// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.

// This module provides an interface to `Deno.core`. For environments
// that don't have access to `Deno.core` some APIs are polyfilled, while
// some are unavailble and throw on call.
// Note: deno_std shouldn't use Deno.core namespace. We should minimize these
// usages.

import { TextEncoder } from "internal:deno_web/08_text_encoding.js";

// deno-lint-ignore no-explicit-any
let DenoCore: any;

// deno-lint-ignore no-explicit-any
const { Deno } = globalThis as any;

// @ts-ignore Deno.core is not defined in types
if (Deno?.[Deno.internal]?.core) {
  // @ts-ignore Deno[Deno.internal].core is not defined in types
  DenoCore = Deno[Deno.internal].core;
} else if (Deno?.core) {
  // @ts-ignore Deno.core is not defined in types
  DenoCore = Deno.core;
} else {
  DenoCore = {};
}

export const core = {
  runMicrotasks: DenoCore.runMicrotasks ?? function () {
    throw new Error(
      "Deno.core.runMicrotasks() is not supported in this environment",
    );
  },
  setHasTickScheduled: DenoCore.setHasTickScheduled ?? function () {
    throw new Error(
      "Deno.core.setHasTickScheduled() is not supported in this environment",
    );
  },
  hasTickScheduled: DenoCore.hasTickScheduled ?? function () {
    throw new Error(
      "Deno.core.hasTickScheduled() is not supported in this environment",
    );
  },
  setNextTickCallback: DenoCore.setNextTickCallback ?? undefined,
  setMacrotaskCallback: DenoCore.setMacrotaskCallback ?? function () {
    throw new Error(
      "Deno.core.setNextTickCallback() is not supported in this environment",
    );
  },
  evalContext: DenoCore.evalContext ??
    function (_code: string, _filename: string) {
      throw new Error(
        "Deno.core.evalContext is not supported in this environment",
      );
    },
  encode: DenoCore.encode ?? function (chunk: string): Uint8Array {
    return new TextEncoder().encode(chunk);
  },
  eventLoopHasMoreWork: DenoCore.eventLoopHasMoreWork ?? function (): boolean {
    return false;
  },
  isProxy: DenoCore.isProxy ?? function (): boolean {
    return false;
  },
  getPromiseDetails: DenoCore.getPromiseDetails ??
    function (_promise: Promise<unknown>): [number, unknown] {
      throw new Error(
        "Deno.core.getPromiseDetails is not supported in this environment",
      );
    },
  setPromiseHooks: DenoCore.setPromiseHooks ?? function () {
    throw new Error(
      "Deno.core.setPromiseHooks is not supported in this environment",
    );
  },
  ops: DenoCore.ops ?? {
    op_napi_open(_filename: string) {
      throw new Error(
        "Node API is not supported in this environment",
      );
    },
  },
};