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

package atspi

import (
	"context"
	"strings"
	"unicode"
	"unicode/utf8"
)

// Match Python web elementLinesAreSingleWords/Chars: CSS text can expose one
// token per native LINE despite belonging to one logical line. The caller
// excludes editable and preformatted text and caches the bounded decision.
func documentLinesAreTokens(ctx context.Context, source reviewTextSource, content string) (bool, error) {
	count := utf8.RuneCountInString(content)
	if count < 2 || count > maxReviewLineCharacters || float64(strings.Count(content, "\ufffc"))/float64(count) > .3 {
		return false, nil
	}
	words := strings.FieldsFunc(content, func(value rune) bool { return unicode.IsSpace(value) || value == '\ufffc' })
	singleWords, singleChars := len(words) > 1, true
	for offset, attempts := 0, 0; offset < count; attempts++ {
		if err := ctx.Err(); err != nil {
			return false, err
		}
		if attempts >= maxReviewRanges {
			return false, nil
		}
		line, err := source.line(ctx, offset)
		if err != nil {
			return false, err
		}
		if line.Start < 0 || line.Start > offset || line.End <= offset || line.End > count {
			return false, nil
		}
		value := strings.TrimSpace(line.Text)
		singleWords = singleWords && len(strings.Fields(line.Text)) == 1
		singleChars = singleChars && (value == "" || value == "\ufffc" || value == "�" || utf8.RuneCountInString(value) == 1)
		if !singleWords && !singleChars {
			return false, nil
		}
		offset = line.End
	}
	return singleWords || singleChars, ctx.Err()
}