/*****************************************************************************\
|                                               ( )_  _                       |
|    _ _    _ __   _ _    __    ___ ___     _ _ | ,_)(_)  ___   ___     _     |
|   ( '_`\ ( '__)/'_` ) /'_ `\/' _ ` _ `\ /'_` )| |  | |/',__)/' _ `\ /'_`\   |
|   | (_) )| |  ( (_| |( (_) || ( ) ( ) |( (_| || |_ | |\__, \| ( ) |( (_) )  |
|   | ,__/'(_)  `\__,_)`\__  |(_) (_) (_)`\__,_)`\__)(_)(____/(_) (_)`\___/'  |
|   | |                ( )_) |                                                |
|   (_)                 \___/'                                                |
|                                                                             |
| General Bots Copyright (c) Pragmatismo.io. All rights reserved.             |
| Licensed under the AGPL-3.0.                                                |
|                                                                             |
| According to our dual licensing model, this program can be used either      |
| under the terms of the GNU Affero General Public License, version 3,        |
| or under a proprietary license.                                             |
|                                                                             |
| The texts of the GNU Affero General Public License with an additional       |
| permission and of our proprietary license can be found at and               |
| in the LICENSE file you have received along with this program.              |
|                                                                             |
| 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 Affero General Public License for more details.                         |
|                                                                             |
| "General Bots" is a registered trademark of Pragmatismo.io.                 |
| The licensing of the program under the AGPLv3 does not imply a              |
| trademark license. Therefore any rights, title and interest in              |
| our trademarks remain entirely with us.                                     |
|                                                                             |
\*****************************************************************************/

const logger = require('../../../src/logger');
const Path = require('path');
const Fs = require('fs');
const promise = require('bluebird');
const parse = promise.promisify(require('csv-parse'));
const UrlJoin = require('url-join');
const marked = require('marked');
const path = require('path');
const asyncPromise = require('async-promises');
const walkPromise = require('walk-promise');
import { Messages } from '../strings';

import { IGBConversationalService, IGBCoreService, IGBInstance } from 'botlib';
import { AzureSearch } from 'pragmatismo-io-framework';
import { Sequelize } from 'sequelize-typescript';
import { GuaribasPackage } from '../../core.gbapp/models/GBModel';
import { GBDeployer } from '../../core.gbapp/services/GBDeployer';
import { GuaribasAnswer, GuaribasQuestion, GuaribasSubject } from '../models';
import { GBConfigService } from './../../core.gbapp/services/GBConfigService';

export class KBServiceSearchResults {
  public answer: GuaribasAnswer;
  public questionId: number;
}

export class KBService {

  public sequelize: Sequelize;

  constructor(sequelize: Sequelize) {
    this.sequelize = sequelize;
  }

  public static getFormattedSubjectItems(subjects: GuaribasSubject[]) {
    if (!subjects) { return ''; }
    const out = [];
    subjects.forEach(subject => {
      out.push(subject.title);
    });
    return out.join(', ');
  }

  public static getSubjectItemsSeparatedBySpaces(subjects: GuaribasSubject[]) {
    const out = [];
    subjects.forEach(subject => {
      out.push(subject.internalId);
    });
    return out.join(' ');
  }

  public async getQuestionById(
    instanceId: number,
    questionId: number
  ): Promise<GuaribasQuestion> {
    return GuaribasQuestion.findOne({
      where: {
        instanceId: instanceId,
        questionId: questionId
      }
    });
  }

  public async getAnswerById(
    instanceId: number,
    answerId: number
  ): Promise<GuaribasAnswer> {
    return GuaribasAnswer.findOne({
      where: {
        instanceId: instanceId,
        answerId: answerId
      }
    });
  }

  public async getAnswerByText(
    instanceId: number,
    text: string
  ): Promise<any> {

    const Op = Sequelize.Op;

    const question = await GuaribasQuestion.findOne({
      where: {
        instanceId: instanceId,
        content: { [Op.like]: `%${text.trim()}%` }
      }
    });

    if (question) {
      const answer = await GuaribasAnswer.findOne({
        where: {
          instanceId: instanceId,
          answerId: question.answerId
        }
      });
      return Promise.resolve({ question: question, answer: answer });
    }
    return Promise.resolve(null);
  }

  public async addAnswer(obj: GuaribasAnswer): Promise<GuaribasAnswer> {
    return new Promise<GuaribasAnswer>(
      (resolve, reject) => {
        GuaribasAnswer.create(obj).then(item => {
          resolve(item);
        }).error((reason) => {
          reject(reason);
        });
      });
  }

  public async ask(
    instance: IGBInstance,
    query: string,
    searchScore: number,
    subjects: GuaribasSubject[]
  ): Promise<KBServiceSearchResults> {

    // Builds search query.

