//go:build webkit_cgo

package webkit

/*
#cgo pkg-config: webkitgtk-6.0 gtk4 javascriptcoregtk-6.0
#include <stdlib.h>
#include <gtk/gtk.h>
#include <webkit/webkit.h>
#include <glib-object.h>
#include <gdk/gdk.h>
#include <jsc/jsc.h>
#include <glib.h>
#include <gio/gio.h>

static GtkWidget* new_window() { return GTK_WIDGET(gtk_window_new()); }
// GTK4: gtk_main_quit removed; leave as no-op for now (Quit handled in Go)
static void connect_destroy_quit(GtkWidget* w) { (void)w; }
static WebKitWebView* as_webview(GtkWidget* w) { return WEBKIT_WEB_VIEW(w); }
// WebsiteDataManager creation will be handled via GTK4/WebKit6 APIs in Go code.

// Forward declare helpers used below
static void maybe_set_cookie_policy(WebKitCookieManager* cm, int policy);

// Construct a WebKitWebView via g_object_new with a fresh UserContentManager.
static GtkWidget* new_webview_with_ucm_and_session(const char* data_dir, const char* cache_dir, const char* cookie_path, WebKitUserContentManager** out_ucm) {
    WebKitUserContentManager* u = webkit_user_content_manager_new();
    if (!u) return NULL;
    // WebKitGTK 6: create NetworkSession with data/cache directories
    WebKitNetworkSession* sess = webkit_network_session_new(
        data_dir ? data_dir : "",
        cache_dir ? cache_dir : "");
    if (!sess) { g_object_unref(u); return NULL; }
    // Configure cookie persistence and policy (no third-party by default)
    WebKitCookieManager* cm = webkit_network_session_get_cookie_manager(sess);
    if (cm) {
        if (cookie_path && cookie_path[0]) {
            webkit_cookie_manager_set_persistent_storage(cm, cookie_path, WEBKIT_COOKIE_PERSISTENT_STORAGE_SQLITE);
        }
        // 2 => no-third-party (default), 0 => always, 1 => never
        maybe_set_cookie_policy(cm, 2);
    }
    // Persist credentials (HTTP auth, etc.)
    webkit_network_session_set_persistent_credential_storage_enabled(sess, TRUE);
    GtkWidget* w = GTK_WIDGET(g_object_new(WEBKIT_TYPE_WEB_VIEW,
        "user-content-manager", u,
        "network-session", sess,
        NULL));
    // WebView holds refs to provided objects; drop our temporary refs
    g_object_unref(sess);
    if (out_ucm) { *out_ucm = u; }
    return w;
}

static gboolean gtk_prefers_dark() {
    GtkSettings* settings = gtk_settings_get_default();
    if (!settings) return FALSE;
    gboolean prefer = FALSE;
    g_object_get(settings, "gtk-application-prefer-dark-theme", &prefer, NULL);
    return prefer;
}

// Note: preferred color scheme is handled via a user script injection to support
// older WebKitGTK versions without the color-scheme API. See enableUserContentManager.

extern void goOnUcmMessage(unsigned long id, const char* json);
extern void goOnTitleChanged(unsigned long id, const char* title);
extern void goOnURIChanged(unsigned long id, const char* uri);
extern void goOnThemeChanged(unsigned long id, int prefer_dark);
extern void* goResolveURIScheme(char* uri, size_t* out_len, char** out_mime);

void on_title_notify(GObject* obj, GParamSpec* pspec, gpointer user_data) {
    (void)pspec;
    WebKitWebView* view = WEBKIT_WEB_VIEW(obj);
    const gchar* title = webkit_web_view_get_title(view);
    GtkWindow* win = GTK_WINDOW(user_data);
    if (title && win) {
        gtk_window_set_title(win, title);
    }
}

void on_title_notify_id(GObject* obj, GParamSpec* pspec, gpointer user_data) {
    (void)pspec; (void)obj;
    const gchar* title = webkit_web_view_get_title(WEBKIT_WEB_VIEW(obj));
    if (title) { goOnTitleChanged((unsigned long)user_data, title); }
}

void on_uri_notify(GObject* obj, GParamSpec* pspec, gpointer user_data) {
    (void)pspec; (void)obj;
    const gchar* uri = webkit_web_view_get_uri(WEBKIT_WEB_VIEW(obj));
    if (uri) { goOnURIChanged((unsigned long)user_data, uri); }
}

