ApiController.java

/**
 * Copyright 2010-2016 Ralph Schaer <ralphschaer@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package ch.ralscha.extdirectspring.controller;

import java.io.IOException;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.util.NumberUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import ch.ralscha.extdirectspring.bean.api.PollingProvider;
import ch.ralscha.extdirectspring.bean.api.RemotingApi;
import ch.ralscha.extdirectspring.bean.api.RemotingApiMixin;
import ch.ralscha.extdirectspring.util.ApiCache;
import ch.ralscha.extdirectspring.util.ApiCacheKey;
import ch.ralscha.extdirectspring.util.ExtDirectSpringUtil;
import ch.ralscha.extdirectspring.util.JsonHandler;
import ch.ralscha.extdirectspring.util.MethodInfo;
import ch.ralscha.extdirectspring.util.MethodInfoCache;

/**
 * Spring managed controller that handles /api.jsp, /api-debug.js, /api-debug-doc.js and
 * /api-{fingerprinted}.js requests.
 */
@Controller
public class ApiController {

	private final ConfigurationService configurationService;

	private final MethodInfoCache methodInfoCache;

	private final ApiCache apiCache;

	private final ObjectMapper objectMapper;

	@Autowired
	public ApiController(ConfigurationService configurationService,
			MethodInfoCache methodInfoCache, ApiCache apiCache) {
		this.configurationService = configurationService;
		this.methodInfoCache = methodInfoCache;
		this.apiCache = apiCache;
		this.objectMapper = new ObjectMapper();
	}

	/**
	 * Method that handles api.js and api-debug.js calls. Generates a javascript with the
	 * necessary code for Ext Direct.
	 *
	 * @param apiNs name of the namespace the variable remotingApiVar will live in.
	 * Defaults to Ext.app
	 * @param actionNs name of the namespace the action will live in.
	 * @param remotingApiVar name of the remoting api variable. Defaults to REMOTING_API
	 * @param pollingUrlsVar name of the polling urls object. Defaults to POLLING_URLS
	 * @param group name of the api group. Multiple groups delimited with comma
	 * @param fullRouterUrl if true the router property contains the full request URL with
	 * method, server and port. Defaults to false returns only the URL without method,
	 * server and port
	 * @param format only valid value is "json2. Ext Designer sends this parameter and the
	 * response is a JSON. Defaults to null and response is Javascript.
	 * @param baseRouterUrl Sets the path to the router and poll controllers. If set
	 * overrides default behavior that uses request.getRequestURI
	 * @param request the HTTP servlet request
	 * @param response the HTTP servlet response
	 * @throws IOException
	 */
	@SuppressWarnings({ "resource" })
	@RequestMapping(value = { "/api.js", "/api-debug.js", "/api-debug-doc.js" },
			method = RequestMethod.GET)
	public void api(@RequestParam(value = "apiNs", required = false) String apiNs,
			@RequestParam(value = "actionNs", required = false) String actionNs,
			@RequestParam(value = "remotingApiVar",
					required = false) String remotingApiVar,
			@RequestParam(value = "pollingUrlsVar",
					required = false) String pollingUrlsVar,
			@RequestParam(value = "group", required = false) String group,
			@RequestParam(value = "fullRouterUrl",
					required = false) Boolean fullRouterUrl,
			@RequestParam(value = "format", required = false) String format,
			@RequestParam(value = "baseRouterUrl", required = false) String baseRouterUrl,
			HttpServletRequest request, HttpServletResponse response) throws IOException {

		if (format == null) {
			response.setContentType(
					this.configurationService.getConfiguration().getJsContentType());
			response.setCharacterEncoding(ExtDirectSpringUtil.UTF8_CHARSET.name());

			String apiString = buildAndCacheApiString(apiNs, actionNs, remotingApiVar,
					pollingUrlsVar, group, fullRouterUrl, baseRouterUrl, request);

			byte[] outputBytes = apiString.getBytes(ExtDirectSpringUtil.UTF8_CHARSET);
			response.setContentLength(outputBytes.length);

