import { BufReader, TextProtoReader, writeAll } from "./deps.ts";
export type Command = (string | number)[];export type Reply = string | number | null | Reply[];
const CRLF = "\r\n";const encoder = new TextEncoder();
const PREFIXES: Readonly<Record<string, string>> = { SIMPLE_STRING: "+", ERROR: "-", INTEGER: ":", BULK_STRING: "$", ARRAY: "*",};
function removePrefix(line: string): string { return line.slice(1);}
function parseInteger(line: string): number { return Number(removePrefix(line));}
function stringifyRequest(command: Command): string { let request = "*" + command.length + CRLF; for (const arg of command) { request += "$" + arg.toString().length + CRLF; request += arg + CRLF; } return request;}
async function writeRequest( conn: Deno.Conn, request: string,): Promise<void> { await writeAll(conn, encoder.encode(request));}
async function readLineOrLines(tpReader: TextProtoReader): Promise<Reply> { const line = await tpReader.readLine(); return await { [PREFIXES.SIMPLE_STRING]: () => removePrefix(line!), [PREFIXES.ERROR]: () => { throw new Error(removePrefix(line!)); }, [PREFIXES.INTEGER]: () => parseInteger(line!), [PREFIXES.BULK_STRING]: () => parseInteger(line!) === -1 ? null : readLineOrLines(tpReader), [PREFIXES.ARRAY]: async () => { const lines = []; for (let i = 0; i < parseInteger(line!); i++) { const lineOrLines = await readLineOrLines(tpReader); lines.push(lineOrLines); } return lines; }, }[line!.charAt(0)]?.() ?? line;}
async function readReply(conn: Deno.Conn): Promise<Reply> { const bufReader = new BufReader(conn); const tpReader = new TextProtoReader(bufReader); return await readLineOrLines(tpReader);}
export async function sendCommand( conn: Deno.Conn, command: Command,): Promise<Reply> { await writeRequest(conn, stringifyRequest(command)); return await readReply(conn);}