package course;
import com.mongodb.DB;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import freemarker.template.Configuration;
import freemarker.template.SimpleHash;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import org.apache.commons.lang3.StringEscapeUtils;
import spark.Request;
import spark.Response;
import spark.Route;
import javax.servlet.http.Cookie;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import static spark.Spark.get;
import static spark.Spark.post;
import static spark.Spark.setPort;
/**
* This class encapsulates the controllers for the blog web application. It delegates all interaction with MongoDB
* to three Data Access Objects (DAOs).
* <p/>
* It is also the entry point into the web application.
*/
public class BlogController {
private final Configuration cfg;
private final BlogPostDAO blogPostDAO;
private final UserDAO userDAO;
private final SessionDAO sessionDAO;
public static void main(String[] args) throws IOException {
if (args.length == 0) {
new BlogController("mongodb://localhost");
}
else {
new BlogController(args[0]);
}
}
public BlogController(String mongoURIString) throws IOException {
final MongoClient mongoClient = new MongoClient(new MongoClientURI(mongoURIString));
final DB blogDatabase = mongoClient.getDB("blog");
blogPostDAO = new BlogPostDAO(blogDatabase);
userDAO = new UserDAO(blogDatabase);
sessionDAO = new SessionDAO(blogDatabase);
cfg = createFreemarkerConfiguration();
setPort(8082);
initializeRoutes();
}
abstract class FreemarkerBasedRoute extends Route {
final Template template;
/**
* Constructor
*
* @param path The route path which is used for matching. (e.g. /hello, users/:name)
*/
protected FreemarkerBasedRoute(final String path, final String templateName) throws IOException {
super(path);
template = cfg.getTemplate(templateName);
}
@Override
public Object handle(Request request, Response response) {
StringWriter writer = new StringWriter();
try {
doHandle(request, response, writer);
} catch (Exception e) {
e.printStackTrace();
response.redirect("/internal_error");
}
return writer;
}
protected abstract void doHandle(final Request request, final Response response, final Writer writer)
throws IOException, TemplateException;
}
private void initializeRoutes() throws IOException {
// this is the blog home page
get(new FreemarkerBasedRoute("/", "blog_template.ftl") {
@Override
public void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String username = sessionDAO.findUserNameBySessionId(getSessionCookie(request));
List<DBObject> posts = blogPostDAO.findByDateDescending(10);
SimpleHash root = new SimpleHash();
root.put("myposts", posts);
if (username != null) {
root.put("username", username);
}
template.process(root, writer);
}
});
// used to display actual blog post detail page
get(new FreemarkerBasedRoute("/post/:permalink", "entry_template.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String permalink = request.params(":permalink");
System.out.println("/post: get " + permalink);
DBObject post = blogPostDAO.findByPermalink(permalink);
if (post == null) {
response.redirect("/post_not_found");
}
else {
// empty comment to hold new comment in form at bottom of blog entry detail page
SimpleHash newComment = new SimpleHash();
newComment.put("name", "");
newComment.put("email", "");
newComment.put("body", "");
SimpleHash root = new SimpleHash();
root.put("post", post);
root.put("comment", newComment);
template.process(root, writer);
}
}
});
// handle the signup post
post(new FreemarkerBasedRoute("/signup", "signup.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String email = request.queryParams("email");
String username = request.queryParams("username");
String password = request.queryParams("password");
String verify = request.queryParams("verify");
HashMap<String, String> root = new HashMap<String, String>();
root.put("username", StringEscapeUtils.escapeHtml4(username));
root.put("email", StringEscapeUtils.escapeHtml4(email));
if (validateSignup(username, password, verify, email, root)) {
// good user
System.out.println("Signup: Creating user with: " + username + " " + password);
if (!userDAO.addUser(username, password, email)) {
// duplicate user
root.put("username_error", "Username already in use, Please choose another");
template.process(root, writer);
}
else {
// good user, let's start a session
String sessionID = sessionDAO.startSession(username);
System.out.println("Session ID is" + sessionID);
response.raw().addCookie(new Cookie("session", sessionID));
response.redirect("/welcome");
}
}
else {
// bad signup
System.out.println("User Registration did not validate");
template.process(root, writer);
}
}
});
// present signup form for blog
get(new FreemarkerBasedRoute("/signup", "signup.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer)
throws IOException, TemplateException {
SimpleHash root = new SimpleHash();
// initialize values for the form.
