/*******************************************************
 Copyright (C) 2018-2021 Georges Da Costa <georges.da-costa@irit.fr>

    This file is part of Mojitos.

    Mojitos is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Mojitos is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with MojitO/S.  If not, see <https://www.gnu.org/licenses/>.

 *******************************************************/

#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>

struct temperature_t {
  char **label_list;
  int *fid_list;
  int nb_elem;
};
  
int get_string(char *filename, char *buffer, int max_size) {
  int fid = open(filename, O_RDONLY);
  //printf("Tries to open : %s : %d\n", filename, fid);
  if(fid == -1)
    return -1;
      
  int nb = read(fid, buffer, max_size);
  if(nb == -1) {
    close(fid);
    return -1;
  }

  buffer[nb]=0;
  close(fid);
  return 0;
}

void add_to_list(char ***list_name, char *source, int nb_elem) {
  //printf("Adds: %s\n", source);
  *list_name = realloc(*list_name, (nb_elem+1)*sizeof(char*));
  (*list_name)[nb_elem] = malloc(strlen(source)+1);
  strcpy((*list_name)[nb_elem], source);

}

void add_temperature_sensor(int id_rep, struct temperature_t *state) {
  static int key=0;
  static char buffer_filename[512];
  static char buffer_label[512];
  
  int delta = sprintf(buffer_label, "Temp_%d_", key);
  
  for(int i=1;;i++) {
    sprintf(buffer_filename, "/sys/class/hwmon/hwmon%d/temp%d_label", id_rep, i);
    if(get_string(buffer_filename, buffer_label+delta, 100) == -1)
      break;

    for(int pos = 0; pos < strlen(buffer_label); pos++) {
      if (buffer_label[pos] == ' ')  buffer_label[pos] = '_';
      if (buffer_label[pos] == '\n') buffer_label[pos] = '\0';
    }
    add_to_list(&state->label_list, buffer_label, state->nb_elem);

    sprintf(buffer_filename, "/sys/class/hwmon/hwmon%d/temp%d_input", id_rep, i);
    state->fid_list = realloc(state->fid_list, (state->nb_elem+1)*sizeof(int));
    state->fid_list[state->nb_elem] = open(buffer_filename, O_RDONLY);

    state->nb_elem++;
    // printf("%s : %s\n", buffer_label, buffer_filename);
  }
  
  key++;
}

unsigned int init_temperature(char *args, void** ptr) {
  struct temperature_t *state = malloc(sizeof(struct temperature_t));
  state->nb_elem = 0;
  state->label_list = NULL;
  state->fid_list = NULL;
  
  char base_name[] = "/sys/class/hwmon/hwmon%d/name";
  static char name[512];
  static char buffer[512];

  int i = 0;
  sprintf(name, base_name, i);
  while(get_string(name, buffer, 8) != -1) {
    if (strcmp(buffer, "coretemp")==0)
      add_temperature_sensor(i, state);

    i++;
    sprintf(name, base_name, i);
  }
  *ptr = (void*) state;
  return state->nb_elem;
}

unsigned int get_temperature(uint64_t* results, void* ptr) {
  struct temperature_t *state = (struct temperature_t*)ptr;
  static char buffer[512];
  for(int i=0; i<state->nb_elem; i++) {
    pread(state->fid_list[i], buffer, 100, 0);
    results[i] = strtoull(buffer, NULL, 10);
  }
  return state->nb_elem;
}

void clean_temperature(void* ptr) {
  struct temperature_t *state = (struct temperature_t*)ptr;
  
  for(int i=0; i<state->nb_elem; i++) {
    free(state->label_list[i]);
    close(state->fid_list[i]);
  }
  free(state->label_list);
  free(state->fid_list);
  free(state);
}

void label_temperature(char**labels, void* ptr) {
  struct temperature_t *state = (struct temperature_t*)ptr;
  for(int i=0; i<state->nb_elem; i++)
    labels[i] = state->label_list[i];
}