/***********************************************************************/ 
/* Course:          Computer Science 402a                              */ 
/* Assignment:      Assignment 3                                       */ 
/* Instructor:      Mark Giesbrecht                                    */ 
/* Submitted by:    Dan Fraser                                         */ 
/* Student Number:  001219229                                          */ 
/* Due Date:        Wednesday, February 16                             */ 
/***********************************************************************/ 
/* calendar.cc - Calendar implementation for the user client           */              
/***********************************************************************/

// see calendar.h for interface descriptions
#include "calendar.h"

#define TEMPSIZE 1024
#define TEMPINT_SIZE 50

pthread_mutex_t busy_mutex = PTHREAD_MUTEX_INITIALIZER;
int my_uid = 0;
int ns_port;
string my_name;
Busy busy;
string nameserver_host;


int main(int argc, char *argv[]) {
  pthread_t server_thread;
  int server_thread_id;
  pthread_attr_t server_attr;
  pthread_attr_init(&server_attr);
  if (argc < 3) {
    cout << "usage: " << argv[0] << " username nameserver" << endl;
    exit(1);
  }

  nameserver_host = argv[2];
  my_name = argv[1];
  printf("starting server thread\n");
  server_thread_id = pthread_create(&server_thread, &server_attr, server, (void *)NULL);
  printf("starting main tread\n");
  while (1) {
    string response;
    print_menu();
    cin >> response;
    switch (atoi(response.c_str())) {
    case 1:
      request_meeting();
      break;
    case 2:
      busy.print();
      break;
    case 3:
      cancel_meeting();
      break;
    case 5:
      unregister_me();
      exit(0);
      break;
    } 
  }
}

void print_menu() {
  cout << endl << "main menu------" << endl;
  cout << "1. request (group) meeting" << endl;
  cout << "2. print calendar" << endl;
  cout << "3. cancel meeting(originated by you)" << endl;
  cout << "4. look up a uid" << endl;
  cout << "5. exit" << endl;
}

void request_meeting() {
  int meeting_length;
  char temp[TEMPSIZE];
  char *temp_str;
  vector<int> times;
  vector<int> times_backup;
  vector<int> uids;
  Meeting *temp_meeting;
  string query;
  cout << endl << "enter length for the meeting (num of 15 min intervals): ";
  cin >> meeting_length;
  cout << "enter start times, separated by spaces: ";
  gets(temp);
  for (temp_str = strtok(temp," "); temp_str != NULL; temp_str = strtok(NULL," ")) {
    times.insert(times.end(),atoi(temp_str));
    cout << "time " << temp_str << " inserted." << endl;
  }
  times_backup = times;
  cout << "enter uids, separated by spaces: ";
  gets(temp);
  for (temp_str = strtok(temp," "); temp_str != NULL; temp_str = strtok(NULL," ")) {
    uids.insert(uids.end(),atoi(temp_str));
    cout << "uid " << temp_str << " inserted." << endl;
  }
  cout << "** adding meeting to originator's calendar" << endl;

  int rc = pthread_mutex_lock(&busy_mutex);
  if (rc) {
    perror("pthread_mutex lock");
    pthread_exit(NULL);
  }
  
  temp_meeting = new Meeting(my_uid, meeting_length);
  for (vector<int>::iterator p = uids.begin(); p != uids.end(); p++) {
    temp_meeting->addAttendee(*p);
  }
  temp_meeting->addAttendee(my_uid);
  temp_meeting->makeTentative();