root.put("username", "");
root.put("password", "");
root.put("email", "");
root.put("password_error", "");
root.put("username_error", "");
root.put("email_error", "");
root.put("verify_error", "");
template.process(root, writer);
}
});
// will present the form used to process new blog posts
get(new FreemarkerBasedRoute("/newpost", "newpost_template.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
// get cookie
String username = sessionDAO.findUserNameBySessionId(getSessionCookie(request));
if (username == null) {
// looks like a bad request. user is not logged in
response.redirect("/login");
}
else {
SimpleHash root = new SimpleHash();
root.put("username", username);
template.process(root, writer);
}
}
});
// handle the new post submission
post(new FreemarkerBasedRoute("/newpost", "newpost_template.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer)
throws IOException, TemplateException {
String title = StringEscapeUtils.escapeHtml4(request.queryParams("subject"));
String post = StringEscapeUtils.escapeHtml4(request.queryParams("body"));
String tags = StringEscapeUtils.escapeHtml4(request.queryParams("tags"));
String username = sessionDAO.findUserNameBySessionId(getSessionCookie(request));
if (username == null) {
response.redirect("/login"); // only logged in users can post to blog
}
else if (title.equals("") || post.equals("")) {
// redisplay page with errors
HashMap<String, String> root = new HashMap<String, String>();
root.put("errors", "post must contain a title and blog entry.");
root.put("subject", title);
root.put("username", username);
root.put("tags", tags);
root.put("body", post);
template.process(root, writer);
}
else {
// extract tags
ArrayList<String> tagsArray = extractTags(tags);
// substitute some <p> for the paragraph breaks
post = post.replaceAll("\\r?\\n", "<p>");
String permalink = blogPostDAO.addPost(title, post, tagsArray, username);
// now redirect to the blog permalink
response.redirect("/post/" + permalink);
}
}
});
get(new FreemarkerBasedRoute("/welcome", "welcome.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String cookie = getSessionCookie(request);
String username = sessionDAO.findUserNameBySessionId(cookie);
if (username == null) {
System.out.println("welcome() can't identify the user, redirecting to signup");
response.redirect("/signup");
}
else {
SimpleHash root = new SimpleHash();
root.put("username", username);
template.process(root, writer);
}
}
});
// process a new comment
post(new FreemarkerBasedRoute("/newcomment", "entry_template.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer)
throws IOException, TemplateException {
String name = StringEscapeUtils.escapeHtml4(request.queryParams("commentName"));
String email = StringEscapeUtils.escapeHtml4(request.queryParams("commentEmail"));
String body = StringEscapeUtils.escapeHtml4(request.queryParams("commentBody"));
String permalink = request.queryParams("permalink");
DBObject post = blogPostDAO.findByPermalink(permalink);
if (post == null) {
response.redirect("/post_not_found");
}
// check that comment is good
else if (name.equals("") || body.equals("")) {
// bounce this back to the user for correction
SimpleHash root = new SimpleHash();
SimpleHash comment = new SimpleHash();
comment.put("name", name);
comment.put("email", email);
comment.put("body", body);
root.put("comment", comment);
root.put("post", post);
root.put("errors", "Post must contain your name and an actual comment");
template.process(root, writer);
}
else {
blogPostDAO.addPostComment(name, email, body, permalink);
response.redirect("/post/" + permalink);
}
}
});
// present the login page
get(new FreemarkerBasedRoute("/login", "login.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
SimpleHash root = new SimpleHash();
root.put("username", "");
root.put("login_error", "");
template.process(root, writer);
}
});
// process output coming from login form. On success redirect folks to the welcome page
// on failure, just return an error and let them try again.
