#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>

namespace fs = std::filesystem;

// The initialization list now perfectly matches the header declaration order
MainWindow::MainWindow()
: m_HeaderBar(),
  m_MainLayout(Gtk::ORIENTATION_VERTICAL, 0),
  m_Notebook(),
  m_ScrolledWindow(),
  m_LogView(),
  m_RefTextBuffer(),
  m_StatusLabel("Ready."),
  m_VBoxBackup(Gtk::ORIENTATION_VERTICAL, 10),
  m_LabelBackupInstruction("<span size='large' weight='bold'>Select what to backup:</span>"),
  m_CheckThemesBackup("GTK Themes (~/.themes)"),
  m_CheckIconsBackup("Icons (~/.icons)"),
  m_CheckWallpapersBackup("Wallpapers (Dynamic)"),
  m_CheckExtensionsBackup("GNOME Extensions"),
  m_CheckDconfBackup("GNOME Settings (dconf)"),
  m_ButtonBackup("Start Backup"),
  m_VBoxRestore(Gtk::ORIENTATION_VERTICAL, 10),
  m_LabelRestoreInstruction("<span size='large' weight='bold'>Select what to restore:</span>"),
  m_CheckThemesRestore("GTK Themes"),
  m_CheckIconsRestore("Icons"),
  m_CheckWallpapersRestore("Wallpapers"),
  m_CheckExtensionsRestore("GNOME Extensions"),
  m_CheckDconfRestore("GNOME Settings"),
  m_CheckDryRunRestore("Dry Run (Simulate only, do not write files)"),
  m_ButtonRestore("Start Restore"),
  m_WorkerRunning(false)
{
    // Connect the inter-thread dispatcher
    m_Dispatcher.connect(sigc::mem_fun(*this, &MainWindow::on_dispatcher_ping));

    const char* home = std::getenv("HOME");
    if (home) {
        std::string log_path = std::string(home) + "/gnome-vault.log";
        m_LogFile.open(log_path, std::ios::app);
    }

    set_default_size(650, 700);
    set_border_width(0);

    m_HeaderBar.set_title("Gnome-Vault");
    m_HeaderBar.set_subtitle("System State Manager");
    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();
    m_LogView.set_buffer(m_RefTextBuffer);
    m_LogView.set_editable(false);
    m_LogView.set_cursor_visible(false);
    m_LogView.set_wrap_mode(Gtk::WRAP_WORD);
    m_LogView.override_background_color(Gdk::RGBA("#1e1e1e")); 
    m_LogView.override_color(Gdk::RGBA("#dcdcdc"));
    
    m_ScrolledWindow.set_policy(Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC);
    m_ScrolledWindow.set_shadow_type(Gtk::SHADOW_IN);
    m_ScrolledWindow.add(m_LogView);
    m_ScrolledWindow.set_size_request(-1, 250);
    m_ScrolledWindow.set_margin_left(10);
    m_ScrolledWindow.set_margin_right(10);

    m_VBoxBackup.set_border_width(15);
    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_CheckThemesBackup.set_active(true);
    m_CheckIconsBackup.set_active(true);
    m_CheckWallpapersBackup.set_active(true);
    m_CheckExtensionsBackup.set_active(true);
    m_CheckDconfBackup.set_active(true);
    
    m_ButtonBackup.set_size_request(-1, 45);
    m_VBoxBackup.pack_end(m_ButtonBackup, Gtk::PACK_SHRINK);

    m_VBoxRestore.set_border_width(15);
    m_VBoxRestore.pack_start(m_LabelRestoreInstruction, 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_CheckThemesRestore.set_active(true);
    m_CheckIconsRestore.set_active(true);
    m_CheckWallpapersRestore.set_active(true);
    m_CheckExtensionsRestore.set_active(true);
    m_CheckDconfRestore.set_active(true);

    m_CheckDryRunRestore.set_active(true); 
    m_VBoxRestore.pack_start(m_CheckDryRunRestore, Gtk::PACK_SHRINK);
    
    m_ButtonRestore.set_size_request(-1, 45);
    m_VBoxRestore.pack_end(m_ButtonRestore, Gtk::PACK_SHRINK);

    m_Notebook.append_page(m_VBoxBackup, "Backup");
    m_Notebook.append_page(m_VBoxRestore, "Restore");

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

    add(m_MainLayout);
    show_all_children();
    add_log_ui("Session Started. Multithreaded Engine Ready.");
}

