1  package hlt;
 2  
 3  import java.util.ArrayList;
 4  import java.util.HashMap;
 5  import java.util.Map;
 6  
 7  public class Constants {
 8      /** The maximum amount of halite a ship can carry. */
 9      public static int MAX_HALITE;
10      /** The cost to build a single ship. */
11      public static int SHIP_COST;
12      /** The cost to build a dropoff. */
13      public static int DROPOFF_COST;
14      /** The maximum number of turns a game can last. */
15      public static int MAX_TURNS;
16      /** 1/EXTRACT_RATIO halite (rounded) is collected from a square per turn. */
17      public static int EXTRACT_RATIO;
18      /** 1/MOVE_COST_RATIO halite (rounded) is needed to move off a cell. */
19      public static int MOVE_COST_RATIO;
20      /** Whether inspiration is enabled. */
21      public static boolean INSPIRATION_ENABLED;
22      /** A ship is inspired if at least INSPIRATION_SHIP_COUNT opponent ships are within this Manhattan distance. */
23      public static int INSPIRATION_RADIUS;
24      /** A ship is inspired if at least this many opponent ships are within INSPIRATION_RADIUS distance. */
25      public static int INSPIRATION_SHIP_COUNT;
26      /** An inspired ship mines 1/X halite from a cell per turn instead. */
27      public static int INSPIRED_EXTRACT_RATIO;
28      /** An inspired ship that removes Y halite from a cell collects X*Y additional halite. */
29      public static double INSPIRED_BONUS_MULTIPLIER;
30      /** An inspired ship instead spends 1/X% halite to move. */
31      public static int INSPIRED_MOVE_COST_RATIO;
32  
33      public static void populateConstants(final String stringFromEngine) {
34          final String[] rawTokens = stringFromEngine.split("[{}, :\"]+");
35          final ArrayList<String> tokens = new ArrayList<>();
36          for (int i = 0; i < rawTokens.length; ++i) {
37              if (!rawTokens[i].isEmpty()) {
38                  tokens.add(rawTokens[i]);
39              }
40          }
41  
42          if ((tokens.size() % 2) != 0) {
43              Log.log("Error: constants: expected even total number of key and value tokens from server.");
44              throw new IllegalStateException();
45          }
46  
47          final Map<String, String> constantsMap = new HashMap<>();
48  
49          for (int i = 0; i < tokens.size(); i += 2) {
50              constantsMap.put(tokens.get(i), tokens.get(i+1));
51          }
52  
53          SHIP_COST = getInt(constantsMap, "NEW_ENTITY_ENERGY_COST");
54          DROPOFF_COST = getInt(constantsMap, "DROPOFF_COST");
55          MAX_HALITE = getInt(constantsMap, "MAX_ENERGY");
56          MAX_TURNS = getInt(constantsMap, "MAX_TURNS");
57          EXTRACT_RATIO = getInt(constantsMap, "EXTRACT_RATIO");
58          MOVE_COST_RATIO = getInt(constantsMap, "MOVE_COST_RATIO");
59          INSPIRATION_ENABLED = getBoolean(constantsMap, "INSPIRATION_ENABLED");
60          INSPIRATION_RADIUS = getInt(constantsMap, "INSPIRATION_RADIUS");
61          INSPIRATION_SHIP_COUNT = getInt(constantsMap, "INSPIRATION_SHIP_COUNT");
62          INSPIRED_EXTRACT_RATIO = getInt(constantsMap, "INSPIRED_EXTRACT_RATIO");
63          INSPIRED_BONUS_MULTIPLIER = getDouble(constantsMap, "INSPIRED_BONUS_MULTIPLIER");
64          INSPIRED_MOVE_COST_RATIO = getInt(constantsMap, "INSPIRED_MOVE_COST_RATIO");
65      }
66  
67      private static int getInt(final Map<String, String> map, final String key) {
68          return Integer.parseInt(getString(map, key));
69      }
70  
71      private static double getDouble(final Map<String, String> map, final String key) {
72          return Double.parseDouble(getString(map, key));
73      }
74  
75      private static boolean getBoolean(final Map<String, String> map, final String key) {
76          final String stringValue = getString(map, key);
77          switch (stringValue) {
78              case "true": return true;
79              case "false": return false;
80              default:
81                  Log.log("Error: constants: " + key + " constant has value of '" + stringValue +
82                      "' from server. Do not know how to parse that as boolean.");
83                  throw new IllegalStateException();
84          }
85      }
86  
87      private static String getString(final Map<String, String> map, final String key) {
88          if (!map.containsKey(key)) {
89              Log.log("Error: constants: server did not send " + key + " constant.");
90              throw new IllegalStateException();
91          }
92          return map.get(key);
93      }
94  }