"use strict";

// Modules from file
import shared, { TPrefixDict } from "../shared.js";

/**
 * Convert prefixes and platform tags from string to ID and vice versa.
 */
export default class PrefixParser {

    //#region Private methods
    /**
     * Gets the key associated with a given value from a dictionary.
     * @param {Object} object Dictionary to search
     * @param {Any} value Value associated with the key
     * @returns {String|undefined} Key found or undefined
     */
    private getKeyByValue(object: TPrefixDict, value: string): string | undefined {
        return Object.keys(object).find(key => object[key] === value);
    }

    /**
     * Makes an array of strings uppercase.
     */
    private toUpperCaseArray(a: string[]): string[] {
        /**
         * Makes a string uppercase.
         */
        function toUpper(s: string): string {
            return s.toUpperCase();
        }
        return a.map(toUpper);
    }

    /**
     * Check if `dict` contains `value` as a value.
     */
    private valueInDict(dict: TPrefixDict, value: string): boolean {
        const array = Object.values(dict);
        const upperArr = this.toUpperCaseArray(array);
        const element = value.toUpperCase();
        return upperArr.includes(element);
    }

    /**
     * Search within the platform prefixes for the
     * desired element and return the dictionary that contains it.
     * @param element Element to search in the prefixes as a key or as a value
     */
    private searchElementInPrefixes(element: string | number): TPrefixDict | null {
        // Local variables
        let dictName = null;

        // Iterate the key/value pairs in order to find the element
        for (const [key, subdict] of Object.entries(shared.prefixes)) {
            // Check if the element is a value in the sub-dict
            const valueInDict = typeof element === "string" && this.valueInDict(subdict, element as string);

            // Check if the element is a key in the subdict
            const keyInDict = typeof element === "number" && Object.keys(subdict).includes(element.toString());
            
            if (valueInDict || keyInDict) {
                dictName = key;
                break;
            }
        }

        return shared.prefixes[dictName] ?? null;
    }
    //#endregion Private methods

    /**
     * Convert a list of prefixes to their respective IDs.
     */
    public prefixesToIDs(prefixes: string[]) : number[] {
        const ids: number[] = [];

        for(const p of prefixes) {
            // Check what dict contains the value
            const dict = this.searchElementInPrefixes(p);

            if (dict) {
                // Extract the key from the dict
                const key = this.getKeyByValue(dict, p);
                ids.push(parseInt(key), 10);
            }
        }
        return ids;
    }

    /**
     * It converts a list of IDs into their respective prefixes.
     */
    public idsToPrefixes(ids: number[]): string[] {
        const prefixes:string[] = [];

        for(const id of ids) {
            // Check what dict contains the key
            const dict = this.searchElementInPrefixes(id);

            // Add the key to the list
            if (dict) {
                prefixes.push(dict[id]);
            }
        }
        return prefixes;
    }
}