/*
 * GnomeSettingsVault - A GNOME configuration backup utility.
 * Copyright (C) 2026 Nicole Portas, nicole@equalmass.com
 *
 * 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, either version 3 of the License, or
 * (at your option) any later version.
 */


#include "MainWindow.hpp"
#include <iostream>
#include <filesystem>
#include <archive.h>
#include <archive_entry.h>
#include <fcntl.h>
#include <unistd.h>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include <chrono>
#include <iomanip>
#include <sstream>
#include <set>

namespace fs = std::filesystem;

MainWindow::MainWindow()
: m_HeaderBar(), m_MainLayout(Gtk::ORIENTATION_VERTICAL, 0), m_Notebook(),
  m_BottomBox(Gtk::ORIENTATION_HORIZONTAL, 10), m_StatusLabel("Ready."), 
  m_CheckDebugMode("Enable Debug Logging"), m_VBoxBackup(Gtk::ORIENTATION_VERTICAL, 10),
  m_LabelBackupInstruction("<span size='large' weight='bold'>Backup</span>"),
  m_CheckThemesBackup("GTK Themes"), m_CheckIconsBackup("Icons"),
  m_CheckWallpapersBackup("Wallpapers"), m_CheckExtensionsBackup("GNOME Extensions"),
  m_CheckDconfBackup("GNOME Settings"), m_ButtonBackup("Start Backup"),
  m_VBoxRestore(Gtk::ORIENTATION_VERTICAL, 10),
  m_LabelRestoreInstruction("<span size='large' weight='bold'>Restore from Vault</span>"),
  m_ButtonSelectVault("Select .gbk Vault File"), m_LabelSelectedVault("No vault selected"),
  m_CheckThemesRestore("GTK Themes"), m_CheckIconsRestore("Icons"),
  m_CheckWallpapersRestore("Wallpapers"), m_CheckExtensionsRestore("GNOME Extensions"),
  m_CheckDconfRestore("GNOME Settings"), m_CheckDryRunRestore("Dry Run"),
  m_ButtonRestore("Start Restore"), m_WorkerRunning(false), m_JobSuccess(true), 
  m_IsDebugMode(false), m_LastJobWasRestore(false)
{
    m_Dispatcher.connect(sigc::mem_fun(*this, &MainWindow::on_dispatcher_ping));
    set_default_size(1000, 700);
    m_HeaderBar.set_title("GnomeSettingsVault 0.1");
    m_HeaderBar.set_show_close_button(true);
    set_titlebar(m_HeaderBar);

    m_LabelBackupInstruction.set_use_markup(true);
    m_LabelRestoreInstruction.set_use_markup(true);

    m_RefTextBuffer = Gtk::TextBuffer::create();
    auto selection_tag = m_RefTextBuffer->create_tag("selection_orange");
    selection_tag->property_background() = "#ff8c00";
    selection_tag->property_foreground() = "#000000";
    
    m_LogView.set_buffer(m_RefTextBuffer);
    m_LogView.set_editable(false);
    m_LogView.set_cursor_visible(true);
    m_LogView.set_can_focus(true);
    
    m_RefTextBuffer->signal_mark_set().connect([this, selection_tag](const Gtk::TextBuffer::iterator& iter, const Glib::RefPtr<Gtk::TextMark>& mark){
        Gtk::TextBuffer::iterator start, end;
        if (m_RefTextBuffer->get_selection_bounds(start, end)) {
            m_RefTextBuffer->apply_tag(selection_tag, start, end);
        } else {
            m_RefTextBuffer->remove_tag(selection_tag, m_RefTextBuffer->begin(), m_RefTextBuffer->end());
        }
    });

    m_LogView.override_background_color(Gdk::RGBA("#1e1e1e")); 
    m_LogView.override_color(Gdk::RGBA("#dcdcdc"));
    
