decode.ts

import { ExtensionCodecType } from "./ExtensionCodec.ts";
import { Decoder } from "./Decoder.ts";
import { ContextOf, SplitUndefined } from "./context.ts";

export type DecodeOptions<ContextType = undefined> =
  & Readonly<
    Partial<{
      extensionCodec: ExtensionCodecType<ContextType>;

      /**
     * Maximum string length.
     * Default to 4_294_967_295 (UINT32_MAX).
     */
      maxStrLength: number;
      /**
     * Maximum binary length.
     * Default to 4_294_967_295 (UINT32_MAX).
     */
      maxBinLength: number;
      /**
     * Maximum array length.
     * Default to 4_294_967_295 (UINT32_MAX).
     */
      maxArrayLength: number;
      /**
     * Maximum map length.
     * Default to 4_294_967_295 (UINT32_MAX).
     */
      maxMapLength: number;
      /**
     * Maximum extension length.
     * Default to 4_294_967_295 (UINT32_MAX).
     */
      maxExtLength: number;
    }>
  >
  & ContextOf<ContextType>;

export const defaultDecodeOptions: DecodeOptions = {};

/**
 * It decodes a MessagePack-encoded buffer.
 *
 * This is a synchronous decoding function. See other variants for asynchronous decoding: `decodeAsync()`, `decodeStream()`, `decodeArrayStream()`.
 */
export function decode<ContextType>(
  buffer: ArrayLike<number> | ArrayBuffer,
  options: DecodeOptions<SplitUndefined<ContextType>> =
    // deno-lint-ignore no-explicit-any
    defaultDecodeOptions as any,
): unknown {
  const decoder = new Decoder<ContextType>(
    options.extensionCodec,
    // deno-lint-ignore no-explicit-any
    (options as typeof options & { context: any }).context,
    options.maxStrLength,
    options.maxBinLength,
    options.maxArrayLength,
    options.maxMapLength,
    options.maxExtLength,
  );
  return decoder.decode(buffer);
}