/**
* Git Date Utility
* Extracts file commit dates from git history for pattern momentum analysis
*/
import { exec } from "child_process";
import { promisify } from "util";
import path from "path";
const execAsync = promisify(exec);
/**
* Get the last commit date for each file in the repository.
* Uses a single git command to efficiently extract all file dates.
*
* @param rootPath - Root path of the git repository
* @returns Map of relative file paths to their last commit date
*/
export async function getFileCommitDates(rootPath: string): Promise<Map<string, Date>> {
const fileDates = new Map<string, Date>();
try {
// Single git command to get all file dates
// Format: ":::ISO_DATE" followed by affected files on new lines
const { stdout } = await execAsync(
'git log --format=":::%cd" --name-only --date=iso-strict',
{
cwd: rootPath,
maxBuffer: 50 * 1024 * 1024, // 50MB buffer for large repos
}
);
let currentDate: Date | null = null;
for (const line of stdout.split('\n')) {
const trimmed = line.trim();
if (!trimmed) continue;
if (trimmed.startsWith(':::')) {
// New commit date marker
const dateStr = trimmed.slice(3);
currentDate = new Date(dateStr);
} else if (currentDate) {
// File path - only store if we don't already have a date (first occurrence = most recent)
const normalizedPath = trimmed.replace(/\\/g, '/');
if (!fileDates.has(normalizedPath)) {
fileDates.set(normalizedPath, currentDate);
}
}
}
console.error(`[git-dates] Loaded commit dates for ${fileDates.size} files`);
} catch (error) {
// Not a git repo or git not available - graceful fallback
const message = error instanceof Error ? error.message : String(error);
if (message.includes('not a git repository') || message.includes('ENOENT')) {
console.error('[git-dates] Not a git repository, skipping temporal analysis');
} else {
console.error(`[git-dates] Failed to get git dates: ${message}`);
}
}
return fileDates;
}
/**
* Calculate pattern trend based on file date.
*
* @param newestDate - The most recent file date using this pattern
* @returns Trend classification
*/
export function calculateTrend(newestDate: Date | undefined): 'Rising' | 'Declining' | 'Stable' | undefined {
if (!newestDate) return undefined;
const now = new Date();
const daysDiff = Math.floor((now.getTime() - newestDate.getTime()) / (1000 * 60 * 60 * 24));
if (daysDiff <= 60) return 'Rising';
if (daysDiff >= 180) return 'Declining';
return 'Stable';
}
