#include "pk.h"
#include "file.h"
#include "frontend.h"
#include <stdint.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>

int vsnprintf(char* out, size_t n, const char* s, va_list vl)
{
  bool format = false;
  bool longarg = false;
  size_t pos = 0;
  for( ; *s; s++)
  {
    if(format)
    {
      switch(*s)
      {
        case 'l':
          longarg = true;
          break;
        case 'p':
          longarg = true;
          if (++pos < n) out[pos-1] = '0';
          if (++pos < n) out[pos-1] = 'x';
        case 'x':
        {
          long num = longarg ? va_arg(vl, long) : va_arg(vl, int);
          for(int i = 2*(longarg ? sizeof(long) : sizeof(int))-1; i >= 0; i--) {
            int d = (num >> (4*i)) & 0xF;
            if (++pos < n) out[pos-1] = (d < 10 ? '0'+d : 'a'+d-10);
          }
          longarg = false;
          format = false;
          break;
        }
        case 'd':
        {
          long num = longarg ? va_arg(vl, long) : va_arg(vl, int);
          if (num < 0) {
            num = -num;
            if (++pos < n) out[pos-1] = '-';
          }
          long digits = 1;
          for (long nn = num; nn /= 10; digits++)
            ;
          for (int i = digits-1; i >= 0; i--) {
            if (pos + i + 1 < n) out[pos + i] = '0' + (num % 10);
            num /= 10;
          }
          pos += digits;
          longarg = false;
          format = false;
          break;
        }
        case 's':
        {
          const char* s2 = va_arg(vl,const char*);
          while(*s2)
            if (++pos < n) out[pos-1] = *s2++;
          longarg = false;
          format = false;
          break;
        }
        case 'c':
        {
          if (++pos < n) out[pos-1] = (char)va_arg(vl,int);
          longarg = false;
          format = false;
          break;
        }
        default:
          panic("bad fmt");
      }
    }
    else if(*s == '%')
      format = true;
    else
      if (++pos < n) out[pos-1] = *s;
  }
  if (pos < n)
    out[pos] = 0;
  else if (n)
    out[n-1] = 0;
  return pos;
}

static void vprintk(const char* s, va_list vl)
{
  char out[256]; // XXX
  int res = vsnprintf(out, sizeof(out), s, vl);
  file_write(stderr, out, res < sizeof(out) ? res : sizeof(out));
}

void printk(const char* s, ...)
{
  va_list vl;
  va_start(vl, s);

  vprintk(s, vl);

  va_end(vl);
}

int snprintf(char* out, size_t n, const char* s, ...)
{
  va_list vl;
  va_start(vl, s);
  int res = vsnprintf(out, n, s, vl);
  va_end(vl);
  return res;
}

void dump_tf(trapframe_t* tf)
{
  static const char* regnames[] = {
    "z ", "ra", "sp", "gp", "tp", "t0",  "t1",  "t2",
    "s0", "s1", "a0", "a1", "a2", "a3",  "a4",  "a5",
    "a6", "a7", "s2", "s3", "s4", "s5",  "s6",  "s7",
    "s8", "s9", "sA", "sB", "t3", "t4",  "t5",  "t6"
  };

  tf->gpr[0] = 0;

  for(int i = 0; i < 32; i+=4)
  {
    for(int j = 0; j < 4; j++)
      printk("%s %lx%c",regnames[i+j],tf->gpr[i+j],j < 3 ? ' ' : '\n');
  }
  printk("pc %lx va %lx insn       %x sr %lx\n", tf->epc, tf->badvaddr,
         (uint32_t)tf->insn, tf->status);
}

void do_panic(const char* s, ...)
{
  va_list vl;
  va_start(vl, s);

  vprintk(s, vl);
  die(-1);

  va_end(vl);
}

void kassert_fail(const char* s)
{
  register uintptr_t ra asm ("ra");
  do_panic("assertion failed @ %p: %s\n", ra, s);
}