import { structuredPatch } from 'diff';
/**
 * Creates a smart diff that returns full content when changes exceed threshold.
 *
 * When more than `threshold` (default 50%) of lines have changed, showing a diff
 * is not useful - we return the full new content instead.
 */
export function createSmartDiff(options) {
    const { oldContent, newContent, threshold = 0.5, label = 'content' } = options;
    const patch = structuredPatch(label, label, oldContent, newContent, 'previous', 'current', {
        context: 3,
    });
    // Count added and removed lines
    let addedLines = 0;
    let removedLines = 0;
    for (const hunk of patch.hunks) {
        for (const line of hunk.lines) {
            if (line.startsWith('+')) {
                addedLines++;
            }
            else if (line.startsWith('-')) {
                removedLines++;
            }
        }
    }
    // No changes - return full content
    if (addedLines === 0 && removedLines === 0) {
        return { type: 'no-change', content: newContent };
    }
    // Calculate change ratio: use max(added, removed) since a replacement counts as both
    // This ensures the ratio stays in 0-100% range
    const oldLineCount = oldContent.split('\n').length;
    const newLineCount = newContent.split('\n').length;
    const maxLines = Math.max(oldLineCount, newLineCount, 1); // Avoid division by zero
    const changedLines = Math.max(addedLines, removedLines);
    const changeRatio = Math.min(changedLines / maxLines, 1); // Cap at 100%
    // Build unified diff string from structured patch
    const diffLines = [`--- ${label} (previous)`, `+++ ${label} (current)`];
    for (const hunk of patch.hunks) {
        diffLines.push(`@@ -${hunk.oldStart},${hunk.oldLines} +${hunk.newStart},${hunk.newLines} @@`);
        diffLines.push(...hunk.lines);
    }
    const diffString = diffLines.join('\n');
    // Return full content if changes exceed threshold OR if diff is longer than full content
    if (changeRatio >= threshold || diffString.length >= newContent.length) {
        return { type: 'full', content: newContent };
    }
    return { type: 'diff', content: diffString };
}
//# sourceMappingURL=diff-utils.js.map