head of the path. */
    perm_obj.obj = lockstack_push(lockstack, objdir_trygetlocal(perm_obj.obj, path[0]));
    if(pathlen > 1) lockstack_pop(lockstack); /*Don't lock the directory we're traversing. */

    /*Recurse through the remaining path, resolving as we go. */
    jove_perm_obj_t traverse_obj = link_try_traverse_objdir(perm_obj.obj, lockstack, pathlen - 1, &path[1]);

    /*Mask permissions against the head object. */
    traverse_obj.permissions &= perm_obj.permissions;
    return traverse_obj;
}

jove_owned_obj_t *link_new(jove_obj_t *tgt, jove_owned_obj_t *dst, uint16_t permissions)
{
    struct obj_link *linkval = obj_deref(dst);
    linkval->obj = *tgt;
    linkval->refcount = 2;
    linkval->permissions = permissions;

    {
        jove_owned_obj_t *tgt_owned = obj_take(tgt);
        obj_settype(tgt_owned, JOVE_OBJ_LINK);
        obj_setvalue(tgt_owned, (uintptr_t)linkval);
        obj_release(tgt_owned);
    }
    return dst;
}