// React to GTK theme preference changes at runtime
void on_theme_changed(GObject* obj, GParamSpec* pspec, gpointer user_data) {
    (void)pspec;
    GtkSettings* settings = GTK_SETTINGS(obj);
    if (!settings) return;
    gboolean prefer = FALSE;
    g_object_get(settings, "gtk-application-prefer-dark-theme", &prefer, NULL);
    goOnThemeChanged((unsigned long)user_data, prefer ? 1 : 0);
}

// NOTE: UCM message callback signature changed in WebKitGTK 6; will be reimplemented later.

void on_uri_scheme(WebKitURISchemeRequest* request, gpointer user_data) {
    (void)user_data;
    const gchar* uri = webkit_uri_scheme_request_get_uri(request);
    size_t n = 0;
    char* mime = NULL;
    void* buf = goResolveURIScheme((char*)uri, &n, &mime);
    if (buf && n > 0 && mime) {
        GInputStream* stream = g_memory_input_stream_new_from_data(buf, (gssize)n, g_free);
        webkit_uri_scheme_request_finish(request, stream, (gint64)n, mime);
        g_object_unref(stream);
        g_free(mime);
    } else {
        GError* err = g_error_new_literal(g_quark_from_string("dumber"), 404, "Not found");
        webkit_uri_scheme_request_finish_error(request, err);
        g_error_free(err);
    }
}

// Script message handler wiring for WebKitGTK 6
// Forward declaration for callback used in g_signal_connect_data
// WebKitGTK 6 delivers JSCValue* for script-message-received::NAME
static void ucm_on_script_message_cb(WebKitUserContentManager* ucm, JSCValue* val, gpointer user_data);
// Uses WebKitScriptMessage and script-message-received::NAME signal.
static void ucm_on_script_message_cb(WebKitUserContentManager* ucm, JSCValue* val, gpointer user_data) {
    (void)ucm;
    if (!val) return;
    gchar* s = jsc_value_to_string(val);
    if (!s) return;
    goOnUcmMessage((unsigned long)user_data, s);
    g_free(s);
}

static gboolean register_ucm_handler(WebKitUserContentManager* ucm, const char* name, unsigned long id) {
    if (!ucm || !name) return FALSE;
    // WebKitGTK 6 signature: (ucm, name, world_name)
    webkit_user_content_manager_register_script_message_handler(ucm, name, NULL);
    gchar* signal = g_strdup_printf("script-message-received::%s", name);
    if (!signal) return FALSE;
    g_signal_connect_data(G_OBJECT(ucm), signal, G_CALLBACK(ucm_on_script_message_cb), (gpointer)id, NULL, 0);
    g_free(signal);
    return TRUE;
}

// ----- Conditional helpers for settings across WebKit versions -----
#ifndef WEBKIT_CHECK_VERSION
#define WEBKIT_CHECK_VERSION(major,minor,micro) (0)
#endif

static void maybe_set_hw_policy(WebKitSettings* settings, int mode) {
#if WEBKIT_CHECK_VERSION(2,40,0)
    // mode: 0=ON_DEMAND, 1=ALWAYS, 2=NEVER
    if (!settings) return;
    if (mode == 1) {
        webkit_settings_set_hardware_acceleration_policy(settings, WEBKIT_HARDWARE_ACCELERATION_POLICY_ALWAYS);
    } else if (mode == 2) {
        webkit_settings_set_hardware_acceleration_policy(settings, WEBKIT_HARDWARE_ACCELERATION_POLICY_NEVER);
    } else {
        // Leave default policy (auto) without forcing a value to avoid referencing
        // WEBKIT_HARDWARE_ACCELERATION_POLICY_ON_DEMAND on older headers.
    }
#else
    (void)settings; (void)mode;
#endif
}

static void maybe_set_draw_indicators(WebKitSettings* settings, int enable) {
#if WEBKIT_CHECK_VERSION(2,36,0)
    if (!settings) return;
    webkit_settings_set_draw_compositing_indicators(settings, enable ? 1 : 0);
#else
    (void)settings; (void)enable;
#endif
}

static void maybe_set_webgl(WebKitSettings* settings, int enable) {
#if WEBKIT_CHECK_VERSION(2,20,0)
    if (!settings) return;
    webkit_settings_set_enable_webgl(settings, enable ? 1 : 0);
#else
    (void)settings; (void)enable;
#endif
}

