import { asAsyncEqualityComparer } from "../equality-comparer/async.js";
import { asEqualityComparer } from "../equality-comparer/sync.js";
import { AsyncEqualityComparer, EqualityComparer, EqualityComparisonOrComparer, MaybeAsyncEqualityComparisonOrComparer } from "../equality-comparer/types.js";
import { MaybeAsyncIterable } from "../types.js";
import { AsyncEqualitySet, EqualitySet } from "./types.js";

export class NativeEqualitySet<T> implements EqualitySet<T> {
  readonly #set = new Set<T>();

  get size() {
    return this.#set.size;
  }

  add(value: T) {
    const exists = this.contains(value);
    this.#set.add(value);
    return !exists;
  }

  addAll(values: Iterable<T>) {
    let result = 0;

    for (const value of values) {
      if (this.add(value)) {
        result++;
      }
    }

    return result;
  }

  contains(value: T) {
    return this.#set.has(value);
  }

  remove(value: T) {
    return this.#set.delete(value);
  }

  clear() {
    this.#set.clear();
  }

  values() {
    return this.#set.values();
  }

  [Symbol.iterator]() {
    return this.#set[Symbol.iterator]();
  }
}

export class CustomEqualitySet<T> implements EqualitySet<T> {
  readonly #list: T[] = [];
  readonly #equater: EqualityComparer<T>;

  constructor(equater: EqualityComparisonOrComparer<T>) {
    this.#equater = asEqualityComparer(equater);
  }

  get size() {
    return this.#list.length;
  }

  add(value: T) {
    if (this.contains(value)) {
      return false;
    }

    this.#list.push(value);

    return true;
  }

  addAll(values: Iterable<T>) {
    let result = 0;

    for (const value of values) {
      if (this.add(value)) {
        result++;
      }
    }

    return result;
  }

  contains(value: T) {
    for (const val of this.#list) {
      if (this.#equater.equals(value, val)) {
        return true;
      }
    }

    return false;
  }

  remove(value: T) {
    const length = this.#list.length;

    for (let i = 0; i < length; i++) {
      if (this.#equater.equals(value, this.#list[i])) {
        this.#list.splice(i, 1);
        return true;
      }
    }

    return false;
  }

  clear() {
    this.#list.length = 0;
  }

  values() {
    return this.#list.values();
  }

  [Symbol.iterator]() {
    return this.#list[Symbol.iterator]();
  }
}

export class NativeAsyncEqualitySet<T> implements AsyncEqualitySet<T> {
  readonly #set = new Set<T>();

  get size() {
    return this.#set.size;
  }

  async add(value: T) {
    const exists = await this.contains(value);
    this.#set.add(value);
    return !exists;
  }

  async addAll(values: MaybeAsyncIterable<T>) {
    let result = 0;

    for await (const value of values) {
      if (await this.add(value)) {
        result++;
      }
    }

    return result;
  }

  async contains(value: T) {
    return this.#set.has(value);
  }

  async remove(value: T) {
    return this.#set.delete(value);
  }

  clear() {
    this.#set.clear();
  }

  values() {
    return this.#set.values();
  }

  [Symbol.iterator]() {
    return this.#set[Symbol.iterator]();
  }
}

export class CustomAsyncEqualitySet<T> implements AsyncEqualitySet<T> {
  readonly #list: T[] = [];
  readonly #equater: AsyncEqualityComparer<T>;

  constructor(equater: MaybeAsyncEqualityComparisonOrComparer<T>) {
    this.#equater = asAsyncEqualityComparer(equater);
  }

  get size() {
    return this.#list.length;
  }

  async add(value: T) {
    if (await this.contains(value)) {
      return false;
    }

    this.#list.push(value);

    return true;
  }

  async addAll(values: MaybeAsyncIterable<T>) {
    let result = 0;

    for await (const value of values) {
      if (await this.add(value)) {
        result++;
      }
    }

    return result;
  }

  async contains(value: T) {
    for (const val of this.#list) {
      if (await this.#equater.equals(value, val)) {
        return true;
      }
    }

    return false;
  }

  async remove(value: T) {
    const length = this.#list.length;

    for (let i = 0; i < length; i++) {
      if (await this.#equater.equals(value, this.#list[i])) {
        this.#list.splice(i, 1);
        return true;
      }
    }

    return false;
  }

  clear() {
    this.#list.length = 0;
  }

  values() {
    return this[Symbol.iterator]();
  }

  [Symbol.iterator]() {
    return this.#list[Symbol.iterator]();
  }
}