// Cthulhu screen reader.
// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"strings"

	"git.stormux.org/storm/cthulhu/internal/atspi"
	"git.stormux.org/storm/cthulhu/internal/config"
	"git.stormux.org/storm/cthulhu/internal/input"
	"git.stormux.org/storm/cthulhu/internal/presentation"
)

// handleBrowserTab presents a selected tab while leaving native focus in chrome.
func (handler *accessibilityEventHandler) handleBrowserTab(event atspi.Event, activity input.Activity) bool {
	state := handler.state
	browser := handler.browser
	objectReview := handler.objectReview
	speech := handler.speech
	brailleOutput := handler.brailleOutput
	live := handler.live
	if event.Source.BrowserTab && (event.Type == atspi.SelectedStateEvent || event.Type == atspi.SelectionChangedEvent) {
		// Python's web page-switch handler presents the tab without moving
		// the locus of focus. Repeated Ctrl+T can keep the same address
		// control focused and produce no further focus events at all.
		selected := event.Type == atspi.SelectedStateEvent && event.Detail1 != 0 ||
			event.Type == atspi.SelectionChangedEvent && event.Source.Selected &&
				strings.EqualFold(event.Source.ToolkitName, "Gecko")
		if !selected || event.Source.StatesKnown && !event.Source.Selected ||
			event.Source.Defunct || !state.owner.containsLoad(event) || event.Source.ID() == state.selectedBrowserTab {
			return true
		}
		state.selectedBrowserTab = event.Source.ID()
		state.tabFocusWindow, state.tabFocusSequence = eventWindow(event), activity.Sequence
		state.pending.caret.clear()
		state.documentLineFocus, state.documentLineRequest, state.documentLineEvent = atspi.ObjectID{}, 0, atspi.Event{}
		state.loadingDocument, state.loadedDocument = atspi.ObjectID{}, atspi.ObjectID{}
		state.chromeLoadedDocument, state.chromeLoadedWindow = atspi.ObjectID{}, atspi.ObjectID{}
		if browser != nil {
			browser.clear()
		}
		if objectReview != nil {
			focus := atspi.ObjectID{}
			if state.current.Autocomplete {
				focus = state.current.ID()
			}
			objectReview.ResetDocument(focus)
		}
		spoken := presentation.FocusSpeechWithOptions(event.Source, state.presentationOptions)
		text := spoken.Text
		if text != "" {
			speech.Enqueue(speechRequest{Text: text, Chunks: spoken.Chunks, Role: event.Source.Role, Cause: event.Type})
		}
		if brailleOutput != nil {
			brailleOptions := config.DefaultSettings().Braille
			textAttributes := config.DefaultTextAttributes()
			if live != nil {
				settings := live.Load()
				brailleOptions, textAttributes = settings.Braille, settings.TextAttributes
			}
			brailleOutput.EnqueueFrame(brailleFocusFrameWithOptions(event.Source, brailleOptions, textAttributes))
		}
		return true
	}
	if event.Source.Autocomplete && eventWindow(event) == state.tabFocusWindow &&
		activity.Sequence != 0 && activity.Sequence == state.tabFocusSequence &&
		(event.Type == atspi.CaretEvent || event.Type == "object:state-changed:expanded") {
		return true // Automatic address reset must not cut off the selected tab.
	}
	return false
}