static void maybe_set_canvas_accel(WebKitSettings* settings, int enable) {
#if WEBKIT_CHECK_VERSION(2,20,0)
    if (!settings) return;
    webkit_settings_set_enable_2d_canvas_acceleration(settings, enable ? 1 : 0);
#else
    (void)settings; (void)enable;
#endif
}

static void maybe_set_media_user_gesture(WebKitSettings* settings, int require) {
#if WEBKIT_CHECK_VERSION(2,20,0)
    if (!settings) return;
    webkit_settings_set_media_playback_requires_user_gesture(settings, require ? 1 : 0);
#else
    (void)settings; (void)require;
#endif
}

// Set cookie accept policy with compile-time compatibility across WebKit versions
static void maybe_set_cookie_policy(WebKitCookieManager* cm, int policy) {
    if (!cm) return;
#if defined(WEBKIT_COOKIE_ACCEPT_POLICY_ALWAYS)
    WebKitCookieAcceptPolicy p = WEBKIT_COOKIE_ACCEPT_POLICY_ALWAYS;
    if (policy == 1) p = WEBKIT_COOKIE_ACCEPT_POLICY_NEVER; // never
    else if (policy == 2) p = WEBKIT_COOKIE_ACCEPT_POLICY_NO_THIRD_PARTY; // no third-party
    webkit_cookie_manager_set_accept_policy(cm, p);
#elif defined(WEBKIT_COOKIE_POLICY_ACCEPT_ALWAYS)
    WebKitCookieAcceptPolicy p = WEBKIT_COOKIE_POLICY_ACCEPT_ALWAYS;
    if (policy == 1) p = WEBKIT_COOKIE_POLICY_ACCEPT_NEVER;
    else if (policy == 2) p = WEBKIT_COOKIE_POLICY_ACCEPT_NO_THIRD_PARTY;
    webkit_cookie_manager_set_accept_policy(cm, p);
#else
    (void)policy; // Not supported in this header version
#endif
}
*/
import "C"

import (
    "errors"
    "log"
    "os"
    "path/filepath"
    "runtime"
    "unsafe"
)

