/*  This file is part of cputemp2maxfreq.

    Copyright (C) 2023-2024 pa4wdh

    cputemp2maxfreq 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.

    cputemp2maxfreq 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 cputemp2maxfreq; see the file COPYING.  If not, see
    <http://www.gnu.org/licenses>.
*/
#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
#include "cputemp2maxfreq.h"
#include "debug.h"
#include "sysfs.h"
#include "cputemp.h"

extern struct s_config config;

// Check if the sensor matches our search criteria and validate the readout
void cputemp_match_and_validate(char *name_file,char *input_file,char *sensor_name,struct s_sensor *sensor)
{
 int datalen;
 long int testdata;
 char buf[255];

// Read the name to see if it matches what we're looking for
 datalen=sysfs_read_str(name_file,buf,sizeof(buf));

 if (datalen<0)
 {
  DEBUG2_CPUTEMP("Failed to read name\n");
  return;
 }

 DEBUG1_CPUTEMP("Name is: %s\n",buf);
 if (strncasecmp(buf,sensor_name,255)==0)
 {
  DEBUG2_CPUTEMP("Name machtes our search criteria\n");
  DEBUG1_CPUTEMP("Input filename: %s\n",input_file);
 
// Validate the sensor by reading it
  testdata=sysfs_read_long_int(input_file);
  DEBUG2_CPUTEMP("Input value: %ld\n",testdata);
  if ((testdata>=VALID_TEMP_MIN) && (testdata<=VALID_TEMP_MAX))
  {
   DEBUG1_CPUTEMP("Input data is valid, marking sensor as valid\n");
   sensor->valid=1;
   strncpy(sensor->name,buf,sizeof(buf));
   strncpy(sensor->filename,input_file,sizeof(sensor->filename));
  } else {
   DEBUG1_CPUTEMP("Input data is invalid, ignoring sensor\n");
  }
 }
}

// Validate if we found a file named temp<number>_label
int cputemp_is_label(char *name)
{
 int count;
 int offset;

// Start with "temp"
 if (strncmp(name,"temp",4)!=0) return 0;

// Must contain an underscore
 offset=0;
 for(count=5;count<7;count++)
 {
  if (name[count]=='_')
  {
   offset=count+1;
   break;
  }
 }
 if (offset==0) return 0;

// Ends with "label"
 if (strncmp(name+offset,"label",5)!=0) return 0;
 if (name[offset+5]==0) return 1;

 return 0;
}

// Read a single hwmon directory and search for the requested sensor name
void cputemp_read_hwmon(char *hwmon,char *sensor_name,struct s_sensor *sensor)
{
 DIR *hwmon_dir;
 struct dirent *hwmon_dirent;
 char name_file[258];
 char input_file[255];
 int offset;

 DEBUG1_CPUTEMP("Searching for sensors in %s\n",hwmon);

 hwmon_dir=opendir(hwmon);
 if (hwmon_dir==NULL)
 {
  DEBUG1_CPUTEMP("Failed to open hwmon dir\n");
  return;
 }

 hwmon_dirent=readdir(hwmon_dir);
 while((hwmon_dirent!=NULL) && (sensor->valid==0))
 {
  DEBUG3_CPUTEMP("%s\n",hwmon_dirent->d_name);

  if (cputemp_is_label(hwmon_dirent->d_name))
  {
   DEBUG2_CPUTEMP("Found label %s\n",hwmon_dirent->d_name);
   snprintf(name_file,258,"%s/%s",hwmon,hwmon_dirent->d_name);
   snprintf(input_file,258,"%s/%s",hwmon,hwmon_dirent->d_name);
   offset=(int) strlen(input_file)-5;
   strncpy(input_file+offset,"input",6);
   cputemp_match_and_validate(name_file,input_file,sensor_name,sensor);
  }
  hwmon_dirent=readdir(hwmon_dir);
 }
 closedir(hwmon_dir);

// Some drivers do note have labels, so check the driver too if we didn't find anything so far
 if (sensor->valid==0)
 {
  DEBUG2_CPUTEMP("Checking driver name\n");
  sprintf(name_file,"%s/name",hwmon);
  sprintf(input_file,"%s/temp1_input",hwmon);
  cputemp_match_and_validate(name_file,input_file,sensor_name,sensor);
 }
}

// Find all entries under /sys/class/hwmon and check them with
// cputemp_read_hwmon
void cputemp_find_sensor(char *sensor_name,struct s_sensor *sensor)
{
 DIR *hwmon_dir;
 struct dirent *hwmon_dirent;
 char subdir[273];

 DEBUG1_CPUTEMP("Searching for sensor %s\n",sensor_name);

// Mark sensor data as invalid, it will be set valid if we find something
 sensor->valid=0;

 hwmon_dir=opendir("/sys/class/hwmon");
 if (hwmon_dir==NULL)
 {
  DEBUG1_CPUTEMP("Failed to open /sys/class/hwmon, is sysfs mounted?\n");
  return;
 }

 hwmon_dirent=readdir(hwmon_dir);
 while((hwmon_dirent!=NULL) && (sensor->valid==0))
 {
  DEBUG3_CPUTEMP("Found file: %s\n",hwmon_dirent->d_name);

// If the name starts with hwmon try to read it
// Note that /sys/class/hwmon actually contains symlinks but we treat them like directories
  if (strncmp(hwmon_dirent->d_name,"hwmon",5)==0)
  {
   snprintf(subdir,273,"/sys/class/hwmon/%s",hwmon_dirent->d_name);
   DEBUG2_CPUTEMP("Found hwmon entry: %s\n",subdir);
   cputemp_read_hwmon(subdir,sensor_name,sensor);
  }
  hwmon_dirent=readdir(hwmon_dir);
 }
 closedir(hwmon_dir);
}