#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"

// Set default config
struct s_config config={
 "",             // Name of this program, set by argparse
 "conservative", // Governor
 70000,          // Temperature
 "/sys/devices/virtual/thermal/thermal_zone0/temp", // Temperature input
 100000,         // Frequency step
 2000000,        // Fallback frequency
 10,             // Interval
 "stdout",       // Logger name
 &logger_stdout, // Logger function
 0,              // Don't log measurement data
 "",             // CSV logfile
 0,              // Don't overwrite CSV logfile
 NULL,           // File handler for CSV file
 0,              // Don't use unix timestamps in log outputs
};
struct s_cpudata cpudata;

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

int main(int argc,char **argv)
{
 long int diff;
 long int newfreq;

 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("Temperature: %ld",config.max_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.max_temp<VALID_TEMP_MIN) || (config.max_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);
 }

// Get and validate CPU data
 cpudata.min_freq=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq");
 cpudata.max_freq=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq");
 cpudata.scale_max=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq");
 cpudata.transition_latency=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency");

 config.logger("CPU data:");
 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",cpudata.transition_latency);

 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");
  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
 signal(SIGTERM,signal_handler);
 signal(SIGINT,signal_handler);
 signal(SIGQUIT,signal_handler);

 while(1)
 {
// Get new measurements
  cpudata.cur_freq=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/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 tempature reported by CPU, exiting");
   failsafe(1);
  }

  DEBUG1_MAIN("Data: %ld %ld %ld %ld %ld\n",cpudata.cur_temp,config.max_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();

// Check if we should increase
  if ((cpudata.cur_temp<config.max_temp) && (cpudata.scale_max<cpudata.max_freq))
  {
   diff=(config.max_temp-cpudata.cur_temp)/1000;
   newfreq=cpudata.scale_max+(config.freq_step*diff);
   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);
   }
   cpudata.scale_max=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/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);
   }
  }

// Check if we should decrease
  if ((cpudata.cur_temp>config.max_temp) && (cpudata.scale_max>cpudata.min_freq))
  {
   diff=(cpudata.cur_temp-config.max_temp)/1000;
   newfreq=cpudata.scale_max-(config.freq_step*diff);
   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);
   }
   cpudata.scale_max=sysfs_read_long_int("/sys/devices/system/cpu/cpufreq/policy0/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);
   }
  }

  sleep(config.interval);
 }
}