/*
 * 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 "PacManager.hpp"
#include "../SafeProcess.hpp"
#include <cstdlib>
#include <unistd.h>
#include <cstdio>
#include <array>
#include <filesystem>
#include <fstream>
#include <sstream>
#include <glib/gi18n.h>
#include <glibmm/miscutils.h>
#include <glibmm/shell.h>

namespace fs = std::filesystem;

bool PacManager::cmd_exists(const std::string& cmd) {
    if (cmd.empty()) return false;
    if (cmd.find('/') != std::string::npos) return access(cmd.c_str(), X_OK) == 0;
    const char* configured_path = std::getenv("PATH");
    std::istringstream dirs(configured_path ? configured_path : "/usr/local/bin:/usr/bin:/bin");
    std::string dir;
    while (std::getline(dirs, dir, ':')) {
        if (dir.empty()) dir = ".";
        if (access((fs::path(dir) / cmd).c_str(), X_OK) == 0) return true;
    }
    return false;
}

static bool run_user_servicectl(const std::vector<std::string>& args) {
    std::vector<std::string> command = {
        "/usr/libexec/bastionguard/bastionguard-service", "--user"};
    command.insert(command.end(), args.begin(), args.end());
    return bg_process::run(command).ok();
}

PacManager::Result PacManager::start_pacd_user() {
    Result r; r.backend = "user-service-manager";

    if (!cmd_exists("/usr/libexec/bastionguard/bastionguard-service")) {
        r.message = _("gestore servizi BastionGuard non disponibile");
        return r;
    }

    if (run_user_servicectl({"daemon-reload"}) &&
        run_user_servicectl({"enable", "--now", "BastionGuard-pacd.service"})) {
        r.ok = true;
        r.message = _("bastionguard-pacd avviato (servizio utente)");
        return r;
    }

    r.message = _("Impossibile avviare bastionguard-pacd (servizio utente)");
    return r;
}

PacManager::Result PacManager::stop_pacd_user() {
    Result r; r.backend = "user-service-manager";

    if (!cmd_exists("/usr/libexec/bastionguard/bastionguard-service")) {
        r.message = _("gestore servizi BastionGuard non disponibile");
        return r;
    }

    // stop best-effort
    run_user_servicectl({"disable", "--now", "BastionGuard-pacd.service"});
    r.ok = true;
    r.message = _("bastionguard-pacd fermato (servizio utente)");
    return r;
}


PacManager::Result PacManager::enable_pac(const std::string& pac_url) {
    auto r = enable_gnome(pac_url);
    if (r.ok) return r;

    r = enable_kde(pac_url);
    if (r.ok) return r;

    r = enable_xfce(pac_url);
    if (r.ok) return r;

    // headless fallback (NON PAC)
    r = enable_env_fallback();
    return r;
}

PacManager::Result PacManager::disable_pac() {
    auto r = disable_gnome();
    if (r.ok) return r;

    r = disable_kde();
    if (r.ok) return r;

    r = disable_xfce();
    if (r.ok) return r;

    r = disable_env_fallback();
    return r;
}

PacManager::Result PacManager::enable_gnome(const std::string& pac_url) {
    Result r; r.backend = "gnome";

    if (!cmd_exists("gsettings")) {
        r.message = _("gsettings non disponibile");
        return r;
    }

    // Imposta PAC (AUTO)
    int rc1 = bg_process::run({"gsettings", "set", "org.gnome.system.proxy", "mode", "auto"}).exit_code;
    int rc2 = bg_process::run({"gsettings", "set", "org.gnome.system.proxy", "autoconfig-url", pac_url}).exit_code;

    if (rc1 == 0 && rc2 == 0) {
        r.ok = true;
        r.message = _("Proxy GNOME impostato su AUTO (PAC)");
        return r;
    }

    r.message = _("Impossibile impostare proxy GNOME via gsettings");
    return r;
}

PacManager::Result PacManager::disable_gnome() {
    Result r; r.backend = "gnome";

    if (!cmd_exists("gsettings")) {
        r.message = _("gsettings non disponibile");
        return r;
    }

    int rc = bg_process::run({"gsettings", "set", "org.gnome.system.proxy", "mode", "none"}).exit_code;
    if (rc == 0) {
        r.ok = true;
        r.message = _("Proxy GNOME ripristinato a NONE");
        return r;
    }
    r.message = _("Impossibile disabilitare proxy GNOME");
    return r;
}


static fs::path kde_kioslaverc() {
    return fs::path(Glib::get_home_dir()) / ".config" / "kioslaverc";
}

PacManager::Result PacManager::enable_kde(const std::string& pac_url) {
    Result r; r.backend = "kde";

    fs::path p = kde_kioslaverc();
    try {
        fs::create_directories(p.parent_path());
    } catch (...) {}

    if (cmd_exists("kwriteconfig6")) {
        auto first = bg_process::run({"kwriteconfig6", "--file", p.string(),
                                       "--group", "Proxy Settings", "--key", "ProxyType", "2"});
        if (first.ok() && bg_process::run({"kwriteconfig6", "--file", p.string(),
                                           "--group", "Proxy Settings", "--key", "AutoConfigScript", pac_url}).ok()) {
            r.ok = true;
            r.message = _("Proxy KDE impostato su PAC (kioslaverc)");
            return r;
        }
    }

    try {
        std::string content;
        if (fs::exists(p)) {
            std::ifstream in(p);
            std::stringstream ss;
            ss << in.rdbuf();
            content = ss.str();
        }
        auto pos = content.find("[Proxy Settings]");
        if (pos != std::string::npos) {
            auto next = content.find("\n[", pos + 1);
            if (next == std::string::npos) content.erase(pos);
            else content.erase(pos, next - pos);
        }

        std::ofstream out(p, std::ios::app);
        out << "\n[Proxy Settings]\n";
        out << "ProxyType=2\n";
        out << "AutoConfigScript=" << pac_url << "\n";
        out.close();

        r.ok = true;
        r.message = _("Proxy KDE impostato su PAC (fallback write kioslaverc)");
        return r;
    } catch (...) {
        r.message = _("Errore scrittura kioslaverc");
        return r;
    }
}

