/*
  htop
  (C) 2004-2010 Hisham H. Muhammad
  Released under the GNU GPL, see the COPYING file
  in the source distribution for its full text.

  This "Meter" written by Ian P. Hands (iphands@gmail.com, ihands@redhat.com).
*/

#include "BatteryMeter.h"
#include "Meter.h"
#include "ProcessList.h"
#include "CRT.h"
#include "String.h"
#include "debug.h"

/*{

typedef enum ACPresence_ {
   AC_ABSENT,
   AC_PRESENT,
   AC_ERROR
} ACPresence;

}*/

int BatteryMeter_attributes[] = {
   BATTERY
};

static unsigned long int parseUevent(FILE * file, const char *key) {
   char line[100];
   unsigned long int dValue = 0;

   while (fgets(line, sizeof line, file)) {
      if (strncmp(line, key, strlen(key)) == 0) {
         char *value;
         strtok(line, "=");
         value = strtok(NULL, "=");
         dValue = atoi(value);
         break;
      }
   }
   return dValue;
}

static unsigned long int parseBatInfo(const char *fileName, const unsigned short int lineNum, const unsigned short int wordNum) {
   const DIR *batteryDir;
   const struct dirent *dirEntries;

   const char batteryPath[] = PROCDIR "/acpi/battery/";
   batteryDir = opendir(batteryPath);

   if (batteryDir == NULL) {
      return 0;
   }

   char *entryName;
   typedef struct listLbl {
      char *content;
      struct listLbl *next;
   } list;

   list *myList = NULL;
   list *newEntry;

   /*
      Some of this is based off of code found in kismet (they claim it came from gkrellm).
      Written for multi battery use...
    */
   for (dirEntries = readdir((DIR *) batteryDir); dirEntries; dirEntries = readdir((DIR *) batteryDir)) {
      entryName = (char *) dirEntries->d_name;

      if (strncmp(entryName, "BAT", 3))
         continue;

      newEntry = calloc(1, sizeof(list));
      newEntry->next = myList;
      newEntry->content = entryName;
      myList = newEntry;
   }

   unsigned long int total = 0;
   for (newEntry = myList; newEntry; newEntry = newEntry->next) {
      const char infoPath[30];
      const FILE *file;
      char line[50];

      snprintf((char *) infoPath, sizeof infoPath, "%s%s/%s", batteryPath, newEntry->content, fileName);

      if ((file = fopen(infoPath, "r")) == NULL) {
         return 0;
      }

      for (unsigned short int i = 0; i < lineNum; i++) {
         fgets(line, sizeof line, (FILE *) file);
      }

      fclose((FILE *) file);

      const char *foundNumTmp = String_getToken(line, wordNum);
      const unsigned long int foundNum = atoi(foundNumTmp);
      free((char *) foundNumTmp);

      total += foundNum;
   }

   free(myList);
   free(newEntry);
   closedir((DIR *) batteryDir);
   return total;
}

static ACPresence chkIsOnline() {
   FILE *file = NULL;
   ACPresence isOn = AC_ERROR;

   if (access(PROCDIR "/acpi/ac_adapter", F_OK) == 0) {
      const struct dirent *dirEntries;
      const char *power_supplyPath = PROCDIR "/acpi/ac_adapter";
      DIR *power_supplyDir = opendir(power_supplyPath);
      char *entryName;

      if (!power_supplyDir) {
         return AC_ERROR;
      }

      for (dirEntries = readdir((DIR *) power_supplyDir); dirEntries; dirEntries = readdir((DIR *) power_supplyDir)) {
         entryName = (char *) dirEntries->d_name;

         if (strncmp(entryName, "A", 1)) {
            continue;
         }


         char statePath[50];
         snprintf((char *) statePath, sizeof statePath, "%s/%s/state", power_supplyPath, entryName);
         file = fopen(statePath, "r");

         if (!file) {
            isOn = AC_ERROR;
            continue;
         }

         char line[100];
         fgets(line, sizeof line, file);
         line[sizeof(line) - 1] = '\0';

         if (file) {
            fclose(file);
            file = NULL;
         }

         const char *isOnline = String_getToken(line, 2);

         if (strcmp(isOnline, "on-line") == 0) {
            free((char *) isOnline);
            isOn = AC_PRESENT;
            // If any AC adapter is being used then stop
            break;

         } else {
            isOn = AC_ABSENT;
         }
         free((char *) isOnline);
      }

      if (power_supplyDir)
         closedir(power_supplyDir);

