/**
 * @fileoverview Utility Library
 * @author Nicholas C. Zakas
 */
//-----------------------------------------------------------------------------
// Regex Patterns
//-----------------------------------------------------------------------------
/**
 * Line ending pattern to match all line endings (CRLF, CR, LF). (CommonMark spec)
 * @see https://spec.commonmark.org/0.31.2/#line-ending
 */
export const lineEndingPattern = /\r\n|[\r\n]/u;
/**
 * CommonMark does not allow any white space between the brackets in a reference link.
 * If that pattern is detected, then it's treated as text and not as a link. This pattern
 * is used to detect that situation.
 */
export const illegalShorthandTailPattern = /\]\[\s+\]$/u;
/**
 * Regular expression to match HTML comments, including multiline comments.
 */
export const htmlCommentPattern = /<!--[\s\S]*?-->/gu;
//-----------------------------------------------------------------------------
// Helpers
//-----------------------------------------------------------------------------
/**
 * Checks if a frontmatter block contains a title matching the given pattern.
 * @param {string} value The frontmatter content.
 * @param {RegExp|null} pattern The pattern to match against.
 * @returns {boolean} Whether a title was found.
 */
export function frontmatterHasTitle(value, pattern) {
    if (!pattern) {
        return false;
    }
    const lines = value.split(lineEndingPattern);
    for (const line of lines) {
        if (pattern.test(line)) {
            return true;
        }
    }
    return false;
}
/**
 * Replaces all HTML comments with whitespace.
 * This preserves offsets and locations of characters
 * outside HTML comments by keeping line breaks and replacing
 * other code units with a space character.
 * @param {string} value The string to remove HTML comments from.
 * @returns {string} The string with HTML comments removed.
 */
export function stripHtmlComments(value) {
    return value.replace(htmlCommentPattern, match => 
    /* eslint-disable-next-line require-unicode-regexp
       -- we want to replace each code unit with a space
    */
    match.replace(/[^\r\n]/g, " "));
}