services.ts

import { blockUI, blockUndo } from "./blockui";
import { Config } from "./config";
import { getjQuery } from "./environment";
import { ErrorHandling } from "./errorhandling";
import { RequestErrorInfo, ServiceOptions, ServiceResponse } from "./servicetypes";

export function resolveUrl(url: string) {
    if (url != null && url.charAt(0) == '~' && url.charAt(1) == '/')
        return Config.applicationPath + url.substring(2);
    return url;
}

export function resolveServiceUrl(url: string) {
    if (url && url.length && url.charAt(0) != '~' && url.charAt(0) != '/' && url.indexOf('://') < 0)
        return resolveUrl("~/Services/") + url;

    return resolveUrl(url);
}

export function getCookie(name: string) {
    let $ = getjQuery();
    if (typeof $?.cookie === "function")
        return $.cookie(name);

    name += '=';
    for (var ca = document.cookie.split(/;\s*/), i = ca.length - 1; i >= 0; i--)
        if (!ca[i].indexOf(name))
            return ca[i].replace(name, '');
}

export function isSameOrigin(url: string) {
    var loc = window.location,
        a = document.createElement('a');

    a.href = url;

    return a.hostname == loc.hostname &&
        a.port == loc.port &&
        a.protocol == loc.protocol;
}

function serviceOptions<TResponse>(url: string, options: ServiceOptions<TResponse>) {
    options = Object.assign(<ServiceOptions<TResponse>>{
        allowRedirect: true,
        async: true,
        blockUI: true,
        method: 'POST',
    }, options);

    options.headers ??= {};
    options.headers["Accept"] ??= "application/json";
    options.headers["Content-Type"] ??= "application/json";
    if (isSameOrigin(url)) {
        var token = getCookie('CSRF-TOKEN');
        if (token)
            options.headers["X-CSRF-TOKEN"] = token;
    }
    return options;
}

let activeRequests: number = 0;

export function requestStarting() {
    activeRequests++;
    let $ = getjQuery();
    if ($ && typeof $.active === "number") {
        ($.active++ === 0) && $.event?.trigger?.("ajaxStart");
    }
    else if (activeRequests === 1) {
        typeof document !== "undefined" && document.dispatchEvent(new Event("ajaxStart"));
    }
}

export function requestFinished() {
    activeRequests--;
    let $ = getjQuery();
    if ($ && typeof $.active === "number") {
        !(--$.active) && $.event?.trigger?.("ajaxStop");
    }
    else if (!activeRequests) {
        typeof document !== "undefined" && document.dispatchEvent(new Event("ajaxStop"));
    }
}

export function getActiveRequests() {
    return activeRequests;
}

function serviceFetch<TResponse extends ServiceResponse>(options: ServiceOptions<TResponse>): Promise<TResponse> {

    if (typeof fetch !== "function")
        return Promise.reject(reason("The fetch method is not available!", "fetch-missing"));

    return (async function () {

        let url = options.service ? resolveServiceUrl(options.service) : resolveUrl(options.url);
        options = serviceOptions(url, options);

        requestStarting();
        try {
            options.blockUI && blockUI();

            try {
                let {
                    allowRedirect: _1,
                    async: _2,
                    blockUI: _3,
                    request: _4,
                    service: _5,
                    url: _6,
                    onCleanup: _7,
                    onError: _8,
                    onSuccess: _9,
                    ...fetchInit
                } = options;

                fetchInit.body = JSON.stringify(options.request);

                var fetchResponse = await fetch(url, fetchInit);

                if (!fetchResponse.ok) {
                    await handleFetchError(fetchResponse, options);
                    return Promise.reject(reason(`Service fetch to '${url}' resulted in HTTP ${fetchResponse.status} error: ${fetchResponse.statusText}!`,
                        "http-error", { fetchResponse, url }));
                }

                let response = await fetchResponse.json() as TResponse;
                if (!response)
                    return Promise.reject(reason(`Received empty response from service fetch to '${url}'!`,
                        "empty-response", { fetchResponse, url }));

                if (response.Error) {
                    handleError(response ?? {}, { status: fetchResponse.status, statusText: fetchResponse.statusText }, options);
                    return Promise.reject(reason(`Service fetch to '${url}' resulted in error: ${response.Error.Message ?? response.Error.Code}!`,
                        "service-error", { response, fetchResponse, url }));
                }

                options.onSuccess?.(response);
                return response;
            }
            finally {
                options.blockUI && blockUndo();
                options.onCleanup && options.onCleanup();
            }
        }
        finally {
            requestFinished();
        }
    })();
}

