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

package app

import (
	"context"
	"errors"
	"log/slog"

	"git.stormux.org/storm/cthulhu/internal/lifecycle"
	"git.stormux.org/storm/cthulhu/internal/platform/session"
	"git.stormux.org/storm/cthulhu/internal/platform/wayland"
	"git.stormux.org/storm/cthulhu/internal/platform/xorg"
)

type desktopInputBackend interface {
	Start(context.Context) error
	Stop(context.Context) error
}

// Missing desktop keyboard capabilities must not prevent AT-SPI, speech and
// braille from running on Wayland. Explicit X11 backends keep their existing
// optional Xwayland startup behavior.
// Other backends retain their own startup contract. The lifecycle runner still
// owns cleanup, including a native listener whose startup failed.
func desktopInputService(name string, backend desktopInputBackend, logger *slog.Logger) lifecycle.Service {
	service := lifecycle.Service{Name: name, Start: backend.Start, Stop: backend.Stop}
	switch backend.(type) {
	case *wayland.Keyboard:
		service.Start = func(ctx context.Context) error {
			err := backend.Start(ctx)
			if ctx.Err() != nil {
				return ctx.Err()
			}
			if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
				return err
			}
			if err != nil {
				logger.Warn("Wayland keyboard access unavailable; continuing with AT-SPI reading only", "error", err)
			}
			return nil
		}
	case *xorg.Listener, *xorg.CommandListener:
		if session.Wayland() {
			service.Start = func(ctx context.Context) error {
				return startOptionalXorg(ctx, name, backend.Start, logger)
			}
		}
	}
	return service
}

func startOptionalXorg(ctx context.Context, name string, start func(context.Context) error, logger *slog.Logger) error {
	err := start(ctx)
	if ctx.Err() != nil {
		return ctx.Err()
	}
	if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
		return err
	}
	if err != nil {
		logger.Warn("X11 input service unavailable on Wayland; continuing without it", "service", name, "error", err)
	}
	return nil
}