    m_RefTextBuffer->create_mark("last_line", m_RefTextBuffer->end());
    m_ScrolledWindow.add(m_LogView);
    m_ScrolledWindow.set_policy(Gtk::POLICY_AUTOMATIC, Gtk::POLICY_ALWAYS);

    m_VBoxBackup.set_border_width(20);
    m_VBoxBackup.pack_start(m_LabelBackupInstruction, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_start(m_CheckThemesBackup, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_start(m_CheckIconsBackup, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_start(m_CheckWallpapersBackup, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_start(m_CheckExtensionsBackup, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_start(m_CheckDconfBackup, Gtk::PACK_SHRINK);
    m_VBoxBackup.pack_end(m_ButtonBackup, Gtk::PACK_SHRINK);
    
    m_VBoxRestore.set_border_width(20);
    m_VBoxRestore.pack_start(m_LabelRestoreInstruction, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_ButtonSelectVault, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_LabelSelectedVault, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckThemesRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckIconsRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckWallpapersRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckExtensionsRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckDconfRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_start(m_CheckDryRunRestore, Gtk::PACK_SHRINK);
    m_VBoxRestore.pack_end(m_ButtonRestore, Gtk::PACK_SHRINK);

    m_Notebook.append_page(m_VBoxBackup, "Backup");
    m_Notebook.append_page(m_VBoxRestore, "Restore");
    
    m_BottomBox.set_border_width(10);
    m_StatusLabel.set_halign(Gtk::ALIGN_START);
    m_BottomBox.pack_start(m_StatusLabel, Gtk::PACK_EXPAND_WIDGET);
    m_BottomBox.pack_end(m_CheckDebugMode, Gtk::PACK_SHRINK);

    m_MainLayout.pack_start(m_Notebook, Gtk::PACK_SHRINK);
    m_MainLayout.pack_start(m_ScrolledWindow, Gtk::PACK_EXPAND_WIDGET);
    m_MainLayout.pack_start(m_BottomBox, Gtk::PACK_SHRINK);

    m_ButtonBackup.signal_clicked().connect(sigc::mem_fun(*this, &MainWindow::on_button_backup_clicked));
    m_ButtonRestore.signal_clicked().connect(sigc::mem_fun(*this, &MainWindow::on_button_restore_clicked));
    m_ButtonSelectVault.signal_clicked().connect(sigc::mem_fun(*this, &MainWindow::on_button_select_vault_clicked));

    add(m_MainLayout);
    show_all_children();
}

MainWindow::~MainWindow() {}

void MainWindow::scan_vault_contents(const std::string& path) {
    struct archive *a = archive_read_new();
    struct archive_entry *entry;
    archive_read_support_format_all(a);
    archive_read_support_filter_all(a);
    std::set<std::string> found;
    if (archive_read_open_filename(a, path.c_str(), 10240) == ARCHIVE_OK) {
        while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
            std::string p = archive_entry_pathname(entry);
            if (p.find("themes.tar.gz") != std::string::npos) found.insert("themes");
            if (p.find("icons.tar.gz") != std::string::npos) found.insert("icons");
            if (p.find("wallpapers.tar.gz") != std::string::npos) found.insert("wallpapers");
            if (p.find("extensions.tar.gz") != std::string::npos) found.insert("extensions");
            if (p.find("settings.ini") != std::string::npos) found.insert("dconf");
        }
    }
    archive_read_free(a);
    m_CheckThemesRestore.set_active(found.count("themes"));
    m_CheckIconsRestore.set_active(found.count("icons"));
    m_CheckWallpapersRestore.set_active(found.count("wallpapers"));
    m_CheckExtensionsRestore.set_active(found.count("extensions"));
    m_CheckDconfRestore.set_active(found.count("dconf"));
}

