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

using namespace std;

class dirTokenizer {
public:

    dirTokenizer(string fullname) : fullname(fullname + "/"), i(0) {
    };
    string next();
    std::string fullname;
    int i;
};

string dirTokenizer::next() {
    int j = fullname.find("/", i + 1);
    if (j == -1) return "";
    string name = fullname.substr(i + 1, j - i - 1);
    i = j;
    return name;
}

class dirNode {
public:
    dirNode(string path, string name);
    void addChild(dirNode *newChild);
    void print(int level);
    dirNode *findNode(string pathname);
    std::string path;
    std::string name;
    dirNode *firstChild;
    dirNode *nextSibling;
};

dirNode::dirNode(string path, string name) {
    this->path = path;
    this->name = name;
    this->firstChild = NULL;
    this->nextSibling = NULL;
}

dirNode *dirNode::findNode(string pathname) {
    dirTokenizer path = dirTokenizer(pathname);
    string dir = path.next();
    dirNode *cur = this;
    if (cur->name != dir) return NULL;
    dir = path.next();
    if (dir == "") return cur;
    cur = cur->firstChild;
    while (cur != NULL) {
        if (cur->name != dir) {
            cur = cur->nextSibling;
            continue;
        }
        dir = path.next();
        if (dir == "") return cur;
        else cur = cur->firstChild;
    }
    return cur;
}

void dirNode::print(int level) {
    for (int i = 0; i < level * 5; i++) cout << " ";
    cout << this->name << endl;
    dirNode *child = this->firstChild;
    while (child != NULL) {
        child->print(level + 1);
        child = child->nextSibling;
    }
}

void dirNode::addChild(dirNode *newChild) {
    if(this->firstChild == NULL) this->firstChild = newChild;
    else {
        dirNode *tmp = this->firstChild;
        while(tmp->nextSibling != NULL)
            tmp = tmp->nextSibling;
        tmp->nextSibling = newChild;
    }
}

//returns root node of tree built

dirNode *build() {
    ifstream inStream;
    inStream.open("ITUnix");
    string aline = "";
    int lineNum = 0;
    string currentDir = "";

    dirNode *root = NULL;
    dirNode *curNode = NULL;

    //create root node
    getline(inStream, aline);
    aline = aline.substr(0, aline.length() - 2); //get rid of /: at the end
    lineNum++;
    cout << lineNum << endl;
    dirTokenizer path(aline);
    currentDir = path.fullname;
    root = new dirNode(path.fullname, path.next());
    curNode = root;

    //build tree off root
    while (!inStream.eof()) {

        getline(inStream, aline);

        if (aline.empty()) { // handles blank lines in files
            continue;
        } else if (aline[0] == '/') {

            aline = aline.substr(0, aline.length() - 1);
            currentDir = aline;
            curNode = root->findNode(currentDir);

        } else {
            curNode->addChild(new dirNode(currentDir + "/" + aline, aline));

        }
    }
    return root;
}

int main(int argc, char *argv[]) {

    if (argc != 2) { //check if arguments were entered correctly
        cout << "Usage: ./list filePath" << endl;
        return 1;
    } else {
        string path = argv[1];
        if (path[0] != '/')
            path = "/" + path;
        cout << path << "<- given path" << endl;
        dirNode *root = build();
        dirNode *cur = NULL;
        if (root->findNode(path) == NULL) {
            cout << "ERROR, NO SUCH PATH EXISTS" << endl;
            return 2;
        } else {
            //root->print(0);
            cur = root->findNode(path);
            cur->print(0);
        }
    }
    return 0;

}