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

"use strict";

const { TextPrompt } = require("botbuilder-dialogs");
const UrlJoin = require("url-join");
const express = require("express");
const logger = require("../../../src/logger");
const request = require("request-promise-native");
var crypto = require("crypto");
var AuthenticationContext = require("adal-node").AuthenticationContext;

import {
  BotFrameworkAdapter,
  BotStateSet,
  ConversationState,
  MemoryStorage,
  UserState
} from "botbuilder";

import { GBMinInstance, IGBPackage } from "botlib";
import { GBAnalyticsPackage } from "../../analytics.gblib";
import { GBCorePackage } from "../../core.gbapp";
import { GBKBPackage } from "../../kb.gbapp";
import { GBDeployer } from "./GBDeployer";
import { GBSecurityPackage } from "../../security.gblib";
import { GBAdminPackage } from "./../../admin.gbapp/index";
import { GBCustomerSatisfactionPackage } from "../../customer-satisfaction.gbapp";
import { GBWhatsappPackage } from "../../whatsapp.gblib";
import {
  IGBAdminService,
  IGBCoreService,
  IGBConversationalService
} from "botlib";
import { GuaribasInstance } from "../models/GBModel";
import { Messages } from "../strings";

/** Minimal service layer for a bot. */

export class GBMinService {
  core: IGBCoreService;
  conversationalService: IGBConversationalService;
  adminService: IGBAdminService;
  deployer: GBDeployer;

  corePackage = "core.gbai";

  /**
   * Static initialization of minimal instance.
   *
   * @param core Basic database services to identify instance, for example.
   */
  constructor(
    core: IGBCoreService,
    conversationalService: IGBConversationalService,
    adminService: IGBAdminService,
    deployer: GBDeployer
  ) {
    this.core = core;
    this.conversationalService = conversationalService;
    this.adminService = adminService;
    this.deployer = deployer;
  }

  /**
   *
   * Constructs a new minimal instance for each bot.
   *
   * @param server        An HTTP server.
   * @param appPackages   List of loaded .gbapp associated with this instance.
   *
   * @return Loaded minimal bot instance.
   *
   * */

  async buildMin(
    server: any,
    appPackages: Array<IGBPackage>,
    instances:GuaribasInstance[]
  ): Promise<GBMinInstance> {
    // Serves default UI on root address '/'.

    let uiPackage = "default.gbui";
    server.use(
      "/",
      express.static(UrlJoin(GBDeployer.deployFolder, uiPackage, "build"))
    );
    
    Promise.all(
      instances.map(async instance => {
        // Gets the authorization key for each instance from Bot Service.

        let webchatToken = await this.getWebchatToken(instance);

        // Serves the bot information object via HTTP so clients can get
        // instance information stored on server.

        server.get("/instances/:botId", (req, res) => {
          (async () => {
            // Returns the instance object to clients requesting bot info.

            let botId = req.params.botId;
            let instance = await this.core.loadInstance(botId);
            if (instance) {
              let speechToken = await this.getSTSToken(instance);

              res.send(
                JSON.stringify({
                  instanceId: instance.instanceId,
                  botId: botId,
                  theme: instance.theme,
                  secret: instance.webchatKey, // TODO: Use token.
                  speechToken: speechToken,
                  conversationId: webchatToken.conversationId,
                  authenticatorTenant: instance.authenticatorTenant,
                  authenticatorClientId: instance.authenticatorClientId
                })
              );
            } else {
              let error = `Instance not found: ${botId}.`;
              res.sendStatus(error);
              logger.error(error);
            }
          })();
        });

        // Build bot adapter.

        var { min, adapter, conversationState } = await this.buildBotAdapter(
          instance
        );

        // Call the loadBot context.activity for all packages.

        this.invokeLoadBot(appPackages, min, server);

        // Serves individual URL for each bot conversational interface...

        let url = `/api/messages/${instance.botId}`;
        server.post(url, async (req, res) => {
          return this.receiver(
            adapter,
            req,
            res,
            conversationState,
            min,
            instance,
            appPackages
          );
        });
        logger.info(
          `GeneralBots(${instance.engineName}) listening on: ${url}.`
        );

        // Serves individual URL for each bot user interface.

        let uiUrl = `/${instance.botId}`;
        server.use(
          uiUrl,
          express.static(UrlJoin(GBDeployer.deployFolder, uiPackage, "build"))
        );

        logger.info(`Bot UI ${uiPackage} accessible at: ${uiUrl}.`);
        let state = `${instance.instanceId}${Math.floor(
          Math.random() * 1000000000
        )}`;