void MainWindow::on_button_select_vault_clicked() {
    Gtk::FileChooserDialog dialog("Choose vault", Gtk::FILE_CHOOSER_ACTION_OPEN);
    dialog.set_transient_for(*this);
    dialog.add_button("_Cancel", Gtk::RESPONSE_CANCEL);
    dialog.add_button("_Open", Gtk::RESPONSE_OK);
    if (dialog.run() == Gtk::RESPONSE_OK) {
        m_SelectedVaultPath = dialog.get_filename();
        m_LabelSelectedVault.set_text("Selected: " + fs::path(m_SelectedVaultPath).filename().string());
        scan_vault_contents(m_SelectedVaultPath);
        add_log_ui("Vault loaded.");
    }
}

void MainWindow::queue_log(const std::string& message) {
    // Only write to disk if debug mode is explicitly checked
    if (m_IsDebugMode) {
        std::ofstream log_file(std::string(std::getenv("HOME")) + "/GnomeSettingsVault.log", std::ios::app);
        if (log_file.is_open()) { log_file << message << std::endl; log_file.close(); }
    }
    
    std::lock_guard<std::mutex> lock(m_LogMutex);
    m_LogQueue.push(message);
    m_Dispatcher.emit();
}

void MainWindow::on_dispatcher_ping() {
    std::lock_guard<std::mutex> lock(m_LogMutex);
    while (!m_LogQueue.empty()) {
        std::string msg = m_LogQueue.front();
        m_LogQueue.pop();
        if (msg == "__UNLOCK_UI__") {
            set_ui_locked(false);
            
            // Trigger Logout Prompt if it was a successful restore
            if (m_JobSuccess && m_LastJobWasRestore) {
                Gtk::MessageDialog dialog(*this, "Restore Complete", false, Gtk::MESSAGE_QUESTION, Gtk::BUTTONS_YES_NO);
                dialog.set_secondary_text("Settings and components have been successfully restored.\n\nGNOME needs to restart to apply all changes smoothly. Would you like to log out now?");
                if (dialog.run() == Gtk::RESPONSE_YES) {
                    system("gnome-session-quit --logout --no-prompt &");
                }
            }
        } else {
            add_log_ui(msg);
        }
    }
}

void MainWindow::add_log_ui(const std::string& message) {
    m_RefTextBuffer->insert(m_RefTextBuffer->end(), message + "\n");
    auto mark = m_RefTextBuffer->get_mark("last_line");
    m_RefTextBuffer->move_mark(mark, m_RefTextBuffer->end());
    if (m_LogView.get_realized()) m_LogView.scroll_to(mark);
}

void MainWindow::set_ui_locked(bool locked) {
    m_ButtonBackup.set_sensitive(!locked);
    m_ButtonRestore.set_sensitive(!locked);
    m_ButtonSelectVault.set_sensitive(!locked);
    m_CheckDebugMode.set_sensitive(!locked);
    
    if (!locked) {
        m_StatusLabel.override_color(m_JobSuccess ? Gdk::RGBA("#44ff44") : Gdk::RGBA("#ff4444"));
        m_StatusLabel.set_text(m_JobSuccess ? "Job Completed Successfully." : "Job Completed with ERRORS.");
    }
}

void MainWindow::run_backup_job(JobConfig config, std::string home_dir) {
    m_JobSuccess = true; std::error_code ec;
    queue_log("--- Starting Backup ---");
    std::string temp_dir = "/tmp/gvault_pack";
    fs::remove_all(temp_dir, ec);
    fs::create_directories(temp_dir);

    if (config.themes) if(!create_tar_archive(home_dir + "/.themes", temp_dir + "/themes.tar.gz", false)) m_JobSuccess = false;
    if (config.icons) if(!create_tar_archive(home_dir + "/.icons", temp_dir + "/icons.tar.gz", false)) m_JobSuccess = false;
    if (config.wallpapers) {
        std::string w_dir = get_wallpaper_directory();
        if(!w_dir.empty()) if(!create_tar_archive(w_dir, temp_dir + "/wallpapers.tar.gz", false)) m_JobSuccess = false;
    }
    if (config.extensions) if(!create_tar_archive(home_dir + "/.local/share/gnome-shell/extensions", temp_dir + "/extensions.tar.gz", false)) m_JobSuccess = false;
    
