trab final ver2

#include<iostream>
#include<fstream>
#include<sstream>
#include<list>
#include<vector>
#include<cmath>
#include<utility>
//#include<bits/stdc++.h>

using namespace std;
const int alphabet_size = 127;

class Node{
    public:
        //Node *parent;
        Node *children[alphabet_size];
        bool isLeaf;
        int id;
        //vector<int> occurencies;
        Node(){//constructor
            for (int i = 0; i < alphabet_size; i++) {
                    children[i] = NULL;
                }
            isLeaf = false;
        }
};

class Trie{
    public:
        Node *root;

        Trie(){//constructor
        //  root= (Node *) calloc(1, sizeof(Node));
            root= new Node;
            //*root= new Node;
        }

        //void insert(string s,int index);
        void insert(string s, int id);
        Node* search(string s); //searches for string and returns the Node if it's found
};

void Trie::insert(string s, int id){
    //int index =
    Node *temp = root;
    for(int i=0; i<s.size();i++){
        int index = s[i];
        if(!temp->children[index])
            temp->children[index]= new Node;
        temp = temp->children[index];
    }
    temp->isLeaf=true;
    temp->id = id;
}

Node* Trie::search(string s){
    Node *temp = root;
    for(int i=0; i<s.size();i++){
        int index = s[i];
        if(!temp->children[index]){
            return nullptr;             //next letter is not in trie, returns null
        }
        temp = temp->children[index];
    }
    if(temp != NULL)
        return temp;    //returns node since got to the end of word and is still in trie
    else{
        return nullptr;
    }
}


class movie{
    public:
        int id;
        string title;
        vector<string> genres;
        float rating;   //I intend to update the average incrementally: count ++; rating = ((rating*(count-1)) + newuserrating) /count;
        int count;

        void init(int entryid, string entrytitle, vector<string> entrygenres){
        id = entryid;
        title = entrytitle;
        genres = entrygenres;
        rating = 0;
        count = 0;
    }
};

class user{
    public:
        int id;
        vector<pair<int, float>> v;

        //movie id, user rating


};

class hashtableu{
    public:

    user *table;
    int size;
    int elements_count;
    int collisions_count;

    hashtableu(int sz)
    {
        this->size = sz;
        table = new user[size];
        elements_count = 0;
        collisions_count=0;
    }

    void insert(int userid, int movieid, float rating){
        int index;
        index = hash(userid);

        //user u;
        //if(u.v.empty())
        //  u.id = userid;
        //pair<string,float> mr;
        //mr = makepair(filmtitle,rating);
        //u.push_back(mr);

        //table[index].push_back(u);
        table[index].v.push_back(make_pair(movieid, rating));


    }


    int hash(int id){
            return id % size;
    }

};


class hashtablem{//hash table só que de filme kk
    public:

        vector<movie> *table;
        int size;       //ideally choose prime number that is at least 120% the number of entries
        int elements_count;
        int collisions_count;

    hashtablem(int sz)
    {
        size = sz;
        table = new vector<movie>[size];
        elements_count = 0;
        collisions_count=0;
    }

    void insert(movie entry){
    //consists in generating the hash function of the correspondent movie and doing the push_back in table[hash]
        int h = hash(entry.id);
        if(!table[h].empty())
            collisions_count++;
        table[h].push_back(entry);
        elements_count++;

    }

    //using the division method for int entries:
    int hash(int id){
        return id % size;
    }

    movie search(int entry){
    int index = hash(entry);
    movie y;
    y.id = -1;
    for(auto x: table[index])
        {
            if(x.id == entry)
            {
                return x;
            }
        }
        return y;   // :]
    }

    void del(int entry){
        int index = hash(entry);
        vector <movie> :: iterator i;
        for (i = table[index].begin();i != table[index].end(); i++) {
            if (i->id == entry)
                break;
        }
        if (i != table[index].end()){
            table[index].erase(i);
            elements_count--;
        }
    }

    void print(){
        //just in case
        for(int i=0;i<size;i++)
        {
            for(auto d: table[i])
                cout<<d.title<<" ";
            cout<<endl;

        }
    }


};


void getmovies(string filename, hashtablem* h, Trie* t){
    int id;
    string title;
    string genre;
    vector<string> genres;

    movie entry;
    ifstream fin;
    string line;  //to read each line
    fin.open(filename);

    string skip;    //used to receive unwanted data
    string aux;

    getline(fin,skip);
    while(fin >> id){   //first data, receives id, and stop if that's
        getline(fin,skip,'"');  //skips past first "
        getline(fin,title,'"'); // reads title
        getline(fin,skip,'"');  //skips past "
        getline(fin,aux,'"');   //gets whole genres string
        stringstream temporary; //ss to parse genres string
        temporary << aux;
        while(getline(temporary,aux,'|'))   //parsing genres between |s
            genres.push_back(aux);
        getline(fin,skip,'\n'); //you know the drill
        entry.init(id,title,genres);    //fills movie object
        h->insert(entry);   //inserts it in hashtablem
        t->insert(title,id);//insert read data in trie
        genres.clear();
    }
    fin.close();
}

void attrating(hashtablem* hmovies, float newrating, int movieid){//function called every time a movie rating is readed to assign the value of it's rating.
    int index, cont=0, aux=0, c;
    index = hmovies->hash(movieid);
    for(auto x: hmovies->table[index])
    {
        if(x.id == movieid)
        {
        hmovies->table[index][cont].count++;
        c= hmovies->table[index][cont].count;
        aux = hmovies->table[index][cont].rating;
        hmovies->table[index][cont].rating= (aux*(c-1)+newrating)/c;  //rating = ((rating*(count-1)) + newuserrating) /count;

