#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 200

struct passenger{
	char *name;
	struct passenger *next;
};

struct flightRecord{
	int flightNo;
	int flightCapacity;
	int reservationCount;
	struct passenger *passengersOnFlight;
	struct passenger *reservesForFlight;
	int dailyNo;
};

flightRecord* initialise(struct flightRecord *flights){
	FILE *text;
	int noOfDailyFlights;
	text = (fopen("text.txt","r"));
	fscanf(text, "%d ", &noOfDailyFlights);
	printf("%d flights are in today.\n\n",noOfDailyFlights);
	flights =(struct flightRecord *)malloc(noOfDailyFlights*sizeof(struct flightRecord));

	printf("Flight Numbers    Flight Capacity\n");
	int i = 0;
	while (!feof(text)){
		fscanf(text,"%d %d ",&(flights+i)->flightNo,&(flights+i)->flightCapacity);
		flights[i].dailyNo = noOfDailyFlights;
		flights[i].reservationCount = 0;
		flights[i].passengersOnFlight = NULL;
		flights[i].reservesForFlight = NULL;
		printf("      %3d             %d\n",flights[i].flightNo,flights[i].flightCapacity);
		i++;
	}
	return flights;
}

void status(struct flightRecord *flights){
	int i = 0;
	struct flightRecord *temp= flights;

	for (i = 0;i < flights->dailyNo ; i++){

			printf("Flight number is: %d \n",temp[i].flightNo);
			printf("Flight capacity is: %d \n",temp[i].flightCapacity);
			printf("The people on flight are:\n");
			while(temp[i].passengersOnFlight != NULL){
				printf("%s\n",temp[i].passengersOnFlight->name);
				temp[i].passengersOnFlight = flights[i].passengersOnFlight->next;

			}
			while(temp[i].reservesForFlight){
				printf("%s\n",temp[i].reservesForFlight->name);
				if(temp[i].reservesForFlight->next)
					temp[i].reservesForFlight = temp[i].reservesForFlight->next;
			}
	}
}

flightRecord* reserve(char name[],int flightNo,struct flightRecord *flights){
	struct flightRecord *temp = flights;
	struct passenger *temp1 =(struct passenger *)malloc(sizeof(struct passenger));
	temp1->name =(char*)malloc((strlen(name)+1)*(sizeof(char)));
	int i = 0,flag = 0;

	for(i;i < flights->dailyNo;i++){
		if(flightNo == temp[i].flightNo){
			flag++;
		}
	}

	if(flag == 0){
		printf("Flight is not found.\n");
	}

	else{

		for(i = 0;i < flights->dailyNo;i++){

			if(flightNo == temp[i].flightNo){
				printf("%d",flightNo);
	            if(temp[i].reservationCount < temp[i].flightCapacity){

	            	struct passenger *tempPas = temp[i].passengersOnFlight;
	            	strcpy(temp1->name,name);

	            	temp1->next = NULL;

	            	if(tempPas == NULL){
	            		tempPas = temp1;
	            		temp[i].reservationCount++;
	            		printf("%d",temp[i].reservationCount);
					}


					else{
						while (tempPas->next){
							tempPas = tempPas->next;
						}
						tempPas->next = temp1;
						temp[i].reservationCount++;
						printf("%d",temp[i].reservationCount);
					}
				}
				else{
					struct passenger *tempRes = temp[i].reservesForFlight;
					strcpy(temp1->name,name);

					temp1->next = NULL;
					if(tempRes == NULL){
						tempRes = temp1;
					}
					else{
						while(tempRes->next){
							tempRes = tempRes->next;
						}
						tempRes->next = temp1;
					}
				}
	        }
	    }
	}
	for(i = 0; i<temp[i].dailyNo;i++){
		while(temp[i].passengersOnFlight){
			printf("%s\n",temp[i].passengersOnFlight->name);
			temp[i].passengersOnFlight = temp[i].passengersOnFlight->next;
		}
	}
	return flights;
}

flightRecord* cancel(char name[],int flightNumber,struct flightRecord *flights){
	struct flightRecord *temp = flights;
	int i = 0,flag = 0;
	for(i;i < flights->dailyNo;i++){
		if(flightNumber == temp[i].flightNo){
			flag++;
		}
	}

