import { readFileSync } from "node:fs";
import chokidar, { type FSWatcher } from "chokidar";
import { DEFAULT_EXCLUDE_PATTERNS, DEFAULT_INCLUDE_PATTERNS } from "@/utils";
import type { IncrementalScanner } from "./incremental-scanner";
import type { ScanOptions } from "./types";
/**
* File system watcher for continuous code scanning
*/
export class CodeWatcher {
private watcher: FSWatcher | null = null;
private debounceTimer: NodeJS.Timeout | null = null;
private changedFiles = new Set<string>();
constructor(private scanner: IncrementalScanner) {}
/**
* Start watching for file changes
*/
async start(options: ScanOptions = {}): Promise<void> {
if (this.watcher) {
console.warn("Watcher already running");
return;
}
const patterns = options.patterns || [...DEFAULT_INCLUDE_PATTERNS];
const ignored = options.exclude || [...DEFAULT_EXCLUDE_PATTERNS];
this.watcher = chokidar.watch(patterns, {
ignored,
persistent: true,
ignoreInitial: true, // Don't trigger on startup
followSymlinks: false, // MUST: Match discoverFiles behavior, prevent infinite loops
awaitWriteFinish: {
stabilityThreshold: 100,
pollInterval: 100,
},
});
// Handle file events
this.watcher.on("change", (path) => {
this.queueChange(path);
});
this.watcher.on("add", (path) => {
this.queueChange(path);
});
this.watcher.on("unlink", (path) => {
this.queueChange(path);
});
this.watcher.on("error", (error) => {
console.error("Watcher error:", error);
});
console.log("Code watcher started", {
patterns,
ignored: ignored.length,
});
}
/**
* Stop watching
*/
async stop(): Promise<void> {
if (this.watcher) {
await this.watcher.close();
this.watcher = null;
if (this.debounceTimer) {
clearTimeout(this.debounceTimer);
this.debounceTimer = null;
}
this.changedFiles.clear();
console.log("Code watcher stopped");
}
}
/**
* Check if watcher is running
*/
isRunning(): boolean {
return this.watcher !== null;
}
/**
* Queue a file change for batch processing
*/
private queueChange(path: string): void {
this.changedFiles.add(path);
// Debounce: wait 1 second after last change before processing
if (this.debounceTimer) {
clearTimeout(this.debounceTimer);
}
this.debounceTimer = setTimeout(() => {
this.processBatch();
}, 1000);
}
/**
* Process batch of changed files
*/
private async processBatch(): Promise<void> {
if (this.changedFiles.size === 0) return;
const files = Array.from(this.changedFiles);
this.changedFiles.clear();
console.log(`Processing ${files.length} changed files...`);
try {
// Read file contents
const fileData = files
.map((path) => {
try {
const content = readFileSync(path, "utf-8");
return { path, content };
} catch (_error) {
// File might have been deleted
return { path, content: "" };
}
})
.filter((f) => f !== null);
// Run incremental scan
const result = await this.scanner.scanIncremental(fileData);
console.log("Incremental scan complete:", {
changes: result.changes.length,
nodesAdded: result.stats.nodesAdded,
nodesUpdated: result.stats.nodesUpdated,
nodesDeleted: result.stats.nodesDeleted,
});
} catch (error) {
console.error("Failed to process batch:", error);
}
}
}