MainWindow::~MainWindow() {
    if (m_WorkerRunning) {
        add_log_ui("Warning: Waiting for background worker to finish before closing...");
        while (m_WorkerRunning) std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
    if (m_LogFile.is_open()) m_LogFile.close();
}

void MainWindow::queue_log(const std::string& message) {
    bool needs_emit = false;
    {
        std::lock_guard<std::mutex> lock(m_LogMutex);
        needs_emit = m_LogQueue.empty(); 
        m_LogQueue.push(message);
    }
    if (needs_emit) {
        m_Dispatcher.emit();
    }
}

void MainWindow::on_dispatcher_ping() {
    std::queue<std::string> local_queue;
    {
        std::lock_guard<std::mutex> lock(m_LogMutex);
        std::swap(local_queue, m_LogQueue);
    }

    while (!local_queue.empty()) {
        std::string msg = local_queue.front();
        local_queue.pop();

        if (msg == "__UNLOCK_UI__") {
            set_ui_locked(false);
            m_StatusLabel.set_text("Operation completed safely.");
        } else {
            add_log_ui(msg);
        }
    }
}

void MainWindow::add_log_ui(const std::string& message) {
    auto now = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
    std::stringstream ss;
    ss << std::put_time(std::localtime(&now), "[%H:%M:%S] ") << message << "\n";
    std::string formatted = ss.str();

    m_RefTextBuffer->insert(m_RefTextBuffer->end(), formatted);
    
    Gtk::TextBuffer::iterator iter = m_RefTextBuffer->end();
    m_RefTextBuffer->place_cursor(iter);

    // THE FIX: Do not attempt to scroll if the window isn't painted on the screen yet!
    // This stops GTK from segfaulting when trying to calculate geometries in the void.
    if (m_LogView.get_realized()) {
        m_LogView.scroll_to(m_RefTextBuffer->get_insert());
    }

    if (m_LogFile.is_open()) {
        m_LogFile << formatted;
        m_LogFile.flush();
    }
}

void MainWindow::set_ui_locked(bool locked) {
    m_ButtonBackup.set_sensitive(!locked);
    m_ButtonRestore.set_sensitive(!locked);
}

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 "";
}

bool MainWindow::create_tar_archive(const std::string& source_dir, const std::string& out_filename) {
    struct archive *a;
    struct archive *disk;
    struct archive_entry *entry;
    char buff[8192];
    int len, fd;

    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());

    disk = archive_read_disk_new();
    archive_read_disk_set_standard_lookup(disk);

    fs::directory_options options = fs::directory_options::skip_permission_denied;
    for (const auto& dirEntry : fs::recursive_directory_iterator(source_dir, options)) {
        std::string path = dirEntry.path().string();
        entry = archive_entry_new();
        archive_entry_copy_pathname(entry, path.c_str());
        archive_read_disk_entry_from_file(disk, entry, -1, nullptr);
        archive_write_header(a, entry);
        
        queue_log("  -> Packing: " + path);

        if (fs::is_regular_file(dirEntry)) {
            fd = ::open(path.c_str(), O_RDONLY);
            if (fd >= 0) {
                while ((len = ::read(fd, buff, sizeof(buff))) > 0) {
                    archive_write_data(a, buff, len);
                }
                ::close(fd);
            }
        }
        archive_entry_free(entry);
    }
    archive_read_free(disk);
    archive_write_close(a);
    archive_write_free(a);
    return true;
}

bool MainWindow::extract_tar_archive(const std::string& archive_path, bool dry_run) {
    struct archive *a;
    struct archive_entry *entry;
    int flags = ARCHIVE_EXTRACT_TIME | ARCHIVE_EXTRACT_PERM | ARCHIVE_EXTRACT_UNLINK | ARCHIVE_EXTRACT_SECURE_NODOTDOT;

    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) {
        queue_log("Error: Failed to open archive " + archive_path);
        archive_read_free(a);
        return false;
    }

    while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
        std::string current_path = archive_entry_pathname(entry);
        if (!current_path.empty() && current_path[0] != '/') {
            current_path = "/" + current_path;
            archive_entry_set_pathname(entry, current_path.c_str());
        }

        if (dry_run) {
            queue_log("  -> [DRY RUN] Would extract: " + current_path);
            archive_read_data_skip(a);
        } else {
            queue_log("  -> Extracting: " + current_path);
            if (archive_read_extract(a, entry, flags) != ARCHIVE_OK) {
                queue_log("    -> Warning: Failed to extract " + current_path + " (" + archive_error_string(a) + ")");
            }
        }
    }
    archive_read_close(a);
    archive_read_free(a);
    return true;
}

void MainWindow::run_backup_job(JobConfig config, std::string home_dir, std::string wallpaper_dir) {
    queue_log("--- Starting Backup Sequence (Worker Thread) ---");

    if (config.themes) {
        std::string target = home_dir + "/.themes";
        if (fs::exists(target)) {
            queue_log("Backing up Themes...");
            create_tar_archive(target, home_dir + "/gnome_themes_backup.tar.gz");
        }
    }
    
    if (config.icons) {
        std::string target = home_dir + "/.icons";
        if (fs::exists(target)) {
            queue_log("Backing up Icons...");
            create_tar_archive(target, home_dir + "/gnome_icons_backup.tar.gz");
        }
    }

    if (config.wallpapers) {
        if (!wallpaper_dir.empty() && wallpaper_dir != home_dir && wallpaper_dir != "/") {
            queue_log("Backing up Wallpapers from: " + wallpaper_dir);
            create_tar_archive(wallpaper_dir, home_dir + "/gnome_wallpapers_backup.tar.gz");
        } else {
            queue_log("Warning: Wallpaper directory too broad or empty. Skipped.");
        }
    }

