#include <stdio.h>
#include <drivers/irq.h>

#include <mm/pmm.h>
#include <mm/paging.h>

#include <tty.h>

#include <drivers/serio.h>

#include <kernel/syscall.h>


/*
Espresso has two types of syscalls.

one: int 16, the only one I've worked on. should be able to be used in kernel code and user-space.
two: syscall/sysenter, the ones I haven't worked on because it has to do with userspace code.
*/


/*
NOTE: passing arguments to fuctions
to pass args to functions, use all registers except eax,
so ebx is arg0, ecx arg1, edx arg2, esi arg3, edi arg4, ebp arg5
*/

void init_sysints(void)
{
  /* actually nothing to do */
  
  set_irq_handler(16, (irq_func_t) int16_handler);
}

/* 0 in eax means success most of the time */
registers_t* int16_handler(registers_t* regs)
{
  //printf("eax: %0x%x\n", regs->eax);

  uint32_t eax = regs->eax;

  if (eax >= __ENUM_END_MARKER__)
  {
    printf("Invalid system call %i\n", eax);
    return regs;
  }
  
  switch (eax)
  {
    case SYS_MAP_PAGE:
      map_page((void*) regs->ebx, (void*) regs->ecx);
      break;
    case SYS_PMM_ALLOC_PAGE:
      eax = (uint32_t) pmm_alloc_page();
      break;
    case SYS_PMM_FREE_PAGE:
      pmm_free_page((void*) regs->ebx);
      break;
    case SYS_SERIAL_WRITE:
      serial_write(regs->ebx);
      break;
    case SYS_SERIAL_READ:
      eax = serial_read();
      break;
    case SYS_SERIAL_PUTS:
      serial_puts((const char*) regs->ebx);
      break;
    case SYS_USE_SERIAL:
      eax = use_serial();
      break;
    case SYS_TERMINAL_SCROLL:
      terminal_scroll();
      break;
    case SYS_TERMINAL_CLEAR:
      terminal_clear();
      break;
    case SYS_TERMINAL_SET_CURSOR:
      terminal_set_cursor(regs->ebx, regs->ecx);
      break;
    case SYS_TERMINAL_GET_CURSOR:
      terminal_get_cursor((int*) regs->ebx, (int*) regs->ecx);
      break;
    case SYS_TERMINAL_WRITE:
      terminal_write((const char*) regs->ebx, regs->ecx);
      break;
    case SYS_TERMINAL_WRITESTRING:
      terminal_writestring((const char*) regs->ebx);
      break;
    case SYS_TERMINAL_DEBUG_WRITESTRING:
      terminal_debug_writestring((const char*) regs->ebx);
      break;
    case SYS_TERMINAL_PUTCHAR:
      terminal_putchar(regs->ebx);
      break;
    case SYS_TERMINAL_PUTENTRYAT:
      terminal_putentryat(regs->ebx, regs->ecx, regs->edx, regs->esi);
      break;
    case SYS_TERMINAL_GETCOLOR:
      eax = terminal_getcolor();
      break;
    case SYS_TERMINAL_SETCOLOR:
      terminal_setcolor(regs->ebx);
      break;
    case SYS_READ:
      eax = read(regs->ebx, (void*) regs->ecx, regs->edx);
      break;
    case SYS_WRITE:
      eax = write(regs->ebx, (void*) regs->ecx, regs->edx);
      break;
    default:
      printf("nothing happened.\n");
      break;
  }

  regs->eax = eax;
  
  return regs;
}