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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();
function removePrefix(line: string): string {  return line.slice(1);}
/** * Transforms a command, which is an array of arguments, into a RESP request string. * @see https://redis.io/docs/reference/protocol-spec/#send-commands-to-a-redis-server * @param command * @returns RESP request string */function stringifyRequest(command: Command): string {  let request = "*" + command.length + CRLF;  for (const arg of command) {    request += "$" + arg.toString().length + CRLF;    request += arg + CRLF;  }  return request;}
/** * Encodes and sends the request string to the server. * @param conn Redis connection * @param request RESP request string */async function writeRequest(  conn: Deno.Conn,  request: string,): Promise<void> {  await writeAll(conn, encoder.encode(request));}
async function readNonNullArray(  tpReader: TextProtoReader,  length: number,): Promise<Reply[]> {  const array = [];  for (let i = 0; i < length; i++) {    const reply: Reply = await readLineOrArray(tpReader);    array.push(reply);  }  return array;}
async function readLineOrArray(tpReader: TextProtoReader): Promise<Reply> {  const line = await tpReader.readLine();  switch (line!.charAt(0)) {    /** Simple string */    case "+":      return removePrefix(line!);    /** Error */    case "-":      return Promise.reject(removePrefix(line!));    /** Integer */    case ":":      return Number(removePrefix(line!));    /** Bulk string */    case "$":      return Number(removePrefix(line!)) === -1        ? null        : /** Skip to reading the next line, which is a string */          await readLineOrArray(tpReader);    /** Array */    case "*": {      const length = Number(removePrefix(line!));      return length === -1 ? null : await readNonNullArray(tpReader, length);    }    /** No prefix */    default:      return line;  }}
/** * Turns the Redis connection into a `TextProtoreader` which is read, line-by-line. * @param conn Redis connection * @returns RESP reply */async function readReply(conn: Deno.Conn): Promise<Reply> {  const bufReader = new BufReader(conn);  const tpReader = new TextProtoReader(bufReader);  return await readLineOrArray(tpReader);}
export async function sendCommand(  conn: Deno.Conn,  command: Command,): Promise<Reply> {  await writeRequest(conn, stringifyRequest(command));  return await readReply(conn);}