#include<stdio.h>
#include<stdlib.h>

// Define a structure to represent a seat in the theater
typedef struct node
{
char row_no; // Row number of the seat
int seat_no,pin; // Seat number and unique pin code of the seat
char book; // Book status (a for available, b for booked)
struct node *next,*prev; // Pointers to next and previous nodes in the linked list
}node;

node *hn=NULL; // Head pointer for the linked list

// Function to create the linked list of seats
void create()
{
node *nn,*cn; // nn: new node, cn: current node
int j=1;
int k=2;
char c ='A';

// Loop to create nodes for each row of seats
do
{
int i=1;
// Loop to create nodes for each seat in a row
do
{
k=(kk)/10+100-k/2; // Calculation to generate unique pin codes
nn=(struct node)malloc(sizeof(node)); // Allocate memory for a new node
nn->next=nn->prev=NULL;
nn->row_no=c; // Assign row number to the node
nn->seat_no=i; // Assign seat number to the node
nn->pin=k; // Assign pin code to the node
nn->book='a'; // Set the book status to available

// If linked list is empty, make the new node the head node
if(hn==NULL)
{
hn=nn;
nn->next=nn->prev=hn;
}
// If linked list is not empty, add the new node to the end
else
{
cn=hn;

// Traverse the linked list to find the last node
while(cn->next!=hn)
cn=cn->next;

// Add the new node to the end of the linked list
cn->next=nn;
nn->prev=cn;
nn->next=hn;
hn->prev=nn;
}
i++;
}while(i<=7); // Repeat the loop for each seat in a row
j++;
c++;
}while(j<=10); // Repeat the loop for each row of seats
}

// Function to display the seats with their availability status
void display()
{
node *cn; // Current node
cn=hn;

// Display the header for Platinum section
printf("------------------------------------------------------------------\n");
printf("| Platinum |\n");

// Traverse the linked list to display each seat
while(cn->next!=hn)  // cn->next is not equal to the head node
{
  if((cn->prev)->row_no!=cn->row_no) // If the row number of the previous node is not equal to the current node
    printf("| ");  // Print a "|"
  printf("%c ",cn->row_no);  // Print the row number
  printf("%d ",cn->seat_no);  // Print the seat number
  if(cn->book=='a') // If the seat is booked with 'a'
    printf("\033[32;40m -> a  \033[0m");  // Print green text with black background
  else  // If the seat is booked with 'b'
    printf("\033[1;31;43m -> b  \033[0m");  // Print red text
  if((cn->next)->row_no!=cn->row_no)  // If the row number of the next node is not equal to the current node
    printf("|\n");  // Print a "|" and a new line
  if(cn->row_no=='C'&&cn->seat_no==7)  // If the row number is 'C' and the seat number is 7
  {
    printf("-----------------------------------------------------------------------\n");  // Print a separator line
    printf("|                             gold                               |\n");  // Print a "gold" category label
  }
  if(cn->row_no=='H'&&cn->seat_no==7)  // If the row number is 'H' and the seat number is 7
  {
    printf("----------------------------------------------------------------------\n");  // Print a separator line
    printf("|                            Silver                              |\n");  // Print a "silver" category label
  }
  cn=cn->next;  // Move to the next node
}

// Print the details of the last node
printf("%c",cn->row_no);
printf("%d",cn->seat_no);
if(cn->book=='a')
  printf("\033[32;40m -> a  \033[0m");
else
  printf("\033[1;31;43m -> b  \033[0m");
printf("|\n");

printf("------------------------------------------------------------------\n\n");
printf("\033[1;33;49mPLATINUM-> 150              GOLD-> 100                  SILVER->60\033[0m\n");
}

// Function to display the booking details after the seats have been successfully booked
void display1(node *tmp[20],int n)
{
    if(n != 1) // Check if any seats were actually booked
    {
        printf("------------------------------------------------------------------\n");
        printf("THANK YOU!\nYOU HAVE SUCCESFULLY BOOKED THE SEATS\n");

        for(int i = 1; i < n; i++)
        {
            printf("%c %d ", tmp[i]->row_no, tmp[i]->seat_no);
            printf("   PIN : %d \n", tmp[i]->pin);
        }

        printf("!!!!!!!!!!!!!!!!!!KEEP PIN SAFELY!!!!!!!!!!!!!!!!!!!\n");
        printf("PINS ARE REQUIRED AT THE TIME OF CANCELATION OF SEATS\n");
        printf("------------------------------------------------------------------\n");
    }
}
void book_seat() {
node *cn, *temp[20];
int n, z, flag;
char row;
int seat;
int ch1;
do {
z = 1;
// Ask user for number of tickets they want to buy
printf("\nEnter the number of tickets you want to buy: ");
scanf("%d", &n);
    // Ask user for the seat numbers
    printf("\nEnter Seat Numbers: \n");
    for (int i = 1; i <= n; i++) {
        printf("NO %d = ", i);
        scanf(" %c", &row);
        scanf("%d", &seat);

