#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <sys/ipc.h>
#include <sys/msg.h>

struct msg_buffer {
   long msg_type;
   char msg[50];
} message;

const char* locations[] = {"Bali", "Mali", "Cook islands", "Bahamas", "Iceland"};

int location_count[] = {0, 0, 0, 0, 0};
int location_min[] = {2, 5, 5, 5, 5};
const char* transports[] = {"Airplane", "Ship", "Bus"};

const char* DATAFILENAME = "data.txt";
const char* TEMPFILENAME = "data_temp.txt";

int locations_len = sizeof(locations) / sizeof(locations[0]);
int transports_len = sizeof(transports) / sizeof(transports[0]);

const int RECORD_SIZE = 60 + sizeof(int) + 20 + sizeof(int);

// char* people[1024][4];
char stuckNamesAtLoc[60][100];

// enum Transport{Airplane, Ship, Bus};

// struct PersonInfo{
//   char name[60];
//   char location[20];
//   char phoneNumber[20];
//   char transport[20];
//   // enum Transport transport;
// };

void handler(int s) {}

void printSeparator()
{
  printf("\n###############################\n\n");
}

void printAllData()
{
  printSeparator();

  int fp = open(DATAFILENAME, O_RDONLY);
  if(fp < 0) {
    printf("no data stored!\n");
    return;
  }

  int chosenLocation;
  int chosenTransport;

  char name[60];
  char phoneNumber[20];

  size_t end = lseek(fp, 0, SEEK_END);
  lseek(fp, 0, SEEK_SET);

  int i = 0;
  while(lseek(fp, 0, SEEK_CUR) != end)
  {
    read(fp, name, sizeof(name));
    read(fp, &chosenLocation, sizeof(chosenLocation));
    read(fp, phoneNumber, sizeof(phoneNumber));
    read(fp, &chosenTransport, sizeof(chosenTransport));

    printf("%d) name: %s, location: %s, phone: %s, transport: %s\n", i, name, locations[chosenLocation], phoneNumber, transports[chosenTransport]);
    ++i;
  }

  printSeparator();
  close(fp);
}

int getIntUserInput()
{
  int input;
  char ch;

  while (scanf("%d", &input) != 1)
  {
    while ((ch = getchar()) != '\n')
    {
      putchar(ch);
    }
    printf(" is not a number.\nPlease enter a number!\n");
  }
  return input;
}


int chooseLocationNum()
{
  int selectedLocationNum;

  printf("The available locations are the following:\n");

  printSeparator();
  for (int i = 0; i < locations_len; ++i)
  {
    printf("%d: %s\n", i, locations[i]);
  }
  printSeparator();

  while(1)
  {
    selectedLocationNum = getIntUserInput();
    if (selectedLocationNum >= 0 && selectedLocationNum < locations_len)
    {
      break;
    }

    printf("Invalid number!\nSelect the number of location you need information about!\n");
    printSeparator();
    for (int i = 0; i < locations_len; ++i)
    {
      printf("%d: %s\n", i, locations[i]);
    }
    printSeparator();
  }

  return selectedLocationNum;
}

int chooseTransportNum()
{
  int selectedTransportNum;

  printf("The available transports are the following:\n");

  printSeparator();
  for (int i = 0; i < transports_len; ++i)
  {
    printf("%d: %s\n", i, transports[i]);
  }
  printSeparator();

  while(1)
  {
    selectedTransportNum = getIntUserInput();
    if (selectedTransportNum >= 0 && selectedTransportNum < transports_len)
    {
      break;
    }

    printf("Invalid number!\nSelect the number of location you need information about!\n");
    printSeparator();
    for (int i = 0; i < transports_len; ++i)
    {
      printf("%d: %s\n", i, transports[i]);
    }
    printSeparator();
  }

  return selectedTransportNum;
}


int getChosenMenuPoint(void)
{
  printf("0) exit the program\n");
  printf("1) input data\n");
  printf("2) delete data\n");
  printf("3) modify existing data\n");
  printf("4) list data by location\n");
  printf("5) list all data\n");

  return getIntUserInput();
}

void enterNewData()
{
  char name[60];
  char phoneNumber[20];

  printf("[Enter name]\n");
  getchar();
  scanf("%[^\n]", name);

  printf("[Enter location numer]\n");
  int chosenLocation = chooseLocationNum();

  printf("[Enter phone number]\n");
  scanf("%s", phoneNumber);

  printf("[Enter transport]\n");
  int chosenTransport = chooseTransportNum();

  int fp = open(DATAFILENAME, O_CREAT | O_RDWR | O_APPEND);

  if(fp < 0) {
    perror("Error opening file.");
    exit(1);
  }

  write(fp, name, sizeof(name));
  write(fp, &chosenLocation, sizeof(chosenLocation));
  write(fp, phoneNumber, sizeof(phoneNumber));
  write(fp, &chosenTransport, sizeof(chosenTransport));

