SPIGOT-355: API for Villager careers

By: Senmori <thesenmori@gmail.com>

paper-api/src/main/java/org/bukkit/entity/Villager.java

@@ -1,5 +1,9 @@
 package org.bukkit.entity;
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.LinkedListMultimap;
+import com.google.common.collect.Multimap;
+import java.util.List;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryHolder;
 import org.bukkit.inventory.Merchant;
@@ -23,6 +27,34 @@ public interface Villager extends Ageable, NPC, InventoryHolder, Merchant {
      */
     public void setProfession(Profession profession);
 
+    /**
+     * Get the current {@link Career} for this Villager.
+     *
+     * @return the {@link Career}
+     */
+    public Career getCareer();
+
+    /**
+     * Set the new {@link Career} for this Villager.
+     * This method will reset the villager's trades to the new career.
+     *
+     * @param career the new career, or null to clear the career to a random one
+     * @throws IllegalArgumentException when the new {@link Career} cannot be
+     * used with this Villager's current {@link Profession}.
+     */
+    public void setCareer(Career career);
+
+    /**
+     * Set the new {@link Career} for this Villager.
+     *
+     * @param career the new career, or null to clear the career to a random one
+     * @param resetTrades true to reset this Villager's trades to the new
+     * career's (if any)
+     * @throws IllegalArgumentException when the new {@link Career} cannot be
+     * used with this Villager's current {@link Profession}.
+     */
+    public void setCareer(Career career, boolean resetTrades);
+
     /**
      * Gets this villager's inventory.
      * <br>
@@ -108,5 +140,125 @@ public interface Villager extends Ageable, NPC, InventoryHolder, Merchant {
         public boolean isZombie() {
             return zombie;
         }
+
+        /**
+         * Get an immutable list of {@link Career} belonging to this Profession.
+         *
+         * @return an immutable list of careers for this profession, or an empty
+         * map if this Profession has no careers.
+         */
+        public List<Career> getCareers() {
+            return Career.getCareers(this);
+        }
+    }
+
+    /**
+     * The Career of this Villager.
+     * Each {@link Profession} has a set of careers it is applicable to. Each
+     * career dictates the trading options that are generated.
+     */
+    public enum Career {
+        /*
+        NOTE: The Career entries are order-specific. They should be maintained in the numerical order they are used in the CB implementation.
+        (e.g. Farmer careers are 1,2,3,4 so Career should reflect that numerical order in their ordinal status)
+         */
+        // Farmer careers
+        /**
+         * Farmers primarily trade for food-related items.
+         */
+        FARMER(Profession.FARMER),
+        /**
+         * Fisherman primarily trade for fish, as well as possibly selling
+         * string and/or coal.
+         */
+        FISHERMAN(Profession.FARMER),
+        /**
+         * Shepherds primarily trade for wool items, and shears.
+         */
+        SHEPHERD(Profession.FARMER),
+        /**
+         * Fletchers primarily trade for string, bows, and arrows.
+         */
+        FLETCHER(Profession.FARMER),
+        // Librarian careers
+        /**
+         * Librarians primarily trade for paper, books, and enchanted books.
+         */
+        LIBRARIAN(Profession.LIBRARIAN),
+        /**
+         * Cartographers primarily trade for explorer maps and some paper.
+         */
+        CARTOGRAPHER(Profession.LIBRARIAN),
+        // Priest careers
+        /**
+         * Clerics primarily trade for rotten flesh, gold ingot, redstone,
+         * lapis, ender pearl, glowstone, and bottle o' enchanting.
+         */
+        CLERIC(Profession.PRIEST),
+        // Blacksmith careers
+        /**
+         * Armorers primarily trade for iron armor, chainmail armor, and
+         * sometimes diamond armor.
+         */
+        ARMORER(Profession.BLACKSMITH),
+        /**
+         * Weapon smiths primarily trade for iron and diamond weapons, sometimes
+         * enchanted.
+         */
+        WEAPON_SMITH(Profession.BLACKSMITH),
+        /**
+         * Tool smiths primarily trade for iron and diamond tools.
+         */
+        TOOL_SMITH(Profession.BLACKSMITH),
+        // Butcher careers
+        /**
+         * Butchers primarily trade for raw and cooked food.
+         */
+        BUTCHER(Profession.BUTCHER),
+        /**
+         * Leatherworkers primarily trade for leather, and leather armor, as
+         * well as saddles.
+         */
+        LEATHERWORKER(Profession.BUTCHER),
+        // Nitwit
+        /**
+         * Nitwit villagers do not do anything. They do not have any trades by
+         * default.
+         */
+        NITWIT(Profession.NITWIT);
+
+        private static final Multimap<Profession, Career> careerMap = LinkedListMultimap.create();
+        private final Profession profession;
+
+        private Career(Profession profession) {
+            this.profession = profession;
+        }
+
+        /**
+         * Get the {@link Profession} this {@link Career} belongs to.
+         *
+         * @return the {@link Profession}.
+         */
+        public Profession getProfession() {
+            return profession;
+        }
+
+        /**
+         * Get an immutable list of {@link Career}s that can be used with a
+         * given {@link Profession}
+         * 
+         * @param profession the profession to get careers for
+         * @return an immutable list of Careers that can be used by a
+         * profession, or an empty map if the profession was not found
+         */
+        public static List<Career> getCareers(Profession profession) {
+            return careerMap.containsKey(profession) ? ImmutableList.copyOf(careerMap.get(profession)) : ImmutableList.<Career>of();
+        }
+
+        static {
+            for (Career career : Career.values()) {
+                careerMap.put(career.profession, career);
+            }
+        }
     }
 }