/*  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 <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include "sysfs.h"
#include "cpufreq.h"
#include "debug.h"
#include "cputemp2maxfreq.h"
#include "failsafe.h"
#include "version.h"
#include "argparse.h"
#include "logger.h"
#include "cputemp.h"
#include "cpulist.h"

// Set default config
struct s_config config={
 .name="",                 // Name of this program, set by argparse
 .governor="conservative", // Governor
 .target_temp=70000,       // Target temperature
 .temp_input="auto",       // Temperature input
 .freq_step=100000,        // Frequency step
 .fallback_freq=2000000,   // Fallback frequency
 .interval=10,             // Interval
 .logger_name="stdout",    // Logger name
 .logger=&logger_stdout,   // Logger function
 .log_data=0,              // Don't log measurement data
 .csvlog="",               // CSV logfile
 .csvoverwrite=0,          // Don't overwrite CSV logfile
 .csvfile=NULL,            // File handler for CSV file
 .use_unixtime=0,          // Don't use unix timestamps in log outputs
 .transition_latency=-1,   // Transition latency, default to autodetect
 .keepstate=0,             // Do not keep state on exit (Set lowest frequency)
 .cpu=-1,                  // Physical CPU to change
};

struct s_cpudata cpudata={
 .min_freq=0,           // CPU's minimum frequency
 .max_freq=0,           // CPU's maximum frequency
 .cur_freq=0,           // CPU's current frequency
 .cur_temp=0,           // CPU's current temperature
 .scale_max=0,          // Governor's maximum scaling frequency
 .transition_latency=0, // CPU's transition latency
 .cpulist=NULL,         // Pointer to the cpulist, set by cpulist_find_cpus
 .cpulist_len=0,        // Number of CPU's in cpulist, set by cpulist_find_cpus
};

void signal_handler(int signum)
{
 config.logger("Received signal %d, exiting.",signum);
 failsafe(0);
}

char *transition_latency_remarks[] = {
 "Autodetected",
 "Set via commandline",
 "This seems low, consider setting it via -d"
};

char *autodetect_sensors[] = {
 "Package id 0",
 "Tctl",
 "k10temp",
 NULL
};

int main(int argc,char **argv)
{
 int count;
 long int diff;
 long int newfreq;
 struct s_sensor sensor;
 char *transition_latency_remark;
 char sensor_string[20];
 struct sigaction sigact={0};

 argparse(argc,argv);
 config.logger("%s version %s, buildtime %s %s",config.name,version(),__DATE__,__TIME__);

// Log configuration
 config.logger("Configuration:");
 config.logger("Governor: %s",config.governor);
 config.logger("Target temperature: %ld",config.target_temp);
 config.logger("Temp input: %s",config.temp_input);
 config.logger("Frequency step: %ld",config.freq_step);
 config.logger("Fallback frquency: %ld",config.fallback_freq);
 config.logger("Interval: %d",config.interval);
 config.logger("Logger: %s (%p)",config.logger_name,config.logger);
 config.logger("Log measurement data: %d",config.log_data);
 if (config.csvlog[0]==0)
 {
  config.logger("CSV Log file: Disabled");
 } else {
  config.logger("CSV Log file: %s",config.csvlog);
  config.logger("Overwrite CSV log: %d",config.csvoverwrite);
 }
 config.logger("Use unix timestamps: %d",config.use_unixtime);
 if (config.transition_latency<0)
 {
  config.logger("Transition latency: Autodetect");
 } else {
  config.logger("Transition latency: %d",config.transition_latency);
 }
 if (config.keepstate==1)
 {
  config.logger("State on exit: Keep last state on normal exit");
 } else {
  config.logger("State on exit: Always set CPU to lowest frequency");
 }
 if (config.cpu<0)
 {
  config.logger("Physical CPU to change: all");
 } else {
  config.logger("Physical CPU to change: %d",config.cpu);
 }

 if ((config.target_temp<VALID_TEMP_MIN) || (config.target_temp>VALID_TEMP_MAX))
 {
  config.logger("Invalid temperature, range is %d-%d",VALID_TEMP_MIN,VALID_TEMP_MAX);
  exit(1);
 }

 if ((config.freq_step<VALID_STEP_MIN) || (config.freq_step>VALID_STEP_MAX))
 {
  config.logger("Invalid frequency step, range is %d-%d",VALID_STEP_MIN,VALID_STEP_MAX);
  exit(1);
 }

 if ((config.interval<VALID_INTERVAL_MIN) || (config.interval>VALID_INTERVAL_MAX))
 {
  config.logger("Invalid poll interval, range is %d-%d",VALID_INTERVAL_MIN,VALID_INTERVAL_MAX);
  exit(1);
 }