			ServletOutputStream outputStream = response.getOutputStream();
			outputStream.write(outputBytes);
			outputStream.flush();
		}
		else {
			response.setContentType(RouterController.APPLICATION_JSON.toString());
			response.setCharacterEncoding(
					RouterController.APPLICATION_JSON.getCharset().name());

			String requestUrlString = request.getRequestURL().toString();

			boolean debug = requestUrlString.contains("api-debug.js");
			String routerUrl = requestUrlString.replaceFirst("api[^/]*?\\.js", "router");

			String apiString = buildApiJson(apiNs, actionNs, remotingApiVar, routerUrl,
					group, debug);
			byte[] outputBytes = apiString.getBytes(ExtDirectSpringUtil.UTF8_CHARSET);
			response.setContentLength(outputBytes.length);

			ServletOutputStream outputStream = response.getOutputStream();
			outputStream.write(outputBytes);
			outputStream.flush();
		}
	}

	/**
	 * Method that handles fingerprinted api.js calls (i.e.
	 * http://server/.../api-1.0.1.js). Generates a javascript with the necessary code for
	 * Ext Direct.
	 *
	 * @param apiNs name of the namespace the variable remotingApiVar will live in.
	 * Defaults to Ext.app
	 * @param actionNs name of the namespace the action will live in.
	 * @param remotingApiVar name of the remoting api variable. Defaults to REMOTING_API
	 * @param pollingUrlsVar name of the polling urls object. Defaults to POLLING_URLS
	 * @param group name of the api group. Multiple groups delimited with comma
	 * @param fullRouterUrl if true the router property contains the full URL with
	 * protocol, server name, port number, and server path. Defaults to false returns only
	 * the URL with server path
	 * @param baseRouterUrl Sets the path to the router and poll controllers. If set
	 * overrides default behavior that uses request.getRequestURI
	 * @param request the HTTP servlet request
	 * @param response the HTTP servlet response
	 * @throws IOException
	 */

	@RequestMapping(value = "/api-{fingerprint}.js", method = RequestMethod.GET)
	public void api(@RequestParam(value = "apiNs", required = false) String apiNs,
			@RequestParam(value = "actionNs", required = false) String actionNs,
			@RequestParam(value = "remotingApiVar",
					required = false) String remotingApiVar,
			@RequestParam(value = "pollingUrlsVar",
					required = false) String pollingUrlsVar,
			@RequestParam(value = "group", required = false) String group,
			@RequestParam(value = "fullRouterUrl",
					required = false) Boolean fullRouterUrl,
			@RequestParam(value = "baseRouterUrl", required = false) String baseRouterUrl,
			HttpServletRequest request, HttpServletResponse response) throws IOException {

		String apiString = buildAndCacheApiString(apiNs, actionNs, remotingApiVar,
				pollingUrlsVar, group, fullRouterUrl, baseRouterUrl, request);

		byte[] outputBytes = apiString.getBytes(ExtDirectSpringUtil.UTF8_CHARSET);
		ExtDirectSpringUtil.handleCacheableResponse(request, response, outputBytes,
				this.configurationService.getConfiguration().getJsContentType());
	}

	private String buildAndCacheApiString(String requestApiNs, String requestActionNs,
			String requestRemotingApiVar, String requestPollingUrlsVar, String group,
			Boolean requestFullRouterUrl, String requestBaseRouterUrl,
			HttpServletRequest request) {

		Configuration configuration = this.configurationService.getConfiguration();
		String apiNs = requestApiNs != null ? requestApiNs : configuration.getApiNs();
		String remotingApiVar = requestRemotingApiVar != null ? requestRemotingApiVar
				: configuration.getRemotingApiVar();
		String pollingUrlsVar = requestPollingUrlsVar != null ? requestPollingUrlsVar
				: configuration.getPollingUrlsVar();
		boolean fullRouterUrl = requestFullRouterUrl != null ? requestFullRouterUrl
				: configuration.isFullRouterUrl();
		String actionNs = requestActionNs != null ? requestActionNs
				: configuration.getActionNs();
		String baseRouterUrl = requestBaseRouterUrl != null ? requestBaseRouterUrl
				: configuration.getBaseRouterUrl();

