/*
 * Copyright (C) 2022 Savoir-faire Linux Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this program.  If not, see
 * <https://www.gnu.org/licenses/>.
 */
import { AccountDetails, VolatileDetails } from 'jami-web-common';
import log from 'loglevel';
import { filter, firstValueFrom, map, Subject } from 'rxjs';
import { Service } from 'typedi';

import { JamiSignal } from './jami-signal.js';
import {
  AccountDetailsChanged,
  ConversationLoaded,
  ConversationReady,
  ConversationRemoved,
  IncomingAccountMessage,
  KnownDevicesChanged,
  MessageReceived,
  NameRegistrationEnded,
  RegisteredNameFound,
  RegistrationStateChanged,
  VolatileDetailsChanged,
} from './jami-signal-interfaces.js';
import { JamiSwig, StringMap, stringMapToRecord, stringVectToArray, vectMapToRecordArray } from './jami-swig.js';
import { require } from './utils.js';

// TODO: Mechanism to map account IDs to a list of WebSockets
// TODO: Convert Records to interfaces and replace them in common/ (e.g. Contact)

@Service()
export class Jamid {
  private readonly jamiSwig: JamiSwig;
  private readonly usernamesToAccountIds: Map<string, string>;
  private readonly events;

  constructor() {
    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
    this.jamiSwig = require('../../jamid.node') as JamiSwig; // TODO: we should put the path in the .env

    this.usernamesToAccountIds = new Map<string, string>();

    // Setup signal handlers
    const handlers: Record<string, unknown> = {};

    // Add default handler for all signals
    const createDefaultHandler = (signal: string) => {
      return (...args: unknown[]) => log.warn('Unhandled', signal, args);
    };
    for (const signal in JamiSignal) {
      handlers[signal] = createDefaultHandler(signal);
    }

    // Overwrite handlers for handled signals using RxJS Subjects, converting multiple arguments to objects
    const onAccountsChanged = new Subject<void>();
    handlers.AccountsChanged = () => onAccountsChanged.next();

    const onAccountDetailsChanged = new Subject<AccountDetailsChanged>();
    handlers.AccountDetailsChanged = (accountId: string, details: AccountDetails) =>
      onAccountDetailsChanged.next({ accountId, details });

    const onVolatileDetailsChanged = new Subject<VolatileDetailsChanged>();
    handlers.VolatileDetailsChanged = (accountId: string, details: VolatileDetails) =>
      onVolatileDetailsChanged.next({ accountId, details });

    const onRegistrationStateChanged = new Subject<RegistrationStateChanged>();
    handlers.RegistrationStateChanged = (accountId: string, state: string, code: number, details: string) =>
      onRegistrationStateChanged.next({ accountId, state, code, details });

    const onNameRegistrationEnded = new Subject<NameRegistrationEnded>();
    handlers.NameRegistrationEnded = (accountId: string, state: number, username: string) =>
      onNameRegistrationEnded.next({ accountId, state, username });

    const onRegisteredNameFound = new Subject<RegisteredNameFound>();
    handlers.RegisteredNameFound = (accountId: string, state: number, address: string, username: string) =>
      onRegisteredNameFound.next({ accountId, state, address, username });

    const onKnownDevicesChanged = new Subject<KnownDevicesChanged>();
    handlers.KnownDevicesChanged = (accountId: string, devices: Record<string, string>) =>
      onKnownDevicesChanged.next({ accountId, devices });

    const onIncomingAccountMessage = new Subject<IncomingAccountMessage>();
    handlers.IncomingAccountMessage = (accountId: string, from: string, message: Record<string, string>) =>
      onIncomingAccountMessage.next({ accountId, from, message });

    const onConversationReady = new Subject<ConversationReady>();
    handlers.ConversationReady = (accountId: string, conversationId: string) =>
      onConversationReady.next({ accountId, conversationId });

    const onConversationRemoved = new Subject<ConversationRemoved>();
    handlers.ConversationRemoved = (accountId: string, conversationId: string) =>
      onConversationRemoved.next({ accountId, conversationId });

    const onConversationLoaded = new Subject<ConversationLoaded>();
    handlers.ConversationLoaded = (
      id: number,
      accountId: string,
      conversationId: string,
      messages: Record<string, string>[]
    ) => onConversationLoaded.next({ id, accountId, conversationId, messages });

    const onMessageReceived = new Subject<MessageReceived>();
    handlers.MessageReceived = (accountId: string, conversationId: string, message: Record<string, string>) =>
      onMessageReceived.next({ accountId, conversationId, message });

