add lastAccess and created

Signed-off-by: zhiqiand <zhiqian@fb.com>

src/main/java/com/facebook/openwifirrm/modules/ConfigManager.java

@@ -171,6 +171,7 @@ public class ConfigManager implements Runnable {
 				return;
 			}
 		}
+		client.refreshAccessToken();
 
 		// Fetch device list
 		List<DeviceWithStatus> devices = client.getDevices();

src/main/java/com/facebook/openwifirrm/modules/DataCollector.java

@@ -218,6 +218,7 @@ public class DataCollector implements Runnable {
 				return;
 			}
 		}
+		client.refreshAccessToken();
 
 		// Fetch device list
 		List<DeviceWithStatus> devices = client.getDevices();

src/main/java/com/facebook/openwifirrm/modules/Modeler.java

@@ -238,6 +238,7 @@ public class Modeler implements Runnable {
 				return;
 			}
 		}
+		client.refreshAccessToken();
 
 		// TODO: backfill data from database?
 

src/main/java/com/facebook/openwifirrm/modules/ProvMonitor.java

@@ -103,6 +103,7 @@ public class ProvMonitor implements Runnable {
 				return;
 			}
 		}
+		client.refreshAccessToken();
 
 		// Fetch data from owprov
 		// TODO: this may change later - for now, we only fetch inventory and

src/main/java/com/facebook/openwifirrm/ucentral/UCentralClient.java

@@ -8,6 +8,7 @@
 
 package com.facebook.openwifirrm.ucentral;
 
+import java.time.Instant;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -30,6 +31,8 @@ import com.facebook.openwifirrm.ucentral.gw.models.ServiceEvent;
 import com.facebook.openwifirrm.ucentral.gw.models.StatisticsRecords;
 import com.facebook.openwifirrm.ucentral.gw.models.SystemInfoResults;
 import com.facebook.openwifirrm.ucentral.gw.models.TokenValidationResult;
+import com.facebook.openwifirrm.ucentral.gw.models.WebTokenRefreshRequest;
+import com.facebook.openwifirrm.ucentral.gw.models.WebTokenResult;
 import com.facebook.openwifirrm.ucentral.gw.models.WifiScanRequest;
 import com.facebook.openwifirrm.ucentral.prov.models.EntityList;
 import com.facebook.openwifirrm.ucentral.prov.models.InventoryTagList;
@@ -137,7 +140,18 @@ public class UCentralClient {
 	 * The access token obtained from uCentralSec, needed only when using public
 	 * endpoints.
 	 */
-	private String accessToken;
+	private WebTokenResult accessToken;
+
+	/**
+	 * The unix timestamp (in seconds) keeps track of when the accessToken is created.
+	 */
+	private long created;
+
+	/**
+	 * The unix timestamp (in seconds) keeps track of last time when the accessToken 
+	 * is accessed.
+	 */
+	private long lastAccess;
 
 	/**
 	 * Constructor.
@@ -184,7 +198,8 @@ public class UCentralClient {
 		Map<String, Object> body = new HashMap<>();
 		body.put("userId", username);
 		body.put("password", password);
-		HttpResponse<String> response = httpPost("oauth2", OWSEC_SERVICE, body);
+		HttpResponse<String> response =
+			httpPost("oauth2", OWSEC_SERVICE, body, null);
 		if (!response.isSuccess()) {
 			logger.error(
 				"Login failed: Response code {}, body: {}",
@@ -195,27 +210,146 @@ public class UCentralClient {
 		}
 
 		// Parse access token from response
-		JSONObject respBody;
+		WebTokenResult token;
 		try {
-			respBody = new JSONObject(response.getBody());
-		} catch (JSONException e) {
+			token = gson.fromJson(response.getBody(), WebTokenResult.class);
+		} catch (JsonSyntaxException e) {
 			logger.error("Login failed: Unexpected response", e);
 			logger.debug("Response body: {}", response.getBody());
 			return false;
 		}
-		if (!respBody.has("access_token")) {
+		if (
+			token == null || token.access_token == null ||
+				token.access_token.isEmpty()
+		) {
 			logger.error("Login failed: Missing access token");
-			logger.debug("Response body: {}", respBody.toString());
+			logger.debug("Response body: {}", response.getBody());
 			return false;
 		}
-		this.accessToken = respBody.getString("access_token");
+		this.accessToken = token;
+		this.created = accessToken.created;
+		this.lastAccess = accessToken.created;
 		logger.info("Login successful as user: {}", username);
-		logger.debug("Access token: {}", accessToken);
+		logger.debug("Access token: {}", accessToken.access_token);
+		logger.debug("Refresh token: {}", accessToken.refresh_token);
 