        }
        cont++;
    }


}


void getrating(string filename, hashtableu* husers, hashtablem* hmovies){
    int userid, movieid;
    float rating;
    movie m;
    string aux;
    char ignore;
    ifstream fin;
    fin.open(filename);
    getline(fin, aux);
    while(fin >> userid){
        fin>>ignore;//ignore the commas
        fin >> movieid;
        fin>>ignore;

        //m = hmovies->search(movieid);


        fin>>rating;
        attrating(hmovies, rating, movieid);
        husers->insert(userid, movieid, rating);

        getline(fin, aux);
    }

    fin.close();

}

void prefixsearch(Node* root, hashtablem h){
        if(root->isLeaf){   //stop condition, prints stuff on screen
            movie movieinfo = h.search(root->id);

            cout << root->id << "   :   " << movieinfo.title << "   :   ";
            int count = 0;
            for(auto x: movieinfo.genres){
                if(count)
                    cout << "|";
                cout << x;
                count++;
            }
            cout << "   :   " << movieinfo.rating << "   :   " << movieinfo.count << endl;
        }
        else{           //else tries on children (just like ww2 german experiments)
            for(int i = 0; i < alphabet_size; i++)
                if(root->children[i])
                    prefixsearch(root->children[i], h);
        }
}


int main(void){
    hashtablem h(5501); //movies
    hashtableu h1(27281);   //users
    Trie t;
    movie m;
    getmovies("movie.csv",&h,&t);
    getrating("minirating.csv",&h1, &h);
    cout << "\nDataset MovieLens 20M - Use 'help' to show commands.\n";
    int quit = 0;
    string input;
    while(!quit){
        cout << ">";
        getline(cin,input);
        istringstream iss(input);
        iss >> input;
        if (input == "help"){
            cout << "movie <title or prefix> - Movies by title or prefix.\n";
            cout << "user <userID>           - Reviews made by user from given userID.\n";
            cout << "top<N> '<genre>'        - Top N movies by rating in given genre (only movies with at least 1000 reviews are shown).\n";
            cout << "tags <list of tags>     - Movies having the given tags (write tags inside apostrophes).\n";
            cout << "quit                    - Quits program.\n";
        }
        else if (input == "movie"){
            string skip;
            getline(iss,skip,' ');  //skip space
            getline(iss,input); //gets full movie name written
            Node *query = t.search(input);  //searches for stuff written
            if(query != nullptr){   //if it found something
                cout << "movieid:title:genres:rating:count" << endl << endl;
                if(query->isLeaf){

                    movie movieinfo = h.search(query->id);

                    cout << query->id << "   :   " << movieinfo.title << "   :   ";
                    int count = 0;
                    for(auto x: movieinfo.genres){
                        if(count)
                            cout << "|";
                        cout << x;
                        count++;
                    }
                    cout << "   :   " << movieinfo.rating << "   :   " << movieinfo.count << endl;
                }
                else
                    prefixsearch(query,h);
            }
            else
                cout << "No results were found." << endl;
        }
        else if (input == "user"){
            iss >> input;
            iss >> input;
            int N = stoi(input);    //gets stuff after 'top' from string into int
            int index = h1.hash(N);
            int auxr=0;
            for(int i=0; i<h1.table[index].v.size();i++){
                auxr = h1.table[index].v[i].first;
                m = h.search(auxr);

                cout<<"user rating: "<<h1.table[index].v[i].second;
                cout<<"  movie title: "<<m.title;
                cout<<"  global rating: "<<m.rating;
                cout<<"  global count: "<<m.count<<endl;




            }
        }
        else if (input.substr(0,3) == "top"){
            int N = stoi(input.substr(3,-1));   //gets stuff after 'top' from string into int
            iss >> input;
            if(input[0] != '\'' && input[-1] != '\'')   //checks for apostrophes
                cout << "Genre not recognised. Remember to write it between apostrophes.\n";
            else{
                //h.searchgenre(N,input.substr(1,input.length()-2)); //searches removing them
            }
        }
        else if (input == "tags"){
            vector<string> tags;
            string skip;
            string aux;
            getline(iss,skip,'\'');
            while(getline(iss,aux,'\''))
                tags.push_back(aux);        //separates between apostrophes and removes them
            if(!tags.empty())
                cout<<"oi"<<endl;
            else
                cout << "Tags not recognised. Remember to write them between apostrophes.\n";
        }
        else if (input == "quit")
            quit = 1;
    }
    return 0;
}