    if (config.dconf) { 
        queue_log("[BACKUP] Exporting GNOME Settings...");
        if (system(("dconf dump / > " + temp_dir + "/settings.ini").c_str()) != 0) m_JobSuccess = false; 
    }

    std::string final_file = home_dir + "/" + config.vault_name + ".gbk";
    queue_log("[BACKUP] Compiling final vault...");
    if(!create_tar_archive(temp_dir, final_file, true)) m_JobSuccess = false;
    
    fs::remove_all(temp_dir, ec);
    queue_log("__UNLOCK_UI__");
    m_WorkerRunning = false;
}

void MainWindow::on_button_backup_clicked() {
    Gtk::MessageDialog dialog(*this, "Vault Name", false, Gtk::MESSAGE_QUESTION, Gtk::BUTTONS_OK_CANCEL);
    Gtk::Entry entry; entry.set_text("GnomeVaultBackup");
    dialog.get_content_area()->pack_start(entry, Gtk::PACK_SHRINK);
    dialog.show_all_children();
    if (dialog.run() == Gtk::RESPONSE_OK) {
        m_IsDebugMode = m_CheckDebugMode.get_active();
        m_LastJobWasRestore = false;
        set_ui_locked(true); m_WorkerRunning = true;
        m_StatusLabel.override_color(Gdk::RGBA("#ffffff"));
        m_StatusLabel.set_text("Backup in progress...");
        
        JobConfig cfg;
        cfg.themes = m_CheckThemesBackup.get_active(); cfg.icons = m_CheckIconsBackup.get_active();
        cfg.wallpapers = m_CheckWallpapersBackup.get_active(); cfg.extensions = m_CheckExtensionsBackup.get_active();
        cfg.dconf = m_CheckDconfBackup.get_active(); cfg.dry_run = false; cfg.vault_name = entry.get_text();
        std::thread(&MainWindow::run_backup_job, this, cfg, std::string(std::getenv("HOME"))).detach();
    }
}

void MainWindow::run_restore_job(JobConfig config, std::string home_dir) {
    m_JobSuccess = true; std::error_code ec;
    queue_log("--- Starting Clean Restore ---");

    auto nuke_leftovers = [&](const std::string& path) {
        fs::remove_all(path + "_vault_new", ec);
        fs::remove_all(path + "_vault_old", ec);
    };
    nuke_leftovers(home_dir + "/.themes");
    nuke_leftovers(home_dir + "/.icons");
    nuke_leftovers(home_dir + "/.local/share/gnome-shell/extensions");

    if (config.extensions && !config.dry_run) {
        queue_log("[SAFE] Disabling extensions to prevent GNOME crash...");
        system("gsettings set org.gnome.shell disable-user-extensions true");
    }

    std::string temp_unpack = "/tmp/gvault_unpack";
    fs::remove_all(temp_unpack, ec);
    fs::create_directories(temp_unpack);
    
    queue_log("[RESTORE] Unpacking vault structure...");
    if (!extract_tar_archive(config.custom_restore_path, temp_unpack, false, false)) m_JobSuccess = false;

    std::string work_path = temp_unpack;
    for (const auto& entry : fs::recursive_directory_iterator(temp_unpack)) {
        if (entry.path().filename() == "settings.ini") { work_path = entry.path().parent_path().string(); break; }
    }

    auto atomic_restore = [&](const std::string& arch_name, const std::string& live_path, const std::string& label) {
        std::string arch_full = work_path + "/" + arch_name + ".tar.gz";
        if (fs::exists(arch_full)) {
            queue_log("[RESTORE] Swapping " + label + "...");
            std::string shadow = live_path + "_vault_new";
            std::string old_path = live_path + "_vault_old";
            
            fs::remove_all(shadow, ec);
            fs::remove_all(old_path, ec);
            fs::create_directories(shadow);
            
