import { HandlerInput, getLocale } from 'ask-sdk-core';

export type ErrorResponse = {
  speak: string;
  reprompt: string;
};
export class ErrorHandlerService {
  public static readonly errorResponses: {
    [locale: string]: ErrorResponse;
  } = {
    'ja-JP': {
      speak: 'すみません。うまく聞き取れませんでした。もう一度お願いします。',
      reprompt: 'もう一度、お願いできますか？',
    },
    en: {
      speak: 'Sorry I could not understand the meaning. Please tell me again',
      reprompt: 'Could you tell me onece more?',
    },
  };

  public static getSupportedLang() {
    return Object.keys(this.errorResponses);
  }

  public static findSpeakableLang(locale: string): string | undefined {
    const errorHandlerSupportedLang = this.getSupportedLang();
    const matched = errorHandlerSupportedLang.find(target => {
      if (target === locale) return true;
      const reg = new RegExp(target);
      return reg.test(locale);
    });
    return matched;
  }

  public static canSpeakRequest(input: HandlerInput): boolean {
    const locale = getLocale(input.requestEnvelope);
    const lang = this.findSpeakableLang(locale);
    return !!lang;
  }

  public static getResponse(input: HandlerInput): ErrorResponse {
    const locale = getLocale(input.requestEnvelope);
    const lang = this.findSpeakableLang(locale);
    if (!lang) return this.errorResponses['en'];
    return this.errorResponses[lang] || this.errorResponses['en'];
  }
}