// Low-level child-process helpers shared by the sandbox backends.
// (Previously also held docker/podman detection; that's gone with the container
// model — see sandbox.ts for bwrap / sandbox-exec backend detection.)

import { spawn } from "node:child_process";

export interface CaptureResult {
	stdout: Buffer;
	stderr: string;
	code: number | null;
}

export interface SpawnOptions {
	input?: Buffer | string;
	signal?: AbortSignal;
	timeout?: number; // seconds
	cwd?: string;
	env?: NodeJS.ProcessEnv;
}

/** Low-level spawn that captures stdout as a Buffer (binary-safe). */
export function spawnCapture(bin: string, args: string[], opts: SpawnOptions = {}): Promise<CaptureResult> {
	return new Promise((resolve, reject) => {
		const child = spawn(bin, args, { stdio: ["pipe", "pipe", "pipe"], cwd: opts.cwd, env: opts.env });
		const out: Buffer[] = [];
		let err = "";
		let timedOut = false;
		let timer: NodeJS.Timeout | undefined;

		const onAbort = () => child.kill("SIGKILL");
		opts.signal?.addEventListener("abort", onAbort, { once: true });

		if (opts.timeout && opts.timeout > 0) {
			timer = setTimeout(() => {
				timedOut = true;
				child.kill("SIGKILL");
			}, opts.timeout * 1000);
		}

		child.stdout.on("data", (d: Buffer) => out.push(d));
		child.stderr.on("data", (d: Buffer) => {
			err += d.toString("utf8");
		});
		child.on("error", (e) => {
			if (timer) clearTimeout(timer);
			opts.signal?.removeEventListener("abort", onAbort);
			reject(e);
		});
		child.on("close", (code) => {
			if (timer) clearTimeout(timer);
			opts.signal?.removeEventListener("abort", onAbort);
			if (opts.signal?.aborted) return reject(new Error("aborted"));
			if (timedOut) return reject(new Error(`timeout:${opts.timeout}`));
			resolve({ stdout: Buffer.concat(out), stderr: err, code });
		});

		if (opts.input !== undefined) child.stdin.write(opts.input);
		child.stdin.end();
	});
}

export interface StreamOptions {
	signal?: AbortSignal;
	timeout?: number; // seconds
	onData?: (chunk: Buffer) => void; // merged stdout+stderr
	cwd?: string;
	env?: NodeJS.ProcessEnv;
}

/** Streaming spawn: merges stdout+stderr to onData. Returns exit code. */
export function spawnStream(bin: string, args: string[], opts: StreamOptions = {}): Promise<{ exitCode: number | null }> {
	return new Promise((resolve, reject) => {
		const child = spawn(bin, args, { stdio: ["pipe", "pipe", "pipe"], cwd: opts.cwd, env: opts.env });
		let timedOut = false;
		let timer: NodeJS.Timeout | undefined;

		const onAbort = () => child.kill("SIGKILL");
		opts.signal?.addEventListener("abort", onAbort, { once: true });

		if (opts.timeout && opts.timeout > 0) {
			timer = setTimeout(() => {
				timedOut = true;
				child.kill("SIGKILL");
			}, opts.timeout * 1000);
		}

		if (opts.onData) {
			child.stdout.on("data", opts.onData);
			child.stderr.on("data", opts.onData);
		}
		child.on("error", (e) => {
			if (timer) clearTimeout(timer);
			opts.signal?.removeEventListener("abort", onAbort);
			reject(e);
		});
		child.on("close", (code) => {
			if (timer) clearTimeout(timer);
			opts.signal?.removeEventListener("abort", onAbort);
			if (opts.signal?.aborted) return reject(new Error("aborted"));
			if (timedOut) return reject(new Error(`timeout:${opts.timeout}`));
			resolve({ exitCode: code });
		});

		child.stdin.end();
	});
}