  close(fp);
  location_count[chosenLocation] += 1;
}

int deleteData()
{
  printAllData();
  printf("choose the index of the line you wanna modify/delete!\n");
  int lineIndexToDelete;

  int fp = open(DATAFILENAME, O_RDONLY);

  if (fp < 0)
  {
    printf("no data stored yet!\n");
    return -1;
  }

  int end = lseek(fp, 0, SEEK_END) / RECORD_SIZE;
  lseek(fp, 0, SEEK_SET);

  while(1)
  {
    lineIndexToDelete = getIntUserInput();
    if (lineIndexToDelete >= 0 && lineIndexToDelete < end)
    {
      break;
    }

    printf("Invalid number!\nSelect a valid number!\n");
  }

  int fp2 = open(TEMPFILENAME, O_CREAT | O_RDWR);

  if (fp2 < 0)
  {
    printf("oh shit here we go again");
    return -1;
  }

  int chosenLocation;
  int chosenTransport;

  char name[60];
  char phoneNumber[20];

  char record[RECORD_SIZE];

  for (int i = 0; i < end; ++i)
  {
    if (lineIndexToDelete != i)
    {
      read(fp, record, RECORD_SIZE);
      write(fp2, record, RECORD_SIZE);

    }
    else
    {
      read(fp, name, sizeof(name));
      read(fp, &chosenLocation, sizeof(chosenLocation));
      read(fp, phoneNumber, sizeof(phoneNumber));
      read(fp, &chosenTransport, sizeof(chosenTransport));
      location_count[chosenLocation] -= 1;
    }
  }

  close(fp);
  close(fp2);

  remove(DATAFILENAME);
  rename(TEMPFILENAME, DATAFILENAME);
  return 0;
}

int rescuePeopleFrom(int locationIndex = -1)
{
  if (locationIndex < 0 || locationIndex > 5)
  {
    return -1;
  }

  int fp = open(DATAFILENAME, O_RDONLY);

  //should never be the case
  if (fp < 0)
  {
    printf("no data stored yet!\n");
    return -1;
  }

  int end = lseek(fp, 0, SEEK_END) / RECORD_SIZE;
  lseek(fp, 0, SEEK_SET);

  int fp2 = open(TEMPFILENAME, O_CREAT | O_RDWR);

  if (fp2 < 0)
  {
    printf("oh shit here we go again");
    return -1;
  }

  int storedLocationIndex;
  int chosenTransport;

  char name[60];
  char phoneNumber[20];

  char record[RECORD_SIZE];

  for (int i = 0; i < end; ++i)
  {
    read(fp, name, sizeof(name));
    read(fp, &storedLocationIndex, sizeof(storedLocationIndex));
    read(fp, phoneNumber, sizeof(phoneNumber));
    read(fp, &chosenTransport, sizeof(chosenTransport));

    if (locationIndex != storedLocationIndex)
    {
      write(fp2, name, sizeof(name));
      write(fp2, &storedLocationIndex, sizeof(storedLocationIndex));
      write(fp2, phoneNumber, sizeof(phoneNumber));
      write(fp2, &chosenTransport, sizeof(chosenTransport));
      // read(fp, record, RECORD_SIZE);
      // write(fp2, record, RECORD_SIZE);

    }
  }

  close(fp);
  close(fp2);

  remove(DATAFILENAME);
  rename(TEMPFILENAME, DATAFILENAME);
  return 0;
}

void modifyData()
{
  if (!deleteData())
  {
    enterNewData();
  }
  else
  {
    printf("there is no data stored yet! Nothing to modify!\n");
  }

}

void getNamesAt(int selectedLocationNum)
{
  int fp = open(DATAFILENAME, O_RDONLY);
  if(fp < 0) {
    printf("no data stored yet!\n");
    return;
  }

  int chosenLocation;
  int chosenTransport;

  char name[60];
  char phoneNumber[20];

  size_t end = lseek(fp, 0, SEEK_END);
  lseek(fp, 0, SEEK_SET);
  int i = 0;
  while(lseek(fp, 0, SEEK_CUR) != end)
  {
    read(fp, name, sizeof(name));
    read(fp, &chosenLocation, sizeof(chosenLocation));
    read(fp, phoneNumber, sizeof(phoneNumber));
    read(fp, &chosenTransport, sizeof(chosenTransport));
    if (chosenLocation == selectedLocationNum)
    {
      i += 1;
      strcpy(stuckNamesAtLoc[i], name);
      printf("faszkivan::::::%d + %s + %s\n", i, stuckNamesAtLoc[i], name);
    }
  }
  sprintf(name, "%d", i);
  strcpy(stuckNamesAtLoc[0], name);
  for (int j = 0; j < 4; ++j)
  {
    printf("------%s\n", stuckNamesAtLoc[j]);
  }
}

void listData(bool silentInit = false)
{
  int selectedLocationNum = -1;
  if (!silentInit && selectedLocationNum == -1)
  {
    printf("[Select the number of location you need information about]\n");

    selectedLocationNum = chooseLocationNum();