    if (config.extensions) {
        std::string target = home_dir + "/.local/share/gnome-shell/extensions";
        if (fs::exists(target)) {
            queue_log("Backing up Extensions...");
            create_tar_archive(target, home_dir + "/gnome_extensions_backup.tar.gz");
        }
    }

    if (config.dconf) {
        queue_log("Dumping dconf settings...");
        std::string cmd = "dconf dump / > " + home_dir + "/gnome_dconf_backup.ini";
        if (system(cmd.c_str()) == 0) {
            queue_log("  -> Success: Dumped dconf");
        } else {
            queue_log("  -> Error: dconf dump failed");
        }
    }

    queue_log("--- Backup Completed ---");
    queue_log("__UNLOCK_UI__");
    m_WorkerRunning = false;
}

void MainWindow::on_button_backup_clicked() {
    if (m_WorkerRunning) return;

    set_ui_locked(true);
    m_WorkerRunning = true;
    m_StatusLabel.set_text("Backup in progress...");

    const char* env_home = std::getenv("HOME");
    std::string home_dir = env_home ? env_home : "";

    if (home_dir.empty()) {
        add_log_ui("Error: HOME environment variable missing.");
        set_ui_locked(false);
        m_WorkerRunning = false;
        return;
    }

    JobConfig config;
    config.themes = m_CheckThemesBackup.get_active();
    config.icons = m_CheckIconsBackup.get_active();
    config.wallpapers = m_CheckWallpapersBackup.get_active();
    config.extensions = m_CheckExtensionsBackup.get_active();
    config.dconf = m_CheckDconfBackup.get_active();
    config.dry_run = false;

    std::string wallpaper_dir = get_wallpaper_directory();

    std::thread(&MainWindow::run_backup_job, this, config, home_dir, wallpaper_dir).detach();
}

void MainWindow::run_restore_job(JobConfig config, std::string home_dir) {
    if (config.dry_run) {
        queue_log("--- Starting DRY RUN Restore (Worker Thread) ---");
        queue_log("NO FILES WILL BE MODIFIED");
    } else {
        queue_log("--- Starting LIVE Restore (Worker Thread) ---");
    }

    if (config.themes) {
        std::string in = home_dir + "/gnome_themes_backup.tar.gz";
        if (fs::exists(in)) {
            queue_log("Processing Themes archive...");
            extract_tar_archive(in, config.dry_run);
        }
    }

    if (config.icons) {
        std::string in = home_dir + "/gnome_icons_backup.tar.gz";
        if (fs::exists(in)) {
            queue_log("Processing Icons archive...");
            extract_tar_archive(in, config.dry_run);
        }
    }

    if (config.wallpapers) {
        std::string in = home_dir + "/gnome_wallpapers_backup.tar.gz";
        if (fs::exists(in)) {
            queue_log("Processing Wallpapers archive...");
            extract_tar_archive(in, config.dry_run);
        }
    }

    if (config.extensions) {
        std::string in = home_dir + "/gnome_extensions_backup.tar.gz";
        if (fs::exists(in)) {
            queue_log("Processing Extensions archive...");
            extract_tar_archive(in, config.dry_run);
        }
    }

    if (config.dconf) {
        std::string in = home_dir + "/gnome_dconf_backup.ini";
        if (fs::exists(in)) {
            if (config.dry_run) {
                queue_log("  -> [DRY RUN] Would load dconf settings from " + in);
            } else {
                queue_log("Injecting dconf settings...");
                std::string cmd = "dconf load / < " + in;
                if (system(cmd.c_str()) == 0) {
                    queue_log("  -> Success: dconf loaded");
                } else {
                    queue_log("  -> Error: dconf load failed");
                }
            }
        }
    }

    queue_log("--- Restore Completed ---");
    queue_log("__UNLOCK_UI__");
    m_WorkerRunning = false;
}

void MainWindow::on_button_restore_clicked() {
    if (m_WorkerRunning) return;

    set_ui_locked(true);
    m_WorkerRunning = true;
    m_StatusLabel.set_text("Restore in progress...");

    const char* env_home = std::getenv("HOME");
    std::string home_dir = env_home ? env_home : "";

    if (home_dir.empty()) {
        add_log_ui("Error: HOME environment variable missing.");
        set_ui_locked(false);
        m_WorkerRunning = false;
        return;
    }

    JobConfig config;
    config.themes = m_CheckThemesRestore.get_active();
    config.icons = m_CheckIconsRestore.get_active();
    config.wallpapers = m_CheckWallpapersRestore.get_active();
    config.extensions = m_CheckExtensionsRestore.get_active();
    config.dconf = m_CheckDconfRestore.get_active();
    config.dry_run = m_CheckDryRunRestore.get_active();

    std::thread(&MainWindow::run_restore_job, this, config, home_dir).detach();
}