/*
 * BastionGuard™
 * Copyright (C) 2025–2026 Calogero Scarnà
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * BastionGuard™ is a trademark of Calogero Scarnà.
 * The BastionGuard™ name and branding are not licensed under the GPL.
 */

#include "FirewallRuleManager.hpp"
#include <cerrno>
#include <iostream>
#include <unordered_set>
#include <vector>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <glib/gi18n.h>

namespace {
int ip_family(const std::string& ip) {
    struct in_addr ipv4 {};
    if (::inet_pton(AF_INET, ip.c_str(), &ipv4) == 1) return AF_INET;
    struct in6_addr ipv6 {};
    if (::inet_pton(AF_INET6, ip.c_str(), &ipv6) == 1) return AF_INET6;
    return AF_UNSPEC;
}
}

bool FirewallRuleManager::run(const std::vector<std::string>& command) {
    if (command.empty()) return false;
    const pid_t pid = ::fork();
    if (pid < 0) return false;
    if (pid == 0) {
        std::vector<char*> argv;
        for (const auto& arg : command) argv.push_back(const_cast<char*>(arg.c_str()));
        argv.push_back(nullptr);
        ::execvp(argv.front(), argv.data());
        _exit(127);
    }
    int status = 0;
    pid_t result;
    do { result = ::waitpid(pid, &status, 0); } while (result < 0 && errno == EINTR);
    const bool ok = result == pid && WIFEXITED(status) && WEXITSTATUS(status) == 0;
    if (!ok) std::cerr << _("[Firewall] Command failed: ") << command[0] << "\n";
    return ok;
}

void FirewallRuleManager::applyWithFirewalld(const std::vector<std::string>& ips) {
    std::unordered_set<std::string> ipv4;
    std::unordered_set<std::string> ipv6;
    for (const auto& ip : ips) {
        switch (ip_family(ip)) {
            case AF_INET: ipv4.insert(ip); break;
            case AF_INET6: ipv6.insert(ip); break;
            default: std::cerr << _("[Firewall] SKIP non-IP: ") << ip << "\n"; break;
        }
    }
    if (ipv4.empty() && ipv6.empty()) {
        std::cerr << _("[Firewall] Nessun IP valido da applicare.\n");
        return;
    }
    const auto add_family = [&](const std::unordered_set<std::string>& entries,
                                const std::string& name, const std::string& family,
                                const std::string& ipset_family) {
        if (entries.empty()) return;
        // Already-existing sets may return nonzero; adding entries is idempotent.
        run({"pkexec", "firewall-cmd", "--permanent", "--new-ipset=" + name,
             "--type=hash:ip", "--option=family=" + ipset_family});
        for (const auto& ip : entries) {
            run({"pkexec", "firewall-cmd", "--permanent", "--ipset=" + name,
                 "--add-entry=" + ip});
        }
        run({"pkexec", "firewall-cmd", "--permanent",
             "--add-rich-rule=rule family=\"" + family + "\" source ipset=\"" + name + "\" reject"});
    };
    add_family(ipv4, "bastionguard-blocklist", "ipv4", "inet");
    add_family(ipv6, "bastionguard-blocklist-v6", "ipv6", "inet6");
    run({"pkexec", "firewall-cmd", "--reload"});
}

void FirewallRuleManager::applyWithUfw(const std::vector<std::string>& ips) {
    std::unordered_set<std::string> filtered;
    for (const auto& ip : ips) {
        if (ip_family(ip) != AF_UNSPEC) filtered.insert(ip);
        else std::cerr << _("[Firewall] SKIP non-IP: ") << ip << "\n";
    }
    if (filtered.empty()) {
        std::cerr << _("[Firewall] Nessun IP valido da applicare.\n");
        return;
    }
    for (const auto& ip : filtered) run({"pkexec", "ufw", "deny", "from", ip});
    run({"pkexec", "ufw", "reload"});
}

void FirewallRuleManager::apply(FirewallType fw, const std::vector<std::string>& ips) {
    switch (fw) {
        case FirewallType::FIREWALLD:
            std::cout << _("[Firewall] Applying rules with firewalld (ipset)\n");
            applyWithFirewalld(ips);
            break;
        case FirewallType::UFW:
            std::cout << _("[Firewall] Applying rules with UFW\n");
            applyWithUfw(ips);
            break;
        default:
            std::cerr << _("[Firewall] Nessun firewall selezionato.\n");
            break;
    }
}