// Tiny wrapper around function-red-black-tree that overrides the [inspect.custom] symbol so when we print it (during debugging) we just see the (key=>value)-pairs instead of the tree structure.

import createRBTree from "functional-red-black-tree";
import { inspect } from "node:util";

function defaultPrintf(depth, options, inspect) {
  const entries = [];
  this.tree.forEach((key, val) => { entries.push(`${inspect(key)} => ${inspect(val)}`); });
  return `RBTree(${this.tree.length}) {${entries.join(', ')}}`;
}

export class RBTreeWrapper {
  constructor(tree, printf = defaultPrintf) {
    this.tree = tree;
    this[inspect.custom] = printf;
  }

  static new(compareFn) {
    return new RBTreeWrapper(createRBTree(compareFn))
  }

  // only for debugging:
  keys() {
    return this.tree.keys;
  }

  // only for debugging:
  entries() {
    return this.tree.keys.map(key => [key, this.tree.get(key)]);
  }
}