import type { BashOperations } from "@earendil-works/pi-coding-agent";
import type { PwshNativeConfig } from "./config.ts";
import type { PowerShellRuntime } from "./runtime.ts";
import { buildPowerShellArguments, buildPowerShellSource } from "./powershell-source.ts";
import { spawnAndStream } from "./process.ts";

function findEnvironmentKey(env: NodeJS.ProcessEnv, name: string): string | undefined {
	const normalized = name.toUpperCase();
	return Object.keys(env).find((key) => key.toUpperCase() === normalized);
}

function setDefault(env: NodeJS.ProcessEnv, name: string, value: string): void {
	const existing = findEnvironmentKey(env, name);
	if (existing === undefined || env[existing] === undefined) env[name] = value;
}

export function createRuntimeEnvironment(
	config: PwshNativeConfig,
	baseEnvironment: NodeJS.ProcessEnv = process.env,
): NodeJS.ProcessEnv {
	const env = { ...baseEnvironment };
	if (config.pythonUtf8) {
		setDefault(env, "PYTHONIOENCODING", "utf-8");
		setDefault(env, "PYTHONUTF8", "1");
	}
	if (config.pythonUnbuffered) setDefault(env, "PYTHONUNBUFFERED", "1");
	return env;
}

export function createPowerShellOperations(
	runtime: PowerShellRuntime,
	config: PwshNativeConfig,
): BashOperations {
	const args = buildPowerShellArguments(config);
	return {
		async exec(command, cwd, options) {
			const source = buildPowerShellSource(command, config);
			const result = await spawnAndStream(runtime.executable, args, cwd, {
				onData: options.onData,
				signal: options.signal,
				timeout: options.timeout,
				env: createRuntimeEnvironment(config, options.env ?? process.env),
				stdin: Buffer.from(source, "utf8").toString("base64"),
			});
			return { exitCode: result.exitCode };
		},
	};
}