#include <string>
#include <iostream>

using namespace std;

template <typename T>
class DynamicArray
{
    private:
        int size; //make sure to change this as needed
        T * array;
    public:
        DynamicArray(); //sets size to zero, array to nullptr
        DynamicArray(DynamicArray const &a);
        int getSize() const;
        void addEntry(const T); //Adds an element at the end of the array
        T getEntry(int) const; //Returns the element at that index
        bool deleteEntry(T); //Deletes an element. if nothing is deleted, the function returns false
        ~DynamicArray();
};

template <typename T>
DynamicArray<T>:: DynamicArray()
{
    size = 0;
    array = new T[size];
}

template <typename T>
DynamicArray<T>:: DynamicArray (const DynamicArray<T> &a) //copy constructor
{
    size = a.getSize();
    T *DynamicArray = new T[size];

    for (int i = 0; i < size; i++) //Copy over the elements
    {
        array[i] = a.getEntry(i);
    }
}

template <typename T>
DynamicArray<T>:: ~DynamicArray() //Deletes the array and sets it's pointer to nullptr when the object is deleted
{
    delete [] array;
}

template <typename T>
int DynamicArray<T>:: getSize() const
{
    return size;
}

template <typename T>
void DynamicArray<T>:: addEntry(T const var)
{
    T *newArray = new T[size+1];
    //Copy contents from old array into the new array
    for (int i = 0; i < size; i++)
    {
        newArray[i] = array[i];
    }

    newArray[size] = var; //initiallize the last element with the argument
    size++; //resizing
    delete[] array; //delete/clear the old array
    array = newArray; //Setting to the new array
    delete [] newArray; //Free memory
}

template <typename T>
T DynamicArray<T>:: getEntry(int index) const
{
    if (index >= size || index < 0) //Check if index in argument is also an existing index in the array
    {
        return 0;
    }
    else
    {
        return array[index];
    }
}

template <typename T>
bool DynamicArray<T>:: deleteEntry(T var)
{
    for (int i = 0; i < size; ++i)
    {
        if (array[i] ==var)
        {
            //replace the var, and move everything down
            for (int j = i; j < size-1; ++j)
            {
                array[j] = array[(j+1)];
            }

            T *newArray = new T[size-1];

            //Copy over the old array into the new array
            //We do this because we want an array that doesn't have an "empty" index at the end
            for(int j = 0; j < size-1; ++j)
            {
                    newArray[j] = array[j];
            }

            array = newArray;

            delete [] newArray;

            newArray = nullptr;

            //decrease size since an element was taken out
            size--;
            return true;
        }
    }
    return false;
}

int main()
{
    DynamicArray<string> names;
    // List of names
    names.addEntry("Frank");
    names.addEntry("Wiggum");
    names.addEntry("Nahasapeemapetilon");
    names.addEntry("Quimby");
    names.addEntry("Flanders");

    // Output list
    cout << "List of names:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    // Add and remove some names
    names.addEntry("Spuckler");
    cout << "After adding a name:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    names.deleteEntry("Nahasapeemapetilon");
    cout << "After removing a name:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    names.deleteEntry("Skinner");
    cout << "After removing a name that isn't on the list:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    names.addEntry("Muntz");
    cout << "After adding another name:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    // Remove all of the names by repeatedly deleting the last one
    while (names.getSize() > 0) {
    names.deleteEntry(names.getEntry(names.getSize() - 1));
    }

    cout << "After removing all of the names:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    names.addEntry("Olivia");
    cout << "After adding a name:" << endl;
    for (int i = 0; i < names.getSize(); i++)
    cout << names.getEntry(i) << endl;
    cout << endl;

    cout << "Testing copy constructor" << endl;
    DynamicArray<string> names2(names);
    // Remove Olivia from names
    names.deleteEntry("Olivia");
    cout << "Copied names:" << endl;
    for (int i = 0; i < names2.getSize(); i++)
    cout << names2.getEntry(i) << endl;
    cout << endl;

    cout << "Testing assignment" << endl;
    DynamicArray<string> names3 = names2;
    // Remove Olivia from names2
    names2.deleteEntry("Olivia");
    cout << "Copied names:" << endl;
    for (int i = 0; i < names3.getSize(); i++)
    cout << names3.getEntry(i) << endl;
    cout << endl;

    cout << "Testing dynamic array of ints" << endl;
    DynamicArray<int> nums;
    nums.addEntry(10);
    nums.addEntry(20);
    nums.addEntry(30);
    for (int i = 0; i < nums.getSize(); i++)
    cout << nums.getEntry(i) << endl;
    cout << endl;

    cout << "Enter a character to exit." << endl;
    char wait;
    cin >> wait;
    return 0;
}