        // Clients get redirected here in order to create an OAuth authorize url and redirect them to AAD.
        // There they will authenticate and give their consent to allow this app access to
        // some resource they own.
        server.get(`/${min.instance.botId}/auth`, function(req, res) {
          let authorizationUrl = UrlJoin(
            min.instance.authenticatorAuthorityHostUrl,
            min.instance.authenticatorTenant,
            "/oauth2/authorize"
          );
          authorizationUrl = `${authorizationUrl}?response_type=code&client_id=${
            min.instance.authenticatorClientId
          }&redirect_uri=${min.instance.botServerUrl}/${
            min.instance.botId
          }/token`;

          res.redirect(authorizationUrl);
        });

        // After consent is granted AAD redirects here.  The ADAL library
        // is invoked via the AuthenticationContext and retrieves an
        // access token that can be used to access the user owned resource.

        server.get(`/${min.instance.botId}/token`, async (req, res) => {
          let state = await min.adminService.getValue(
            min.instance.instanceId,
            "AntiCSRFAttackState"
          );

          if (req.query.state != state) {
            let msg =
              "WARNING: state field was not provided as anti-CSRF token";
            logger.error(msg);
            throw new Error(msg);
          }

          var authenticationContext = new AuthenticationContext(
            UrlJoin(
              min.instance.authenticatorAuthorityHostUrl,
              min.instance.authenticatorTenant
            )
          );

          let resource = "https://graph.microsoft.com";

          authenticationContext.acquireTokenWithAuthorizationCode(
            req.query.code,
            UrlJoin(instance.botServerUrl, min.instance.botId, "/token"),
            resource,
            instance.authenticatorClientId,
            instance.authenticatorClientSecret,
            async (err, token) => {
              if (err) {
                let msg = `Error acquiring token: ${err}`;
                logger.error(msg);
                res.send(msg);
              } else {
                await this.adminService.setValue(
                  instance.instanceId,
                  "refreshToken",
                  token.refreshToken
                );
                await this.adminService.setValue(
                  instance.instanceId,
                  "accessToken",
                  token.accessToken
                );
                await this.adminService.setValue(
                  instance.instanceId,
                  "expiresOn",
                  token.expiresOn.toString()
                );
                await this.adminService.setValue(
                  instance.instanceId,
                  "AntiCSRFAttackState",
                  null
                );

                res.redirect(min.instance.botServerUrl);
              }
            }
          );
        });

        // Setups handlers.
        // send: function (context.activity, next) {
        //   logger.info(
        //     `[SND]: ChannelID: ${context.activity.address.channelId}, ConversationID: ${context.activity.address.conversation},
        //      Type: ${context.activity.type}              `)
        //   this.core.createMessage(
        //     this.min.conversation,
        //     this.min.conversation.startedBy,
        //     context.activity.source,
        //     (data, err) => {
        //       logger.info(context.activity.source)
        //     }
        //   )
        //   next()
      })
    );
  }

  private async buildBotAdapter(instance: any) {
    let adapter = new BotFrameworkAdapter({
      appId: instance.marketplaceId,
      appPassword: instance.marketplacePassword
    });

    const storage = new MemoryStorage();
    const conversationState = new ConversationState(storage);
    const userState = new UserState(storage);
    adapter.use(new BotStateSet(conversationState, userState));

    // The minimal bot is built here.

    let min = new GBMinInstance();
    min.botId = instance.botId;
    min.bot = adapter;
    min.userState = userState;
    min.core = this.core;
    min.conversationalService = this.conversationalService;
    min.adminService = this.adminService;
    min.instance = await this.core.loadInstance(min.botId);
    min.dialogs.add("textPrompt", new TextPrompt());

    return { min, adapter, conversationState };
  }

  private invokeLoadBot(appPackages: any[], min: any, server: any) {
    appPackages.forEach(e => {
      e.sysPackages = new Array<IGBPackage>();

      // NOTE: A semicolon is necessary before this line.

      [
        GBAdminPackage,
        GBAnalyticsPackage,
        GBCorePackage,
        GBSecurityPackage,
        GBKBPackage,
        GBCustomerSatisfactionPackage,
        GBWhatsappPackage
      ].forEach(sysPackage => {
        let p = Object.create(sysPackage.prototype) as IGBPackage;
        p.loadBot(min);
        e.sysPackages.push(p);
        if (sysPackage.name === "GBWhatsappPackage") {
          let url = "/instances/:botId/whatsapp";
          server.post(url, (req, res) => {
            p["channel"].received(req, res);
          });
        }
      }, this);
      e.loadBot(min);
    }, this);
  }

