//================================================================
/**
 * @packageDocumentation
 * @module std.base
 */
//================================================================
import { SetContainer } from "./SetContainer";

import { IForwardIterator } from "../../iterator/IForwardIterator";
import { Pair } from "../../utility/Pair";
import { ErrorGenerator } from "../../internal/exception/ErrorGenerator";

/**
 * Basic set container blocking duplicated key.
 *
 * @template Key Key type
 * @template Source Derived type extending this {@link UniqueSet}
 * @template IteratorT Iterator type
 * @template ReverseT Reverse iterator type
 *
 * @author Jeongho Nam - https://github.com/samchon
 */
export abstract class UniqueSet<
    Key,
    Source extends UniqueSet<Key, Source, IteratorT, ReverseT>,
    IteratorT extends UniqueSet.Iterator<Key, Source, IteratorT, ReverseT>,
    ReverseT extends UniqueSet.ReverseIterator<
        Key,
        Source,
        IteratorT,
        ReverseT
    >,
> extends SetContainer<Key, true, Source, IteratorT, ReverseT> {
    /* ---------------------------------------------------------
        ACCESSOR
    --------------------------------------------------------- */
    /**
     * @inheritDoc
     */
    public count(key: Key): number {
        return this.find(key).equals(this.end()) ? 0 : 1;
    }

    /* ---------------------------------------------------------
        INSERT
    --------------------------------------------------------- */
    /**
     * Insert an element.
     *
     * @param key Key to insert.
     * @return {@link Pair} of an iterator to the newly inserted element and `true`, if the specified *key* doesn't exist, otherwise {@link Pair} of iterator to ordinary element and `false`.
     */
    public insert(key: Key): Pair<IteratorT, boolean>;

    /**
     * Insert an element with hint.
     *
     * @param hint Hint for the position where the element can be inserted.
     * @param pair A tuple to be referenced for the insert.
     * @return An iterator to the newly inserted element, if the specified key doesn't exist, otherwise an iterator to the ordinary element.
     */
    public insert(hint: IteratorT, key: Key): IteratorT;

    /**
     * Insert range elements.
     *
     * @param first Input iterator of the first position.
     * @param last Input iteartor of the last position.
     */
    public insert<
        InputIterator extends Readonly<IForwardIterator<Key, InputIterator>>,
    >(first: InputIterator, last: InputIterator): void;

    public insert(...args: any[]): any {
        return (super.insert as Function)(...args);
    }

    protected _Insert_by_range<
        InputIterator extends Readonly<IForwardIterator<Key, InputIterator>>,
    >(first: InputIterator, last: InputIterator): void {
        for (; !first.equals(last); first = first.next())
            this._Insert_by_key(first.value);
    }

    /* ---------------------------------------------------------
        ERASE
    --------------------------------------------------------- */
    /**
     * Extract an element by key.
     *
     * @param key Key to search for.
     * @return The extracted element.
     */
    public extract(key: Key): Key;

    /**
     * Extract an element by iterator.
     *
     * @param pos The iterator to the element for extraction.
     * @return Iterator following the *pos*, strained by the extraction.
     */
    public extract(it: IteratorT): IteratorT;

    public extract(param: Key | IteratorT): any {
        if (param instanceof this.end().constructor)
            return this._Extract_by_iterator(param as IteratorT);
        else return this._Extract_by_val(param as Key);
    }

    private _Extract_by_val(key: Key): Key {
        const it = this.find(key);
        if (it.equals(this.end()) === true)
            throw ErrorGenerator.key_nout_found(this, "extract", key);

        this._Erase_by_range(it);
        return key;
    }

    private _Extract_by_iterator(it: IteratorT): IteratorT {
        if (it.equals(this.end()) === true || this.has(it.value) === false)
            return this.end();

        this._Erase_by_range(it);
        return it;
    }

    protected _Erase_by_val(key: Key): number {
        const it = this.find(key);
        if (it.equals(this.end()) === true) return 0;

        this._Erase_by_range(it);
        return 1;
    }

    /* ---------------------------------------------------------
        UTILITY
    --------------------------------------------------------- */
    /**
     * @inheritDoc
     */
    public merge(source: Source): void {
        for (let it = source.begin(); !it.equals(source.end()); ) {
            if (this.has(it.value) === false) {
                this.insert(it.value);
                it = source.erase(it);
            } else it = it.next();
        }
    }
}

/**
 *
 */
export namespace UniqueSet {
    /**
     * Iterator of {@link UniqueSet}
     *
     * @author Jenogho Nam <http://samchon.org>
     */
    export type Iterator<
        Key,
        SourceT extends UniqueSet<Key, SourceT, IteratorT, ReverseT>,
        IteratorT extends Iterator<Key, SourceT, IteratorT, ReverseT>,
        ReverseT extends ReverseIterator<Key, SourceT, IteratorT, ReverseT>,
    > = SetContainer.Iterator<Key, true, SourceT, IteratorT, ReverseT>;

    /**
     * Reverse iterator of {@link UniqueSet}
     *
     * @author Jenogho Nam <http://samchon.org>
     */
    export type ReverseIterator<
        Key,
        SourceT extends UniqueSet<Key, SourceT, IteratorT, ReverseT>,
        IteratorT extends Iterator<Key, SourceT, IteratorT, ReverseT>,
        ReverseT extends ReverseIterator<Key, SourceT, IteratorT, ReverseT>,
    > = SetContainer.ReverseIterator<Key, true, SourceT, IteratorT, ReverseT>;
}