function reason(message: string, kind: string, extra?: any) {
    var error: Error;
    if (extra?.cause != null) {
        error = (Error as any)(message, { cause: extra.cause });
    }
    else {
        error = Error(message);
    }
    if (kind != null) {
        (error as any).kind = kind;
    }
    (error as any).origin = "serviceCall";
    if (extra != null) {
        if ((error as any).cause)
            delete extra.cause;
        Object.assign(error, extra);
    }

    return error;
}

export function serviceCall<TResponse extends ServiceResponse>(options: ServiceOptions<TResponse>): PromiseLike<TResponse> {

    if (options?.async ?? true)
        return serviceFetch(options);

    let url: string;
    return new Promise((resolve, reject) => {
        try {
            url = options.service ? resolveServiceUrl(options.service) : resolveUrl(options.url);
            options = serviceOptions(url, options);

            var xhr = new XMLHttpRequest();
            xhr.open(options.method, url, false);

            if (options.cache == "no-store")
                options.headers["Cache-Control"] ??= "no-cache, no-store, max-age=0";
            else if (options.cache === "no-cache")
                options.headers["Cache-Control"] ??= "no-cache";

            for (var x in options.headers) {
                xhr.setRequestHeader(x, options.headers[x]);
            }

            requestStarting();
            try {
                if (options.signal) {
                    options.signal.addEventListener("abort", () => {
                        xhr.abort();
                    }, { once: true });
                }

                xhr.send(JSON.stringify(options.request));
                try {
                    if (xhr.status !== 200) {
                        handleXHRError(xhr, options);
                        return reject(reason(`HTTP ${xhr.status} error on service call to '${url}': ${xhr.statusText}!`,
                            "http-error", { status: xhr.status, statusText: xhr.statusText, url }));
                    }

                    let response = JSON.parse(xhr.responseText) as TResponse;
                    if (!response)
                        return reject(reason(`Empty response received on service call to '${url}'!`,
                            "empty-response", { url }));

                    if (response.Error) {
                        handleError(response, { status: xhr.status, statusText: xhr.statusText }, options);
                        return reject(reason(`Service call to '${url}' resulted in error: ${response.Error.Message ?? response.Error.Code}!`,
                            "service-error", { response, url }));
                    }

                    options.onSuccess?.(response);
                    return resolve(response);
                }
                finally {
                    options.blockUI && blockUndo();
                    options.onCleanup && options.onCleanup();
                }
            }
            finally {
                requestFinished();
            }
        }
        catch (exception) {
            reject(reason(`Service call to '${url}' thrown exception: ${exception.toString()}`, 
                "exception", { cause: exception, url }));
        }
    });
}

export function serviceRequest<TResponse extends ServiceResponse>(service: string, request?: any,
    onSuccess?: (response: TResponse) => void, options?: ServiceOptions<TResponse>): PromiseLike<TResponse> {
    return serviceCall(Object.assign({
        service: service,
        request: request,
        onSuccess: onSuccess
    }, options));
}

function handleError(response: any, errorInfo: RequestErrorInfo, options: ServiceOptions<any>) {

    if (Config.notLoggedInHandler != null &&
        response &&
        response.Error &&
        response.Error.Code == 'NotLoggedIn' &&
        Config.notLoggedInHandler(options, response)) {
        return;
    }

    if (options?.onError?.(response, errorInfo) ||
        options?.errorMode === 'none')
        return;

    ErrorHandling.showServiceError(response?.Error, errorInfo, options?.errorMode);
};

function handleRedirect(getHeader: (key: string) => string): boolean {
    var l: any = null;
    try {
        l = getHeader('Location');
    }
    catch ($t1) {
        l = null;
    }
    if (l) {
        window.top.location.href = l;
        return true;
    }
}

async function handleFetchError(response: Response, options: ServiceOptions<any>): Promise<void> {

    if (response.status === 403 && options.allowRedirect && handleRedirect(response.headers.get))
        return;

    if ((response.headers.get('content-type') || '').toLowerCase().indexOf('json') >= 0) {
        var json = (await response.json()) as ServiceResponse;
        if (json && json.Error) {
            handleError(json, {
                status: response.status,
                statusText: response.statusText
            }, options);
            return;
        }
    }

    handleError(null, {
        status: response.status,
        statusText: response.statusText,
        responseText: await response.text()
    }, options);
}

function handleXHRError(xhr: XMLHttpRequest, options: ServiceOptions<any>) {
    if (xhr.status === 403 && options.allowRedirect && handleRedirect(xhr.getResponseHeader))
        return;

    if ((xhr.getResponseHeader('content-type') || '')
        .toLowerCase().indexOf('application/json') >= 0) {
        var json = JSON.parse(xhr.responseText);
        if (json && json.Error) {
            handleError(json, { status: xhr.status, statusText: xhr.statusText }, options);
            return;
        }
    }

    handleError(null, { status: xhr.status, statusText: xhr.statusText, responseText: xhr.responseText }, options);
}