            if (extract_tar_archive(arch_full, shadow, config.dry_run, false)) {
                if (!config.dry_run) {
                    sync();
                    if (fs::exists(live_path)) {
                        fs::rename(live_path, old_path, ec);
                        if (ec) { queue_log("  !!! Warning: Could not isolate old " + label + ". Retrying via delete."); fs::remove_all(live_path, ec); }
                    }
                    fs::rename(shadow, live_path, ec);
                    if (ec) { 
                        queue_log("  !!! ERROR: Rename failed for " + label + "."); 
                        m_JobSuccess = false; 
                    } else { 
                        if (m_IsDebugMode) queue_log("  -> " + label + " swapped successfully."); 
                        fs::remove_all(old_path, ec); 
                    }
                }
            } else m_JobSuccess = false;
        }
    };

    if (config.themes) atomic_restore("themes", home_dir + "/.themes", "Themes");
    if (config.icons) atomic_restore("icons", home_dir + "/.icons", "Icons");
    if (config.extensions) atomic_restore("extensions", home_dir + "/.local/share/gnome-shell/extensions", "Extensions");
    
    if (config.wallpapers && fs::exists(work_path + "/wallpapers.tar.gz")) {
        queue_log("[RESTORE] Restoring Wallpapers...");
        if (!extract_tar_archive(work_path + "/wallpapers.tar.gz", "/", config.dry_run, true)) m_JobSuccess = false;
    }

    if (config.dconf && fs::exists(work_path + "/settings.ini") && !config.dry_run) {
        queue_log("[RESTORE] Injecting Dconf settings...");
        if (system(("dconf load / < " + work_path + "/settings.ini").c_str()) != 0) m_JobSuccess = false;
    }

    if (config.extensions && !config.dry_run) {
        queue_log("[SAFE] Re-enabling extensions...");
        system("gsettings set org.gnome.shell disable-user-extensions false");
    }

    fs::remove_all(temp_unpack, ec);
    queue_log("__UNLOCK_UI__");
}

void MainWindow::on_button_restore_clicked() {
    if (m_SelectedVaultPath.empty()) return;
    
    m_IsDebugMode = m_CheckDebugMode.get_active();
    m_LastJobWasRestore = true;
    set_ui_locked(true); m_WorkerRunning = true;
    
    m_StatusLabel.override_color(Gdk::RGBA("#ffffff"));
    m_StatusLabel.set_text("Restore in progress...");
    
    JobConfig cfg;
    cfg.themes = m_CheckThemesRestore.get_active(); cfg.icons = m_CheckIconsRestore.get_active();
    cfg.wallpapers = m_CheckWallpapersRestore.get_active(); cfg.extensions = m_CheckExtensionsRestore.get_active();
    cfg.dconf = m_CheckDconfRestore.get_active(); cfg.dry_run = m_CheckDryRunRestore.get_active();
    cfg.custom_restore_path = m_SelectedVaultPath;
    
    std::thread(&MainWindow::run_restore_job, this, cfg, std::string(std::getenv("HOME"))).detach();
}

bool MainWindow::create_tar_archive(const std::string& source_dir, const std::string& out_filename, bool strip_path) {
    struct archive *a = archive_write_new();
    archive_write_add_filter_gzip(a);
    archive_write_set_format_pax_restricted(a);
    archive_write_open_filename(a, out_filename.c_str());
    fs::path base_path = fs::absolute(source_dir);
    bool ok = true;
    
    if (m_IsDebugMode) queue_log("  -> Compressing: " + source_dir);

