#include <iostream>
#include <string>
#include <sstream>
#include "linked_list.h"

using namespace std;

struct linked_list::list_node {
    list_node(int init_data = 0, list_node * link = nullptr) {
        data = init_data;
        next = link;
    }

    int data;
    list_node * next;
};

linked_list::linked_list() {
    front = nullptr;
    back = nullptr;
    count = 0;
}

void linked_list::add(int data) {
    if (back == nullptr) {
        front = new list_node(data);
        back = front;
        count = 0;
    } else {
        back->next = new list_node(data);
        back = back->next;
    }
    count++;
}

string linked_list::to_string() const {
    ostringstream out;
    out << "[";
    if (count > 0) {
        out << front->data;
        list_node * current = front->next;
        while (current != nullptr) {
            out << ", " << current->data;
            current = current->next;
        }
    }
    out << "]";
    return out.str();
}

bool linked_list::contains(int value) const {
    list_node * current = front;
    while (current != nullptr) {
        if (current->data == value) {
            return true;
        }
        current = current->next;
    }
    return false;
}

int linked_list::size() const {
    return count;
}

void linked_list::clear() {
    delete_nodes(front);
    front = nullptr;
    back = nullptr;
    count = 0;
}

linked_list::linked_list(const linked_list & rhs) {
    copy_from(rhs.front);
    count = rhs.count;
}

linked_list::~linked_list() {
    delete_nodes(front);
}

linked_list & linked_list::operator=(const linked_list & rhs) {
    if (this != &rhs) {
        delete_nodes(front);
        copy_from(rhs.front);
        count = rhs.count;
    }
    return *this;
}

const int & linked_list::operator[](int index) const {
    return node_at(index)->data;
}

int & linked_list::operator[](int index) {
    return node_at(index)->data;
}

void linked_list::delete_nodes(list_node * current) {
    while (current != nullptr) {
        list_node * temp = current;
        current = current->next;
        delete temp;
    }
}

void linked_list::copy_from(list_node * other) {
    if (other == nullptr) {
        front = nullptr;
        back = nullptr;
    } else {
        front = new list_node(other->data);
        list_node * current1 = front;
        list_node * current2 = other->next;
        while (current2 != nullptr) {
            current1->next = new list_node(current2->data);
            current2 = current2->next;
            current1 = current1->next;
        }
        back = current1;
    }
}

linked_list::list_node * linked_list::node_at(int index) const {
    list_node * current = front;
    while (index > 0) {
        current = current->next;
        index--;
    }
    return current;
}

void print(const linked_list & list) {
    cout << "[";
    if (list.size() > 0) {
        cout << list[0];
        for (int i = 1; i < list.size(); i++) {
            cout << ", " << list[i];
        }
    }
    cout << "]";
}