    // Expose all signals in an events object to allow other handlers to subscribe after jamiSwig.init()
    this.events = {
      onAccountsChanged: onAccountsChanged.asObservable(),
      onAccountDetailsChanged: onAccountDetailsChanged.asObservable(),
      onVolatileDetailsChanged: onVolatileDetailsChanged.asObservable(),
      onRegistrationStateChanged: onRegistrationStateChanged.asObservable(),
      onNameRegistrationEnded: onNameRegistrationEnded.asObservable(),
      onRegisteredNameFound: onRegisteredNameFound.asObservable(),
      onKnownDevicesChanged: onKnownDevicesChanged.asObservable(),
      onIncomingAccountMessage: onIncomingAccountMessage.asObservable(),
      onConversationReady: onConversationReady.asObservable(),
      onConversationRemoved: onConversationRemoved.asObservable(),
      onConversationLoaded: onConversationLoaded.asObservable(),
      onMessageReceived: onMessageReceived.asObservable(),
    };

    this.setupSignalHandlers();

    // RxJS Subjects are used as signal handlers for the following reasons:
    // 1. You cannot change event handlers after calling jamiSwig.init()
    // 2. You cannot specify multiple handlers for the same event
    // 3. You cannot specify a default handler
    this.jamiSwig.init(handlers);
  }

  stop() {
    this.jamiSwig.fini();
  }

  getVolatileAccountDetails(accountId: string): VolatileDetails {
    return stringMapToRecord(this.jamiSwig.getVolatileAccountDetails(accountId)) as unknown as VolatileDetails;
  }

  getAccountDetails(accountId: string): AccountDetails {
    return stringMapToRecord(this.jamiSwig.getAccountDetails(accountId)) as unknown as AccountDetails;
  }

  setAccountDetails(accountId: string, accountDetails: AccountDetails) {
    const accountDetailsStringMap: StringMap = new this.jamiSwig.StringMap();
    for (const [key, value] of Object.entries(accountDetails)) {
      accountDetailsStringMap.set(key, value);
    }
    this.jamiSwig.setAccountDetails(accountId, accountDetailsStringMap);
  }

  async addAccount(details: Map<string, string | number | boolean>) {
    const detailsStringMap: StringMap = new this.jamiSwig.StringMap();

    detailsStringMap.set('Account.type', 'RING');
    for (const [key, value] of details.entries()) {
      detailsStringMap.set('Account.' + key, value.toString());
    }

    const accountId = this.jamiSwig.addAccount(detailsStringMap);
    return firstValueFrom(
      this.events.onRegistrationStateChanged.pipe(
        filter((value) => value.accountId === accountId),
        // TODO: is it the only state?
        // TODO: Replace with string enum in common/
        filter(({ state }) => state === 'REGISTERED')
      )
    );
  }

  removeAccount(accountId: string) {
    this.jamiSwig.removeAccount(accountId);
  }

  getAccountList(): string[] {
    return stringVectToArray(this.jamiSwig.getAccountList());
  }

  sendAccountTextMessage(accountId: string, contactId: string, type: string, message: string) {
    const messageStringMap: StringMap = new this.jamiSwig.StringMap();
    messageStringMap.set(type, message);
    this.jamiSwig.sendAccountTextMessage(accountId, contactId, messageStringMap);
  }

  async lookupUsername(username: string, accountId?: string) {
    const hasRingNs = this.jamiSwig.lookupName(accountId || '', '', username);
    if (!hasRingNs) {
      throw new Error('Jami does not have NS');
    }
    return firstValueFrom(
      this.events.onRegisteredNameFound.pipe(
        filter((value) => value.username === username),
        map(({ accountId: _, ...response }) => response) // Remove accountId from response
      )
    );
  }

