#include "command.h"

#include "memory.h"
#include "discovery.h"
#include "io.h"
#include "utils.h"
#include "config.h"

#include <assert.h>
#include <unistd.h>
#include <sys/wait.h>

// TODO: This file is UNSAFE. This file is purely here for MVP purposes, and to self-host this program itself.

Command command_create_f_to_o(CommandOptions* co)
{
  assert(co != NULL);

  size_t len_args = 6;

  size_t flag_count = 0;

  StringView* dep_flags_buf = NULL;
  
  switch(co->bp)
  {
  case B_DEBUG:
    len_args += co->c->debug_compiler_flags_c;
    flag_count = co->c->debug_compiler_flags_c;
    dep_flags_buf = co->c->debug_compiler_flags;
    break;
  case B_PROD:
    len_args += co->c->prod_compiler_flags_c;
    flag_count = co->c->prod_compiler_flags_c;
    dep_flags_buf = co->c->prod_compiler_flags;
    break;
  default:
    DIE("No configuration was selected!");
  }
  
  const char** args_buf = (const char**)arena_alloc(co->a, sizeof(const char*) * len_args);
  args_buf[0] = co->app.buf;
  args_buf[1] = "-c";
  args_buf[2] = co->files[0].buf;
  args_buf[3] = "-o";

  StringView o_ext = STR_LIT(co->sp, ".o");
  StringView f_o = string_concat_ss(co->sp, &co->files[0], &o_ext);
  args_buf[4] = f_o.buf;
  args_buf[5] = "-MMD";
  
  for (size_t i = 0; i < flag_count; i++)
  {
    args_buf[i + 5] = dep_flags_buf[i].buf;
  }

  args_buf[len_args] = NULL;

  LOG_DEBUG("Command created, first 4 args: %s %s %s %s %s | total args: %d", args_buf[0], args_buf[1], args_buf[2], args_buf[3], args_buf[4], len_args);
  
  return (Command){.a = co->a, .app = co->app, .args = args_buf};
}

// TODO: Add input sanitization to cmd->app and cmd->args
int command_run(Command* cmd)
{
  assert(cmd != NULL);
  if(cmd->args == NULL) DIE("No arguments were supplied to the command");

  pid_t pid = fork();

  if(pid == -1) DIE("fork failed, could not create child process.");
  
  if(pid == 0)
  {
    if(execvp(cmd->app.buf, (char*const*)cmd->args) == -1)
      DIE("Failed to launch command: %s.", cmd->app.buf);
  }

  int wstatus = 0;
  if(waitpid(pid, &wstatus, 0) == -1) DIE("wait failed.");
  LOG_DEBUG("Command calling app %s exited with status code %d on child process PID %d.", cmd->app.buf, wstatus, pid);
  return wstatus;
}