post(new FreemarkerBasedRoute("/login", "login.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String username = request.queryParams("username");
String password = request.queryParams("password");
System.out.println("Login: User submitted: " + username + " " + password);
DBObject user = userDAO.validateLogin(username, password);
if (user != null) {
// valid user, let's log them in
String sessionID = sessionDAO.startSession(user.get("_id").toString());
if (sessionID == null) {
response.redirect("/internal_error");
}
else {
// set the cookie for the user's browser
response.raw().addCookie(new Cookie("session", sessionID));
response.redirect("/welcome");
}
}
else {
SimpleHash root = new SimpleHash();
root.put("username", StringEscapeUtils.escapeHtml4(username));
root.put("password", "");
root.put("login_error", "Invalid Login");
template.process(root, writer);
}
}
});
// tells the user that the URL is dead
get(new FreemarkerBasedRoute("/post_not_found", "post_not_found.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
SimpleHash root = new SimpleHash();
template.process(root, writer);
}
});
// allows the user to logout of the blog
get(new FreemarkerBasedRoute("/logout", "signup.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
String sessionID = getSessionCookie(request);
if (sessionID == null) {
// no session to end
response.redirect("/login");
}
else {
// deletes from session table
sessionDAO.endSession(sessionID);
// this should delete the cookie
Cookie c = getSessionCookieActual(request);
c.setMaxAge(0);
response.raw().addCookie(c);
response.redirect("/login");
}
}
});
// used to process internal errors
get(new FreemarkerBasedRoute("/internal_error", "error_template.ftl") {
@Override
protected void doHandle(Request request, Response response, Writer writer) throws IOException, TemplateException {
SimpleHash root = new SimpleHash();
root.put("error", "System has encountered an error.");
template.process(root, writer);
}
});
}
// helper function to get session cookie as string
private String getSessionCookie(final Request request) {
if (request.raw().getCookies() == null) {
return null;
}
for (Cookie cookie : request.raw().getCookies()) {
if (cookie.getName().equals("session")) {
return cookie.getValue();
}
}
return null;
}
// helper function to get session cookie as string
private Cookie getSessionCookieActual(final Request request) {
if (request.raw().getCookies() == null) {
return null;
}
for (Cookie cookie : request.raw().getCookies()) {
if (cookie.getName().equals("session")) {
return cookie;
}
}
return null;
}
// tags the tags string and put it into an array
private ArrayList<String> extractTags(String tags) {
// probably more efficent ways to do this.
//
// whitespace = re.compile('\s')
tags = tags.replaceAll("\\s", "");
String tagArray[] = tags.split(",");
// let's clean it up, removing the empty string and removing dups
ArrayList<String> cleaned = new ArrayList<String>();
for (String tag : tagArray) {
if (!tag.equals("") && !cleaned.contains(tag)) {
cleaned.add(tag);
}
}
return cleaned;
}
// validates that the registration form has been filled out right and username conforms
public boolean validateSignup(String username, String password, String verify, String email,
HashMap<String, String> errors) {
String USER_RE = "^[a-zA-Z0-9_-]{3,20}$";
String PASS_RE = "^.{3,20}$";
String EMAIL_RE = "^[\\S]+@[\\S]+\\.[\\S]+$";
errors.put("username_error", "");
errors.put("password_error", "");
errors.put("verify_error", "");
errors.put("email_error", "");
if (!username.matches(USER_RE)) {
errors.put("username_error", "invalid username. try just letters and numbers");
return false;
}
if (!password.matches(PASS_RE)) {
errors.put("password_error", "invalid password.");
return false;
}
if (!password.equals(verify)) {
errors.put("verify_error", "password must match");
return false;
}
if (!email.equals("")) {
if (!email.matches(EMAIL_RE)) {
errors.put("email_error", "Invalid Email Address");
return false;
}
}
return true;
}
private Configuration createFreemarkerConfiguration() {
Configuration retVal = new Configuration();
retVal.setClassForTemplateLoading(BlogController.class, "/freemarker");
return retVal;
}
}