/*
 * Copyright (C) 2018 StApps
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <https://www.gnu.org/licenses/>.
 */
import {SCThingsField} from './Classes';
import {SCOrganization} from './things/Organization';
import {SCPerson} from './things/Person';
import {isThingWithTranslations} from './types/Guards';
import {SCTranslations} from './types/i18n';
import {SCISO8601Date} from './types/Time';
import {SCUuid} from './types/UUID';

/**
 * Types a thing can be
 */
export enum SCThingType {
  AcademicEvent = 'academic event',
  Article = 'article',
  Book = 'book',
  Building = 'building',
  Catalog = 'catalog',
  CourseOfStudies = 'course of studies',
  DateSeries = 'date series',
  Diff = 'diff',
  Dish = 'dish',
  Favorite = 'favorite',
  Floor = 'floor',
  Message = 'message',
  Offer = 'offer', // Currently not in use
  Organization = 'organization',
  Person = 'person',
  PointOfInterest = 'point of interest',
  Room = 'room',
  Semester = 'semester',
  Setting = 'setting',
  SportCourse = 'sport course',
  Ticket = 'ticket',
  Tour = 'tour',
  Video = 'video',
}

/**
 * A thing
 */
export interface SCThing {
  /**
   * Alternate names of the thing
   */
  alternateNames?: string[];
  /**
   * Description of the thing
   *
   * @minLength 1
   */
  description?: string;
  /**
   * Image of the thing
   */
  image?: string;
  /**
   * Name of the thing
   *
   * @minLength 1
   */
  name: string;
  /**
   * Origin of the thing
   */
  origin: SCThingOrigin;
  /**
   * Translations of specific values of the object
   *
   * Take precedence over "main" value for selected languages.
   */
  translations?: SCTranslations<SCThingTranslatableProperties>;
  /**
   * Type of the thing
   */
  type: string;
  /**
   * Universally unique identifier of the thing
   */
  uid: SCUuid;
  /**
   * URL of the thing
   */
  url?: string;
}

/**
 * Origin of a thing
 */
export interface SCThingOrigin {
  /**
   * When the thing was indexed last from the origin
   */
  indexed: SCISO8601Date;

  /**
   * Maintainer of the origin
   *
   * e.g. restaurant of a dish
   */
  maintainer?: SCPerson | SCOrganization;

  /**
   * When the thing was modified last in the origin
   */
  modified?: SCISO8601Date;

  /**
   * Name of the origin
   */
  name: string;

  /**
   * Original ID of the thing in the origin
   */
  originalId?: string;

  /**
   * Entity that is responsible for the entity
   *
   * e.g. an organizer for an event
   */
  responsibleEntity?: SCPerson | SCOrganization;

  /**
   * Main URL of the origin
   */
  url?: string;
}

/**
 * Meta information about things
 */
export class SCThingMeta {
  /**
   * Translations of fields
   */
  static fieldTranslations: any = {
    de: {
      alternateNames: 'alternative Namen',
      description: 'Beschreibung',
      image: 'Bild',
      name: 'Name',
      translations: 'Übersetzungen',
      type: 'Typ',
      uid: 'Identifikation',
      url: 'URL',
    },
    en: {
      alternateNames: 'alternate names',
      description: 'description',
      uid: 'identification',
    },
  };

  /**
   * Translations of values of fields
   */
  static fieldValueTranslations: any = {
    de: {
      type: {
        AcademicTerm: 'Studienabschnitt',
        Article: 'Artikel',
        Book: 'Buch',
        Catalog: 'Katalog',
        Date: 'Termin',
        Diff: 'Unterschied',
        Dish: 'Essen',
        Event: 'Veranstaltung',
        Favorite: 'Favorit',
        FloorPlan: 'Etagenplan',
        Message: 'Nachricht',
        Offer: 'Angebot',
        Organization: 'Organisation',
        Person: 'Person',
        Place: 'Ort',
        Setting: 'Einstellung',
        Thing: 'Ding',
        Ticket: 'Ticket',
        Tour: 'Tour',
        Video: 'Video',
      },
    },
  };

  /**
   * Get field translation
   *
   * @param {keyof SCTranslations<T extends SCThing>} language Language to get field translation for
   * @param {keyof T} field Field to get translation for
   * @returns {string} Translated field or field itself
   */
  static getFieldTranslation<T extends SCThing>(language: keyof SCTranslations<T>,
                                                field: SCThingsField): string {
    if (typeof this.fieldTranslations[language] !== 'undefined'
      && typeof this.fieldTranslations[language][field] !== 'undefined') {
      return this.fieldTranslations[language][field];
    }

    return field as string;
  }

  /**
   * Get field value translation
   *
   * @param {keyof SCTranslations<T>} language Language to get value translation for
   * @param {string} field Field to get value translation for
   * @param {T} thing SCThing to get value translation for
   * @returns {string} Translated value or value itself
   */
  static getFieldValueTranslation<T extends SCThing>(language: keyof SCTranslations<T>,
                                                     field: SCThingsField,
                                                     thing: T): string {

    let translations: SCTranslations<SCThingTranslatableProperties>;

    if (isThingWithTranslations(thing)) {
      translations = thing.translations;

      const languageTranslations: SCThingTranslatableProperties | undefined = translations[language];

      if (typeof languageTranslations !== 'undefined') {
        if (typeof (languageTranslations as any)[field] !== 'undefined') {
          return (languageTranslations as any)[field];
        }
      }
    }

    // get translation from meta object
    if (typeof this.fieldValueTranslations[language] !== 'undefined'
      && typeof this.fieldValueTranslations[language][field] !== 'undefined'
      && typeof (thing as any)[field] !== 'undefined'
      && typeof this.fieldValueTranslations[language][field][(thing as any)[field]]) {
      return this.fieldValueTranslations[language][field][(thing as any)[field]];
    }

    // fallback to value itself
    return (thing as any)[field];
  }
}

/**
 * Translatable properties of things
 */
export interface SCThingTranslatableProperties {
  /**
   * Translation of the description of the thing
   */
  description?: string;
  /**
   * Translation of the name of the thing
   */
  name?: string;
  /**
   * Origin of the thing
   */
  origin?: {
    /**
     * Translation of the name of the origin of the thing
     */
    name: string;
  };
}