PacManager::Result PacManager::disable_kde() {
    Result r; r.backend = "kde";

    fs::path p = kde_kioslaverc();
    if (!fs::exists(p)) {
        r.message = _("kioslaverc non esiste");
        return r;
    }

    if (cmd_exists("kwriteconfig6")) {
        if (bg_process::run({"kwriteconfig6", "--file", p.string(),
                             "--group", "Proxy Settings", "--key", "ProxyType", "0"}).ok()) {
            r.ok = true;
            r.message = _("Proxy KDE ripristinato a NONE");
            return r;
        }
    }

    try {
        std::string content;
        {
            std::ifstream in(p);
            std::stringstream ss;
            ss << in.rdbuf();
            content = ss.str();
        }

        auto tpos = content.find("ProxyType=");
        if (tpos != std::string::npos) {
            auto eol = content.find('\n', tpos);
            content.replace(tpos, (eol == std::string::npos ? content.size()-tpos : eol-tpos),
                            "ProxyType=0");
        } else {
            content += "\n[Proxy Settings]\nProxyType=0\n";
        }

        std::ofstream out(p, std::ios::trunc);
        out << content;
        out.close();

        r.ok = true;
        r.message = _("Proxy KDE ripristinato a NONE (fallback)");
        return r;
    } catch (...) {
        r.message = _("Errore scrittura kioslaverc");
        return r;
    }
}



PacManager::Result PacManager::enable_xfce(const std::string& pac_url) {
    Result r; r.backend = "xfce";

    if (!cmd_exists("xfconf-query")) {
        r.message = "xfconf-query non disponibile";
        return r;
    }

    const int rc1 = bg_process::run({"xfconf-query", "-c", "xfce4-settings-manager",
                                     "-p", "/proxy/mode", "-s", "2"}).exit_code;
    const int rc2 = bg_process::run({"xfconf-query", "-c", "xfce4-settings-manager",
                                     "-p", "/proxy/autoconfig-url", "-s", pac_url}).exit_code;

    if (rc1 == 0 && rc2 == 0) {
        r.ok = true;
        r.message = _("Proxy XFCE impostato su AUTO (PAC)");
        return r;
    }

    r.message = _("Impossibile impostare proxy XFCE (canale/proprietà potrebbero differire)");
    return r;
}

PacManager::Result PacManager::disable_xfce() {
    Result r; r.backend = "xfce";

    if (!cmd_exists("xfconf-query")) {
        r.message = "xfconf-query non disponibile";
        return r;
    }

    int rc = bg_process::run({"xfconf-query", "-c", "xfce4-settings-manager", "-p", "/proxy/mode", "-s", "0"}).exit_code;
    if (rc == 0) {
        r.ok = true;
        r.message = _("Proxy XFCE ripristinato a NONE");
        return r;
    }

    r.message = _("Impossibile disabilitare proxy XFCE");
    return r;
}


static fs::path envd_file() {
    return fs::path(Glib::get_home_dir()) / ".config" / "environment.d" / "90-bastionguard-proxy.conf";
}

PacManager::Result PacManager::enable_env_fallback() {
    Result r; r.backend = "env";
    try {
        fs::path f = envd_file();
        fs::create_directories(f.parent_path());

        // Proxy locale (adattalo alla tua porta reale)
        std::ofstream out(f, std::ios::trunc);
        out << "http_proxy=http://127.0.0.1:3129\n";
        out << "https_proxy=http://127.0.0.1:3129\n";
        out << "HTTP_PROXY=http://127.0.0.1:3129\n";
        out << "HTTPS_PROXY=http://127.0.0.1:3129\n";
        out.close();

        r.ok = true;
        r.message = _("Fallback headless: environment.d impostato (richiede relogin/riavvio sessione)");
        return r;
    } catch (...) {
        r.message = _("Impossibile scrivere environment.d fallback");
        return r;
    }
}

PacManager::Result PacManager::disable_env_fallback() {
    Result r; r.backend = "env";
    try {
        fs::path f = envd_file();
        if (fs::exists(f)) fs::remove(f);
        r.ok = true;
        r.message = _("Fallback headless: environment.d rimosso");
        return r;
    } catch (...) {
        r.message = _("Impossibile rimuovere environment.d fallback");
        return r;
    }
}

PacManager::Result PacManager::enable_pac_with_pacd(const std::string& pac_url) {
    auto s = start_pacd_user();
    if (!s.ok) return s;

    return enable_pac(pac_url);
}

PacManager::Result PacManager::disable_pac_with_pacd() {
    auto d = disable_pac();

    stop_pacd_user();

    return d;
}