package com.google.sps.servlets;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Given a tweet or sentence, the servlet will extract salient terms from those
 * and store them in a list.
 */
@WebServlet("/keyword")
public class KeywordServlet extends HttpServlet {

  private static final List<String> tweets = new ArrayList<>();
  private static final List<String> terms = Arrays.asList("Black Lives Matter", "COVID-19");

  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    // TODO: Extract saliency
    String json = mustacheJsonBuilder(terms);
    response.getWriter().println(json);
  }

  @Override
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
    final String tweet = request.getParameter("keyword-sentence");
    if (tweet != null && !tweet.equals("")) {
      tweets.add(request.getParameter("keyword-sentence"));
    }
    response.sendRedirect("/index.html");
  }

  /**
   * Generates and returns a JSON usable by Mustache.
   */
  private String mustacheJsonBuilder(Collection<String> toJson) {
    String builder = "{\"keywords\": [";
    for (String term : toJson) {
      builder += "{\"term\": \"" + term + "\"},";
    }

    // Remove extra comma at the end.
    builder = builder.substring(0, builder.length() - 1) + "]}";
    return builder;
  }

}


@@ -413,19 +413,8 @@
 erms
- from those
 %0A * 
@@ -816,16 +816,17 @@
 saliency
+.
 %0A    Str
@@ -1474,39 +1474,50 @@
  += 
-%22%7B%5C%22term%5C%22: %5C%22%22 + term + %22%5C%22%7D,%22
+String.format(%22%7B%5C%22term%5C%22: %5C%22%25s%5C%22%7D,%22, term)
 ;%0A  
@@ -1648,12 +1648,11 @@
 er;%0A  %7D%0A
-%0A
 %7D%0A%0A

Fix nits, switch to String.format for building Json