C++ IMAP example MacOS version

main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <curl/curl.h>
#include <vector>
#include <sstream>
#include <regex>
using namespace std;

// ====================== ANSI COLORS for macOS / Linux ======================
enum Color {
    CGRAY   = 90,
    CCYAN   = 36,
    CGREEN  = 32,
    CYELLOW = 33,
    CWHITE  = 37,
    CBLUE   = 34,
    CRED    = 31
};

void set_color(int c) {
    cout << "\033[" << c << "m";
}

void reset_color() {
    cout << "\033[0m";
}

// ====================== DECODING FUNCTIONS
string base64_decode(const string& in) {
    string out;
    vector<int> T(256, -1);
    for (int i = 0; i < 64; i++)
        T["ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[i]] = i;

    int val = 0, valb = -8;
    for (unsigned char c : in) {
        if (T[c] == -1) break;
        val = (val << 6) + T[c];
        valb += 6;
        if (valb >= 0) {
            out.push_back(char((val >> valb) & 0xFF));
            valb -= 8;
        }
    }
    return out;
}

string decode_qp(const string& input) {
    string result;
    for (size_t i = 0; i < input.size(); ++i) {
        if (input[i] == '=' && i + 2 < input.size() &&
            isxdigit(static_cast<unsigned char>(input[i + 1])) &&
            isxdigit(static_cast<unsigned char>(input[i + 2]))) {
            result += static_cast<char>(stoi(input.substr(i + 1, 2), nullptr, 16));
            i += 2;
        }
        else if (input[i] == '=' && i + 1 < input.size() && (input[i + 1] == '\r' || input[i + 1] == '\n')) {
            if (input[i + 1] == '\r' && i + 2 < input.size() && input[i + 2] == '\n') i += 2;
            else i++;
        }
        else {
            result += input[i];
        }
    }
    return result;
}

string decode_mime_header(string h) {
    string out;
    size_t pos = 0;
    while ((pos = h.find("=?UTF-8?B?")) != string::npos) {
        out += h.substr(0, pos);
        size_t e = h.find("?=", pos);
        if (e == string::npos) break;
        out += base64_decode(h.substr(pos + 10, e - pos - 10));
        h = h.substr(e + 2);
    }
    while ((pos = out.find("=?UTF-8?Q?")) != string::npos) {
        string before = out.substr(0, pos);
        size_t e = out.find("?=", pos);
        if (e == string::npos) break;
        string qp = out.substr(pos + 10, e - pos - 10);
        for (char& c : qp) if (c == '_') c = ' ';
        before += decode_qp(qp);
        out = before + out.substr(e + 2);
    }
    out += h;
    return out;
}

string extract_plain(const string& raw) {
    if (raw.empty()) return "";

    size_t alt_pos = raw.find("multipart/alternative");
    if (alt_pos == string::npos) return "";

    size_t b_pos = raw.find("boundary=\"", alt_pos);
    if (b_pos == string::npos) return "";
    b_pos += 10;
    string boundary = raw.substr(b_pos, raw.find('"', b_pos) - b_pos);

    string delim = "--" + boundary;
    size_t pos = 0;

    while ((pos = raw.find(delim, pos)) != string::npos) {
        pos += delim.length();
        if (pos + 2 < raw.size() && raw[pos] == '-' && raw[pos + 1] == '-') break;

        if (raw[pos] == '\r') pos++;
        if (raw[pos] == '\n') pos++;

        size_t next = raw.find(delim, pos);
        if (next == string::npos) break;

        string part = raw.substr(pos, next - pos);

        if (part.find("text/plain") != string::npos) {
            size_t body_start = part.find("\r\n\r\n");
            if (body_start == string::npos) body_start = part.find("\n\n");
            if (body_start != string::npos) {
                body_start += (part[body_start] == '\r' ? 4 : 2);
                string body = part.substr(body_start);
                if (part.find("quoted-printable") != string::npos)
                    body = decode_qp(body);
                return body;
            }
        }
    }
    return "";
}

string clean_and_replace_links(const string& input) {
    string s = input;
    s = regex_replace(s, regex(R"(\r)"), "");

    regex url_re(R"((https?://[^\s>\]\)]+))");
    string result;
    auto it = sregex_iterator(s.begin(), s.end(), url_re);
    auto end_it = sregex_iterator();
    size_t last_pos = 0;

    for (; it != end_it; ++it) {
        const smatch& m = *it;
        result += s.substr(last_pos, m.position() - last_pos);

        string url = m.str(1);
        if (url.length() > 50) {
            result += "[посилання: " + url.substr(0, 47) + "...]";
        } else {
            result += "[посилання: " + url + "]";
        }
        last_pos = m.position() + m.length();
    }
    result += s.substr(last_pos);

