#include "process.h"
#include "api/error.h"
#include "api/process.h"
#include "hal/smp.h"
#include "proc/scheduler.h"
#include "sys/objdir.h"
#include <string.h>

struct rbtree_node *pcb_tree;
pid_t __next_pid = 1;

int
pcb_new(jove_owned_obj_t *pcb_obj, size_t size, jove_owned_obj_t *rootdir_obj)
{
    struct pcb_header *pcb_header = obj_deref(pcb_obj);

    memset(pcb_header, 0, size);

    pcb_header->size = size;
    pcb_header->pid = __next_pid++;
    pcb_header->rootdir = obj_release(rootdir_obj);

    pcb_header->tree_node.get_key = (void*)pcb_getpid;
    pcb_tree = rbtree_insert(pcb_tree, &pcb_header->tree_node);

    pcb_header->state = PCB_STATE_EMBRYO;
    pcb_header->ksp = (void*)pcb_obj + size - sizeof(uintmax_t);
    return _pcb_new_arch((pcb_t*)pcb_header);
}

int
pcb_send(pcb_t *pcb, pid_t target, jove_owned_obj_t *subject, size_t timeout)
{
    struct pcb_header *pcb_header = (struct pcb_header*)pcb;
    struct pcb_header *target_pcb = (struct pcb_header*)rbtree_search(pcb_tree, target);
    if(target_pcb == 0) {
        return -EBADPROC;
    }

    if(target_pcb->recv.obj == NULL && 
            (target_pcb->recv.pid == pcb_getpid(pcb) || target_pcb->recv.pid == 0))
    {
        target_pcb->recv.obj = subject;
        target_pcb->recv.pid = pcb_getpid(pcb);
        return scheduler_yield(target);
    }

    if(timeout == 0) {
        return -EFULL;
    }

    pcb_header->send.obj = subject;
    pcb_header->send.pid = target;
    
    scheduler_block_for_mail(pcb_header, timeout, target);
    
    if(pcb_header->send.obj) return -ETIMEOUT;
    return 0;
}

int 
pcb_recv(pcb_t *pcb, pid_t target, jove_owned_obj_t *dest_obj, size_t timeout)
{
    struct pcb_header *pcb_header = (struct pcb_header*)pcb;
    struct pcb_header *target_pcb = (struct pcb_header*)rbtree_search(pcb_tree, target);
    if(target_pcb == 0) {
        return -EBADPROC;
    }

    if(pcb_header->recv.obj) {
        goto recv_success;
        return 0;
    }

    if(timeout == 0) {
        return -EEMPTY;
    }

    pcb_header->recv.pid = target;
    scheduler_block_for_mail(pcb_header, timeout, target);
    
    if(!pcb_header->recv.obj) {
        pcb_header->recv.pid = -1;
        return -ETIMEOUT;
    }

recv_success:
    objdir_swapobj(pcb_header->recv.obj, dest_obj);
    obj_release(pcb_header->recv.obj);
    pcb_header->recv.obj = 0;
    pcb_header->recv.pid = -1;

    return 0;
}

pcb_t *pcb_frompid(pid_t pid)
{
    return (pcb_t*)rbtree_search((struct rbtree_node*)pcb_tree, pid);
}

jove_owned_obj_t*
process_current(void)
{
    return processor_getpcb(((processor_t*)processor_current()));
}

pid_t
pcb_getpid(pcb_t *pcb)
{
    return ((struct pcb_header*)pcb)->pid;
}

jove_obj_t*
pcb_getrootdir(pcb_t *pcb)
{
    return ((struct pcb_header*)pcb)->rootdir;
}

jove_owned_obj_t*
pcb_getpagedir(jove_owned_obj_t *rootdir_obj)
{
    return objdir_getlocal(rootdir_obj, PCB_ROOTDIR_PAGEDIR_I);
}

jove_owned_obj_t*
pcb_getself(jove_owned_obj_t *rootdir_obj)
{
    return objdir_getlocal(rootdir_obj, PCB_ROOTDIR_SELF_I);
}

enum pcb_state 
pcb_getstate(pcb_t *pcb)
{
    return ((struct pcb_header*)pcb)->state;
}

intmax_t 
pcb_getstatecode(pcb_t *pcb)
{
    return ((struct pcb_header*)pcb)->state_code;
}

void*
pcb_getksp(pcb_t *pcb)
{
    return ((struct pcb_header*)pcb)->ksp;
}

void**
pcb_getksp_ref(pcb_t *pcb)
{
    return &((struct pcb_header*)pcb)->ksp;
}