// Autodetect temperature input if needed
 if (config.temp_input[0]!='/')
 {
  if (strcmp(config.temp_input,"auto")==0)
  {
   config.logger("Starting temperature sensor autodetection");
   sensor.valid=0;
   if (config.cpu>=0)
   {
    sprintf(sensor_string,"Package id %d",config.cpu);
    DEBUG1_MAIN("Searching for sensor \"%s\" because of -P option\n",sensor_string);
    cputemp_find_sensor(sensor_string,&sensor);
   }
   if (sensor.valid==0)
   {
    for(count=0;autodetect_sensors[count]!=NULL;count++)
    {
     DEBUG1_MAIN("Searching for sensor \"%s\"\n",autodetect_sensors[count]);
     cputemp_find_sensor(autodetect_sensors[count],&sensor);
     if (sensor.valid==1) break;
    }
   }
  } else {
   DEBUG1_MAIN("Starting temperature sensor detection with name \"%s\"\n",config.temp_input);
   cputemp_find_sensor(config.temp_input,&sensor);
  }
  if (sensor.valid==1)
  {
   DEBUG1_MAIN("Found sensor \"%s\"\n",sensor.name);
   DEBUG1_MAIN("Sensor file: %s\n",sensor.filename);
   strncpy(config.temp_input,sensor.filename,sizeof(config.temp_input));
   config.logger("Detection returned temperature input: %s",config.temp_input);
   config.logger("Temperature input name: %s",sensor.name);
  } else {
   config.logger("Detection failed to return a valid sensor, set it using -i");
   exit(1);
  }
 }

// Find CPU's
 cpulist_find_cpus();
 if (cpudata.cpulist_len==0)
 {
  if (config.cpu>=0)
  {
   config.logger("No CPU's found for physical CPU %d, exiting",config.cpu);
  } else {
   config.logger("Failed to find any CPU, is sysfs mounted?");
  }
  exit(1);
 }

// Get and validate CPU data
 cpudata.min_freq=cpufreq_get_long_int("cpuinfo_min_freq");
 cpudata.max_freq=cpufreq_get_long_int("cpuinfo_max_freq");
 cpudata.scale_max=cpufreq_get_long_int("scaling_max_freq");
 if (config.transition_latency<0)
 {
  transition_latency_remark=transition_latency_remarks[0];
  cpudata.transition_latency=cpufreq_get_long_int("cpuinfo_transition_latency");
  if (cpudata.transition_latency<1000)  transition_latency_remark=transition_latency_remarks[2];
 } else {
  transition_latency_remark=transition_latency_remarks[1];
  cpudata.transition_latency=config.transition_latency;
 }

 config.logger("CPU data:");
 config.logger("Number of CPU's: %d",cpudata.cpulist_len);
 config.logger("Minimum frequency: %ld",cpudata.min_freq);
 config.logger("Maximum frequency: %ld",cpudata.max_freq);
 config.logger("Scaling maximum frequency: %ld",cpudata.scale_max);
 config.logger("Transition Latency: %ld (%s)",cpudata.transition_latency,transition_latency_remark);

 if ((cpudata.min_freq<VALID_FREQ_MIN) || (cpudata.min_freq>VALID_FREQ_MAX) ||
     (cpudata.max_freq<VALID_FREQ_MIN) || (cpudata.max_freq>VALID_FREQ_MAX) ||
     (cpudata.scale_max<VALID_FREQ_MIN) || (cpudata.scale_max>VALID_FREQ_MAX) ||
     (cpudata.transition_latency<VALID_TRANS_MIN) || (cpudata.transition_latency>VALID_TRANS_MAX))
 {
// If we have to fail now, there's not much we can do because we have no data
  config.logger("Invalid CPU data, exiting");
  cpulist_free();
  exit(1);
 }