  for (vector<int>::iterator p = times.begin(); p != times.end(); p++) {
    if(busy.check(*p, meeting_length)) {
      cout << "allocating meeting" << endl;
      busy.allocate(temp_meeting, *p, meeting_length);
    } else {
      cout << "erasing conflicting time" << endl;
      vector<int>::iterator temp = p;
      times.erase(temp);
    }
  }  
  if (times.size() <= 0) {
    cout << "** No meeting time possible **" << endl;
    busy.deallocate(temp_meeting);
    return;
  }
  rc = pthread_mutex_unlock(&busy_mutex);
  if (rc) {
    perror("pthread_mutex unlock");
    pthread_exit(NULL);
  }
  cout << "okay, building request query" << endl;
  query = "meeting";
  sprintf(temp, " %d %d", my_uid, meeting_length);
  query += temp;
  for (vector<int>::const_iterator i = times.begin();
       i != times.end(); i++) {
    sprintf(temp," %d",*i);
    query += temp;
  }  
  cout << query << endl;
  for (vector<int>::const_iterator i = uids.begin();
       i != uids.end(); i++) {
    vector<int> available_times;
    available_times = check_times(query, *i);
    cout << "checking availability" << endl;
    vector<int>::iterator j = times.begin();
    while ((j != times.end()) && (times.size() > 0)) {
      cout << "checking time " << *j << endl;
      if (find(available_times.begin(), available_times.end(), *j) == available_times.end()) {
	vector<int>::iterator temp;
	temp = j;
	cout << "erasing conflicted time: " << *temp << endl;
	times.erase(temp);
      }
      j++;
    }
    if (times.size() == 0) {
      cout << "**** NO COMMON MEETING TIME POSSIBLE ****" << endl;
      // cancel meetings here
      cout << "okay, cancel request query" << endl;
      query = "cancel_temp";
      for (vector<int>::const_iterator i = times_backup.begin();
	   i != times_backup.end(); i++) {
	sprintf(temp," %d",*i);
	query += temp;
      }  
      cout << "cancelling with query: "<<query << endl;
      for (vector<int>::const_iterator i = uids.begin();
	   i != uids.end(); i++) {
	send_request(query,*i);
      }
      break;
    }
  }
  if (times.size() > 0) {
    // confirm meeting with myself
    cout << "* confirming local meeting" << endl;
    rc = pthread_mutex_lock(&busy_mutex);
    if (rc) {
      perror("pthread_mutex lock");
      pthread_exit(NULL);
    }
    temp_meeting = busy.getMeeting(*times.begin());
    if (!busy.deallocate(temp_meeting)) {
      perror("unable to deallocate local temp meeting");
      return;
    } else {
      temp_meeting->makeConfirmed();
      temp_meeting->setStart() = *times.begin();
      busy.allocate(temp_meeting,*times.begin(), temp_meeting->getLength());
    }
    rc = pthread_mutex_unlock(&busy_mutex);
    if (rc) {
      perror("pthread_mutex unlock");
      pthread_exit(NULL);
    }
    // confirm meeting with all uid's
    char temp_int[TEMPINT_SIZE];
    string query = "confirm ";
    sprintf(temp_int,"%d",*(times.begin()));
    query += temp_int;
    cout << "confirming with query: "<<query << endl;
    for (vector<int>::const_iterator i = uids.begin();
	 i != uids.end(); i++) {
      send_request(query,*i);
    }
  }
}

void cancel_meeting() {
  char temp_int[TEMPINT_SIZE];
  string cancel_message;
  int meeting_time;
  Meeting *del_meeting;
  vector<int> *attendees;
  cout << "enter a time during the meeting to be deleted: ";
  cin >> meeting_time;
  del_meeting = busy.getMeeting(meeting_time);
  if (del_meeting == NULL) {
    cout << "there is no meeting at that time." << endl;
    return;
  }
  attendees = del_meeting->getAttendees();
  if (find(attendees->begin(), attendees->end(), my_uid) == attendees->end()) {
    cout << "only the originator of a meeting can cancel it." << endl;
    return;
  }
  cancel_message = "cancel ";
  sprintf(temp_int, "%d", meeting_time);
  cancel_message += temp_int;
  for (vector<int>::iterator p = attendees->begin(); p != attendees->end(); p++ ) {
    cout << "sending cancel message to uid " << *p << endl;
    send_request(cancel_message,*p);
  }
}

bool send_request(string request, int uid) {
  StreamSocket user;
  char buffer[TEMPSIZE];
  char *temp;
  string again = "n";
  string again2 = "n";
  int result = -1;
  HostInfo hi("","",0);
  do {
    do {

