import { notImplemented, intoCallbackAPIWithIntercept, MaybeEmpty,} from "../_utils.ts";
const { readFile: denoReadFile, readFileSync: denoReadFileSync } = Deno;
type ReadFileCallback = ( err: MaybeEmpty<Error>, data: MaybeEmpty<string | Uint8Array>) => void;
interface ReadFileOptions { encoding?: string | null; flag?: string;}
function getEncoding( optOrCallback?: ReadFileOptions | ReadFileCallback): string | null { if (!optOrCallback || typeof optOrCallback === "function") { return null; } else { if (optOrCallback.encoding) { if ( optOrCallback.encoding === "utf8" || optOrCallback.encoding === "utf-8" ) { return "utf8"; } else if (optOrCallback.encoding === "buffer") { return "buffer"; } else { notImplemented(); } } return null; }}
function maybeDecode( data: Uint8Array, encoding: string | null): string | Uint8Array { if (encoding === "utf8") { return new TextDecoder().decode(data); } return data;}
export function readFile( path: string, optOrCallback: ReadFileCallback | ReadFileOptions, callback?: ReadFileCallback): void { let cb: ReadFileCallback | undefined; if (typeof optOrCallback === "function") { cb = optOrCallback; } else { cb = callback; }
const encoding = getEncoding(optOrCallback);
intoCallbackAPIWithIntercept<Uint8Array, string | Uint8Array>( denoReadFile, (data: Uint8Array): string | Uint8Array => maybeDecode(data, encoding), cb, path );}
export function readFileSync( path: string, opt?: ReadFileOptions): string | Uint8Array { return maybeDecode(denoReadFileSync(path), getEncoding(opt));}