#include <aux/elf.h>
#include <libk/std.h>
#include <libk/string.h>
#include <mm/liballoc.h>
#include <mm/pmm.h>
#include <proc/proc.h>
#include <sync/spin_lock.h>

struct proc* proc_from_elf (uint8_t* elf_contents) {
  struct proc* proc = malloc (sizeof (*proc));
  if (proc == NULL)
    return NULL;

  memset (proc, 0, sizeof (*proc));

  proc->pd.lock = SPIN_LOCK_INIT;
  proc->pd.cr3_paddr = mm_alloc_user_pd_phys ();
  if (proc->pd.cr3_paddr == 0) {
    free (proc);
    return NULL;
  }

  proc->pdata.syscall_stack = pmm_alloc (KSTACK_SIZE / PAGE_SIZE);
  if (proc->pdata.syscall_stack == PMM_ALLOC_ERR) {
    free (proc);
    return NULL;
  }

  proc->pdata.user_stack = pmm_alloc (USTACK_SIZE / PAGE_SIZE);
  if (proc->pdata.user_stack == PMM_ALLOC_ERR) {
    free (proc);
    pmm_free (proc->pdata.syscall_stack, USTACK_SIZE / PAGE_SIZE);
    return NULL;
  }

  uintptr_t user_stack = proc->pdata.user_stack;

  proc->pdata.syscall_stack += KSTACK_SIZE;
  proc->pdata.user_stack += USTACK_SIZE;

  proc_map (proc, user_stack, PROC_USTACK_TOP - USTACK_SIZE, USTACK_SIZE / PAGE_SIZE,
            MM_PG_USER | MM_PG_PRESENT | MM_PG_RW);

  struct elf_aux aux = proc_load_segments (proc, elf_contents);

  proc->pdata.regs.ss = 0x20 | 0x03;
  proc->pdata.regs.rsp = (uint64_t)PROC_USTACK_TOP;
  proc->pdata.regs.rflags = 0x202;
  proc->pdata.regs.cs = 0x18 | 0x03;
  proc->pdata.regs.rip = aux.entry;
  proc->lock = SPIN_LOCK_INIT;
  atomic_store (&proc->state, PROC_READY);

  return proc;
}