package app

import (
	"context"
	"time"
	"unicode/utf8"

	"git.stormux.org/storm/cthulhu/internal/atspi"
	"git.stormux.org/storm/cthulhu/internal/braille"
)

type brailleRouter interface {
	RouteBraille(context.Context, atspi.BrailleRoute) error
}

func (worker *brailleWorker) route(ctx context.Context, event braille.RoutingEvent) {
	worker.mu.Lock()
	frame := worker.frame
	length := utf8.RuneCountInString(frame.Text)
	if worker.secure || worker.stopping || frame.ID == 0 || event.ID != frame.ID || event.Offset < 0 ||
		(frame.Virtual == nil && event.Offset >= length) || (frame.Virtual != nil && event.Offset > length) {
		worker.mu.Unlock()
		return
	}
	if route := frame.Virtual; route != nil {
		if worker.ocr == nil || event.Offset < route.Start || event.Offset > route.End {
			worker.mu.Unlock()
			return
		}
		routeCtx, cancel := context.WithTimeout(ctx, time.Second)
		worker.routeCancel = cancel
		worker.mu.Unlock()
		defer cancel()
		worker.ocr.RouteBraille(routeCtx, route.Generation, route.SourceStart+event.Offset-route.Start)
		return
	}
	if worker.router == nil && frame.Document == nil {
		worker.mu.Unlock()
		return
	}
	var target *braille.TextRoute
	for _, route := range frame.Routes {
		if event.Offset >= route.Start && event.Offset < route.End {
			target = &route
			break
		}
	}
	if target == nil {
		worker.mu.Unlock()
		return
	}
	routeCtx, cancel := context.WithTimeout(ctx, time.Second)
	worker.routeCancel = cancel
	worker.mu.Unlock()
	defer cancel()
	if document := frame.Document; document != nil {
		if worker.document == nil {
			return
		}
		worker.logger.Debug("routing document braille", "frame_id", frame.ID, "document_epoch", document.Epoch,
			"source_bus", target.BusName, "source_path", target.Path, "source_start", target.SourceStart,
			"native_offset", target.SourceStart+min(event.Offset-target.Start, target.TextLength))
		err := worker.document.RouteDocumentBraille(routeCtx, document.Epoch,
			atspi.NewObjectID(document.FocusBus, document.FocusPath), atspi.NewObjectID(document.DocumentBus, document.DocumentPath),
			atspi.NewObjectID(target.BusName, target.Path), target.SourceText, target.SourceStart,
			target.SourceStart+min(event.Offset-target.Start, target.TextLength))
		if err != nil && routeCtx.Err() == nil {
			worker.logger.Debug("document braille routing rejected", "error", err)
		}
		return
	}
	err := worker.router.RouteBraille(routeCtx, atspi.BrailleRoute{
		Focus: atspi.NewObjectID(target.BusName, target.Path), Line: target.SourceText, Start: target.SourceStart,
		Offset: target.SourceStart + min(event.Offset-target.Start, target.TextLength),
	})
	if err != nil && routeCtx.Err() == nil {
		worker.logger.Debug("braille routing rejected", "error", err)
	}
}