#include <string>
#include <iostream>
#include <cassert>
#include <vector>
#include <map>
#include <fstream>
#include <algorithm>
#include <iomanip>
#include <fstream>

using namespace std;

struct Date {
    int year, month, day = 0;
};

struct Currency {
    double dollar, euro = 0;
    bool first = 0;
};


bool operator < (Date lhs, Date rhs) {
    if (lhs.year < rhs.year) {
        return true;
    } else if (lhs.year == rhs.year and lhs.month < rhs.month) {
        return true;
    } else if (lhs.year == rhs.year and lhs.month == rhs.month and lhs.day < rhs.day) {
        return true;
    } else {
        return false;
    }
}

bool operator == (Date lhs, Date rhs) {
    if (lhs.year == rhs.year and lhs.month == rhs.month and lhs.day == rhs.day) {
        return true;
    }
    return false;
}

bool operator > (Date lhs, Date rhs) {
    if (lhs.year > rhs.year) {
        return true;
    } else if (lhs.year == rhs.year and lhs.month > rhs.month) {
        return true;
    } else if (lhs.year == rhs.year and lhs.month == rhs.month and lhs.day > rhs.day) {
        return true;
    } else {
        return false;
    }
}

class Currencies {
public:

    void SaveFile(string filename) {
        ofstream out;
        out.open(filename);
        for (auto item : db) {
            out.precision(2);
            out << item.first.day << "." << item.first.month << "." << item.first.year;
            out << ' ';
            out << item.second.dollar;
            out << ' ';
            out << item.second.euro;
            out << endl;
        }
    }

    void NewEntry(Date date, Currency currency) {
        if (db.find(date) != db.end()) {
            cout << "Entry already exists, rewriting" << endl;
        }
        if (db.empty()) {
            currency.first = 1;
        }
        db[date] = currency;
        cout << "Done!" << endl;
        cout << date.year << " " << date.month << " " << date.day << " " << currency.dollar  << " " << currency.euro << " " << endl;
    }

    void LoadFile(string filename, Currencies db) {
        ifstream in;
        Date date;
        Currency currency;
        string s;
        while (!in.eof()) {
            in.open(filename);
            getline(in, s, '.');
            date.year = stoi(s);
            getline(in, s, '.');
            date.month = stoi(s);
            getline(in, s, ' ');
            date.day = stoi(s);
            getline(in, s, ' ');
            currency.dollar = stoi(s);
            getline(in, s, ' ');
            currency.euro = stoi(s);
        }
        db.NewEntry(date, currency);
    }

    void ShowInfo(Date rhs, Date lhs) {
        double tempe, tempd = 0;
        for (auto item : db) {
            if (item.first == lhs or item.second.first == 1) {
                cout.precision(2);
                cout << item.first.day << "." << item.first.month << "." << item.first.year;
                cout << setw(5);
                cout << item.second.dollar;
                cout << setw(5);
                cout << item.second.euro;
                cout << endl;
                continue;
            } else if (item.first < rhs and item.first > lhs) {
                cout.precision(2);
                cout << item.first.day << "." << item.first.month << "." << item.first.year;
                int i = item.second.dollar - tempd;
                if (i > 0) {
                    cout << setw(3);
                    cout << '+' << i;
                } else if (i < 0) {
                    cout << setw(3);
                    cout << i;
                } else {
                    cout << setw(5);
                    cout << i;
                }
                i = item.second.euro - tempe;
                if (i > 0) {
                    cout << setw(3);
                    cout << '+' << i;
                } else if (i < 0) {
                    cout << setw(3);
                    cout << i;
                } else {
                    cout << setw(5);
                    cout << i;
                }
                cout << endl;
            } else if (item.first == rhs) {
                cout.precision(2);
                cout << item.first.day << "." << item.first.month << "." << item.first.year;
                cout << setw(5);
                cout << item.second.dollar;
                cout << setw(5);
                cout << item.second.euro;
                cout << endl;
            }
            tempe = item.second.euro;
            tempd = item.second.dollar;
        }
    }

