feat: defer everything until the api config is loaded (#926)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/926
Reviewed-by: dpschen <dpschen@noreply.kolaente.de>
Co-authored-by: konrad <k@knt.li>
Co-committed-by: konrad <k@knt.li>

src/helpers/checkAndSetApiUrl.ts

@@ -0,0 +1,118 @@
+import {store} from '@/store'
+
+const API_DEFAULT_PORT = '3456'
+
+export const ERROR_NO_API_URL = 'noApiUrlProvided'
+
+const updateConfig = () => store.dispatch('config/update') 
+
+export const checkAndSetApiUrl = (url: string): Promise<string> => {
+	// Check if the url has an http prefix
+	if (
+		!url.startsWith('http://') &&
+		!url.startsWith('https://')
+	) {
+		url = `http://${url}`
+	}
+
+	const urlToCheck: URL = new URL(url)
+	const origUrlToCheck = urlToCheck
+
+	const oldUrl = window.API_URL
+	window.API_URL = urlToCheck.toString()
+
+	// Check if the api is reachable at the provided url
+	return updateConfig()
+		.catch(e => {
+			// Check if it is reachable at /api/v1 and http
+			if (
+				!urlToCheck.pathname.endsWith('/api/v1') &&
+				!urlToCheck.pathname.endsWith('/api/v1/')
+			) {
+				urlToCheck.pathname = `${urlToCheck.pathname}api/v1`
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it has a port and if not check if it is reachable at https
+			if (urlToCheck.protocol === 'http:') {
+				urlToCheck.protocol = 'https:'
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it is reachable at /api/v1 and https
+			urlToCheck.pathname = origUrlToCheck.pathname
+			if (
+				!urlToCheck.pathname.endsWith('/api/v1') &&
+				!urlToCheck.pathname.endsWith('/api/v1/')
+			) {
+				urlToCheck.pathname = `${urlToCheck.pathname}api/v1`
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it is reachable at port API_DEFAULT_PORT and https
+			if (urlToCheck.port !== API_DEFAULT_PORT) {
+				urlToCheck.protocol = 'https:'
+				urlToCheck.port = API_DEFAULT_PORT
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it is reachable at :API_DEFAULT_PORT and /api/v1 and https
+			urlToCheck.pathname = origUrlToCheck.pathname
+			if (
+				!urlToCheck.pathname.endsWith('/api/v1') &&
+				!urlToCheck.pathname.endsWith('/api/v1/')
+			) {
+				urlToCheck.pathname = `${urlToCheck.pathname}api/v1`
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it is reachable at port API_DEFAULT_PORT and http
+			if (urlToCheck.port !== API_DEFAULT_PORT) {
+				urlToCheck.protocol = 'http:'
+				urlToCheck.port = API_DEFAULT_PORT
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			// Check if it is reachable at :API_DEFAULT_PORT and /api/v1 and http
+			urlToCheck.pathname = origUrlToCheck.pathname
+			if (
+				!urlToCheck.pathname.endsWith('/api/v1') &&
+				!urlToCheck.pathname.endsWith('/api/v1/')
+			) {
+				urlToCheck.pathname = `${urlToCheck.pathname}api/v1`
+				window.API_URL = urlToCheck.toString()
+				return updateConfig()
+			}
+			throw e
+		})
+		.catch(e => {
+			window.API_URL = oldUrl
+			throw e
+		})
+		.then(r => {
+			if (typeof r !== 'undefined') {
+				localStorage.setItem('API_URL', window.API_URL)
+				return window.API_URL
+			}
+			
+			throw new Error(ERROR_NO_API_URL)
+		})
+}