#include "pch.h"
#include <iostream>
#include <vector>
#include <fstream>
#include<string>
#include <algorithm>
#include "interface.h"
using namespace std;

const int SIZE = 250;

struct Students
{
    char fullname[SIZE];
    int course;
    int group;
    char label[SIZE];
};



int numberOfRecords(char* direction)
{
    Students item;
    ifstream file;
    file.open(direction);
    file.seekg(0, ios::end);
    int result = file.tellg() / sizeof(item);
    file.close();
    return result;
}

vector<Students> getAllRecordsFromFile(char* direction)
{
    int countOfRecords = numberOfRecords(direction);
    vector<Students> records(countOfRecords);
    fstream file(direction, ios::binary | ios::in);
    for (int i = 0; i < countOfRecords; i++)
        file.read(reinterpret_cast<char*>(&records[i]), sizeof(records[i]));
    file.close();
    return records;
}

void transfer(char* direction)
{
    int k = 0;
    vector<Students> records = getAllRecordsFromFile(direction);
    vector<Students> transfer(records.size());
    for (int i = 0; i < records.size(); i++)
    {
        if (!strcmp(records[i].label, "b") && records[i].course < 4)
        {
            records[i].course++;
            transfer[k] = records[i];
            k++;
        }
        if (!strcmp(records[i].label, "s") && records[i].course < 5)
        {
            records[i].course++;
            transfer[k] = records[i];
            k++;
        }
        if (!strcmp(records[i].label, "m") && records[i].course < 2)
        {
            records[i].course++;
            transfer[k] = records[i];
            k++;
        }
    }
    fstream file(direction, ios::binary | ios::in);
    file.close();
    file.open(direction, ios::binary | ios::out);
    for (int i = 0; i < k; i++)
        file.write(reinterpret_cast<char*>(&transfer[i]), sizeof(transfer[i]));
    file.close();


}

void showRecords(char* direction)
{
    int countOfRecords = numberOfRecords(direction);
    vector<Students> records = getAllRecordsFromFile(direction);
    if (!records.empty())
    {
        for (int i = 0; i < countOfRecords; i++)
        {
            cout << "\n" << i + 1 << "  студент\n";
            cout << "fullname " << records[i].fullname;
            cout << "\ncourse " << records[i].course;
            cout << "\ngroup " << records[i].group;
            cout << "\nlabel " << records[i].label << "\n\n";
        }
    }
    else cout << "записей нет\n";
}

void addRecordToBack(char* direction)
{
    ofstream file;
    Students item;
    int n = 0;
    cout << "Введите кол-во новых записей: "; n = Input(0, 10);
    file.open(direction, ios::binary | ios::out | ios::app);
    for (int i = 0; i < n; i++)
    {
        cin.clear();
        cout << i + 1 << " студент\n";
        cout << "fullname "; cin.getline(item.fullname, SIZE, '\n');
        cout << "course "; item.course=Input(1,SIZE);
        cout << "group "; item.group=Input(1,SIZE);
        cin.clear();
        cout << "label "; cin.getline(item.label, SIZE, '\n');
        file.write(reinterpret_cast<char*>(&item), sizeof(item));
    }
    file.close();
}
//



void deleteRecord(char* direction)
{
    int countOfRecords = numberOfRecords(direction), n, k = 0;
    vector<Students> arrayOfRecords(countOfRecords - 1);
    cout << "Введите номер записи для удаления: "; n = Input(0, countOfRecords + 1);
    fstream file(direction, ios::binary | ios::in);
    for (int i = 0; i < countOfRecords; i++)
    {
        if (i != n - 1)
        {
            file.read(reinterpret_cast<char*>(&arrayOfRecords[k]), sizeof(arrayOfRecords[k]));
            k++;
        }
    }
    file.close();
    file.open(direction, ios::binary | ios::out);
    file.close();
    file.open(direction, ios::binary | ios::out);
    for (int i = 0; i < countOfRecords - 1; i++)
        file.write(reinterpret_cast<char*>(&arrayOfRecords[i]), sizeof(arrayOfRecords[i]));
    file.close();
}

void editRecord(char* direction)
{
    int n, nField, k = 0;
    int countOfRecords = numberOfRecords(direction);
    vector<Students> arrayOfRecords = getAllRecordsFromFile(direction);
    cout << "Кол-во записей: " << countOfRecords << "\n";
    cout << "Введите номер записи для редактирования: "; n = Input(0, countOfRecords + 1);
    cout << "\n 1 - fullname, 2 - course, 3 - group, 4 - label\n";
    cout << "Введите номер поля для редактирования: "; nField = Input(1, 5);

    switch (nField)
    {
    case 1:
    {
        cin.clear();
        cout << "fullname "; cin.getline(arrayOfRecords[n - 1].fullname, SIZE, '\n');
        break;
    }
    case 2:
    {
        cin.clear();
        cout << "course "; cin >> arrayOfRecords[n - 1].course; cout << endl;
        break;
    }
    case 3:
    {
        cin.clear();
        cout << "group "; cin >> arrayOfRecords[n - 1].group; cout << endl;
        break;
    }
    case 4:
    {
        cin.clear();
        cout << "label "; cin.getline(arrayOfRecords[n - 1].label, SIZE, '\n');
        break;
    }
    }
    fstream file(direction, ios::binary | ios::out);
    for (int i = 0; i < countOfRecords; i++)
        file.write(reinterpret_cast<char*>(&arrayOfRecords[i]), sizeof(arrayOfRecords[i]));
    file.close();
}