const omniboxDefaultScript = `(() => {
  try {
    if (window.__dumber_omnibox_loaded) return; window.__dumber_omnibox_loaded = true;
    const H = { el:null,input:null,list:null,visible:false,suggestions:[],debounceTimer:0,
      post(m){ try{ window.webkit?.messageHandlers?.dumber?.postMessage(JSON.stringify(m)); }catch(_){} },
      render(){ if(!this.el) this.mount(); this.el.style.display=this.visible?'block':'none'; if(this.visible) this.input.focus(); },
      mount(){ const r=document.createElement('div'); r.style.cssText='position:fixed;inset:0;z-index:2147483647;display:none;';
        const b=document.createElement('div'); b.style.cssText='max-width:720px;margin:8vh auto;padding:10px 12px;background:#16181a;color:#e6e6e6;border:1px solid #2a2e33;border-radius:10px;box-shadow:0 12px 36px rgba(0,0,0,.55);backdrop-filter:saturate(120%) blur(2px);font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,\"Helvetica Neue\",Arial,sans-serif;';
        const i=document.createElement('input'); i.type='text'; i.placeholder='Type URL or search…'; i.style.cssText='display:block;width:100%;box-sizing:border-box;padding:12px 14px;border-radius:8px;border:1px solid #3a3f45;background:#0f1113;color:#e6e6e6;font-size:15px;outline:none;';
        const l=document.createElement('div'); l.style.cssText='margin-top:10px;max-height:52vh;overflow:auto;border-top:1px solid #2a2e33;';
        b.appendChild(i); b.appendChild(l); r.appendChild(b); document.documentElement.appendChild(r);
        i.addEventListener('keydown', (e)=>{ if(e.key==='Escape'){H.toggle(false);} else if(e.key==='Enter'){ const pick=H.suggestions[H.selectedIndex|0]; const v=(pick&&pick.url)||i.value||''; if(v) H.post({type:'navigate', url:v}); H.toggle(false);} else if(e.key==='ArrowDown' || e.key==='ArrowUp'){ e.preventDefault(); const n=H.suggestions.length; if(n){ H.selectedIndex=(H.selectedIndex||0)+(e.key==='ArrowDown'?1:-1); if(H.selectedIndex<0)H.selectedIndex=n-1; if(H.selectedIndex>=n)H.selectedIndex=0; H.paintList(); } } });
        i.addEventListener('input', ()=>{ clearTimeout(H.debounceTimer); const q=i.value; H.debounceTimer=setTimeout(()=>H.post({type:'query', q, limit:10}), 120); });
        this.el=r; this.input=i; this.list=l; this.selectedIndex=-1; this.paintList(); },
      paintList(){ const l=this.list; if(!l) return; l.textContent=''; this.suggestions.forEach((s,i)=>{ const it=document.createElement('div'); it.style.cssText='padding:10px 12px;display:flex;gap:10px;align-items:center;cursor:pointer;border-bottom:1px solid #252a2f;'+(i===this.selectedIndex?'background:#0c0f12;':'');
          const icon=document.createElement('img'); icon.src=s.favicon||''; icon.width=18; icon.height=18; icon.loading='lazy'; icon.style.cssText='flex:0 0 18px;width:18px;height:18px;border-radius:4px;opacity:.95;'; icon.onerror=()=>{ icon.style.display='none'; };
          const url=document.createElement('div'); url.textContent=s.url||''; url.style.cssText='flex:1;min-width:0;color:#cfe6ff;font-size:13.5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;';
          it.appendChild(icon); it.appendChild(url);
          it.addEventListener('mouseenter',()=>{ H.selectedIndex=i; H.paintList(); });
          it.addEventListener('click',()=>{ H.post({type:'navigate', url:s.url}); H.toggle(false); });
          l.appendChild(it);
        }); },
      toggle(v){ this.visible=(typeof v==='boolean')?v:!this.visible; this.render(); }, setSuggestions(a){ this.suggestions=Array.isArray(a)?a:[]; this.selectedIndex=-1; this.paintList(); }
    };
    window.addEventListener('keydown', (e)=>{ if((e.ctrlKey||e.metaKey) && (e.key==='l'||e.key==='L')){ e.preventDefault(); H.toggle(true); } }, true);
    window.__dumber_setSuggestions = (a)=> H.setSuggestions(a);
    window.__dumber_toggle = ()=> H.toggle();
  } catch(_){}
})();`

type nativeView struct {
    win  *C.GtkWidget
    view *C.GtkWidget
    wv   *C.WebKitWebView
    ucm  *C.WebKitUserContentManager
}

// WebView represents a browser view powered by WebKit2GTK.
type WebView struct {
    config    *Config
    zoom      float64
    url       string
    destroyed bool
    native    *nativeView
    window    *Window
    id        uintptr
    msgHandler func(payload string)
    titleHandler func(title string)
    uriHandler   func(uri string)
}

// NewWebView constructs a new WebView instance with native WebKit2GTK widgets.
func NewWebView(cfg *Config) (*WebView, error) {
    log.Printf("[webkit] Initializing GTK and creating WebView (CGO)")
    if C.gtk_init_check() == 0 {
        return nil, errors.New("failed to initialize GTK")
    }

    if cfg == nil {
        cfg = &Config{}
    }

    // Prepare persistent website data/caches
    dataDir := cfg.DataDir
    cacheDir := cfg.CacheDir
    if dataDir == "" { dataDir = filepath.Join(os.TempDir(), "dumber-webkit-data") }
    if cacheDir == "" { cacheDir = filepath.Join(os.TempDir(), "dumber-webkit-cache") }
    _ = os.MkdirAll(dataDir, 0o755)
    _ = os.MkdirAll(cacheDir, 0o755)

    cData := C.CString(dataDir)
    cCache := C.CString(cacheDir)
    cookieFile := filepath.Join(dataDir, "cookies.db")
    cCookie := C.CString(cookieFile)
    defer C.free(unsafe.Pointer(cData))
    defer C.free(unsafe.Pointer(cCache))
    defer C.free(unsafe.Pointer(cCookie))
    // Use default WebContext to register the custom URI scheme handler; the
    // WebView itself is created with a WebKitNetworkSession for persistence.
    ctx := C.webkit_web_context_get_default()