// Modify fallback frequency if needed
 if (config.fallback_freq<cpudata.min_freq)
 {
  config.logger("Fallback frequency is lower than CPU's minimum frequency, setting to %ld",cpudata.min_freq);
  config.fallback_freq=cpudata.min_freq;
 }
 if (config.fallback_freq>cpudata.max_freq)
 {
  config.logger("Fallback frequency is higher than CPU's maximum frequency, setting to %ld",cpudata.max_freq);
  config.fallback_freq=cpudata.max_freq;
 }

// Set the governor
 if (strcmp(config.governor,"keep")!=0)
 {
  if (cpufreq_set_str("scaling_governor",config.governor,0)<0)
  {
   config.logger("Failed to set governor, error %d (%s)",errno,strerror(errno));

// We failed to set the governor, call the failsafe
   failsafe(1);
  }
 }

// Initialise CSV logging
 if (config.csvlog[0]!=0) csvlog_init();

// Set signal handlers
 sigact.sa_handler=&signal_handler;
 sigemptyset(&sigact.sa_mask);
 sigaddset(&sigact.sa_mask,SIGTERM);
 sigaddset(&sigact.sa_mask,SIGINT);
 sigaddset(&sigact.sa_mask,SIGQUIT);
 sigaction(SIGTERM,&sigact,NULL);
 sigaction(SIGINT,&sigact,NULL);
 sigaction(SIGQUIT,&sigact,NULL);

 while(1)
 {
// Get new measurements
  cpudata.cur_freq=cpufreq_get_long_int("scaling_cur_freq");
  if ((cpudata.cur_freq<VALID_FREQ_MIN) || (cpudata.cur_freq>VALID_FREQ_MAX))
  {
   config.logger("Invalid current frequency reported by CPU, exiting");
   failsafe(1);
  }

  cpudata.cur_temp=sysfs_read_long_int(config.temp_input);
  if ((cpudata.cur_temp<VALID_TEMP_MIN) || (cpudata.cur_temp>VALID_TEMP_MAX))
  {
   config.logger("Invalid current temperature reported by CPU, exiting");
   failsafe(1);
  }

  cpudata.scale_max=cpufreq_get_long_int("scaling_max_freq");
  if ((cpudata.scale_max<VALID_FREQ_MIN) || (cpudata.scale_max>VALID_FREQ_MAX))
  {
   config.logger("Invalid scale_max_freq reported, exiting");
   failsafe(1);
  }

  DEBUG1_MAIN("Data: %ld %ld %ld %ld %ld\n",cpudata.cur_temp,config.target_temp,cpudata.max_freq,cpudata.scale_max,cpudata.cur_freq);
  if (config.log_data>0)
  {
   config.logger("CPU Temperature: %ld, CPU Frequency: %ld",cpudata.cur_temp/1000,cpudata.cur_freq);
  }
  if (config.csvfile!=NULL) csvlog_write();

  diff=config.target_temp-cpudata.cur_temp;

// Check if we should increase
  if ((diff>=1000) && (cpudata.scale_max<cpudata.max_freq))
  {
   newfreq=cpudata.scale_max+(config.freq_step*(diff/1000));
   if (newfreq>cpudata.max_freq) newfreq=cpudata.max_freq;
   DEBUG1_MAIN("Increase to %ld\n",newfreq);
   config.logger("Increase scaling_max_freq to %ld",newfreq);

// Set new value and validate
   if (cpufreq_set_long_int("scaling_max_freq",newfreq,cpudata.transition_latency)<0)
   {
    config.logger("Failed to set scaling_max_freq, exiting");
    failsafe(1);
   }
  }

// Check if we should decrease
  if ((diff<=-1000) && (cpudata.scale_max>cpudata.min_freq))
  {
   newfreq=cpudata.scale_max+(config.freq_step*(diff/1000));
   if (newfreq<cpudata.min_freq) newfreq=cpudata.min_freq;
   DEBUG1_MAIN("Decrease to %ld\n",newfreq);
   config.logger("Decrease scaling_max_freq to %ld",newfreq);

// Set new value and validate
   if (cpufreq_set_long_int("scaling_max_freq",newfreq,cpudata.transition_latency)<0)
   {
    config.logger("Failed to set scaling_max_freq, exiting");
    failsafe(1);
   }
  }

  sleep(config.interval);
 }
}