/**
 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import {printIteratorEntries, printIteratorValues} from '../collections';
import type {Config, NewPlugin, Printer, Refs} from '../types';

// SENTINEL constants are from https://github.com/facebook/immutable-js
const IS_ITERABLE_SENTINEL = '@@__IMMUTABLE_ITERABLE__@@';
const IS_LIST_SENTINEL = '@@__IMMUTABLE_LIST__@@';
const IS_KEYED_SENTINEL = '@@__IMMUTABLE_KEYED__@@';
const IS_MAP_SENTINEL = '@@__IMMUTABLE_MAP__@@';
const IS_ORDERED_SENTINEL = '@@__IMMUTABLE_ORDERED__@@';
const IS_RECORD_SENTINEL = '@@__IMMUTABLE_RECORD__@@'; // immutable v4
const IS_SEQ_SENTINEL = '@@__IMMUTABLE_SEQ__@@';
const IS_SET_SENTINEL = '@@__IMMUTABLE_SET__@@';
const IS_STACK_SENTINEL = '@@__IMMUTABLE_STACK__@@';

const getImmutableName = (name: string) => 'Immutable.' + name;
const printAsLeaf = (name: string) => '[' + name + ']';
const SPACE = ' ';
const LAZY = '…'; // Seq is lazy if it calls a method like filter

const printImmutableEntries = (
  val: any,
  config: Config,
  indentation: string,
  depth: number,
  refs: Refs,
  printer: Printer,
  type: string,
): string =>
  ++depth > config.maxDepth
    ? printAsLeaf(getImmutableName(type))
    : getImmutableName(type) +
      SPACE +
      '{' +
      printIteratorEntries(
        val.entries(),
        config,
        indentation,
        depth,
        refs,
        printer,
      ) +
      '}';

// Record has an entries method because it is a collection in immutable v3.
// Return an iterator for Immutable Record from version v3 or v4.
function getRecordEntries(val: any): Iterator<any> {
  let i = 0;
  return {
    next() {
      if (i < val._keys.length) {
        const key = val._keys[i++];
        return {done: false, value: [key, val.get(key)]};
      }
      return {done: true, value: undefined};
    },
  };
}

const printImmutableRecord = (
  val: any,
  config: Config,
  indentation: string,
  depth: number,
  refs: Refs,
  printer: Printer,
): string => {
  // _name property is defined only for an Immutable Record instance
  // which was constructed with a second optional descriptive name arg
  const name = getImmutableName(val._name || 'Record');
  return ++depth > config.maxDepth
    ? printAsLeaf(name)
    : name +
        SPACE +
        '{' +
        printIteratorEntries(
          getRecordEntries(val),
          config,
          indentation,
          depth,
          refs,
          printer,
        ) +
        '}';
};

const printImmutableSeq = (
  val: any,
  config: Config,
  indentation: string,
  depth: number,
  refs: Refs,
  printer: Printer,
): string => {
  const name = getImmutableName('Seq');

  if (++depth > config.maxDepth) {
    return printAsLeaf(name);
  }

  if (val[IS_KEYED_SENTINEL]) {
    return (
      name +
      SPACE +
      '{' +
      // from Immutable collection of entries or from ECMAScript object
      (val._iter || val._object
        ? printIteratorEntries(
            val.entries(),
            config,
            indentation,
            depth,
            refs,
            printer,
          )
        : LAZY) +
      '}'
    );
  }

  return (
    name +
    SPACE +
    '[' +
    (val._iter || // from Immutable collection of values
    val._array || // from ECMAScript array
    val._collection || // from ECMAScript collection in immutable v4
    val._iterable // from ECMAScript collection in immutable v3
      ? printIteratorValues(
          val.values(),
          config,
          indentation,
          depth,
          refs,
          printer,
        )
      : LAZY) +
    ']'
  );
};

const printImmutableValues = (
  val: any,
  config: Config,
  indentation: string,
  depth: number,
  refs: Refs,
  printer: Printer,
  type: string,
): string =>
  ++depth > config.maxDepth
    ? printAsLeaf(getImmutableName(type))
    : getImmutableName(type) +
      SPACE +
      '[' +
      printIteratorValues(
        val.values(),
        config,
        indentation,
        depth,
        refs,
        printer,
      ) +
      ']';

export const serialize: NewPlugin['serialize'] = (
  val: any,
  config: Config,
  indentation: string,
  depth: number,
  refs: Refs,
  printer: Printer,
) => {
  if (val[IS_MAP_SENTINEL]) {
    return printImmutableEntries(
      val,
      config,
      indentation,
      depth,
      refs,
      printer,
      val[IS_ORDERED_SENTINEL] ? 'OrderedMap' : 'Map',
    );
  }

  if (val[IS_LIST_SENTINEL]) {
    return printImmutableValues(
      val,
      config,
      indentation,
      depth,
      refs,
      printer,
      'List',
    );
  }
  if (val[IS_SET_SENTINEL]) {
    return printImmutableValues(
      val,
      config,
      indentation,
      depth,
      refs,
      printer,
      val[IS_ORDERED_SENTINEL] ? 'OrderedSet' : 'Set',
    );
  }
  if (val[IS_STACK_SENTINEL]) {
    return printImmutableValues(
      val,
      config,
      indentation,
      depth,
      refs,
      printer,
      'Stack',
    );
  }

  if (val[IS_SEQ_SENTINEL]) {
    return printImmutableSeq(val, config, indentation, depth, refs, printer);
  }

  // For compatibility with immutable v3 and v4, let record be the default.
  return printImmutableRecord(val, config, indentation, depth, refs, printer);
};

// Explicitly comparing sentinel properties to true avoids false positive
// when mock identity-obj-proxy returns the key as the value for any key.
export const test: NewPlugin['test'] = (val: any) =>
  val &&
  (val[IS_ITERABLE_SENTINEL] === true || val[IS_RECORD_SENTINEL] === true);

const plugin: NewPlugin = {serialize, test};

export default plugin;
