#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

int get_file_len(const char *filename) {
	ifstream fin(filename, std::ifstream::ate | std::ifstream::binary);
	if (!fin.is_open()) {
		return -1;
	}
	int len= fin.tellg();
	fin.close();
	return len;
}

void task1() {
	cout << get_file_len("D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\file.doc") << endl;
}

void task2(const char *filename) {
	int freq[256];
	for (long i = 0; i < 256; freq[i++] = 0);

	ifstream fin(filename,ios::binary);
	if (!fin.is_open()) {
		cout << "AAAAAAA" << endl;
		return;
	}
	char q;
	while (fin.get(q)) {
		freq[q]++;
	}
	for (int i = 0; i < 256; i++) {
		cout << i << "\t|" << freq[i]<<endl;
	}

}

void encode(const char *filename,const char *key_file, int cols = 5) {
	vector<int> key;
	for (int i = 0; i < cols; i++) {
		key.push_back(0);
	}
	ifstream fkey(key_file);
	for (int i = 0; i < cols; i++) {
		fkey >> key[i];
	}
	fkey.close();

	int len = get_file_len(filename);
	if (len == -1) {
		return;
	}
	int len_ = len;
	if (len % cols) {
		len_ += cols - len % cols;
	}
	vector<vector<char>> result;
	for (int i = 0; i < cols; i++) {
		result.push_back({});
	}

	ifstream f2code(filename, ios::binary);

	for (int i = 0; i < len_;i++) {
		if (i >= len)
			result[key[i % cols]-1].push_back('z');
		else
			result[key[i % cols]-1].push_back(f2code.get());
	}
	f2code.close();


	char *fout_name = NULL;
	fout_name = _strdup(filename);
	strcat(fout_name, ".ddlab1");
	ofstream fout(fout_name, ofstream::binary);

	for (int i = 0; i < cols; i++) {
		for (int j = 0; j < result[i].size(); j++) {
			fout.put(result[i][j]);
		}
	}
	fout.close();

}
void decode(const char* filename, const char* key_file, int cols = 5) {
	vector<vector<char>> result;
	for (int i = 0; i < cols; i++) {
		result.push_back({});
	}
	vector<int> key;
	for (int i = 0; i < cols; i++) {
		key.push_back(0);
	}
	ifstream fkey(key_file);
	for (int i = 0; i < cols; i++) {
		fkey >> key[i];
	}
	fkey.close();

	int len = get_file_len(filename);

	int rows = len / cols;

	ifstream fin(filename, ifstream::binary);

	for (int i = 0; i < cols; i++) {
		for (int j = 0; j < rows; j++) {
			result[i].push_back(fin.get());
		}
	}
	fin.close();

	char* fout_name = NULL;
	fout_name = _strdup(filename);
	strcat(fout_name, ".ddlab1_decoded");
	ofstream fout(fout_name, ofstream::binary);

	for (int i = 0; i < rows; i++) {
		for (int j = 0; j < cols; j++) {
			fout << result[key[j] - 1][i];
		}
	}
	fout.close();
}


int main() {
	task1();

	task2("D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\file.doc");

	encode("D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\file.doc",
		"D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\key.txt");

	decode("D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\file.doc.ddlab1",
		"D:\\MTReload\\MIET\\DD\\DD_Lab1\\x64\\Debug\\key.txt");

	return 0;
}