/*
 * This file is part of fwm-sysdaemon
 *  get_powerstat.c - retrieve power status information from kernel
 *
 * Copyright (c) 2021, 2022 firk (firk@cantconnect.ru)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The origin of this software must not be misrepresented; you must
 *    not claim that you wrote the original software.
 * 4. Altered versions in any form must be plainly marked as such, and
 *    must not be misinterpreted as being the original software.
 *
 * This software is provided by the author and contributors `as is'
 * without any express or implied warranty.
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "util.h"
#include "get_powerstat.h"

static void get_ac_stat(powerstat *r, int dd) {
  char tmp[30];
  if(txtfile_read(dd, "online", tmp, sizeof(tmp), NULL)<0) r->get_ac_err = 1;
  else if(atoi(tmp)) r->is_ac_powered = 1;
}

static void get_bat_stat(powerstat *r, int dd) {
  int h1, h2;
  char tmp[30];
  ull u;
  h1 = h2 = 0;
  
  if(txtfile_read(dd, "status", tmp, sizeof(tmp), NULL)<0) r->get_bat_err = 1; else {
    if(!strcmp(tmp,"Charging")) r->is_charging = 1;
  }
  if(txtfile_read(dd, "energy_now", tmp, sizeof(tmp), NULL)<0) r->get_bat_err = 1; else {
    if(!parse_ull(tmp, &u)) r->get_bat_err = 1; else { h1=1; r->charged = u; }
  }
  if(txtfile_read(dd, "energy_full", tmp, sizeof(tmp), NULL)<0) r->get_bat_err = 1; else {
    if(!parse_ull(tmp, &u)) r->get_bat_err = 1; else { h2=1; r->total = u; }
  }
  if(txtfile_read(dd, "capacity", tmp, sizeof(tmp), NULL)<0) r->get_bat_err = 1; else {
    if(!parse_ull(tmp, &u)) r->get_bat_err = 1; else r->charge_pctt = (u<=100)?(u*10):1000;
  }
  if(h1 && h2) {
    if(r->charged<r->total) r->charge_pctt = r->charged*1000 / r->total;
    else r->charge_pctt = 1000;
  }
}

extern int get_powerstat(powerstat * r, char const *batname, char const *acname) {
  int powfd, dd, e;
  DIR *dp;
  struct dirent * de;
  char type[30];

  bzero(r, sizeof(*r));
  r->is_ac_powered = 0;
  r->is_charging = 0;
  r->charge_pctt = -1;
  r->get_ac_err = -1;
  r->get_bat_err = -1;
  while((powfd = open("/sys/class/power_supply", O_DIRECTORY))<0) if(errno!=EINTR) return -1;
  if(acname) {
    if(!*acname) r->get_ac_err = 0;
    else if((dd = openat(powfd, acname, O_DIRECTORY))<0) r->get_ac_err = 1;
    else { r->get_ac_err = 0; get_ac_stat(r, dd); close(dd); }
  }
  if(batname) {
    if(!*batname) r->get_bat_err = 0;
    else if((dd = openat(powfd, batname, O_DIRECTORY))<0) r->get_bat_err = 1;
    else { r->get_bat_err = 0; strncpy(r->batname, batname, sizeof(r->batname)); get_bat_stat(r, dd); close(dd); }
  }
  if(acname && batname) { close(powfd); return 0; }
  if(!(dp = fdopendir(powfd))) { e=errno; close(powfd); errno=e; return -1; }
  while(errno=0, de=readdir(dp)) {
    if(*de->d_name=='.') continue;
    if((dd = openat(powfd, de->d_name, O_DIRECTORY))<0) continue;
    if(txtfile_read(dd, "type", type, sizeof(type), NULL)>=0) {
      if(!acname && !strcmp(type,"Mains")) { r->get_ac_err = 0; get_ac_stat(r, dd); }
      else if(!batname && !strcmp(type,"Battery")) { r->get_bat_err = 0; strncpy(r->batname, de->d_name, sizeof(r->batname)); get_bat_stat(r, dd); }
    }
    close(dd);
  }
  e = errno;
  closedir(dp);
  if(e) { errno = e; return -1; }
  return 0;
}