    for (const auto& dirEntry : fs::recursive_directory_iterator(base_path, fs::directory_options::skip_permission_denied)) {
        std::string full = dirEntry.path().string();
        std::string store = strip_path ? fs::relative(dirEntry.path(), base_path).string() : full;
        if (store == "." || store == "..") continue;
        struct archive_entry *entry = archive_entry_new();
        archive_entry_set_pathname(entry, store.c_str());
        struct stat st;
        if (lstat(full.c_str(), &st) != 0) { archive_entry_free(entry); ok = false; continue; }
        archive_entry_copy_stat(entry, &st);
        if (S_ISLNK(st.st_mode)) {
             char link_target[4096]; ssize_t len = readlink(full.c_str(), link_target, sizeof(link_target)-1);
             if (len != -1) { link_target[len]='\0'; archive_entry_set_symlink(entry, link_target); }
        }
        archive_write_header(a, entry);
        if (m_IsDebugMode) queue_log("    -> Packed: " + store);
        if (S_ISREG(st.st_mode)) {
            int fd = ::open(full.c_str(), O_RDONLY);
            if (fd >= 0) {
                char buff[65536]; ssize_t len;
                while ((len = ::read(fd, buff, sizeof(buff))) > 0) archive_write_data(a, buff, len);
                ::close(fd);
            } else ok = false;
        }
        archive_entry_free(entry);
    }
    archive_write_close(a); archive_write_free(a);
    return ok;
}

bool MainWindow::extract_tar_archive(const std::string& archive_path, const std::string& dest_dir, bool dry_run, bool use_absolute) {
    struct archive *a = archive_read_new();
    archive_read_support_format_all(a);
    archive_read_support_filter_all(a);
    if (archive_read_open_filename(a, archive_path.c_str(), 10240) != ARCHIVE_OK) return false;
    int flags = ARCHIVE_EXTRACT_TIME | ARCHIVE_EXTRACT_PERM | ARCHIVE_EXTRACT_UNLINK | ARCHIVE_EXTRACT_SECURE_NODOTDOT;
    struct archive_entry *entry;
    bool status = true;
    
    while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
        std::string stored_path = archive_entry_pathname(entry);
        if (!use_absolute) {
            size_t pos = stored_path.find("/.themes/");
            if (pos == std::string::npos) pos = stored_path.find("/.icons/");
            if (pos == std::string::npos) pos = stored_path.find("/extensions/");
            if (pos != std::string::npos) {
                size_t start = stored_path.find('/', pos + 1);
                if (start != std::string::npos) stored_path = stored_path.substr(start + 1);
            }
        }
        std::string target = use_absolute ? archive_entry_pathname(entry) : dest_dir + "/" + stored_path;
        archive_entry_set_pathname(entry, target.c_str());
        
        if (dry_run) { 
            if (m_IsDebugMode) queue_log("    -> [DRY] " + target); 
            archive_read_data_skip(a); 
        } else {
            if (use_absolute && fs::exists(target) && fs::is_regular_file(target)) {
                int fd = ::open(target.c_str(), O_WRONLY | O_TRUNC);
                if (fd >= 0) ::close(fd);
            }
            if (archive_read_extract(a, entry, flags) != ARCHIVE_OK) {
                if (!fs::is_directory(target)) {
                    if (m_IsDebugMode) queue_log("      !!! FAIL: " + std::string(archive_error_string(a)) + " -> " + target);
                    status = false;
                }
            } else {
                if (m_IsDebugMode) queue_log("    -> Restored: " + target);
            }
        }
    }
    archive_read_close(a); archive_read_free(a);
    return status;
}

std::string MainWindow::get_wallpaper_directory() {
    char buffer[256]; std::string result = "";
    FILE* pipe = popen("gsettings get org.gnome.desktop.background picture-uri-dark 2>/dev/null", "r");
    if (pipe) { while (fgets(buffer, sizeof(buffer), pipe) != nullptr) result += buffer; pclose(pipe); }
    size_t file_pos = result.find("file://");
    if (file_pos != std::string::npos) {
        std::string path = result.substr(file_pos + 7);
        path.erase(std::remove(path.begin(), path.end(), '\''), path.end());
        path.erase(std::remove(path.begin(), path.end(), '\n'), path.end());
        return fs::path(path).parent_path().string();
    }
    return "";
}