  /**
   * Bot Service hook method.
   */
  private receiver(
    adapter: BotFrameworkAdapter,
    req: any,
    res: any,
    conversationState: ConversationState,
    min: any,
    instance: any,
    appPackages: any[]
  ) {

    return adapter.processActivity(req, res, async context => {
      
      const state = conversationState.get(context);
      const dc = min.dialogs.createContext(context, state);
      dc.context.activity.locale = "en-US"; // TODO: Make dynamic.
      
      try {
        
        const user = min.userState.get(dc.context);

        if (!user.loaded) {
          await min.conversationalService.sendEvent(dc, "loadInstance", {
            instanceId: instance.instanceId,
            botId: instance.botId,
            theme: instance.theme,
            secret: instance.webchatKey
          });
          user.loaded = true;
          user.subjects = [];
        }

        logger.info(
          `User>: ${context.activity.text} (${context.activity.type}, ${
            context.activity.name
          }, ${context.activity.channelId}, {context.activity.value})`
        );
        if (
          context.activity.type === "conversationUpdate" &&
          context.activity.membersAdded.length > 0
        ) {
          let member = context.activity.membersAdded[0];
          if (member.name === "GeneralBots") {
            logger.info(`Bot added to conversation, starting chat...`);
            appPackages.forEach(e => {
              e.onNewSession(min, dc);
            });

            // Processes the root dialog.

            await dc.begin("/");
          } else {
            logger.info(`Member added to conversation: ${member.name}`);
          }

          // Processes messages.
        } else if (context.activity.type === "message") {
          // Checks for /admin request.

          if (context.activity.text === "admin") {
            await dc.begin("/admin");

            // Checks for /menu JSON signature.
          } else if (context.activity.text.startsWith('{"title"')) {
            await dc.begin("/menu", {
              data: JSON.parse(context.activity.text)
            });

            // Otherwise, continue to the active dialog in the stack.
          } else {
            if (dc.activeDialog) {
              await dc.continue();
            } else {
              await dc.begin("/answer", { query: context.activity.text });
            }
          }

          // Processes events.
        } else if (context.activity.type === "event") {
          // Empties dialog stack before going to the target.

          await dc.endAll();

          if (context.activity.name === "whoAmI") {
            await dc.begin("/whoAmI");
          } else if (context.activity.name === "showSubjects") {
            await dc.begin("/menu");
          } else if (context.activity.name === "giveFeedback") {
            await dc.begin("/feedback", {
              fromMenu: true
            });
          } else if (context.activity.name === "showFAQ") {
            await dc.begin("/faq");
          } else if (context.activity.name === "answerEvent") {
            await dc.begin("/answerEvent", {
              questionId: (context.activity as any).data,
              fromFaq: true
            });
          } else if (context.activity.name === "quality") {
            await dc.begin("/quality", {
              score: (context.activity as any).data
            });
          } else if (context.activity.name === "updateToken") {
            let token = (context.activity as any).data;
            await dc.begin("/adminUpdateToken", { token: token });
          } else {
            await dc.continue();
          }
        }
      } catch (error) {
          let msg = `ERROR: ${error.message} ${
            error.stack ? error.stack : ""
          }`;
          logger.error(msg);
          
          await dc.context.sendActivity(Messages[dc.context.activity.locale].very_sorry_about_error)
          await dc.begin("/ask", { isReturning: true });
          
      }
    });
  }

  /**
   * Get Webchat key from Bot Service.
   *
   * @param instance The Bot instance.
   *
   */
  async getWebchatToken(instance: any) {
    let options = {
      url: "https://directline.botframework.com/v3/directline/tokens/generate",
      method: "POST",
      headers: {
        Authorization: `Bearer ${instance.webchatKey}`
      }
    };

    try {
      let json = await request(options);
      return Promise.resolve(JSON.parse(json));
    } catch (error) {
      let msg = `Error calling Direct Line client, verify Bot endpoint on the cloud. Error is: ${error}.`;
      return Promise.reject(new Error(msg));
    }
  } 

  /**
   * Gets a Speech to Text / Text to Speech token from the provider.
   *
   * @param instance The general bot instance.
   *
   */
  async getSTSToken(instance: any) {
    // TODO: Make dynamic: https://CHANGE.api.cognitive.microsoft.com/sts/v1.0

    let options = {
      url: "https://westus.api.cognitive.microsoft.com/sts/v1.0/issueToken",
      method: "POST",
      headers: {
        "Ocp-Apim-Subscription-Key": instance.speechKey
      }
    };

    try {
      return await request(options);
    } catch (error) {
      let msg = `Error calling Speech to Text client. Error is: ${error}.`;
      return Promise.reject(new Error(msg));
    }
  }
}