      hi = uid_lookup(ns_port, uid);
      if (hi.getRealname() == "ERROR") {
	cout << "user not found in nameserver, try again (y/n): ";
	cin >> again2;
      }
    } while ((hi.getRealname() == "ERROR") && (again2 == "y"));
    if (hi.getRealname() != "ERROR") {
      result = user.connect(hi.getHostname(), hi.getPort());
      if (result < 0) {
	cout << "unable to contact user, try again (y/n): ";
	cin >> again;
      }
    }
  } while ((result < 0) && (again == "y"));
  if (result < 0) {
    cout << "message send failed." << endl;
    return 0;
  } else {
    user.send(request);
    user.receive(buffer,sizeof(buffer));
    temp = strtok(buffer," ");
    if (strcmp(temp,"OK") != 0) {
      perror("error returned by server");
      return 0;
    } else {
      return 1;
    }
  }
}

vector<int> check_times(string request, int uid) {
  StreamSocket user;
  vector<int> times;
  char buffer[TEMPSIZE];
  char *temp;
  string again = "n";
  string again2 = "n";
  int result = -1;
  HostInfo hi("","",0);
  do {
    do {

      hi = uid_lookup(ns_port, uid);
      if (hi.getRealname() == "ERROR") {
	cout << "user not found in nameserver, try again (y/n): ";
	cin >> again2;
      }
    } while ((hi.getRealname() == "ERROR") && (again2 == "y"));
    if (hi.getRealname() != "ERROR") {
      result = user.connect(hi.getHostname(), hi.getPort());
      if (result < 0) {
	cout << "unable to contact user, try again (y/n): ";
	cin >> again;
      }
    }
  } while ((result < 0) && (again == "y"));
  if (result < 0) {
    cout << "ignoring uid, continuing with meeting setup" << endl;
  } else {
    cout << "sending request" << endl;
    user.send(request);
    cout << "waiting for response" << endl;
    user.receive(buffer, sizeof(buffer));
    cout << "got back: " << buffer << endl;
    temp = strtok(buffer," ");
    if (strcmp(temp,"OK") != 0) {
      perror("invalid response from server");
      return times;
    } else {
      while ((temp = strtok(NULL, " ")) != NULL) {
	times.insert(times.begin(), atoi(temp));
	cout << "inserted time: " << atoi(temp) << endl;
      }
    }
  }
  return times;  
}




    
HostInfo uid_lookup(int port, int uid) {
  char *request = (char*) malloc(sizeof(char) * REQUEST_SIZE);
  cout << "looking up user with uid " << uid << endl;
  HostInfo hi("","",0);
  rpc_hostInfo *rpc_hi;

  CLIENT *clnt;
  clnt = clnt_create(nameserver_host.c_str(), NAMESERVER, DATE_VERS, "tcp");
  if (clnt <= 0) {
    clnt_pcreateerror("connecting to other nameserver");
    exit(1);
  }
  sprintf(request, "%d",uid);
  rpc_hi = find_1(&uid, clnt);

  if (strcmp(rpc_hi->name,"OK") != 0) {
    printf("warning, couldn't find user\n");
  }

  hi.setHostname() = rpc_hi->host;
  hi.setPort() = rpc_hi->port;
  hi.setRealname() = rpc_hi->name;
  cout << "returning from name lookup" << endl;
  clnt_destroy(clnt);
  return hi;

}

void unregister_me() {
  //  char request[REQUEST_SIZE];
  int *result;
  rpc_hostInfo hi;
  CLIENT *clnt;
  clnt = clnt_create(nameserver_host.c_str(), NAMESERVER, DATE_VERS, "tcp");
  if (clnt <= 0) {
    perror("clnt_create");
    exit(1);
  }
  printf("unregistering from nameserver\n");
  hi.uid = my_uid;
  hi.gossip = 0;
  result = unregister_1(&hi, clnt);
  printf("back from request with: %d\n", *result);
  
  if (*result < 0) {
    perror("unable to unregister from nameserver");
    exit(1);
  }
  clnt_destroy(clnt);  
}