HighlightBookmarkScanner.cs

using System.Text;

using ColumnizerLib;

using LogExpert.Core.Classes.Highlight;

namespace LogExpert.Core.Classes.Bookmark;

/// <summary>
/// Scans all lines of a log file against highlight entries that have <see cref="HighlightEntry.IsSetBookmark"/> set,
/// producing a list of auto-generated bookmarks. This is a pure computation unit with no UI dependencies.
/// </summary>
public static class HighlightBookmarkScanner
{
    /// <summary>
    /// Scans lines [0..lineCount) for highlight matches and returns bookmarks for matching lines.
    /// </summary>
    /// <param name="lineCount">Total number of lines in the file.</param>
    /// <param name="getLine">
    /// Delegate that returns the log line at a given index. May return null for unavailable lines.
    /// </param>
    /// <param name="entries">
    /// The highlight entries to check. Only entries with <see cref="HighlightEntry.IsSetBookmark"/> == true produce
    /// bookmarks.
    /// </param>
    /// <param name="fileName">
    /// The file name, passed to <see cref="ParamParser"/> for bookmark comment template resolution.
    /// </param>
    /// <param name="progressBarModulo">
    /// Interval of lines for reporting progress via the <paramref name="progress"/> callback.
    /// </param>
    /// <param name="cancellationToken">Token to support cooperative cancellation.</param>
    /// <param name="progress">
    /// Optional progress callback receiving the current line index (for progress reporting).
    /// </param>
    /// <returns>List of auto-generated bookmarks for all matched lines.</returns>
    public static List<Entities.Bookmark> Scan (int lineCount, Func<int, ILogLineMemory> getLine, IList<HighlightEntry> entries, string fileName, int progressBarModulo = 1000, IProgress<int> progress = null, CancellationToken cancellationToken = default)
    {
        ArgumentNullException.ThrowIfNull(getLine);

        List<Entities.Bookmark> result = [];

        // Pre-filter: only entries with IsSetBookmark matter
        var bookmarkEntries = entries.Where(e => e.IsSetBookmark).ToList();
        if (bookmarkEntries.Count == 0)
        {
            return result;
        }

        for (var i = 0; i < lineCount; i++)
        {
            cancellationToken.ThrowIfCancellationRequested();

            var line = getLine(i);
            if (line == null)
            {
                continue;
            }

            var (setBookmark, bookmarkComment, sourceHighlightText) = GetBookmarkAction(line, bookmarkEntries);

            if (setBookmark)
            {
                var comment = ResolveComment(bookmarkComment, line, i, fileName);
                result.Add(Entities.Bookmark.CreateAutoGenerated(i, comment, sourceHighlightText));
            }

            if (i % progressBarModulo == 0)
            {
                progress?.Report(i);
            }
        }

        return result;
    }

    /// <summary>
    /// Checks a single line against the bookmark-producing highlight entries. Returns whether a bookmark should be set,
    /// the concatenated comment template, and the source highlight text.
    /// </summary>
    private static (bool SetBookmark, string BookmarkComment, string SourceHighlightText) GetBookmarkAction (ITextValueMemory line, List<HighlightEntry> bookmarkEntries)
    {
        var setBookmark = false;
        var bookmarkCommentBuilder = new StringBuilder();
        var sourceHighlightText = string.Empty;

        foreach (var entry in bookmarkEntries.Where(entry => CheckHighlightEntryMatch(entry, line)))
        {
            setBookmark = true;
            sourceHighlightText = entry.SearchText;

            if (!string.IsNullOrEmpty(entry.BookmarkComment))
            {
                _ = bookmarkCommentBuilder.Append(entry.BookmarkComment).Append("\r\n");
            }
        }

        return (setBookmark, bookmarkCommentBuilder.ToString().TrimEnd('\r', '\n'), sourceHighlightText);
    }

    /// <summary>
    /// Matches a highlight entry against a line. Replicates the logic from LogWindow.CheckHighlightEntryMatch so the
    /// scanner works identically to the existing tail-mode matching.
    /// </summary>
    private static bool CheckHighlightEntryMatch (HighlightEntry entry, ITextValueMemory column)
    {
        if (entry.IsRegex)
        {
            if (entry.Regex.IsMatch(column.Text.ToString()))
            {
                return true;
            }
        }
        else
        {
            if (entry.IsCaseSensitive)
            {
                if (column.Text.Span.Contains(entry.SearchText.AsSpan(), StringComparison.Ordinal))
                {
                    return true;
                }
            }
            else
            {
                if (column.Text.Span.Contains(entry.SearchText.AsSpan(), StringComparison.OrdinalIgnoreCase))
                {
                    return true;
                }
            }
        }

        return false;
    }

    /// <summary>
    /// Resolves the bookmark comment template using ParamParser, matching SetBookmarkFromTrigger behavior.
    /// </summary>
    private static string ResolveComment (string commentTemplate, ILogLineMemory line, int lineNum, string fileName)
    {
        if (string.IsNullOrEmpty(commentTemplate))
        {
            return commentTemplate;
        }

        try
        {
            var paramParser = new ParamParser(commentTemplate);
            return paramParser.ReplaceParams(line, lineNum, fileName);
        }
        catch (ArgumentException)
        {
            // Invalid regex in template — return raw template (matches SetBookmarkFromTrigger behavior)
            return commentTemplate;
        }
    }
}