import * as DOMPurify from 'dompurify';
import * as log from 'loglevel';
import { ChatMessageDTO } from "../dto/ChatMessageDTO";
import { MessageCipherDTO } from "../dto/MessageCipherDTO";
import { ChatModel } from "../model/ChatModel";
import { Observer } from "../observe/Observer";
import { EncryptionService } from "../service/EncryptionService";
import { MarkDownService } from "../service/MarkDownService";
import { JsonAPI } from "../singleton/JsonAPI";
import { ChatMessageViewModel } from "../viewmodel/ChatMessageViewModel";
import { ChatViewDeps } from "./ChatViewDeps";
import { fetchHandler } from "./FetchHandler";
import { ObserverData } from '../observe/ObserverData';
import { NotificationService } from '../service/NotificationService';

export class ChatView implements Observer<ChatMessageViewModel> {
    private readonly _chatModel: ChatModel;
    private readonly _messageContainer: HTMLElement;
    private readonly _messageSendTemplate: Handlebars.TemplateDelegate<ChatMessageViewModel>;
    private readonly _messageReceiveTemplate: Handlebars.TemplateDelegate<ChatMessageViewModel>;
    private readonly _markdownService: MarkDownService;
    private readonly _encryptionService: EncryptionService;
    private readonly _notificationService: NotificationService;


    constructor(deps: ChatViewDeps) {
        this._messageContainer = deps.messageContainer;
        this._chatModel = deps.chatModel;
        this._messageSendTemplate = deps.messageSendTemplate;
        this._messageReceiveTemplate = deps.messageReceiveTemplate;
        this._markdownService = deps.markdownService;
        this._encryptionService = deps.encryptionService;
        this._notificationService = deps.notificationService;
        this._initEventListeners();

        $(document).ready(function () {
            $('#action_menu_btn').click(function () {
                $('.action_menu').toggle();
            });
        });

        this._chatMessagePageLoadAjax();
    }

    update(cd: ObserverData<ChatMessageViewModel>): void {
        log.info('ChatView: updating view');

        switch (cd.op) {
            case "clear": {
                $(this._messageContainer).html("");
            } break;
            case "new": {
                const rev: ChatMessageViewModel[] = Object.create(cd.data)
                // rev.reverse();
                let arr: string[] = [];
                rev.forEach((vm: ChatMessageViewModel) => {
                    const vmTemp: ChatMessageViewModel = { ...vm };
                    vmTemp.message = this._markdownService.render(vm.message);
                    /** Very Important!!!
                    * Sanitizing HTML before displaying on webpage to prevent XSS attacks!!
                    */
                    let rendered;
                    if (vmTemp.fromUser == JsonAPI.principleName) {
                        rendered = DOMPurify.sanitize(this._messageSendTemplate(vmTemp));

                    }
                    else {
                        rendered = DOMPurify.sanitize(this._messageReceiveTemplate(vmTemp));
                    }
                    $(this._messageContainer).append(rendered);
                });
                $(this._messageContainer).stop().animate({
                    scrollTop: $(this._messageContainer)[0].scrollHeight
                }, 1500);
            } break;
            default: {
                const rev: ChatMessageViewModel[] = Object.create(cd.data)
                rev.reverse();
                let arr: string[] = [];
                rev.forEach((vm: ChatMessageViewModel) => {
                    const vmTemp: ChatMessageViewModel = { ...vm };
                    vmTemp.message = this._markdownService.render(vm.message);
                    /** Very Important!!!
                    * Sanitizing HTML before displaying on webpage to prevent XSS attacks!!
                    */
                    let rendered;
                    if (vmTemp.fromUser == JsonAPI.principleName) {
                        rendered = DOMPurify.sanitize(this._messageSendTemplate(vmTemp));

                    }
                    else {
                        rendered = DOMPurify.sanitize(this._messageReceiveTemplate(vmTemp));
                    }
                    $(this._messageContainer).prepend(rendered);
                });
            }
        }