    void ShowMinMax(Date rhs, Date lhs) {
        vector<double> d, e;
        if (!db.empty()) {
            for (auto item : db) {
                        if ((item.first > lhs and item.first < rhs) or item.first == rhs or item.first == lhs) {
                            d.push_back(item.second.dollar);
                            e.push_back(item.second.euro);
                        }
                    }
                    cout << "Min dollar value is " << *min_element(d.begin(), d.end()) << endl;
                    cout << "Max dollar value is " << *max_element(d.begin(), d.end()) << endl;
                    cout << "Min euro value is " << *min_element(e.begin(), e.end()) << endl;
                    cout << "Max euro value is " << *max_element(e.begin(), e.end()) << endl;
        } else {
            cout << "Database is empty!" << endl;
        }
    }
private:
    map<Date, Currency> db;
};

bool is_number(const string& s)
{
    return !s.empty() && find_if(s.begin(),
        s.end(), [](char c) { return !isdigit(c); }) == s.end();
}

Currency CurrencyParser() {
    Currency currency;
    string s;
    for (;;) {
        cout << "Waiting for dollar input" << endl;
        cin >> s;
        if (!is_number(s)) {
            cout << "Wrong dollar format" << endl;
            continue;
        }
        if (currency.dollar < 0) {
            cout << "Currency value can't be negative" << endl;
            continue;
        }
        currency.dollar = atof(s.c_str());
        break;
    }
    for (;;) {
        cout << "Waiting for euro input";
        cin >> s;
        if (!is_number(s)) {
            cout << "Wrong euro format" << endl;
            continue;
        }
        if (currency.euro < 0) {
            cout << "Currency value can't be negative" << endl;
            continue;
        }
        currency.euro = atof(s.c_str());
        break;
    }
    return currency;
}

Date DateParser() {
    Date date;
    vector<int> months {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    string s;
    for (;;) {
        cout << "Waiting for year input" << endl;
        cin >> s;
        if (!is_number(s)) {
            cout << "Wrong year format" << endl;
            continue;
        } else if (stoi(s) < 0) {
            cout << "Year can't be negative" << endl;
            continue;
        }
        date.year = stoi(s);
        break;
    }
    for (;;) {
        cout << "Waiting for month input" << endl;
        cin >> s;
        if (!is_number(s)) {
            cout << "Wrong month format" << endl;
            continue;
        } else if (stoi(s) < 1 or stoi(s) > 12) {
            cout << "Wrong month, use 1-12" << endl;
            continue;
        }
        date.month = stoi(s);
        break;
    }
    for (;;) {
        cout << "Waiting for day input" << endl;
        cin >> s;
        if (!is_number(s)) {
            cout << "Wrong day format" << endl;
            continue;
        } else if (stoi(s) < 0) {
            cout << "Day can't be negative" << endl;
            continue;
        } else if (stoi(s) > months[date.month]) {
            cout << "Wrong amount of days, max is " << months[date.month] << endl;
            continue;
        }
        date.day = stoi(s);
        break;
    }
    return date;
}

void ShowMenu() {
    cout << "System menu" << endl;
    cout << "1. Load file" << endl;
    cout << "2. New entry" << endl;
    cout << "3. Show info" << endl;
    cout << "4. Show min and max values" << endl;
    cout << "5. Save file" << endl;
    cout << "6. Exit" << endl;
}

void MenuInput(Currencies db) {
    int input = 0;
    string s;
    do {
        ShowMenu();
        cin >> input;
        switch (input) {
        case 1:
            cout << "Waiting for filename input: ";
            cin >> s;
            db.LoadFile(s, db);
            break;
        case 2:
            db.NewEntry(DateParser(), CurrencyParser());
            break;
        case 3:
            db.ShowInfo(DateParser(), DateParser());
            break;
        case 4:
            db.ShowMinMax(DateParser(), DateParser());
            break;
        case 5:
            cout << "Waiting for filename input: ";
            cin >> s;
            db.SaveFile(s);
            break;
        case 6:
            exit(1);
            break;
        }
    } while (input != 6);

}

int main() {
    Currencies db;
    MenuInput(db);
}