    printf("selected location is: %s.  The following people are stuck there:\n", locations[selectedLocationNum]);
    printSeparator();
  }

  int fp = open(DATAFILENAME, O_RDONLY);
  if(fp < 0) {
    printf("no data stored yet!\n");
    return;
  }

  int chosenLocation;
  int chosenTransport;

  char name[60];
  char phoneNumber[20];

  size_t end = lseek(fp, 0, SEEK_END);
  lseek(fp, 0, SEEK_SET);

  while(lseek(fp, 0, SEEK_CUR) != end)
  {
    read(fp, name, sizeof(name));
    read(fp, &chosenLocation, sizeof(chosenLocation));
    read(fp, phoneNumber, sizeof(phoneNumber));
    read(fp, &chosenTransport, sizeof(chosenTransport));

    if (silentInit)
    {
      location_count[chosenLocation] += 1;
    }
    else if (chosenLocation == selectedLocationNum)
    {
      printf("name: %s, location: %s, phone: %s, transport: %s\n", name, locations[chosenLocation], phoneNumber, transports[chosenTransport]);
    }
  }

  if (!silentInit)
  {
    printSeparator();
  }
  close(fp);
}

void rescue(int locIndex)
{
  int pfd[2];
  if (pipe(pfd) == -1)
  {
    printf("pipe error!");
    exit(1);
  }
  signal(SIGUSR1, handler);
  if (fork() == 0) //child
  {
    printf("[CHI] Preparation for rescue has started...\n");
    sleep(2);
    printf("[CHI] Rescue team ready...\n");
    kill(getppid(), SIGUSR1);
    char peopleToSave[60][100];
    read(pfd[0], peopleToSave, sizeof(char) * 60 * 100);
    int numOfPeople = atoi(peopleToSave[0]);
    for (int i = 1; i < numOfPeople + 1; ++i)
    {
      printf("[CHI] STUCK EMBERKENEV: %s\n", peopleToSave[i]);
    }
    sleep(2);
    rescuePeopleFrom(locIndex);
    printf("[CHI] Rescue team got home...\n");

    key_t key;
    int msgId;

    printf("------------00\n");
    key = ftok("progfile", 65);
    msgId = msgget(key, 0666 | IPC_CREAT); //0666 -> readwrite
    printf("------------1\n");
    message.msg_type = 1;
    printf("------------2\n");

    char str[50];
    sprintf(str, "%d people saved from: %s..", numOfPeople, locations[locIndex]);
    strcpy(message.msg, str);

    printf("------------%s3\n", message.msg);
    kill(getppid(), SIGUSR1);
    msgsnd(msgId, &message, sizeof(message), 0);
    printf("------------4\n");
    exit(0);
  }
  else // parent
  {
    printf("[PAR] Preparing information for rescue team...\n");
    getNamesAt(locIndex);
    // printf("[PAR] wtf: %s\n", stuckNamesAtLoc[0]);
    // printf("[PAR] wtf: %s\n", stuckNamesAtLoc[1]);
    printf("[PAR] locindex: %d\n", locIndex);
    printf("[PAR] Information for rescue team is ready...\n");
    printf("[PAR] Waiting for rescue team to be ready...\n");
    pause();
    printf("[PAR] starting information sharing...\n");
    write(pfd[1], stuckNamesAtLoc, sizeof(char) * 60 * 100);
    printf("[PAR] Waiting for rescue to happen...\n");
    pause();
    printf("[PAR] Starting msg process\n");

    key_t key;
    int msgId;

    key = ftok("progfile", 65);
    msgId = msgget(key, 0666 | IPC_CREAT);

    msgrcv(msgId, &message, sizeof(message), 1, 0);

    printf("[PAR] %s\n", message);
    msgctl(msgId, IPC_RMID, NULL);
  }

}

void checkForRescue()
{
  for (int i = 0; i < 5; ++i)
  {
    if (location_count[i] >= location_min[i])
    {
      printf("Let's rescue some people from: %s!\n", locations[i]);
      rescue(i);
    }
  }
}

int main()
{
  if (access(DATAFILENAME, F_OK) == -1) {
    printf("file does not exist.. creating data.txt\n");

    FILE* fp = fopen(DATAFILENAME, "w");
    fclose(fp);
  }

  listData(1); //init number of stuck people per location
  checkForRescue();

  int n = -1;
  while (n = getChosenMenuPoint()) //it will exit if n is 0
  {
    switch (n)
    {
      case 1:
        enterNewData();
        checkForRescue();
        break;
      case 2:
        deleteData();
        checkForRescue();
        break;
      case 3:
        modifyData();
        checkForRescue();
        break;
      case 4:
        listData();
        break;
      case 5:
        printAllData();
      break;
      case 6:
        for (int i = 0; i < 5; ++i)
          {
            printf("%d, ", location_count[i]);
          }
          printf("\n");
      default:
        printf("Please input a valid menu point number!\n");
        break;
    }
  }

  return 0;
}