    // Register custom URI scheme handler for "dumb://"
    {
        sch := C.CString("dumb")
        C.webkit_web_context_register_uri_scheme(ctx, sch, (C.WebKitURISchemeRequestCallback)(C.on_uri_scheme), nil, nil)
        C.free(unsafe.Pointer(sch))
    }
    // Cookie manager persistent storage handled via NetworkSession in new_webview_with_ucm_and_session

    // Create WebView through g_object_new with a fresh UCM (GTK4/WebKit 6 style)
    var createdUcm *C.WebKitUserContentManager
    viewWidget := C.new_webview_with_ucm_and_session(cData, cCache, cCookie, &createdUcm)
    if viewWidget == nil {
        return nil, errors.New("failed to create WebKitWebView")
    }

    // Create a top-level window to host the view
    win := C.new_window()
    if win == nil {
        return nil, errors.New("failed to create GtkWindow")
    }

    // Pack view widget into the window
    // GTK4: containers removed; use gtk_window_set_child
    C.gtk_window_set_child((*C.GtkWindow)(unsafe.Pointer(win)), viewWidget)
    C.gtk_window_set_default_size((*C.GtkWindow)(unsafe.Pointer(win)), 1024, 768)
    C.connect_destroy_quit(win)

    v := &WebView{
        config: cfg,
        zoom:   1.0,
        native: &nativeView{win: win, view: viewWidget, wv: C.as_webview(viewWidget), ucm: createdUcm},
        window: &Window{win: win},
    }
    // Assign an ID for accelerator dispatch
    v.id = nextViewID()
    registerView(v.id, v)
    // Attach GTK4 input controllers (keyboard, mouse)
    AttachKeyboardControllers(v)

    // Watch for GTK theme changes and propagate to page at runtime
    if settings := C.gtk_settings_get_default(); settings != nil {
        cprop := C.CString("notify::gtk-application-prefer-dark-theme")
        C.g_signal_connect_data(C.gpointer(unsafe.Pointer(settings)), cprop, C.GCallback(C.on_theme_changed), C.gpointer(v.id), nil, 0)
        C.free(unsafe.Pointer(cprop))
    }

    // Native zoom shortcuts (independent of app services)
    // Ctrl+='=' and Ctrl+'+' → Zoom In; Ctrl+'-' → Zoom Out; Ctrl+'0' → Reset
    _ = v.RegisterKeyboardShortcut("cmdorctrl+=", func() {
        nz := v.zoom
        if nz <= 0 { nz = 1.0 }
        nz *= 1.1
        if nz < 0.25 { nz = 0.25 }
        if nz > 5.0 { nz = 5.0 }
        _ = v.SetZoom(nz)
    })
    _ = v.RegisterKeyboardShortcut("cmdorctrl+plus", func() {
        nz := v.zoom
        if nz <= 0 { nz = 1.0 }
        nz *= 1.1
        if nz < 0.25 { nz = 0.25 }
        if nz > 5.0 { nz = 5.0 }
        _ = v.SetZoom(nz)
    })
    _ = v.RegisterKeyboardShortcut("cmdorctrl-", func() {
        nz := v.zoom
        if nz <= 0 { nz = 1.0 }
        nz /= 1.1
        if nz < 0.25 { nz = 0.25 }
        if nz > 5.0 { nz = 5.0 }
        _ = v.SetZoom(nz)
    })
    _ = v.RegisterKeyboardShortcut("cmdorctrl+0", func() { _ = v.SetZoom(1.0) })
    // Update window title when page title changes
    cNotifyTitle1 := C.CString("notify::title")
    C.g_signal_connect_data(C.gpointer(unsafe.Pointer(viewWidget)), cNotifyTitle1, C.GCallback(C.on_title_notify), C.gpointer(unsafe.Pointer(win)), nil, 0)
    C.free(unsafe.Pointer(cNotifyTitle1))
    // Also dispatch title change to Go with view id
    cNotifyTitle2 := C.CString("notify::title")
    C.g_signal_connect_data(C.gpointer(unsafe.Pointer(viewWidget)), cNotifyTitle2, C.GCallback(C.on_title_notify_id), C.gpointer(v.id), nil, 0)
    C.free(unsafe.Pointer(cNotifyTitle2))
    // Notify URI changes to Go to keep current URL in sync
    cNotifyURI := C.CString("notify::uri")
    C.g_signal_connect_data(C.gpointer(unsafe.Pointer(viewWidget)), cNotifyURI, C.GCallback(C.on_uri_notify), C.gpointer(v.id), nil, 0)
    C.free(unsafe.Pointer(cNotifyURI))
    // Apply hardware acceleration and related settings based on cfg.Rendering
    if settings := C.webkit_web_view_get_settings(v.native.wv); settings != nil {
        // Hardware acceleration policy (guarded by version)
        switch cfg.Rendering.Mode {
        case "gpu":
            C.maybe_set_hw_policy(settings, 1)
            C.maybe_set_webgl(settings, 1)
            C.maybe_set_canvas_accel(settings, 1)
        case "cpu":
            C.maybe_set_hw_policy(settings, 2)
            C.maybe_set_webgl(settings, 0)
            C.maybe_set_canvas_accel(settings, 0)
        default: // auto
            C.maybe_set_hw_policy(settings, 0)
            C.maybe_set_webgl(settings, 1)
            C.maybe_set_canvas_accel(settings, 1)
        }
        // Optional compositing indicators for debugging (guarded by version)
        if cfg.Rendering.DebugGPU { C.maybe_set_draw_indicators(settings, 1) }
        // Reduce media pipeline churn by requiring a user gesture for playback
        C.maybe_set_media_user_gesture(settings, 1)
    }

