/*
Written by: Iurii Tatishchev
=============================
CIS 22C
Project: Stack ADT
*/

#include <fstream>
#include <iostream>
#include <string>
#include <cstdlib>

#include "StackADT.h"

using namespace std;

void printInfo();
void processNumbers(const string&, Stack<int> &);
void printStack(Stack<int> &);

int main() {
    printInfo();

    cout << "Enter input file name: ";
    string filename;
    getline(cin, filename); // assume valid
    cout << endl;

    // Create a stack
    Stack<int> s;

    // Process the numbers in the file
    processNumbers(filename, s);

    // Print remaining stack elements
    printStack(s);

    return 0;
}


/*
This function displays the project's title
*/
void printInfo() {
    cout << " ~*~ Project: Stack ADT ~*~ " << endl;
}

void processNumbers(const string& filename, Stack<int> &s) {
    ifstream inFile(filename);
    // Check if the file was opened successfully
    if (!inFile.is_open()) {
        cout << "There was an error opening \"" << filename << "\". Exiting.\n";
        exit(1);
    }
    cout << "\nInput File: " << filename << "\n";

    int number;
    Stack<int> maxStack;
    inFile >> number;
    while(inFile.good()) {
        switch (number) {
            // Each time we read 0, display the number of elements in the stack.
            case 0:
                cout << "Count: " << s.getLength() << "\n";
                break;
            // Each time we read 1, display the top element of the stack and the maximum element in the stack.
            case 1:
                // If there are no elements in the stack display "Top: Empty".
                if (s.isEmpty()) {
                    cout << "Top: Empty\n";
                    break;
                }
                cout << "Top: " << s.peek() << "\n";
                cout << "Max: " << maxStack.peek() << "\n";
                break;
            default:
                // Each time we read a number greater than 1, we push it onto the stack.
                if (number > 1) {
                    s.push(number);
                    maxStack.push(max(maxStack.isEmpty()? 0 : maxStack.peek(), number));
                }
                // Each time we read a negative number,
                // we pop and print the number removed from the stack and the largest value in the stack.
                // If there are no numbers in the stack, display "Pop: Empty".
                // If there's only one number in the stack, after removing it, print it.
                else {
                    if (s.isEmpty()) {
                        cout << "Pop: Empty\n";
                    } else {
                        cout << "Pop: " << s.pop() << "\n";
                        maxStack.pop();
                        if (!maxStack.isEmpty()) cout << "Max: " << maxStack.peek() << "\n";
                    }
                }
                break;
        }
        inFile >> number;
    }
    // Don't forget to close the file
    inFile.close();
}

/*
This function pops and prints all elements in the stack.
*/
void printStack(Stack<int> &s) {
    cout << "Stack: ";
    if (s.isEmpty()) {
        cout << "Empty\n";
        return;
    }

    while (s.getLength() != 1) {
        cout << s.pop() << ", ";
    }
    cout << s.pop() << ".\n";
}