    }

    private _initEventListeners(): void {
        this._addChatFormEL();
    }

    private _addChatFormEL() {
        const chatForm = document.getElementById('chatMessageForm') as HTMLSelectElement;

        if (chatForm == null) {
            log.error("Chat form is null");
        }
        else {
            chatForm.addEventListener('submit', (e) => this._createChatMessageDTO(e, chatForm))

        }

    }

    private _createChatMessageDTO(e: Event, chatForm: HTMLSelectElement): void {
        e.preventDefault();

        let contactName = JsonAPI.contactName;

        if (contactName == null) {
            log.error("Contact name is null");
            return;
        }

        if (!chatForm.checkValidity()) {
            log.error("Form is not valid");
            chatForm.classList.add('was-validated');
            return;
        }
        chatForm.classList.add('was-validated');


        const chatInput = document.getElementById('chatInput') as HTMLInputElement;
        const passphraseInput = document.getElementById('passphrase') as HTMLInputElement;

        if (chatInput.value == '' || chatInput.value == null) {
            this._notificationService.error("Please enter a message");
            log.error("Chat input is null.");
            return;
        }

        if (passphraseInput.value == '' || passphraseInput.value == null) {
            this._notificationService.error("Please enter a passphrase");
            log.error("Passphrase is null.");
            return;
        }

        const messageContent = chatInput.value;
        const msgTime = new Date();
        const context: ChatMessageViewModel = {
            fromUser: JsonAPI.principleName || "error", 
            toUser: "",
            message: messageContent,
            messageTime: msgTime
        };

        this.update({data: new Array(context), op: "new"})

        let messageCipher: MessageCipherDTO = this._encryptionService.encrypt(passphraseInput.value, messageContent)
        let chatMessageDTO = {
            "fromUser": JsonAPI.principleName || "",
            "toUser": contactName,
            "messageCipher": messageCipher,
            messageTime: msgTime
        }
        this._sendMessageAJAX(chatMessageDTO);
    }

    private _sendMessageAJAX(chatMessageDTO: ChatMessageDTO): void {
        let headers = new Headers();
        //	console.log("Token = " + btoa("hmm" + ":" + "hmm"))

        // headers.append('Accept','application/json')
        headers.append('Content-Type', 'application/json');
        // headers.append('Authorization', basicAuthToken);
        // @ts-ignore
        headers.append('X-AUTH-TOKEN', JsonAPI.authToken);
        fetch(JsonAPI.MESSAGE_POST, {
            method: 'POST',
            headers: headers,
            body: JSON.stringify(chatMessageDTO)
        })
            .then(response => {
                log.debug(response);
                return response.clone();
            })
            .then(response => fetchHandler(response, this._notificationService));

    }

    private _chatMessagePageLoadAjax() {
        this._messageContainer.addEventListener('scroll', (e) => {
            if ($(this._messageContainer).scrollTop() == 0 && $(this._messageContainer).html() != "") {
                let currentMsg = $('.msg:first');
                log.debug('Reached top')
                let passphrase: string;
                let passphraseInput = document.getElementById('passphrase') as HTMLInputElement;

                if (passphraseInput == null) {
                    log.error('passphraseInput element reference is null');
                    return;
                }
                passphrase = passphraseInput.value
                if (passphrase == '' || passphrase == null) {
                    // alert('Please input passphrase')
                    // alertify.error('Please enter a passphrase');
                    log.error('passphrase is empty or null');
                    return;
                }
                if (JsonAPI.contactName != null)
                    this._chatModel.getMessages(JsonAPI.contactName, passphrase, null, "page").then(() => {
                        if (currentMsg != null) {
                            // log.debug(currentMsg.offset()!.top)
                            $(this._messageContainer).scrollTop(currentMsg.position().top - $('.msg').position()!.top)
                        }
                    });
            }
        })
    }
}