Make app function.

js/auth.js

@@ -0,0 +1,53 @@
+function auth_url () {
+	let params = [
+		`client_id=${this.auth.client_id}`,
+		`response_type=token`,
+		`redirect_uri=${encodeURIComponent(this.auth.redirect)}`,
+		`scope=${encodeURIComponent(this.auth.scopes.join(" "))}`,
+		`show_dialog=${this.auth.show_dialog}`
+	];
+
+	// Create the state data if we are using it
+	if (this.auth.use_state) {
+		let state = Math.random().toString(36).substring(2, 15) + Math.random().toString(36).substring(2, 15);
+		params.push(`state=${state}`);
+		localStorage.setItem(`top-spotify-state`, state);
+	};
+
+	return `${this.auth.base_url}?${params.join("&")}`;
+};
+
+
+function verify_auth () {
+	let params = new URLSearchParams(window.location.hash.slice(1));
+
+	// Check to ensure the authorization was a success
+	if (params.get(`access_token`)) {
+		this.get_user()
+
+		// Check if we compare state
+		if (this.use_state) {
+
+			// Compare given state to localstorage state
+			let LS_state = localStorage.getItem(`top-spotify-state`);
+			if (LS_state = params.get(`state`)) {
+				console.info(`State compare success`)
+				this.authed = true;
+				return true
+			}
+			console.error(`State compare failed`)
+			return false
+		} else {
+			return true
+		}
+	} else {
+		let error = (new URLSearchParams(window.location.search)).get(`error`)
+
+		// Authorization failed, error to the user
+		if (error !== null) {
+			this.error.auth = `Authentication failed or was cancelled, please try again.`;
+			window.location.hash = ``;
+		}
+		return false;
+	}
+}