 		// Load system endpoints
 		return loadSystemEndpoints();
 	}
 
+	/**
+	 * when using public endpoints, refresh the access token if it's expired.
+	 */
+	public synchronized void refreshAccessToken() {
+		if (usePublicEndpoints) {
+			refreshAccessTokenImpl();
+		}
+	}
+
+	/**
+	 * Check if the token is completely expired even if
+	 * for a token refresh request
+	 *
+	 * @return true if the refresh token is expired
+	 */
+	private boolean isAccessTokenExpired() {
+		if (accessToken == null) {
+			return true;
+		}
+		return created + accessToken.expires_in <
+			Instant.now().getEpochSecond();
+	}
+
+	/**
+	 * Check if an access token is expired.
+	 *
+	 * @return true if the access token is expired
+	 */
+	private boolean isAccessTokenTimedOut() {
+		if (accessToken == null) {
+			return true;
+		}
+		return lastAccess + accessToken.idle_timeout <
+			Instant.now().getEpochSecond();
+	}
+
+	/**
+	 * Refresh the access toke when time out. If the refresh token is expired, login again.
+	 * If the access token is expired, POST a WebTokenRefreshRequest to refresh token.
+	 */
+	private void refreshAccessTokenImpl() {
+		if (!usePublicEndpoints) {
+			return;
+		}
+		if (isAccessTokenExpired()) {
+			synchronized (this) {			
+				if (isAccessTokenExpired()) {
+					logger.info("Token is expired, login again");
+					login();
+				}
+			}
+		} else if (isAccessTokenTimedOut()) {
+			synchronized (this) {
+				if (isAccessTokenTimedOut()) {
+					logger.debug("Access token timed out, refreshing the token");
+					accessToken = refreshToken();
+					created = Instant.now().getEpochSecond();
+					lastAccess = created;
+					if (accessToken != null) {
+						logger.debug("Successfully refresh token.");
+					}else{
+						logger.error(
+							"Fail to refresh token with access token: {}",
+							accessToken.access_token
+						);
+					}
+				}
+			}
+		}
+	}
+
+	/**
+	 * POST a WebTokenRefreshRequest to refresh the access token.
+	 *
+	 * @return valid access token if success, otherwise return null.
+	 */
+	private WebTokenResult refreshToken() {
+		if (accessToken == null) {
+			return null;
+		}
+		WebTokenRefreshRequest refreshRequest = new WebTokenRefreshRequest();
+		refreshRequest.userId = username;
+		refreshRequest.refreshToken = accessToken.refresh_token;
+		logger.debug("refresh token: {}", accessToken.refresh_token);
+		Map<String, Object> parameters =
+			Collections.singletonMap("grant_type", "refresh_token");
+		HttpResponse<String> response =
+			httpPost(
+				"oauth2",
+				OWSEC_SERVICE,
+				refreshRequest,
+				parameters
+			);
+		if (!response.isSuccess()) {
+			logger.error(
+				"Failed to refresh token: Response code {}, body: {}",
+				response.getStatus(),
+				response.getBody()
+			);
+			return null;
+		}
+		try {
+			return gson.fromJson(response.getBody(), WebTokenResult.class);
+		} catch (JsonSyntaxException e) {
+			logger.error(
+				"Failed to serialize WebTokenResult: Unexpected response:",
+				e
+			);
+			logger.debug("Response body: {}", response.getBody());
+			return null;
+		}
+	}
+
 	/** Read system endpoint URLs from uCentralSec. */
 	private boolean loadSystemEndpoints() {
 		// Make request
@@ -324,8 +458,12 @@ public class UCentralClient {
 			.connectTimeout(connectTimeoutMs)
 			.socketTimeout(socketTimeoutMs);
 		if (usePublicEndpoints) {
-			if (accessToken != null) {
-				req.header("Authorization", "Bearer " + accessToken);
+			if (!isAccessTokenExpired()) {
+				req.header(
+					"Authorization",
+					"Bearer " + accessToken.access_token
+				);
+				lastAccess = Instant.now().getEpochSecond();
 			}
 		} else {
 			req
@@ -339,26 +477,29 @@ public class UCentralClient {
 		}
 	}
 
-	/** Send a POST request with a JSON body. */
+	/** Send a POST request with a JSON body and query params. */
 	private HttpResponse<String> httpPost(
 		String endpoint,
 		String service,
-		Object body
+		Object body,
+		Map<String, Object> parameters
 	) {
 		return httpPost(
 			endpoint,
 			service,
 			body,
+			parameters,
 			socketParams.connectTimeoutMs,
 			socketParams.socketTimeoutMs
 		);
 	}
 
-	/** Send a POST request with a JSON body using given timeout values. */
+	/** Send a POST request with a JSON body and query params using given timeout values. */
 	private HttpResponse<String> httpPost(
 		String endpoint,
 		String service,
 		Object body,
+		Map<String, Object> parameters,
 		int connectTimeoutMs,
 		int socketTimeoutMs
 	) {
@@ -367,9 +508,16 @@ public class UCentralClient {
 			.header("accept", "application/json")
 			.connectTimeout(connectTimeoutMs)
 			.socketTimeout(socketTimeoutMs);
+		if (parameters != null && !parameters.isEmpty()) {
+			req.queryString(parameters);
+		}
 		if (usePublicEndpoints) {
-			if (accessToken != null) {
-				req.header("Authorization", "Bearer " + accessToken);
+			if (!isAccessTokenExpired()) {
+				req.header(
+					"Authorization",
+					"Bearer " + accessToken.access_token
+				);
+				lastAccess = Instant.now().getEpochSecond();
 			}
 		} else {
 			req
@@ -454,6 +602,7 @@ public class UCentralClient {
 			String.format("device/%s/wifiscan", serialNumber),
 			OWGW_SERVICE,
 			req,
+			null,
 			socketParams.connectTimeoutMs,
 			socketParams.wifiScanTimeoutMs
 		);
@@ -482,7 +631,8 @@ public class UCentralClient {
 		HttpResponse<String> response = httpPost(
 			String.format("device/%s/configure", serialNumber),
 			OWGW_SERVICE,
-			req
+			req,
+			null
 		);
 		if (!response.isSuccess()) {
 			logger.error("Error: {}", response.getBody());

src/main/java/com/facebook/openwifirrm/ucentral/gw/models/WebTokenRefreshRequest.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.openwifirrm.ucentral.gw.models;
+
+public class WebTokenRefreshRequest {
+	public String userId;
+	public String refreshToken;
+}