import { readKey } from '../common/fns.ts';
import { ITerminal, ITerminalSize } from '../common/types.ts';

const DenoTerminalIO: ITerminal = {
	argv: Deno.args,
	inputLoop: async function* (): AsyncGenerator<Uint8Array, null> {
		yield (await DenoTerminalIO.readStdinRaw()) ?? new Uint8Array(0);

		return null;
	},
	getTerminalSize: function getSize(): Promise<ITerminalSize> {
		const size: { rows: number; columns: number } = Deno.consoleSize();

		return Promise.resolve({
			rows: size.rows,
			cols: size.columns,
		});
	},
	readStdin: async function (): Promise<string | null> {
		const raw = await DenoTerminalIO.readStdinRaw();
		return readKey(raw ?? new Uint8Array(0));
	},
	readStdinRaw: async function (): Promise<Uint8Array | null> {
		const reader = Deno.stdin.readable.getReader();
		const chunk = await reader.read();
		const res = chunk?.value;
		reader.releaseLock();
		return res ?? null;
	},
	writeStdout: async function (s: string): Promise<void> {
		const buffer: Uint8Array = new TextEncoder().encode(s);
		const stdout: WritableStream<Uint8Array> = Deno.stdout.writable;

		const writer: WritableStreamDefaultWriter<Uint8Array> = stdout.getWriter();
		await writer.ready;
		await writer.write(buffer);
		writer.releaseLock();
	},
};

export default DenoTerminalIO;