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

package review

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

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

// readDocumentBraille reads the accepted line and selection ranges for its
// inline fragments. Optional display reads never fail or repeat navigation.
func (worker *Worker) readDocumentBraille(ctx context.Context, result Result) Result {
	if !worker.documentBraille.Load() || !result.Moved || result.Err != nil || result.CaretErr != nil ||
		!worker.CurrentDocumentResult(result) || worker.focus() != result.DocumentFocus ||
		result.DocumentCaretCommand >= TableLeft || result.DocumentPosition.Snapshot.Role == "password text" {
		return result
	}
	// Explicitly named links are atomic browse objects. Their native text may
	// contain only a numeric badge; braille must use the same accessible label
	// as speech rather than enriching it with that incomplete child text.
	if snapshot := result.DocumentPosition.Snapshot; snapshot.Role == "link" && wholeCaretNode(snapshot) {
		return result
	}
	reader, ok := worker.nativeCapturerFor(result.DocumentFocus).(DocumentCaretReader)
	if !ok || !result.DocumentPosition.Object.Valid() {
		return result
	}
	// Display enrichment must not hold ordinary speech/navigation for the
	// longer whole-document capture timeout.
	deadline, cancel := context.WithTimeout(ctx, min(worker.captureTimeout, 100*time.Millisecond))
	defer cancel()
	line, err := reader.ReadDocumentCaret(deadline, result.DocumentPosition.Object, result.DocumentPosition.Offset, atspi.DocumentCaretBrailleLine)
	if err != nil {
		result.DocumentBrailleErr = err
		return result
	}
	if line.Start < 0 || result.DocumentPosition.Offset < line.Start ||
		result.DocumentPosition.Offset-line.Start > utf8.RuneCountInString(documentBrailleNativeText(line)) || line.Text == "" {
		result.DocumentBrailleErr = atspi.ErrNoDocumentCaret
		return result
	}
	result.DocumentBrailleLine = &line
	if assembled := result.DocumentCaretLine; assembled != nil {
		copyLine := *assembled
		copyLine.Contents = append([]atspi.DocumentContent(nil), assembled.Contents...)
		for index := range copyLine.Contents {
			content := &copyLine.Contents[index]
			content.Snapshot.SelectionStart, content.Snapshot.SelectionEnd = 0, 0
			selected := line
			if content.Snapshot.ID() != result.DocumentPosition.Object.ID() {
				if !content.Reference.Valid() {
					continue
				}
				selected, err = reader.ReadDocumentCaret(deadline, content.Reference, content.Start, atspi.DocumentCaretBrailleLine)
				if err != nil {
					continue
				}
			}
			start, end := content.Start-selected.Start, content.Start-selected.Start+utf8.RuneCountInString(content.RawText)
			runes := []rune(documentBrailleNativeText(selected))
			if start < 0 || end > len(runes) || string(runes[start:end]) != content.RawText {
				continue
			}
			content.Snapshot.SelectionStart, content.Snapshot.SelectionEnd = selected.SelectionStart, selected.SelectionEnd
			content.Snapshot.TextAttributeRuns = selected.TextAttributeRuns
		}
		result.DocumentCaretLine = &copyLine
	}
	return result
}

// Braille expansion changes display characters, never the native offset domain.
func documentBrailleNativeText(line atspi.DocumentCaretText) string {
	if line.Expanded {
		return line.RawText
	}
	return line.Text
}