#include "types.h"
#include "fcntl.h"
#include "riscv.h"
#include "param.h"
#include "defs.h"
#include "memlayout.h"
#include "spinlock.h"
#include "proc.h"

uint64
sys_exit(void)
{
  int n;
  argint(0, &n);
  exit(n);
  return 0;  // not reached
}

uint64
sys_getpid(void)
{
  return myproc()->pid;
}

uint64
sys_fork(void)
{
  return fork();
}

uint64
sys_wait(void)
{
  uint64 p;
  argaddr(0, &p);
  return wait(p);
}

uint64
sys_sbrk(void)
{
  uint64 addr;
  int n;

  argint(0, &n);
  addr = myproc()->sz;
  if(growproc(n) < 0)
    return -1;
  return addr;
}

uint64
sys_sleep(void)
{
  int n;
  uint ticks0;


  argint(0, &n);
  acquire(&tickslock);
  ticks0 = ticks;
  while(ticks - ticks0 < n){
    if(killed(myproc())){
      release(&tickslock);
      return -1;
    }
    sleep(&ticks, &tickslock);
  }

  // backtrace();

  release(&tickslock);
  return 0;
}


#ifdef LAB_PGTBL
int
sys_pgaccess(void)
{
  uint64 base, mask;
  int len;

  
  argaddr(0, &base);
  argint(1, &len);
  argaddr(2, &mask);
  return pgaccess(base, len, mask);
}
#endif

uint64
sys_kill(void)
{
  int pid;

  argint(0, &pid);
  return kill(pid);
}

// return how many clock tick interrupts have occurred
// since start.
uint64
sys_uptime(void)
{
  uint xticks;

  acquire(&tickslock);
  xticks = ticks;
  release(&tickslock);
  return xticks;
}

uint64
sys_trace(void)
{
  argint(0, &myproc()->trace_mask);

  return -(myproc()->trace_mask <= 1);
}

uint64
sys_sysinfo(void)
{
  uint64 si; // user pointer to struct sysinfo

  argaddr(0, &si);
  return sys_info(si);
}

uint64
sys_sigalarm(void)
{
  struct proc *p = myproc();
  uint64 handler;

  argint(0, &p->alarm_interval);
  argaddr(1, &handler);
  p->alarm_handler = handler;

  return 0;
}

uint64
sys_sigreturn(void)
{
  struct proc *p = myproc();
  // retore saved trapframe to resume
  memmove(p->trapframe, p->atpfm, sizeof(struct trapframe));
  p->alarm_tickspassed = 0;
  p->alarm_caninvoke = 1;
  // make sure return the original a0 in trapframe to pass test3
  return p->trapframe->a0;
}

uint64
sys_mmap(void)
{
  uint64 addr, len, offset;
  int prot, flags, fd;
  struct file* file;

  argaddr(0, &addr);
  argaddr(1, &len);
  argint(2, &prot);
  argint(3, &flags);
  if(argfd(4, &fd, &file) == -1)
    return 0xffffffffffffffff;
  argaddr(5, &offset);

  if(!(fileperm(file) & PROT_WRITE) && (prot & PROT_WRITE) && (flags == MAP_SHARED))
    return 0xffffffffffffffff;

  return mmap(addr, len, prot, flags, fd, file, offset);
}

uint64
sys_munmap(void)
{
  uint64 addr, len;

  argaddr(0, &addr);
  argaddr(1, &len);

  return munmap(addr, len);
}