    if cfg.ZoomDefault > 0 {
        v.zoom = cfg.ZoomDefault
        C.webkit_web_view_set_zoom_level(v.native.wv, C.gdouble(v.zoom))
    }
    if cfg.EnableDeveloperExtras {
        settings := C.webkit_web_view_get_settings(v.native.wv)
        if settings != nil {
            C.webkit_settings_set_enable_developer_extras(settings, C.gboolean(1))
        }
    }
    // Apply default fonts if provided in cfg
    if settings := C.webkit_web_view_get_settings(v.native.wv); settings != nil {
        if cfg.DefaultSansFont != "" {
            csans := C.CString(cfg.DefaultSansFont)
            C.webkit_settings_set_sans_serif_font_family(settings, (*C.gchar)(csans))
            C.free(unsafe.Pointer(csans))
            // Also set default font family to sans
            csans2 := C.CString(cfg.DefaultSansFont)
            C.webkit_settings_set_default_font_family(settings, (*C.gchar)(csans2))
            C.free(unsafe.Pointer(csans2))
        }
        if cfg.DefaultSerifFont != "" {
            cserif := C.CString(cfg.DefaultSerifFont)
            C.webkit_settings_set_serif_font_family(settings, (*C.gchar)(cserif))
            C.free(unsafe.Pointer(cserif))
        }
        if cfg.DefaultMonospaceFont != "" {
            cmono := C.CString(cfg.DefaultMonospaceFont)
            C.webkit_settings_set_monospace_font_family(settings, (*C.gchar)(cmono))
            C.free(unsafe.Pointer(cmono))
        }
        if cfg.DefaultFontSize > 0 {
            C.webkit_settings_set_default_font_size(settings, C.guint(cfg.DefaultFontSize))
        }
    }
    if cfg.InitialURL != "" {
        _ = v.LoadURL(cfg.InitialURL)
    }
    // Ensure native resources are released if user forgets to call Destroy
    runtime.SetFinalizer(v, func(v *WebView) { _ = v.Destroy() })
    log.Printf("[webkit] WebView created (CGO)")

    // Initialize UCM scripts and handlers
    if v.native != nil && v.native.ucm != nil {
        v.enableUserContentManager()
    }
    return v, nil
}

func (w *WebView) LoadURL(rawURL string) error {
    if w == nil || w.destroyed || w.native == nil || w.native.wv == nil {
        return ErrNotImplemented
    }
    w.url = rawURL
    curl := C.CString(rawURL)
    defer C.free(unsafe.Pointer(curl))
    C.webkit_web_view_load_uri(w.native.wv, (*C.gchar)(curl))
    log.Printf("[webkit] LoadURL: %s", rawURL)
    return nil
}

func (w *WebView) Show() error {
    if w == nil || w.destroyed || w.native == nil || w.native.win == nil {
        return ErrNotImplemented
    }
    C.gtk_widget_set_visible(w.native.view, C.gboolean(1))
    C.gtk_widget_set_visible(w.native.win, C.gboolean(1))
    C.gtk_window_present((*C.GtkWindow)(unsafe.Pointer(w.native.win)))
    log.Printf("[webkit] Show window")
    return nil
}