    s = regex_replace(result, regex("(\n){3,}"), "\n\n");
    return s;
}

// ====================== UI FUNCTIONS ======================
void print_line() {
    set_color(CGRAY);
    cout << " ==========================================\n";
    reset_color();
}

void print_header_ui() {
    cout << "\n";
    print_line();
    set_color(CCYAN);
    cout << " >> Email Reader v1.5 (100 листів) — macOS версія\n";
    reset_color();
    print_line();
    cout << "\n";
}

void print_field(const string& label, const string& value, int vc = CWHITE) {
    set_color(CYELLOW); cout << label;
    set_color(vc);      cout << value << "\n";
    reset_color();
}

void print_body(const string& body) {
    cout << "\n";
    set_color(CCYAN); cout << " тіло листа:\n\n";
    reset_color();

    istringstream iss(body);
    string line;
    while (getline(iss, line)) {
        if (line.empty()) {
            cout << "\n";
            continue;
        }
        set_color((line.find("[посилання:") != string::npos) ? CBLUE : CWHITE);
        cout << " " << line << "\n";
        reset_color();
    }
}

void print_meta(size_t bytes, int msg_num) {
    cout << "\n";
    print_line();
    set_color(CGRAY);
    cout << " лист #" << msg_num << " | розмір: " << bytes << " байт\n";
    reset_color();
    print_line();
    cout << "\n";
}

// ====================== CURL CALLBACK ======================
static size_t write_callback(void* ptr, size_t size, size_t nmemb, void* data) {
    ((string*)data)->append((char*)ptr, size * nmemb);
    return size * nmemb;
}

// ====================== MAIN ======================
int main() {
    const string email = "your_email@gmail.com";
    const string password = "**** **** **** ****"; // ваш пароль додатка !!! https://support.google.com/accounts/answer/185833?dark=1&sjid=3195842429112725011-EU

    CURL* curl = curl_easy_init();
    if (!curl) {
        cerr << "помилка ініціалізації curl\n";
        return 1;
    }

    string response;
    curl_easy_setopt(curl, CURLOPT_URL, "imaps://imap.gmail.com/INBOX");
    curl_easy_setopt(curl, CURLOPT_USERNAME, email.c_str());
    curl_easy_setopt(curl, CURLOPT_PASSWORD, password.c_str());
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
    curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_ALL);
    curl_easy_setopt(curl, CURLOPT_TIMEOUT, 120L);

    // SELECT INBOX
    curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "SELECT INBOX");
    curl_easy_perform(curl);
    response.clear();

    print_header_ui();

    for (int i = 1; i <= 100; ++i) {
        string fetch_cmd = "FETCH " + to_string(i) + " (BODY[HEADER.FIELDS (FROM TO SUBJECT)] BODY[])";

        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, fetch_cmd.c_str());
        response.clear();

        CURLcode res = curl_easy_perform(curl);

        if (res != CURLE_OK || response.empty()) {
            cout << "помилка при завантаженні листа #" << i << "\n";
            continue;
        }

        // дебаг останнього листа
        if (i == 100) {
            ofstream("debug_response.txt") << response;
        }

        // парсинг заголовків
        auto find_header = [&](const string& name) -> string {
            size_t p = response.find(name + ":");
            if (p == string::npos) return "";
            size_t start = p + name.size() + 1;
            size_t end = response.find('\n', start);
            string val = response.substr(start, end - start);
            if (!val.empty() && val.back() == '\r') val.pop_back();
            return val;
        };

        string from    = find_header("From");
        string to      = find_header("To");
        string subject = find_header("Subject");

        // витягуємо BODY[]
        size_t body_tag = response.find("BODY[] {");
        if (body_tag == string::npos) continue;

        size_t open_br = response.find('{', body_tag);
        size_t close_br = response.find('}', open_br);
        size_t body_size = stoul(response.substr(open_br + 1, close_br - open_br - 1));

        size_t body_start = response.find('\n', close_br) + 1;
        string full_body = response.substr(body_start, body_size);

        string text = extract_plain(full_body);
        if (!text.empty()) {
            text = clean_and_replace_links(text);

            set_color(CCYAN);
            cout << "=== лист #" << i << " ===\n";
            reset_color();

            print_field(" від: ", decode_mime_header(from));
            print_field(" кому: ", decode_mime_header(to));
            print_field(" тема: ", decode_mime_header(subject), CGREEN);

            print_body(text);
            print_meta(full_body.size(), i);
        }
    }

    curl_easy_cleanup(curl);

    cout << "\nготово! натисніть будь-яку клавішу...\n";
    cin.get();
    return 0;
}