  async lookupAddress(address: string, accountId?: string) {
    const hasRingNs = this.jamiSwig.lookupAddress(accountId || '', '', address);
    if (!hasRingNs) {
      throw new Error('Jami does not have NS');
    }
    return firstValueFrom(
      this.events.onRegisteredNameFound.pipe(
        filter((value) => value.address === address),
        map(({ accountId: _, ...response }) => response) // Remove accountId from response
      )
    );
  }

  async registerUsername(accountId: string, username: string, password: string) {
    const hasRingNs = this.jamiSwig.registerName(accountId, password, username);
    if (!hasRingNs) {
      throw new Error('Jami does not have NS');
    }
    return firstValueFrom(this.events.onNameRegistrationEnded.pipe(filter((value) => value.accountId === accountId)));
  }

  getDevices(accountId: string): Record<string, string> {
    return stringMapToRecord(this.jamiSwig.getKnownRingDevices(accountId));
  }

  addContact(accountId: string, contactId: string) {
    this.jamiSwig.addContact(accountId, contactId);
  }

  removeContact(accountId: string, contactId: string) {
    this.jamiSwig.removeContact(accountId, contactId, false);
  }

  blockContact(accountId: string, contactId: string) {
    this.jamiSwig.removeContact(accountId, contactId, true);
  }

  getContacts(accountId: string): Record<string, string>[] {
    return vectMapToRecordArray(this.jamiSwig.getContacts(accountId));
  }

  getContactDetails(accountId: string, contactId: string): Record<string, string> {
    return stringMapToRecord(this.jamiSwig.getContactDetails(accountId, contactId));
  }

  getDefaultModerators(accountId: string): string[] {
    return stringVectToArray(this.jamiSwig.getDefaultModerators(accountId));
  }

  // TODO: Ideally, we would fetch the username directly from Jami instead of
  // keeping an internal map.
  getAccountIdFromUsername(username: string): string | undefined {
    return this.usernamesToAccountIds.get(username);
  }

  private setupSignalHandlers() {
    this.events.onAccountsChanged.subscribe(() => {
      log.debug('Received AccountsChanged');
    });

    this.events.onAccountDetailsChanged.subscribe((signal) => {
      log.debug('Received AccountsDetailsChanged', JSON.stringify(signal));
    });

    this.events.onVolatileDetailsChanged.subscribe(({ accountId, details }) => {
      log.debug(`Received VolatileDetailsChanged: {"accountId":"${accountId}", ...}`);
      // Keep map of usernames to account IDs
      const username = details['Account.registeredName'];
      if (username) {
        this.usernamesToAccountIds.set(username, accountId);
      }
    });

    this.events.onRegistrationStateChanged.subscribe((signal) => {
      log.debug('Received RegistrationStateChanged:', JSON.stringify(signal));
    });

    this.events.onNameRegistrationEnded.subscribe((signal) => {
      log.debug('Received NameRegistrationEnded:', JSON.stringify(signal));
    });

    this.events.onRegisteredNameFound.subscribe((signal) => {
      log.debug('Received RegisteredNameFound:', JSON.stringify(signal));
    });

    this.events.onKnownDevicesChanged.subscribe(({ accountId }) => {
      log.debug(`Received KnownDevicesChanged: {"accountId":"${accountId}", ...}`);
    });

    this.events.onIncomingAccountMessage.subscribe((signal) => {
      log.debug('Received IncomingAccountMessage:', JSON.stringify(signal));
    });

    this.events.onConversationReady.subscribe((signal) => {
      log.debug('Received ConversationReady:', JSON.stringify(signal));
    });

    this.events.onConversationRemoved.subscribe((signal) => {
      log.debug('Received ConversationRemoved:', JSON.stringify(signal));
    });

    this.events.onConversationLoaded.subscribe((signal) => {
      log.debug('Received ConversationLoaded:', JSON.stringify(signal));
    });

    this.events.onMessageReceived.subscribe((signal) => {
      log.debug('Received MessageReceived:', JSON.stringify(signal));
      // TODO: Send message to client using WebSocket
    });
  }
}