	if(flag == 0){
		printf("Flight is not found.\n");
	}
	else{

		for(i = 0;i < temp[i].dailyNo ; i++){
			if(flightNumber == temp[i].flightNo){

				if(temp[i].reservationCount < temp[i].flightCapacity){
					struct passenger *cur = temp[i].passengersOnFlight;
					struct passenger *temp1;
					while(strcpy(cur->name,name)!= 0){
						cur = cur->next;
					}
					if (strcmp(cur->name,name)==0){
						temp1 = cur;
						cur = cur->next;
					}
					free(temp);
					temp[i].reservationCount--;
					cur = temp[i].passengersOnFlight;
					if (temp[i].reservesForFlight != NULL){
						if(temp[i].reservationCount < temp[i].flightCapacity){
							while(cur){
								cur = cur->next;
							}
							cur->next = temp[i].reservesForFlight;
							temp[i].reservesForFlight = temp[i].reservesForFlight->next;
						}
					}
				}
				else{
					struct passenger *cur = temp[i].reservesForFlight;
					struct passenger *temp1;
					while(strcpy(cur->name,name)){
						cur = cur->next;
					}
					if (strcmp(cur->name,name)==0){
						temp1 = cur;
						cur = cur->next;
					}
					free(temp);
				}

			}
		}
	}
	return flights;
}
void inquire(struct flightRecord *flights,char name[]){
	int i;
	struct flightRecord *temp = flights;
	for(i = 0; i < flights->dailyNo ; i++){
	   while(temp[i].passengersOnFlight != NULL){
			if(strcmp(temp[i].passengersOnFlight->name,name)==0){
				printf("%s reserved on flight %d.",name,temp[i].flightNo);
			}
			temp[i].passengersOnFlight = flights[i].passengersOnFlight->next;

		}
		while(temp[i].reservesForFlight != NULL){
			if(strcmp(temp[i].reservesForFlight->name,name)==0){
				printf("%s in reserve list for flight %d.",name,temp[i].flightNo);
			}
			temp[i].reservesForFlight = temp[i].reservesForFlight->next;
		}
		printf("\n");
	}
}
void processCommands(struct flightRecord *flights){
	printf("\n");
	char command[10];
	char name[100];
	char flightNo[10];
	int totalSpaces = 0;
	int space = 0;
	int i , j , k, l;
	while(strcmp(command,"EXIT")!= 0){
		 i = 0, j = 0 , k= 0 , l = 0;
		 totalSpaces = 0;
		 space = 0;
		 memset(command,'\0',10);
		 memset(name,'\0',100);
		 memset(flightNo,'\0',10);
		printf("Enter the command: <COMMAND> <NAME> <FLIGHT NO>:");

		char input[200];
		fgets(input, MAX, stdin);
		fflush(stdin);

		while(input[i] != '\0'){
			if(input[i] == ' ')
				totalSpaces++;
			i++;
		}
		i = 0;
		while(input[i] != '\n'){
			if(input[i] == ' '){
				space++;
			}
			if (space == totalSpaces){
				flightNo[l] = input[i];
				l++;
			}
			if(space == 0){
				command[j] = input[i];
				j++;
			}
			else if (space > 0){
				if(space < totalSpaces){
					if(input[i] == ' ' && space == 1 ){
						name[k] = input[i+1];
					}
					else{
						name[k] = input[i];
						k++;
					}
				}
			}
			i++;
		}
		printf( "%s-%s-\n",name,flightNo);
		command[j] = '\0';
		name[k] = '\0';
		flightNo[l] = '\0';
		int flightNumber = atoi(flightNo);

		if (strcmp(command,"STATUS") == 0){
				status(flights);
		}

		else if(strcmp(command,"RESERVE")== 0){
			flights = reserve(name,flightNumber,flights);
		}
		else if(strcmp(command,"CANCEL")== 0){
			flights = cancel(name,flightNumber,flights);
		}
		else if(strcmp(command,"INQUIRE")==0){
			inquire(flights,name);
		}
	}
	struct flightRecord *temp = flights;

	printf("Thank you for using reservation system.");
}

int main(){
	struct flightRecord *flights;
	flights = initialise(flights);
	processCommands(flights);

	return 0;
}