/*****************************************************************************\
|                                               ( )_  _                       |
|    _ _    _ __   _ _    __    ___ ___     _ _ | ,_)(_)  ___   ___     _     |
|   ( '_`\ ( '__)/'_` ) /'_ `\/' _ ` _ `\ /'_` )| |  | |/',__)/' _ `\ /'_`\   |
|   | (_) )| |  ( (_| |( (_) || ( ) ( ) |( (_| || |_ | |\__, \| (˅) |( (_) )  |
|   | ,__/'(_)  `\__,_)`\__  |(_) (_) (_)`\__,_)`\__)(_)(____/(_) (_)`\___/'  |
|   | |                ( )_) |                                                |
|   (_)                 \___/'                                                |
|                                                                             |
| 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.                                     |
|                                                                             |
\*****************************************************************************/

/**
 * @fileoverview Knowledge base services and logic.
 */

var Excel = require('exceljs');
const Path = require('path');
const Fs = require('fs');
import urlJoin = require('url-join');
const marked = require('marked');
const path = require('path');
const asyncPromise = require('async-promises');
const walkPromise = require('walk-promise');
// tslint:disable-next-line:newline-per-chained-call
const parse = require('bluebird').promisify(require('csv-parse'));
const { SearchService } = require('azure-search-client');

import { GBDialogStep, GBLog, IGBConversationalService, IGBCoreService, IGBInstance, GBMinInstance } from 'botlib';
import { Sequelize } from 'sequelize-typescript';
import { AzureDeployerService } from '../../azuredeployer.gbapp/services/AzureDeployerService';
import { GuaribasPackage } from '../../core.gbapp/models/GBModel';
import { GBDeployer } from '../../core.gbapp/services/GBDeployer';
import { GuaribasAnswer, GuaribasQuestion, GuaribasSubject } from '../models';
import { Messages } from '../strings';
import { GBConfigService } from './../../core.gbapp/services/GBConfigService';
import { GBServer } from '../../../src/app';


/**
 * Result for quey on KB data.
 */
export class KBServiceSearchResults {
  public answer: GuaribasAnswer;
  public questionId: number;
}

/**
 * All services related to knowledge base management.
 */
export class KBService {
  public sequelize: Sequelize;

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

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

    return out.join(', ');
  }

  public static getSubjectItemsSeparatedBySpaces(subjects: GuaribasSubject[]) {
    const out = [];
    if (subjects === undefined) { return ''; }
    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 !== null) {
      const answer = await GuaribasAnswer.findOne({
        where: {
          instanceId: instanceId,
          answerId: question.answerId
        }
      });

      return Promise.resolve({ question: question, answer: answer });
    }

    return Promise.resolve(undefined);
  }

  public async addAnswer(obj: GuaribasAnswer): Promise<GuaribasAnswer> {
    return await GuaribasAnswer.create(obj);
  }

  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 !== null) {
      const text = KBService.getSubjectItemsSeparatedBySpaces(subjects);
      if (text !== null) {
        query = `${query} ${text}`;
      }
    }

    // tslint:disable:no-unsafe-any
    if (instance.searchKey !== null && GBConfigService.get('STORAGE_DIALECT') === 'mssql') {
      const client = new SearchService(instance.searchHost.split('.')[0], instance.searchKey);
      const results = await client.indexes.use(instance.searchIndex)
        .buildQuery()
        .filter((f) => f.eq('instanceId', instance.instanceId))
        .search(query)
        .top(1)
        .executeQuery();

      const values = results.result.value;

      if (values && values.length > 0 && values[0]['@search.score'] >= searchScore) {
        const value = await this.getAnswerById(instance.instanceId, values[0].answerId);
        if (value !== null) {
          return Promise.resolve({ answer: value, questionId: values[0].questionId });
        } else {
          return Promise.resolve({ answer: undefined, 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: undefined, questionId: 0 });
      }
    }
  }

  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[]> {
    if (subjects) {
      const where = {
        from: from,
        // tslint:disable-next-line: no-null-keyword
        subject1: null,
        // tslint:disable-next-line: no-null-keyword
        subject2: null,
        // tslint:disable-next-line: no-null-keyword
        subject3: null,
        // tslint:disable-next-line: no-null-keyword
        subject4: null
      };

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

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

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

      if (subjects[3] && subjects[3].internalId) {
        where.subject4 = subjects[3].internalId;
      }

      return await GuaribasQuestion.findAll({
        where: where
      });
    } else {
      return await GuaribasQuestion.findAll({
        where: { from: from }
      });
    }
  }

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

    var workbook = new Excel.Workbook();
    let data = await workbook.xlsx.readFile(filePath);

    let lastQuestionId: number;
    let lastAnswer: GuaribasAnswer;
    let rows = data._worksheets[1]._rows;

    return asyncPromise.eachSeries(rows, async line => {
      // Extracts values from columns in the current line.

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

      // 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 {
            GBLog.info(`[GBImporter] File not found: ${mediaFilename}.`);
            answer = '';
          }
        }

        // Processes subjects hierarchy splitting by dots.

        const subjectArray = subjectsText.split('.');
        let subject1: string;
        let subject2: string;
        let subject3: string;
        let 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: lastQuestionId !== null ? lastQuestionId : 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 !== undefined && lastQuestionId !== 0) {
          await lastAnswer.update({ nextId: lastQuestionId });
        }
        lastAnswer = answer1;
        lastQuestionId = question1.questionId;

        return Promise.resolve(question1.questionId);
      } else {
        // Skips the header.

