import {Injectable} from '@angular/core';
import {InvalidMobilePhoneNumberError} from './InvalidMobilePhoneNumber.error';
import {InvalidMobileOperatorError} from './InvalidMobileOperator.error';

/**
 * English name of mobile operators are enum keys and persian name of them are values.
 * All characters of all of the keys are in lowercase
 */
export enum operatorsNames {        // eslint-disable-line no-shadow
    IRANCELL = 'ایرانسل',
    MCI = 'همراه اول',
    TALIA = 'تالیا',
    RIGHTEL = 'رایتل',
    SPADAN = 'اسپادان',
    TKC = 'شبکه مستقل تلفن همراه کیش',
    SHATEL = 'شاتل',
    APTEL = 'آپتل',
    AZARTEL = 'آذرتل',
    SAMANTEL = 'سامانتل',
    LOTUSTEL = 'لوتوس‌تل',
    ANARESTAN = 'انارستان'
}

/**
 * A constant object. Keys are Mobile operator names and values are arrays those keep mobile codes.
 */
export const MobileCodes = {
    irancell: ['0901', '0902', '0903', '0904', '0905', '0930', '0933', '0935', '0936', '0937', '0938', '0939', '0941'],
    mci: ['0910', '0911', '0912', '0913', '0914', '0915', '0916', '0917', '0918', '0919', '0990', '0991', '0992'],
    talia: ['0932'],
    rightel: ['0920', '0921', '0922'],
    spadan: ['0931'],
    tkc: ['0934'],
    shatel: ['099810', '099811', '099812'],
    aptel: ['099910', '099911', '099913'],
    azartel: ['099914'],
    samantel: ['099996', '099997', '099998', '099999'],
    lotustel: ['09990'],
    anarestan: ['09944']
};

/**
 * This service using for validating phone numbers sold by Iranian Mobile operators.
 *
 * You can get operator name and validation result of a phone number by methods of this service.
 */
@Injectable({
    providedIn: 'root'
})
export class MobilePhoneNumberService {

    /**
     * This method only checks if phoneNumber follows valid pattern. means starting by +98 or 0, then a 9 digit and then 9 digits.
     * This method will not check validity of the phoneNumber code and can accept invalid strings those only locking like phone numbers and
     * in reality are not a valid phone number.
     *
     * @link isValidPhoneNumber
     * @param phoneNumber Digits in this string should be english digits.
     */
    isPhoneNumberPatternValid(phoneNumber: string): boolean {
        const generalRegex = new RegExp(/^((\+98|0)9\d{9})$/);
        return generalRegex.test(phoneNumber);
    }

    /**
     * Removes +98 from the phoneNumber and replaces it with a 0 character.
     *
     * @param phoneNumber Digits in this string should be english digits.
     */
    normalizePhoneNumber(phoneNumber: string): string {
        return phoneNumber.replace('+98', '0');
    }

    /**
     * Checks all codes of all operators in MobileCodes object. IF finds a matched code, returns persian or english name of that operator from
     * operatorsNames enum.
     *
     * @return operator name in english or persian according to the nameInEnglish parameter
     * @throws InvalidMobileOperatorError if pattern is correct but operator code is not valid.
     * @throws InvalidMobilePhoneNumberError If pattern is not correct
     * @param phoneNumber Digits in this string should be english digits.
     * @param nameInEnglish if true, operator name will return in English. if false operator name will return in persian
     * @link MobileCodes
     * @link operatorsNames
     */
    getPhoneNumberOperator(phoneNumber: string, nameInEnglish: boolean = false): string {
        if (!this.isPhoneNumberPatternValid(phoneNumber)) {
            throw new InvalidMobilePhoneNumberError();
        }
        const NormalizedPhoneNumber = this.normalizePhoneNumber(phoneNumber);
        for (const operator of Object.keys(MobileCodes)) {
            for (const code of MobileCodes[operator as keyof typeof MobileCodes]) {
                if (NormalizedPhoneNumber.indexOf(code) === 0) {
                    return nameInEnglish ? operator : operatorsNames[operator as keyof typeof operatorsNames];
                }
            }
        }
        throw new InvalidMobileOperatorError();
    }

    /**
     * @return If phoneNumber follows correct pattern and has valid operator, return true. Otherwise returns false.
     * @param phoneNumber Digits in this string should be english digits.
     * @link getPhoneNumberOperator
     */
    isValidPhoneNumber(phoneNumber: string): boolean {
        try {
            this.getPhoneNumberOperator(phoneNumber);
            return true;
        } catch (e) {
            return false;
        }
    }
}