1 files changed, 121 insertions, 0 deletions
diff --git a/code/app/src/lib/api/_fetch.ts b/code/app/src/lib/api/_fetch.ts
new file mode 100644
index 0000000..b28e398
--- /dev/null
+++ b/code/app/src/lib/api/_fetch.ts
@@ -0,0 +1,121 @@
+import { Temporal } from "temporal-polyfill";
+import { clear_session_data } from "$lib/session";
+import type { Result } from "rustic";
+import { Err, Ok } from "rustic";
+import { redirect } from "@sveltejs/kit";
+import { browser } from "$app/environment";
+import { goto } from "$app/navigation";
+import { SignInPageMessage, signInPageMessageQueryKey } from "$routes/(main)/(public)/sign-in";
+import { log_error } from "$lib/logger";
+
+export async function http_post_async<T>(url: string, body?: object | string, timeout = -1, skip_401_check = false, abort_signal?: AbortSignal): Promise<InternalFetchResponse<T>> {
+    const init = make_request_init("post", body, abort_signal);
+    const response = await internal_fetch_async({ url, init, timeout });
+    if (!skip_401_check && await redirect_if_401_async(response)) return Err("Server returned 401");
+    return make_response_async(response);
+}
+
+export async function http_get_async<T>(url: string, timeout = -1, skip_401_check = false, abort_signal?: AbortSignal): Promise<Result<InternalFetchResponse<T>, string>> {
+    const init = make_request_init("get", undefined, abort_signal);
+    const response = await internal_fetch_async({ url, init, timeout });
+    if (!skip_401_check && await redirect_if_401_async(response)) return Err("Server returned 401");
+    return make_response_async(response);
+}
+
+export async function http_delete_async<T>(url: string, body?: object | string, timeout = -1, skip_401_check = false, abort_signal?: AbortSignal): Promise<Result<InternalFetchResponse<T>, string>> {
+    const init = make_request_init("delete", body, abort_signal);
+    const response = await internal_fetch_async({ url, init, timeout });
+    if (!skip_401_check && await redirect_if_401_async(response)) return Err("Server returned 401");
+    return make_response_async(response);
+}
+
+async function internal_fetch_async(request: InternalFetchRequest): Promise<Response> {
+    if (!request.init) throw new Error("request.init is required");
+    const fetch_request = new Request(request.url, request.init);
+    let response: any;
+
+    try {
+        if (request.timeout && request.timeout > 500) {
+            response = await Promise.race([
+                fetch(fetch_request),
+                new Promise((_, reject) => setTimeout(() => reject(new Error("Timeout")), request.timeout))
+            ]);
+        } else {
+            response = await fetch(fetch_request);
+        }
+    } catch (error: any) {
+        log_error(error);
+        if (error.message === "Timeout") {
+            console.error("Request timed out");
+        } else if (error.message === "Network request failed") {
+            console.error("No internet connection");
+        } else {
+            throw error;
+        }
+    }
+
+    return response;
+}
+
+async function redirect_if_401_async(response: Response): Promise<boolean> {
+    if (response.status === 401) {
+        const redirectUrl = `/sign-in?${signInPageMessageQueryKey}=${SignInPageMessage.LOGGED_OUT}`;
+        clear_session_data();
+        if (browser) {
+            await goto(redirectUrl)
+        } else {
+            throw redirect(307, redirectUrl);
+        }
+    }
+    return false;
+}
+
+async function make_response_async<T>(response: Response): Promise<Result<InternalFetchResponse<T>, string>> {
+    const result = {
+        ok: response.ok,
+        status: response.status,
+        http_response: response,
+    } as InternalFetchResponse<T>;
+
+    if (response.status !== 204) {
+        try {
+            result.data = await response.json() as T;
+        } catch (error) {
+            log_error("", { error, result })
+            return Err("Deserialisation threw");
+        }
+    }
+    return Ok(result);
+}
+
+function make_request_init(method: string, body?: any, signal?: AbortSignal): RequestInit {
+    const init = {
+        method,
+        signal,
+        headers: {
+            "X-TimeZone": Temporal.Now.timeZone().id,
+        }
+    } as RequestInit;
+
+    if (body) {
+        init.body = JSON.stringify(body);
+        init.headers["Content-Type"] = "application/json;charset=UTF-8"
+    }
+
+    return init;
+}
+
+
+export type InternalFetchRequest = {
+    url: string,
+    init: RequestInit,
+    timeout?: number
+    retry_count?: number,
+}
+
+export type InternalFetchResponse<T> = {
+    ok: boolean,
+    status: number,
+    data: T | undefined,
+    http_response: Response
+}
+\ No newline at end of file