#include <process.h>
#include <utils.h>
#include <errcode.h>
#include <logger.h>
#include <thread.h>
#include <kmalloc.h>
#include <mman.h>
#include <exec.h>
#include <initrd.h>
#include <string.h>
#include <interrupt.h>

int32_t global_pid_counter = 0;

static inline
process_t *_make_process(const char *filename)
{
  process_t *ret = kmalloc(sizeof(process_t));

  file_node_t *file = initrd_get(initrd_root, filename);
  if (file == 0x0)
    panic(ERR_NOT_EXIST);

  *ret = (process_t){
    .pid = global_pid_counter++,
    .th = 0x0,

    .exitcode = 0,

    .stack = allocate_page(256),
    .stack_size = 256 << 12,

    .mem = allocate_page(256),
    .mem_size = 256 << 12,

    .regs = kmalloc(sizeof(trapframe_t)),
  };
  memcpy(ret->mem, file->filecontent, file->filesize);
  memset(ret->regs, 0x0, sizeof(trapframe_t));
  *ret->regs = (trapframe_t){
    .spsr_el1 = 0x0, // enable all interrupt
    .elr_el1 = (uint64_t)ret->mem,
    .sp_el0 = ((uint64_t)ret->stack + ret->stack_size - 64),
  };

  return ret;
}

// void run_process_by_name(const char *filename)
int32_t run_process_by_name(uint64_t param)
{
  const char *filename = (void *)param;
  thread_t *th = get_current();

  th->process = _make_process(filename);
  th->process->th = th;
  LOG("Run process by name"); DEBUG_THREAD(filename);
  LOG(th->process->stack); DEBUG_THREAD(th->process->regs->sp_el0);
  LOG(th->process->mem); DEBUG_THREAD(th->process->regs->elr_el1);

  disable_interrupt();
  user_exec(th->process->regs);

  __builtin_unreachable();
  return 0;
}

// void run_process(process_t *)
int32_t run_process(uint64_t param)
{
  process_t *process = (void *)param;
  thread_t *th = get_current();

  th->process = process;
  th->process->th = th;
  LOG("Run process"); DEBUG_THREAD(process->pid);

  disable_interrupt();
  user_exec(th->process->regs);

  __builtin_unreachable();
  return 0;
}

process_t *fork_process(const process_t *from)
{
  process_t *ret = kmalloc(sizeof(process_t));
  *ret = (process_t){
    .pid = global_pid_counter++,
    .th = 0x0,

    .exitcode = from->exitcode,

    .stack = allocate_page(256),
    .stack_size = 256 << 12,

    .mem = allocate_page(256),
    .mem_size = 256 << 12,

    .regs = kmalloc(sizeof(trapframe_t)),
  };
  memcpy(ret->stack, from->stack, from->stack_size);
  memcpy(ret->mem, from->mem, from->mem_size);
  *ret->regs = (trapframe_t){
    .x0 = 0, // fork return value
    .fp = from->regs->fp - (uint64_t)from->stack + (uint64_t)ret->stack,
    .lr = from->regs->lr - (uint64_t)from->mem + (uint64_t)ret->mem,
    .sp_el0 = from->regs->sp_el0 - (uint64_t)from->stack + (uint64_t)ret->stack,
    .elr_el1 = from->regs->elr_el1 - (uint64_t)from->mem + (uint64_t)ret->mem,
  };

  return ret;
}