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

  public async sendAnswer(min: GBMinInstance, channel: string, step: GBDialogStep, answer: GuaribasAnswer) {
    if (answer.content.endsWith('.mp4')) {
      await this.playVideo(min.conversationalService, step, answer);
    }
    else if (answer.format === '.md') {

      await this.playMarkdown(min, answer, channel, step, min.conversationalService);

    } else if (answer.content.endsWith('.ogg')) {

      await this.playAudio(min, answer, channel, step, min.conversationalService);
    } else {
      await step.context.sendActivity(answer.content);
      await min.conversationalService.sendEvent(step, 'stop', undefined);
    }
  }

  private async playAudio(min: GBMinInstance, answer: GuaribasAnswer, channel: string, step: GBDialogStep, conversationalService: IGBConversationalService) {
    conversationalService.sendAudio(min, step, answer.content);
  }

  private async playMarkdown(min: GBMinInstance, answer: GuaribasAnswer, channel: string, step: GBDialogStep, conversationalService: IGBConversationalService) {
    let html = answer.content;
    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);
    if (channel === 'webchat' &&
      GBConfigService.get('DISABLE_WEB') !== 'true') {
      await this.sendMarkdownToWeb(step, conversationalService, html, answer);
    }
    else if (channel === 'whatsapp') {
      await this.sendMarkdownToMobile(step, answer, conversationalService, min);
    }
  }

  private async sendMarkdownToWeb(step: GBDialogStep, conversationalService: IGBConversationalService, html: string, answer: GuaribasAnswer) {
    const locale = step.context.activity.locale;
    await step.context.sendActivity(Messages[locale].will_answer_projector);
    html = html.replace(/src\=\"kb\//g, `src=\"../kb/`);
    await conversationalService.sendEvent(step, 'play', {
      playerType: 'markdown',
      data: {
        content: html,
        answer: answer,
        prevId: answer.prevId,
        nextId: answer.nextId
      }
    });
  }

  private async sendMarkdownToMobile(step: GBDialogStep, answer: GuaribasAnswer, conversationalService: IGBConversationalService, min: GBMinInstance) {

    let text = answer.content;

    let sleep = (ms) => {
      return new Promise(resolve => {
        setTimeout(resolve, ms)
      })
    }

    enum State {
      InText,
      InImage,
      InImageBegin,
      InImageCaption,
      InImageAddressBegin,
      InImageAddressBody
    };
    let state = State.InText;
    let currentImage = '';
    let currentText = '';

    //![General Bots](/instance/images/gb.png)
    for (var i = 0; i < text.length; i++) {
      const c = text.charAt(i);

      switch (state) {
        case State.InText:
          if (c === '!') {
            state = State.InImageBegin;
          }
          else {
            currentText = currentText.concat(c);
          }
          break;
        case State.InImageBegin:
          if (c === '[') {
            if (currentText !== '') {
              await step.context.sendActivity(currentText);
              await sleep(3000);
            }

            currentText = '';
            state = State.InImageCaption;
          }
          else {
            state = State.InText;
            currentText = currentText.concat('!').concat(c);
          }
          break;
        case State.InImageCaption:
          if (c === ']') {
            state = State.InImageAddressBegin;
          }
          break;
        case State.InImageAddressBegin:
          if (c === '(') {
            state = State.InImageAddressBody;
          }
          break;
        case State.InImageAddressBody:
          if (c === ')') {
            state = State.InText;
            let url = urlJoin(GBServer.globals.publicAddress, currentImage);
            await conversationalService.sendFile(min, step, url);
            await sleep(5000);
            currentImage = '';
          }
          else {
            currentImage = currentImage.concat(c);
          }
          break;
      }

    }
    if (currentText !== '') {
      await step.context.sendActivity(currentText);
    }
  }

  private async playVideo(conversationalService: IGBConversationalService, step: GBDialogStep, answer: GuaribasAnswer) {
    await conversationalService.sendEvent(step, 'play', {
      playerType: 'video',
      data: answer.content
    });
  }

  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('.xlsx')) {
          return this.importKbTabularFile(urlJoin(file.root, file.name), instance.instanceId, packageId);
        }
      })
    );
  }

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

    const doIt = async (subjects: GuaribasSubject[], parentSubjectId: number) => {
      return asyncPromise.eachSeries(subjects, async item => {
        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(subjectsLoaded.children, undefined);
  }

  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, new AzureDeployerService(deployer).getKBSearchSchema(instance.searchIndex));
  }

  /**
   * 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);
    GBLog.info(`[GBDeployer] Opening package: ${localPath}`);
    const packageObject = JSON.parse(Fs.readFileSync(urlJoin(localPath, 'package.json'), 'utf8'));

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

    deployer.rebuildIndex(instance, new AzureDeployerService(deployer).getKBSearchSchema(instance.searchIndex));
    GBLog.info(`[GBDeployer] Finished import of ${localPath}`);
  }
}