import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";

import type { ExtensionConfig } from "./types.js";

import { getSubagentConfigPath } from "./paths.js";

export function getSubagentSessionRoot(parentSessionFile: string | null): string {
	if (parentSessionFile) {
		const baseName = path.basename(parentSessionFile, ".jsonl");
		const sessionsDir = path.dirname(parentSessionFile);
		return path.join(sessionsDir, baseName);
	}
	return fs.mkdtempSync(path.join(os.tmpdir(), "pi-subagent-session-"));
}

export function loadSubagentConfig(): ExtensionConfig {
	const configPath = getSubagentConfigPath();
	try {
		if (fs.existsSync(configPath)) {
			return JSON.parse(fs.readFileSync(configPath, "utf8")) as ExtensionConfig;
		}
	} catch {}
	return {};
}

export function expandTildePath(p: string): string {
	return p.startsWith("~/") ? path.join(os.homedir(), p.slice(2)) : p;
}

export function ensureAccessibleDir(dirPath: string): void {
	fs.mkdirSync(dirPath, { recursive: true });
	try {
		fs.accessSync(dirPath, fs.constants.R_OK | fs.constants.W_OK);
	} catch {
		try {
			fs.rmSync(dirPath, { force: true, recursive: true });
		} catch {}
		fs.mkdirSync(dirPath, { recursive: true });
		fs.accessSync(dirPath, fs.constants.R_OK | fs.constants.W_OK);
	}
}