        // Check if seat is available and book it
        cn = hn;
        while (cn->next != hn) {
            if (cn->row_no == row && cn->seat_no == seat) {
                if (cn->book == 'a') {
                    cn->book = 'b';
                    temp[z] = cn;
                    z++;
                } else {
                    printf("INVALID CHOICE!\n");
                    printf("%c%d Seat is already reserved\n", cn->row_no, cn->seat_no);
                }
            }
            cn = cn->next;
        }
        // Check if the last node is the required seat
        if (cn->row_no == row && cn->seat_no == seat) {
            if (cn->book == 'a') {
                cn->book = 'b';
                temp[z] = cn;
                z++;
            } else {
                printf("INVALID CHOICE!\n");
                printf("%c%d Seat is already reserved\n", cn->row_no, cn->seat_no);
            }
        }
    }
    // Display the seats that have been booked successfully
    display1(temp, z);

    // Ask user if they want to check seat status, book other seats, or exit
    printf("\n\nPress 1 to check seat status\n");
    printf("Press 2 to book other seats\n");
    printf("Press 3 to exit booking portal\n");
    printf("Input: ");
    scanf("%d", &ch1);
    if (ch1 == 1) {
        // display();
    }
} while (ch1 == 2);
}

// Function to cancel a booked seat
void cancel()
{
    // variable to store the row number of the seat to be cancelled
    char row;
    // variable to store the user's choice of action after cancelling a seat
    int ch;
    // variables to store the seat number and pin of the seat to be cancelled
    int seat,pin;
    // pointer to traverse the linked list of seats
    node *cn;
    do
    {
    // initializing ch to 1
    ch=1;
    // setting cn to the head node of the linked list
    cn=hn;
    // Prompting the user to input the seat number
    printf("SEAT NUMBER :");
    // Reading the row number of the seat
    scanf(" %c",&row);
    // Reading the seat number
    scanf("%d",&seat);
    // Prompting the user to input the pin
    printf("PIN :");
    // Reading the pin
    scanf("%d",&pin);
    // Traversing the linked list of seats
    while(cn->next!=hn)
    {
    // If the seat number and pin match, ask the user for confirmation to cancel the seat
    if(cn->row_no==row && cn->seat_no==seat && cn->pin==pin)
    {
        printf("Are you sure u want to cancle the Seat (y/n) ");
        char c;
        scanf(" %c",&c);
        if(c=='y'||c=='Y')
        {
            printf("SEAT CANCELED SUCCESFULLY!\n");
            // changing the booking status of the seat to 'a' (available)
            cn->book='a';
        }
    }
    // If the seat number matches but the pin does not, display an error message
    else if(cn->row_no==row && cn->seat_no==seat && cn->pin!=pin)
    {
        printf("invalid SEAT NUMBER && PIN combination!!!!\n");
    }
    // moving to the next seat
    cn=cn->next;
    }
    // same as above but for the last seat in the linked list
    if(cn->row_no==row && cn->seat_no==seat && cn->pin==pin)
    {
        printf("Are you sure u want to cancle (y/n) ");
        char c;
        scanf("%c",&c);
        if(c=='y'||c=='Y')
        {
            printf("SEAT CANCELED SUCCESFULLY!\n");
            cn->book='a';
        }
    }
    else if(cn->row_no==row && cn->seat_no==seat && cn->pin!=pin)
    {
        printf("invalid SEAT NUMBER && PIN combination!!!!\n");
    }
    // Prompting the user to either check the seat status, cancel more seats, or exit the cancellation portal
    printf("\n\nPRESS 1 To Check Seat Status\n");
    printf("PRESS 2 To Cancle More Tickets\n
    printf("PRESS 3 To Exit CANCELATION PORTAL\n");
    printf("\ninput: ");
    scanf("%d",&ch);
    if(ch==1);
        // display();
    }
    while(ch==2);
}