/**
 * Bash command execution with streaming support and cancellation.
 *
 * Provides unified bash execution for AgentSession.executeBash() and direct calls.
 */

import { cspawn, Exception, ptree } from "@oh-my-pi/pi-utils";
import { getShellConfig } from "../utils/shell";
import { getOrCreateSnapshot, getSnapshotSourceCommand } from "../utils/shell-snapshot";
import { OutputSink } from "./streaming-output";
import type { BashOperations } from "./tools/bash";

export interface BashExecutorOptions {
	cwd?: string;
	timeout?: number;
	onChunk?: (chunk: string) => void;
	signal?: AbortSignal;
}

export interface BashResult {
	output: string;
	exitCode: number | undefined;
	cancelled: boolean;
	truncated: boolean;
	fullOutputPath?: string;
}

export async function executeBash(command: string, options?: BashExecutorOptions): Promise<BashResult> {
	const { shell, args, env, prefix } = await getShellConfig();

	const snapshotPath = await getOrCreateSnapshot(shell, env);
	const snapshotPrefix = getSnapshotSourceCommand(snapshotPath);

	const prefixedCommand = prefix ? `${prefix} ${command}` : command;
	const finalCommand = `${snapshotPrefix}${prefixedCommand}`;

	const stream = new OutputSink({ onLine: options?.onChunk });

	const child = cspawn([shell, ...args, finalCommand], {
		cwd: options?.cwd,
		env,
		signal: options?.signal,
		timeout: options?.timeout,
	});

	// Pump streams - errors during abort/timeout are expected
	await Promise.allSettled([
		child.stdout.pipeTo(stream.createWritable()),
		child.stderr.pipeTo(stream.createWritable()),
	])
		.then(() => stream.close())
		.catch(() => {});

	// Wait for process exit
	try {
		await child.exited;
		return {
			exitCode: child.exitCode ?? 0,
			cancelled: false,
			...stream.dump(),
		};
	} catch (err) {
		// Exception covers NonZeroExitError, AbortError, TimeoutError
		if (err instanceof Exception) {
			if (err.aborted) {
				const isTimeout = err instanceof ptree.TimeoutError || err.message.toLowerCase().includes("timed out");
				const annotation = isTimeout
					? `Command timed out after ${Math.round((options?.timeout ?? 0) / 1000)} seconds`
					: undefined;
				return {
					exitCode: undefined,
					cancelled: true,
					...stream.dump(annotation),
				};
			}

			// NonZeroExitError
			return {
				exitCode: err.exitCode,
				cancelled: false,
				...stream.dump(),
			};
		}

		throw err;
	}
}

export async function executeBashWithOperations(
	command: string,
	cwd: string,
	operations: BashOperations,
	options?: BashExecutorOptions,
): Promise<BashResult> {
	const stream = new OutputSink({ onLine: options?.onChunk });
	const writable = stream.createWritable();
	const writer = writable.getWriter();

	const closeStreams = async () => {
		try {
			await writer.close();
		} catch {}
		try {
			await writable.close();
		} catch {}
		try {
			await stream.close();
		} catch {}
	};

	try {
		const result = await operations.exec(command, cwd, {
			onData: (data) => writer.write(data),
			signal: options?.signal,
			timeout: options?.timeout,
		});

		await closeStreams();

		const cancelled = options?.signal?.aborted ?? false;

		return {
			exitCode: cancelled ? undefined : (result.exitCode ?? undefined),
			cancelled,
			...stream.dump(),
		};
	} catch (err) {
		await closeStreams();

		if (options?.signal?.aborted) {
			return {
				exitCode: undefined,
				cancelled: true,
				...stream.dump(),
			};
		}

		throw err;
	}
}