    query = query.toLowerCase();
    query = query.replace('?', ' ');
    query = query.replace('!', ' ');
    query = query.replace('.', ' ');
    query = query.replace('/', ' ');
    query = query.replace('\\', ' ');

    if (subjects) {
      const text = KBService.getSubjectItemsSeparatedBySpaces(subjects);
      if (text) {
        query = `${query} ${text}`;
      }
    }
    // TODO: Filter by instance. what = `${what}&$filter=instanceId eq ${instanceId}`
    try {
      if (instance.searchKey && GBConfigService.get('STORAGE_DIALECT') == 'mssql') {
        const service = new AzureSearch(
          instance.searchKey,
          instance.searchHost,
          instance.searchIndex,
          instance.searchIndexer
        );
        const results = await service.search(query);
        if (results && results.length > 0 &&
          results[0]['@search.score'] >= searchScore) {
          const value = await this.getAnswerById(
            instance.instanceId,
            results[0].answerId);
          if (value) {
            return Promise.resolve({ answer: value, questionId: results[0].questionId });
          } else {
            return Promise.resolve({ answer: null, questionId: 0 });
          }
        }
      } else {
        const data = await this.getAnswerByText(instance.instanceId, query);
        if (data) {
          return Promise.resolve(
            { answer: data.answer, questionId: data.question.questionId });
        } else {
          return Promise.resolve({ answer: null, questionId: 0 });
        }
      }
    } catch (reason) {
      return Promise.reject(new Error(reason));
    }
  }

  public async getSubjectItems(
    instanceId: number,
    parentId: number
  ): Promise<GuaribasSubject[]> {
    const where = { parentSubjectId: parentId, instanceId: instanceId };
    return GuaribasSubject.findAll({
      where: where
    });
  }

  public async getFaqBySubjectArray(from: string, subjects: any): Promise<GuaribasQuestion[]> {
    const where = {
      from: from, subject1: null, subject2: null, subject3: null, subject4:null
    };

    if (subjects) {
      if (subjects[0]) {
        where.subject1 = subjects[0].internalId;
      }

      if (subjects[1]) {
        where.subject2 = subjects[1].internalId;
      }

      if (subjects[2]) {
        where.subject3 = subjects[2].internalId;
      }

      if (subjects[3]) {
        where.subject4 = subjects[3].internalId;
      }
    }
    return await GuaribasQuestion.findAll({
      where: where
    });
  }

  public async importKbTabularFile(
    filePath: string,
    instanceId: number,
    packageId: number
  ): Promise<GuaribasQuestion[]> {

    const file = Fs.readFileSync(filePath, 'UCS-2');
    const opts = {
      delimiter: '\t'
    };

    let lastQuestion: GuaribasQuestion;
    let lastAnswer: GuaribasAnswer;

    const data = await parse(file, opts);
    return asyncPromise.eachSeries(data, async line => {

      // Extracts values from columns in the current line.

      const subjectsText = line[0];
      const from = line[1];
      const to = line[2];
      const question = line[3];
      let answer = line[4];

      // Skips the first line.

      if (!(subjectsText === 'subjects' && from == 'from')) {
        let format = '.txt';

        // Extracts answer from external media if any.

        if (answer.indexOf('.md') > -1) {
          const mediaFilename = UrlJoin(path.dirname(filePath), '..', 'articles', answer);
          if (Fs.existsSync(mediaFilename)) {
            answer = Fs.readFileSync(mediaFilename, 'utf8');
            format = '.md';
          } else {
            logger.info(`[GBImporter] File not found: ${mediaFilename}.`);
            answer = '';
          }
        }

        // Processes subjects hierarchy splitting by dots.

        const subjectArray = subjectsText.split('.');
        let subject1: string, subject2: string, subject3: string,
          subject4: string;
        let indexer = 0;

        subjectArray.forEach(element => {
          if (indexer == 0) {
            subject1 = subjectArray[indexer].substring(0, 63);
          } else if (indexer == 1) {
            subject2 = subjectArray[indexer].substring(0, 63);
          } else if (indexer == 2) {
            subject3 = subjectArray[indexer].substring(0, 63);
          } else if (indexer == 3) {
            subject4 = subjectArray[indexer].substring(0, 63);
          }
          indexer++;
        });

        // Now with all the data ready, creates entities in the store.

        const answer1 = await GuaribasAnswer.create({
          instanceId: instanceId,
          content: answer,
          format: format,
          packageId: packageId,
          prevId: lastQuestion ? lastQuestion.questionId : 0
        });

        const question1 = await GuaribasQuestion.create({
          from: from,
          to: to,
          subject1: subject1,
          subject2: subject2,
          subject3: subject3,
          subject4: subject4,
          content: question,
          instanceId: instanceId,
          answerId: answer1.answerId,
          packageId: packageId
        });

        if (lastAnswer && lastQuestion) {
          await lastAnswer.updateAttributes({ nextId: lastQuestion.questionId });
        }
        lastAnswer = answer1;
        lastQuestion = question1;

        return Promise.resolve(lastQuestion);