func (w *WebView) Hide() error {
    if w == nil || w.destroyed || w.native == nil || w.native.win == nil {
        return ErrNotImplemented
    }
    C.gtk_widget_set_visible(w.native.view, C.gboolean(0))
    C.gtk_widget_set_visible(w.native.win, C.gboolean(0))
    return nil
}

func (w *WebView) Destroy() error {
    if w == nil || w.native == nil || w.native.win == nil {
        return ErrNotImplemented
    }
    // GTK4: destroy windows via gtk_window_destroy
    C.gtk_window_destroy((*C.GtkWindow)(unsafe.Pointer(w.native.win)))
    w.destroyed = true
    unregisterView(w.id)
    log.Printf("[webkit] Destroy window")
    return nil
}

// Window returns the associated native window.
func (w *WebView) Window() *Window { return w.window }

// GetCurrentURL returns the current URI from WebKit.
func (w *WebView) GetCurrentURL() string {
    if w == nil || w.native == nil || w.native.wv == nil { return "" }
    uri := C.webkit_web_view_get_uri(w.native.wv)
    if uri == nil { return "" }
    return C.GoString((*C.char)(unsafe.Pointer(uri)))
}

func (w *WebView) GoBack() error {
    if w == nil || w.native == nil || w.native.wv == nil { return ErrNotImplemented }
    C.webkit_web_view_go_back(w.native.wv)
    return nil
}

func (w *WebView) GoForward() error {
    if w == nil || w.native == nil || w.native.wv == nil { return ErrNotImplemented }
    C.webkit_web_view_go_forward(w.native.wv)
    return nil
}

// RegisterScriptMessageHandler registers a callback invoked when the content script posts a message.
func (w *WebView) RegisterScriptMessageHandler(cb func(payload string)) { w.msgHandler = cb }

func (w *WebView) dispatchScriptMessage(payload string) {
    if w != nil && w.msgHandler != nil { w.msgHandler(payload) }
}

// RegisterTitleChangedHandler registers a callback invoked when the page title changes.
func (w *WebView) RegisterTitleChangedHandler(cb func(title string)) { w.titleHandler = cb }

func (w *WebView) dispatchTitleChanged(title string) {
    if w != nil && w.titleHandler != nil { w.titleHandler(title) }
}

// RegisterURIChangedHandler registers a callback invoked when the current page URI changes.
func (w *WebView) RegisterURIChangedHandler(cb func(uri string)) { w.uriHandler = cb }

func (w *WebView) dispatchURIChanged(uri string) {
    if w != nil && w.uriHandler != nil { w.uriHandler(uri) }
}

// enableUserContentManager registers the 'dumber' message handler and injects the omnibox script.
func (w *WebView) enableUserContentManager() {
    if w == nil || w.native == nil || w.native.ucm == nil { return }
    // Register handler "dumber"
    cname := C.CString("dumber")
    ok := C.register_ucm_handler(w.native.ucm, cname, C.ulong(w.id))
    if ok == 0 {
        log.Printf("[webkit] Failed to register UCM handler; fallback bridge will handle messages")
    }
    C.free(unsafe.Pointer(cname))

