/*
THIS CODE HAS BEEN TESTED AND IS FULLY OPERATIONAL.

Problem Statement: Consider a scenario for Hospital to cater services to different kinds of patients as Serious (top priority), b) non-serious (medium priority), c) General Checkup (Least priority). Implement the priority queue to cater services to the patients. 

Code from DataStructuresAndAlgorithms (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-content/DataStructuresAndAlgorithms/
*/

// BEGINNING OF CODE
#include<iostream>
#include<string>
#include <list>
using namespace std;

// creating LinkList
class Node
{
    public :
    Node *next;
    int priority;
    string data;
    Node(string d,int prior){
        priority = prior;
        data = d;
        next = NULL;
    }
};

class PriorityQueue{
    public:
    Node *front=NULL;
     
    //d is patient name , prior is priority
    void insert(string d,int prior){
        Node *temp,*rear;
        temp = new Node(d,prior);
        if(front == NULL){
            front = temp;
        }
        else
        {
            //compare until position is found
            rear = front;
            while(
                rear->next!=NULL &&
                 rear->next->priority >= prior
            ){
                rear=rear->next;
            }
            temp->next = rear->next;
            rear->next = temp;
        }

    }
    //to get name of first patient
    void peek(){
        cout<<"First patient is:\t"<<front->data;
    }
    void pop(){
        //to remove first patient
        if(front==NULL)
            return;
        front=front->next;
    }

    //display all the queue
    void dis()
    {
        string currPrior="";
        if(front== NULL){
            cout<<endl<<"Empty queue."<<endl;
            return;
        }
        cout<<endl;
        Node *curr= front;
        while(curr!=NULL){
            //hardCode the category
            if(curr->priority!=0){
                if(curr->priority==3)
                    currPrior="Serious patient";
                else if(curr->priority==2)
                    currPrior="Not serious patient";
                else
                    currPrior="General checkup";
            }
            cout<<curr->data<<" with priority:\t"<<currPrior<<endl;
            curr=curr->next;
        }
    }
};


int main(){

    string name;
    int priority,ch;

    cout<<endl;
    PriorityQueue q;
    do{
        cout<<endl<<"--- MAIN MENU ---";
        cout<<endl<<"1 -> Add patient";
        cout<<endl<<"2 -> Remove patient";
        cout<<endl<<"3 -> Get all patients";
        cout<<endl<<"0 -> Exit";
        cout<<endl<<"Choose an option (0-3):\t";
        cin>>ch;
    
        switch (ch)
        {
            case 1:
            { 
                cout<<"Patient name is:\t";
                cin.ignore();
                getline(cin,name,'\n');
                cout<<endl<<"Enter priority (3-High, 2-Medium, 1-General):\t";
                cin>>priority;
                q.insert(name,priority);
                break;
            }
            case 2:
            {
                q.pop();
                break;
            }
            case 3:{
                q.dis();
                break;
            }
            case 0:
            	cout<<endl<<"// END OF CODE\n\n";
                exit(1);
                break;
        
        default:
            break;
        }
    } while(ch!=0);
}
// END OF CODE