      } else {

        // Skips the header.

        return Promise.resolve(null);
      }
    });
  }

  public async sendAnswer(conversationalService: IGBConversationalService,
                          step: any, answer: GuaribasAnswer) {

    if (answer.content.endsWith('.mp4')) {
      await conversationalService.sendEvent(step, 'play', {
        playerType: 'video',
        data: answer.content
      });
    } else if (answer.content.length > 140 &&
      step.context._activity.channelId === 'webchat') {
      const locale = step.context.activity.locale;

      await step.context.sendActivity(Messages[locale].will_answer_projector); // TODO: Handle rnd.
      let html = answer.content;

      if (answer.format === '.md') {
        marked.setOptions({
          renderer: new marked.Renderer(),
          gfm: true,
          tables: true,
          breaks: false,
          pedantic: false,
          sanitize: false,
          smartLists: true,
          smartypants: false,
          xhtml: false
        });
        html = marked(answer.content);
      }
      await conversationalService.sendEvent(step, 'play',
                                            {
          playerType: 'markdown', data: {
            content: html, answer: answer,
            prevId: answer.prevId, nextId: answer.nextId
          }
        });
    } else {
      await step.context.sendActivity(answer.content);
      await conversationalService.sendEvent(step, 'stop', null);
    }
  }

  public async importKbPackage(
    localPath: string,
    packageStorage: GuaribasPackage,
    instance: IGBInstance
  ): Promise<any> {

    // Imports subjects tree into database and return it.

    await this.importSubjectFile(
      packageStorage.packageId,
      UrlJoin(localPath, 'subjects.json'),
      instance);

    // Import all .tsv files in the tabular directory.

    return this.importKbTabularDirectory(
      localPath,
      instance,
      packageStorage.packageId
    );
  }

  public async importKbTabularDirectory(
    localPath: string,
    instance: IGBInstance,
    packageId: number
  ): Promise<any> {

    const files = await walkPromise(UrlJoin(localPath, 'tabular'));

    return Promise.all(files.map(async file => {
      if (file.name.endsWith('.tsv')) {
        return this.importKbTabularFile(
          UrlJoin(file.root, file.name),
          instance.instanceId,
          packageId);
      }
    }));

  }

  public async importSubjectFile(
    packageId: number,
    filename: string,
    instance: IGBInstance
  ): Promise<any> {
    const subjects = JSON.parse(Fs.readFileSync(filename, 'utf8'));

    const doIt = async (subjects: GuaribasSubject[], parentSubjectId: number) => {
      return asyncPromise.eachSeries(subjects, async item => {
        const mediaFilename = item.id + '.png';

        const value = await GuaribasSubject.create({
          internalId: item.id,
          parentSubjectId: parentSubjectId,
          instanceId: instance.instanceId,
          from: item.from,
          to: item.to,
          title: item.title,
          description: item.description,
          packageId: packageId
        });

        if (item.children) {
          return Promise.resolve(doIt(item.children, value.subjectId));
        } else {
          return Promise.resolve(item);
        }
      });
    };
    return doIt(subjects.children, null);
  }

  public async undeployKbFromStorage(
    instance: IGBInstance,
    deployer: GBDeployer,
    packageId: number
  ) {

    await GuaribasQuestion.destroy({
      where: { instanceId: instance.instanceId, packageId: packageId }
    });
    await GuaribasAnswer.destroy({
      where: { instanceId: instance.instanceId, packageId: packageId }
    });
    await GuaribasSubject.destroy({
      where: { instanceId: instance.instanceId, packageId: packageId }
    });
    await GuaribasPackage.destroy({
      where: { instanceId: instance.instanceId, packageId: packageId }
    });

    await deployer.rebuildIndex(instance);
  }

  /**
  * Deploys a knowledge base to the storage using the .gbkb format.
  *
  * @param localPath Path to the .gbkb folder.
  */
  public async deployKb(core: IGBCoreService, deployer: GBDeployer, localPath: string) {
    const packageType = Path.extname(localPath);
    const packageName = Path.basename(localPath);
    logger.info(`[GBDeployer] Opening package: ${localPath}`);
    const packageObject = JSON.parse(
      Fs.readFileSync(UrlJoin(localPath, 'package.json'), 'utf8')
    );

    const instance = await core.loadInstance(packageObject.botId);
    logger.info(`[GBDeployer] Importing: ${localPath}`);
    const p = await deployer.deployPackageToStorage(
      instance.instanceId,
      packageName);
    await this.importKbPackage(localPath, p, instance);

    deployer.rebuildIndex(instance);
    logger.info(`[GBDeployer] Finished import of ${localPath}`);
  }
}