   } else {

      const char *power_supplyPath = "/sys/class/power_supply";

      if (access("/sys/class/power_supply", F_OK) == 0) {
         const struct dirent *dirEntries;
         DIR *power_supplyDir = opendir(power_supplyPath);
         char *entryName;

         if (!power_supplyDir) {
            return AC_ERROR;
         }

         for (dirEntries = readdir((DIR *) power_supplyDir); dirEntries; dirEntries = readdir((DIR *) power_supplyDir)) {
            entryName = (char *) dirEntries->d_name;

            if (strncmp(entryName, "A", 1)) {
               continue;
            }

            char onlinePath[50];
            snprintf((char *) onlinePath, sizeof onlinePath, "%s/%s/online", power_supplyPath, entryName);
            file = fopen(onlinePath, "r");

            if (!file) {
               isOn = AC_ERROR;
               continue;
            }

            isOn = (fgetc(file) - '0');

            if (file) {
               fclose(file);
               file = NULL;
            }

            if (isOn == AC_PRESENT) {
               // If any AC adapter is being used then stop
               break;
            } else {
               continue;
            }
         }

         if (power_supplyDir)
            closedir(power_supplyDir);
      }
   }

   // Just in case :-)
   if (file)
      fclose(file);

   return isOn;
}

static double getProcBatData() {
   const unsigned long int totalFull = parseBatInfo("info", 3, 4);
   if (totalFull == 0)
      return 0;

   const unsigned long int totalRemain = parseBatInfo("state", 5, 3);
   if (totalRemain == 0)
      return 0;

   double percent = totalFull > 0 ? ((double) totalRemain * 100) / (double) totalFull : 0;
   return percent;
}

static double getSysBatData() {
   const struct dirent *dirEntries;
   const char *power_supplyPath = "/sys/class/power_supply/";
   DIR *power_supplyDir = opendir(power_supplyPath);


   if (!power_supplyDir) {
      return 0;
   }

   char *entryName;

   unsigned long int totalFull = 0;
   unsigned long int totalRemain = 0;

   for (dirEntries = readdir((DIR *) power_supplyDir); dirEntries; dirEntries = readdir((DIR *) power_supplyDir)) {
      entryName = (char *) dirEntries->d_name;

      if (strncmp(entryName, "BAT", 3)) {
         continue;
      }

      const char ueventPath[50];

      snprintf((char *) ueventPath, sizeof ueventPath, "%s%s/uevent", power_supplyPath, entryName);

      FILE *file;
      if ((file = fopen(ueventPath, "r")) == NULL) {
         closedir(power_supplyDir);
         return 0;
      }

      if ((totalFull += parseUevent(file, "POWER_SUPPLY_ENERGY_FULL="))) {
         totalRemain += parseUevent(file, "POWER_SUPPLY_ENERGY_NOW=");
      } else {
         //reset file pointer
         if (fseek(file, 0, SEEK_SET) < 0) {
            fclose(file);
            return 0;
         }
      }

      //Some systems have it as CHARGE instead of ENERGY.
      if ((totalFull += parseUevent(file, "POWER_SUPPLY_CHARGE_FULL="))) {
         totalRemain += parseUevent(file, "POWER_SUPPLY_CHARGE_NOW=");
      } else {
        //reset file pointer
         if (fseek(file, 0, SEEK_SET) < 0) {
            fclose(file);
            return 0;
         }
      }

      fclose(file);
   }

   const double percent = totalFull > 0 ? ((double) totalRemain * 100) / (double) totalFull : 0;
   closedir(power_supplyDir);
   return percent;
}

static void BatteryMeter_setValues(Meter * this, char *buffer, int len) {
   double percent = getProcBatData();

   if (percent == 0) {
      percent = getSysBatData();
      if (percent == 0) {
         snprintf(buffer, len, "n/a");
         return;
      }
   }

   this->values[0] = percent;

   const char *onAcText, *onBatteryText, *unknownText;

   unknownText = "%.1f%%";
   if (this->mode == TEXT_METERMODE) {
      onAcText = "%.1f%% (Running on A/C)";
      onBatteryText = "%.1f%% (Running on battery)";
   } else {
      onAcText = "%.1f%%(A/C)";
      onBatteryText = "%.1f%%(bat)";
   }

   ACPresence isOnLine = chkIsOnline();

   if (isOnLine == AC_PRESENT) {
      snprintf(buffer, len, onAcText, percent);
   } else if (isOnLine == AC_ABSENT) {
      snprintf(buffer, len, onBatteryText, percent);
   } else {
      snprintf(buffer, len, unknownText, percent);
   }

   return;
}

MeterType BatteryMeter = {
   .setValues = BatteryMeter_setValues,
   .display = NULL,
   .mode = TEXT_METERMODE,
   .items = 1,
   .total = 100.0,
   .attributes = BatteryMeter_attributes,
   .name = "Battery",
   .uiName = "Battery",
   .caption = "Battery: "
};