#include "UserTable.h"
#include <algorithm>
#include <fstream>

const User UserTable::user_not_found = User{-1, "Not Found"};

UserTable::UserTable() : users{new User[capacity]} {}

UserTable::UserTable(const std::string &fname) : UserTable{} {
    std::ifstream ufile(fname);

    if (ufile.is_open()) {
        while (ufile) {
            int cn;
            if (ufile >> cn) {
                ufile.ignore(); // skip space
                char n[80];
                ufile.getline(n, 80);
                addUser(User(cn, n));
            }
        }
    } else {
        std::cout << "Could not open " << fname << std::endl;
    }
}

void UserTable::addUser(const User &u) {
    // gör tabellen större vid behov
    ensureCapacity(n + 1);

    // 1. Hitta rätt plats
    int pos{0};
    while ((pos < n) && (users[pos].getCardNbr() < u.getCardNbr())) {
        ++pos;
    }

    // 2. skapa lucka i vektorn
    for (int i = n; i > pos; --i) {
        users[i] = users[i - 1];
    }

    // 3. stoppa in den nya användaren i luckan
    users[pos] = u;

    ++n;
}

User UserTable::find(int c) const {
    // binärsökning (baserad på Holm, 2007)

    int low = 0;
    int high = n - 1;
    int mid = -1;
    bool found = false;
    while (low < high && !found) {
        mid = (low + high) / 2;
        //
        const int midnbr = users[mid].getCardNbr();
        if (c == midnbr) {
            found = true;
        } else if (users[mid].getCardNbr() < c) {
            low = mid + 1;
        } else {
            high = mid - 1;
        }
    }

    return found ? users[mid] : user_not_found;
}
User UserTable::find(std::string name) const {
    auto it = std::find_if(users, users + n, [&name](const User &u) {
        return u.getName() == name;
    });

    // If it is at the 'end' of users, the result is not found
    return (it != users+n) ? *it : user_not_found;
}

void UserTable::ensureCapacity(int s) {
    if (s > capacity) {
        while (s > capacity) {
            capacity *= 4;
        }
        auto tmp = new User[capacity];
        std::copy(users, users + n, tmp);
        delete[] users;
        users = tmp;
    }
}
void UserTable::print(std::ostream &os) const {
    os << "-------------" << std::endl;
    for (int i = 0; i != getNbrUsers(); ++i) {
        const auto &u = users[i];
        os << "(" << u.getCardNbr() << ") " << u.getName() << std::endl;
    }
    os << "=============" << std::endl;
}
/**
 * Testmetod för binärsökningen:
 * går igenom alla användare och kollar att deras kortnummer kan sökas upp.
 * Om något kortnummer inte kunde sökas upp returneras detta. Annars, om
 * alla sökningar lyckades, returneras 0.
 */
int testFindNbr(const UserTable ut) {
    for (int i = 0; i < ut.n; i++) {
        int nbr = ut.users[i].getCardNbr();
        User found = ut.find(nbr);
        if (found != ut.users[i]) {
            return nbr;
        }
    }
    return 0;
}