Chatto/chatto/src/main/javascript/ts/src/model/ChatModelHelper.ts

import * as log from "loglevel";
import { ChatMessageDTO } from "../dto/ChatMessageDTO";
import { EncryptionService } from "../service/EncryptionService";
import { NotificationService } from "../service/NotificationService";
import { JsonAPI } from "../singleton/JsonAPI";
import { Sprintf } from "../singleton/Sprintf";
import { ChatMessageViewModel } from "../viewmodel/ChatMessageViewModel";
import { fetchErrorHandler } from "./FetchErrorHandler";

export class ChatModelHelper {
    private readonly _encryptionService: EncryptionService;
    private readonly _notificationService: NotificationService;


    constructor(encryptionService: EncryptionService, notificationService: NotificationService) {
        this._encryptionService = encryptionService;
        this._notificationService = notificationService;
    }


    public async getMessages(userName: string, passphrase: string, page: number | null, lastMessageTime: string | null, op: string): Promise<ChatMessageViewModel[]> {
        switch (lastMessageTime) {
            case null: {
                    const data: ChatMessageDTO[] = await this._getPaginatedMessagesAjax(userName, page!);
                    const cVMs = Promise.all(data.map(vm => this._toChatMessageVMAsync(vm, passphrase)).reverse());
                    return cVMs;
            }
            default: {
                const data: ChatMessageDTO[] = await this._getNewMessagesAjax(userName, lastMessageTime!);
                return data.map(vm => this._toChatMessageVM(vm, passphrase));
            }
        }
    }

    public async isPassphraseValid(passphrase: string, userName: string): Promise<boolean> {
        const messages: ChatMessageDTO[] = await this._getPaginatedMessagesAjax(userName, 0);
        if(messages.length === 0) return true;
        try {
            this._encryptionService.decrypt(passphrase, messages[0].messageCipher)
        } catch (error) {
            return false;
        }
        return true
    }

    private async _toChatMessageVMAsync(chatMessageDTO: ChatMessageDTO, passphrase: string): Promise<ChatMessageViewModel> {
        const vm = new ChatMessageViewModel();
        vm.fromUser = chatMessageDTO.fromUser;
        vm.toUser = chatMessageDTO.toUser;
        // vm.messageTime = chatMessageDTO.messageTime;
        chatMessageDTO.messageTime == null ? log.error("Message time somehow null") : vm.messageTime = chatMessageDTO.messageTime;
        vm.message = await this._encryptionService.decryptAsPromise(passphrase, chatMessageDTO.messageCipher);
        return vm;
    }

    private _toChatMessageVM(chatMessageDTO: ChatMessageDTO, passphrase: string): ChatMessageViewModel {
        const vm = new ChatMessageViewModel();
        vm.fromUser = chatMessageDTO.fromUser;
        vm.toUser = chatMessageDTO.toUser;
        // vm.messageTime = chatMessageDTO.messageTime;
        chatMessageDTO.messageTime == null ? log.error("Message time somehow null") : vm.messageTime = chatMessageDTO.messageTime;
        vm.message = this._encryptionService.decrypt(passphrase, chatMessageDTO.messageCipher) as string;
        return vm;
    }

    private async _getAllMessagesAjax(toUser: string): Promise<any> {
        const headers = new Headers();
        if (JsonAPI.authToken == null) {
            log.error("authToken null");
            return;
        };
        headers.append('X-AUTH-TOKEN', JsonAPI.authToken);
        const url = Sprintf(JsonAPI.CHAT_MESSAGES_GET, toUser);
        log.debug(url)
        const response = await fetch(url, {
            method: 'GET',
            headers: headers
        });
        log.debug(response.clone());
        if (fetchErrorHandler(response.clone(), this._notificationService)) {
            return null;
        }
        const data: Promise<any> = await response.json();
        return data;
    }

    private async _getPaginatedMessagesAjax(toUser: string, page: number): Promise<any> {
        const headers = new Headers();
        if (JsonAPI.authToken == null) {
            log.error("authToken null");
            return;
        };
        headers.append('X-AUTH-TOKEN', JsonAPI.authToken);
        const url = Sprintf(JsonAPI.CHAT_MESSAGE_PAGE_GET, toUser, page, 5);
        log.debug(url)
        const response = await fetch(url, {
            method: 'GET',
            headers: headers
        });
        log.debug(response.clone());
        if (fetchErrorHandler(response.clone(), this._notificationService)) {
            return null;
        }
        const data: Promise<any> = await response.json();
        return data;
    }

    private async _getNewMessagesAjax(toUser: string, lastMessageTimeStamp: string): Promise<any> {
        const headers = new Headers();
        if (JsonAPI.authToken == null) {
            log.error("authToken null");
            return;
        };
        headers.append('X-AUTH-TOKEN', JsonAPI.authToken);
        const response = await fetch(`${JsonAPI.CHAT_MESSAGES_GET}/${toUser}/${lastMessageTimeStamp}`, {
            method: 'GET',
            headers: headers
        });
        log.debug(response.clone());
        if (fetchErrorHandler(response.clone(), this._notificationService)) {
            return null;
        }
        const data: Promise<any> = await response.json();
        return data;
    }
}