    // Inject color-scheme preference script at document-start to inform sites of system theme
    preferDark := C.gtk_prefers_dark() != 0
    if preferDark {
        log.Printf("[theme] GTK prefers: dark")
    } else {
        log.Printf("[theme] GTK prefers: light")
    }
    var schemeJS string
    if preferDark {
        schemeJS = "(() => { try { const d=true; const cs=d?'dark':'light'; console.log('[dumber] color-scheme set:' + cs); try{ window.webkit?.messageHandlers?.dumber?.postMessage(JSON.stringify({type:'theme', value: cs})) }catch(_){} const meta=document.createElement('meta'); meta.name='color-scheme'; meta.content='dark light'; document.documentElement.appendChild(meta); const s=document.createElement('style'); s.textContent=':root{color-scheme:dark;}'; document.documentElement.appendChild(s); const qD='(prefers-color-scheme: dark)'; const qL='(prefers-color-scheme: light)'; const orig=window.matchMedia; window.matchMedia=function(q){ if(typeof q==='string'&&(q.includes(qD)||q.includes(qL))){ const m={matches:q.includes('dark')?d:!d,media:q,onchange:null,addListener(){},removeListener(){},addEventListener(){},removeEventListener(){},dispatchEvent(){return false;}}; return m;} return orig.call(window,q); }; } catch(e){ console.warn('[dumber] color-scheme injection failed', e) } })();"
    } else {
        schemeJS = "(() => { try { const d=false; const cs=d?'dark':'light'; console.log('[dumber] color-scheme set:' + cs); try{ window.webkit?.messageHandlers?.dumber?.postMessage(JSON.stringify({type:'theme', value: cs})) }catch(_){} const meta=document.createElement('meta'); meta.name='color-scheme'; meta.content='light dark'; document.documentElement.appendChild(meta); const s=document.createElement('style'); s.textContent=':root{color-scheme:light;}'; document.documentElement.appendChild(s); const qD='(prefers-color-scheme: dark)'; const qL='(prefers-color-scheme: light)'; const orig=window.matchMedia; window.matchMedia=function(q){ if(typeof q==='string'&&(q.includes(qD)||q.includes(qL))){ const m={matches:q.includes('dark')?d:!d,media:q,onchange:null,addListener(){},removeListener(){},addEventListener(){},removeEventListener(){},dispatchEvent(){return false;}}; return m;} return orig.call(window,q); }; } catch(e){ console.warn('[dumber] color-scheme injection failed', e) } })();"
    }
    cScheme := C.CString(schemeJS)
    defer C.free(unsafe.Pointer(cScheme))
    schemeScript := C.webkit_user_script_new((*C.gchar)(cScheme), C.WEBKIT_USER_CONTENT_INJECT_ALL_FRAMES, C.WEBKIT_USER_SCRIPT_INJECT_AT_DOCUMENT_START, nil, nil)
    if schemeScript != nil {
        C.webkit_user_content_manager_add_script(w.native.ucm, schemeScript)
        C.webkit_user_script_unref(schemeScript)
    }

    // Add user script at document-start
    src := C.CString(omniboxDefaultScript)
    defer C.free(unsafe.Pointer(src))
    script := C.webkit_user_script_new((*C.gchar)(src), C.WEBKIT_USER_CONTENT_INJECT_ALL_FRAMES, C.WEBKIT_USER_SCRIPT_INJECT_AT_DOCUMENT_START, nil, nil)
    if script != nil {
        C.webkit_user_content_manager_add_script(w.native.ucm, script)
        C.webkit_user_script_unref(script)
        log.Printf("[webkit] UCM omnibox script injected at document-start")
    }

    // Inject Wails runtime fetch interceptor for homepage bridging
    wailsBridge := `(() => { try { const origFetch = window.fetch.bind(window); const waiters = Object.create(null); window.__dumber_wails_resolve = (id, json) => { const w = waiters[id]; if(!w) return; delete waiters[id]; try { const headers = new Headers({"Content-Type":"application/json"}); w.resolve(new Response(json, { headers })); } catch(e){ w.reject(e); } }; window.fetch = (input, init) => { try { const url = new URL(input instanceof Request ? input.url : input, window.location.origin); if (url.pathname === '/wails/runtime') { const args = url.searchParams.get('args'); let payload = {}; try { payload = args ? JSON.parse(args) : {}; } catch(_){} const id = String(Date.now()) + '-' + Math.random().toString(36).slice(2); return new Promise((resolve, reject) => { waiters[id] = { resolve, reject }; try { window.webkit?.messageHandlers?.dumber?.postMessage(JSON.stringify({ type: 'wails', id, payload })); } catch (e) { reject(e); } }); } } catch(_){} return origFetch(input, init); }; } catch(_){} })();`
    cWails := C.CString(wailsBridge)
    defer C.free(unsafe.Pointer(cWails))
    wailsScript := C.webkit_user_script_new((*C.gchar)(cWails), C.WEBKIT_USER_CONTENT_INJECT_ALL_FRAMES, C.WEBKIT_USER_SCRIPT_INJECT_AT_DOCUMENT_START, nil, nil)
    if wailsScript != nil {
        C.webkit_user_content_manager_add_script(w.native.ucm, wailsScript)
        C.webkit_user_script_unref(wailsScript)
    }

    // No JS fallback bridge — native UCM is active
}