		String requestUrlString;

		if (baseRouterUrl != null) {
			requestUrlString = baseRouterUrl + (baseRouterUrl.endsWith("/") ? "" : "/");
		}
		else if (fullRouterUrl) {
			requestUrlString = request.getRequestURL().toString();
		}
		else {
			requestUrlString = request.getRequestURI();
		}
		String stripApiRegex = "api[^/]*?\\.js";
		String routerUrl = requestUrlString.replaceFirst(stripApiRegex, "") + "router";
		String basePollUrl = requestUrlString.replaceFirst(stripApiRegex, "") + "poll";

		if (!requestUrlString.contains("/api-debug-doc.js")) {
			boolean debug = requestUrlString.contains("api-debug.js");

			ApiCacheKey apiKey = new ApiCacheKey(apiNs, actionNs, remotingApiVar,
					pollingUrlsVar, routerUrl, group, debug);
			String apiString = this.apiCache.get(apiKey);
			if (apiString == null) {
				apiString = buildApiString(apiNs, actionNs, remotingApiVar,
						pollingUrlsVar, routerUrl, basePollUrl, group, debug, false);
				this.apiCache.put(apiKey, apiString);
			}
			return apiString;
		}

		return buildApiString(apiNs, actionNs, remotingApiVar, pollingUrlsVar, routerUrl,
				basePollUrl, group, true, true);

	}

	private String buildApiString(String apiNs, String actionNs, String remotingApiVar,
			String pollingUrlsVar, String routerUrl, String basePollUrl, String group,
			boolean debug, boolean doc) {

		RemotingApi remotingApi = new RemotingApi(
				this.configurationService.getConfiguration().getProviderType(), routerUrl,
				actionNs);

		remotingApi.setTimeout(this.configurationService.getConfiguration().getTimeout());
		remotingApi.setMaxRetries(
				this.configurationService.getConfiguration().getMaxRetries());

		Object enableBuffer = this.configurationService.getConfiguration()
				.getEnableBuffer();
		if (enableBuffer instanceof String
				&& StringUtils.hasText((String) enableBuffer)) {
			String enableBufferString = (String) enableBuffer;
			if (enableBufferString.equalsIgnoreCase("true")) {
				remotingApi.setEnableBuffer(Boolean.TRUE);
			}
			else if (enableBufferString.equalsIgnoreCase("false")) {
				remotingApi.setEnableBuffer(Boolean.FALSE);
			}
			else {
				Integer enableBufferMs = NumberUtils.parseNumber(enableBufferString,
						Integer.class);
				remotingApi.setEnableBuffer(enableBufferMs);
			}
		}
		else if (enableBuffer instanceof Number || enableBuffer instanceof Boolean) {
			remotingApi.setEnableBuffer(enableBuffer);
		}

		if (this.configurationService.getConfiguration().getBufferLimit() != null) {
			remotingApi.setBufferLimit(
					this.configurationService.getConfiguration().getBufferLimit());
		}

		buildRemotingApi(remotingApi, group);

		StringBuilder sb = new StringBuilder();

		if (StringUtils.hasText(apiNs)) {
			sb.append("Ext.ns('");
			sb.append(apiNs);
			sb.append("');");
		}

		if (debug) {
			sb.append("\n\n");
		}

		if (StringUtils.hasText(actionNs)) {
			sb.append("Ext.ns('");
			sb.append(actionNs);
			sb.append("');");

			if (debug) {
				sb.append("\n\n");
			}
		}

		String jsonConfig;
		if (!doc) {
			jsonConfig = writeValueAsString(remotingApi, debug);
		}
		else {
			ObjectMapper mapper = new ObjectMapper();
			mapper.addMixIn(RemotingApi.class, RemotingApiMixin.class);
			try {
				jsonConfig = mapper.writer().withDefaultPrettyPrinter()
						.writeValueAsString(remotingApi);
			}
			catch (JsonProcessingException e) {
				jsonConfig = null;
				LogFactory.getLog(ApiController.class).info("serialize object to json",
						e);
			}
		}

		if (StringUtils.hasText(apiNs)) {
			sb.append(apiNs).append(".");
		}
		sb.append(remotingApiVar).append(" = ");
		sb.append(jsonConfig);
		sb.append(";");

		List<PollingProvider> pollingProviders = remotingApi.getPollingProviders();
		if (!pollingProviders.isEmpty()) {

			if (debug) {
				sb.append("\n\n");
			}

			if (StringUtils.hasText(apiNs)) {
				sb.append(apiNs).append(".");
			}
			sb.append(pollingUrlsVar).append(" = {");
			if (debug) {
				sb.append("\n");
			}

			for (int i = 0; i < pollingProviders.size(); i++) {
				if (debug) {
					sb.append("  ");
				}

				sb.append("\"");
				sb.append(pollingProviders.get(i).getEvent());
				sb.append("\"");
				sb.append(" : \"").append(basePollUrl).append("/");
				sb.append(pollingProviders.get(i).getBeanName());
				sb.append("/");
				sb.append(pollingProviders.get(i).getMethod());
				sb.append("/");
				sb.append(pollingProviders.get(i).getEvent());
				sb.append("\"");
				if (i < pollingProviders.size() - 1) {
					sb.append(",");
					if (debug) {
						sb.append("\n");
					}
				}
			}
			if (debug) {
				sb.append("\n");
			}
			sb.append("};");
		}

		return sb.toString();
	}

	private String buildApiJson(String requestApiNs, String requestActionNs,
			String requestRemotingApiVar, String routerUrl, String group, boolean debug) {

		Configuration configuration = this.configurationService.getConfiguration();
		String apiNs = requestApiNs != null ? requestApiNs : configuration.getApiNs();

		String remotingApiVar = requestRemotingApiVar != null ? requestRemotingApiVar
				: configuration.getRemotingApiVar();

		String actionNs = requestActionNs != null ? requestActionNs
				: configuration.getActionNs();

		RemotingApi remotingApi = new RemotingApi(
				this.configurationService.getConfiguration().getProviderType(), routerUrl,
				actionNs);

		if (StringUtils.hasText(apiNs)) {
			remotingApi.setDescriptor(apiNs + "." + remotingApiVar);
		}
		else {
			remotingApi.setDescriptor(remotingApiVar);
		}

		buildRemotingApi(remotingApi, group);

		return writeValueAsString(remotingApi, debug);

	}

	private void buildRemotingApi(RemotingApi remotingApi, String requestedGroup) {
		String group = requestedGroup != null ? requestedGroup.trim() : requestedGroup;
		for (Map.Entry<MethodInfoCache.Key, MethodInfo> entry : this.methodInfoCache) {
			MethodInfo methodInfo = entry.getValue();
			if (isSameGroup(group, methodInfo.getGroup())) {
				if (methodInfo.getAction() != null) {
					remotingApi.addAction(entry.getKey().getBeanName(),
							methodInfo.getAction());
				}
				else if (methodInfo.getPollingProvider() != null) {
					remotingApi.addPollingProvider(methodInfo.getPollingProvider());
				}
			}
		}
	}

	private static boolean isSameGroup(String requestedGroups, String annotationGroups) {
		if (requestedGroups != null) {
			if (!requestedGroups.isEmpty() && annotationGroups != null
					&& !annotationGroups.isEmpty()) {
				for (String requestedGroup : requestedGroups.split(",")) {
					for (String annotationGroup : annotationGroups.split(",")) {
						if (ExtDirectSpringUtil.equal(requestedGroup, annotationGroup)) {
							return true;
						}
					}
				}
			}
			else if (requestedGroups.isEmpty()
					&& (annotationGroups == null || annotationGroups.trim().isEmpty())) {
				return true;
			}
			return false;
		}

		return true;
	}

	private String writeValueAsString(Object obj, boolean indent) {
		try {
			if (indent) {
				return this.objectMapper.writer().withDefaultPrettyPrinter()
						.writeValueAsString(obj);
			}
			return this.objectMapper.writeValueAsString(obj);
		}
		catch (Exception e) {
			LogFactory.getLog(JsonHandler.class).info("serialize object to json", e);
			return null;
		}
	}

}