1 files changed, 111 insertions, 1 deletions

diff --git a/src/ch/epfl/xblast/server/GameState.java b/src/ch/epfl/xblast/server/GameState.java
index 5386311..522a367 100644
--- a/src/ch/epfl/xblast/server/GameState.java
+++ b/src/ch/epfl/xblast/server/GameState.java
@@ -295,7 +295,36 @@ public final class GameState {
      * @return the next game state
      */
     public GameState next(Map<PlayerID, Optional<Direction>> speedChangeEvents, Set<PlayerID> bombDropEvents) {
-        return null; // TODO
+        // 1. blasts evolution
+        List<Sq<Cell>> blasts1 = GameState.nextBlasts(this.blasts, this.board, this.explosions);
+
+        // 2. board evolution
+        Set<Cell> blastedCells1 = GameState.blastedCells(blasts1);
+        Map<Cell, PlayerID> consumedBonuses = this.consumedBonuses();
+        Board board1 = GameState.nextBoard(this.board, consumedBonuses.keySet(), blastedCells1);
+
+        // 3. existing explosions evolution
+        List<Sq<Sq<Cell>>> explosions1 = GameState.nextExplosions(this.explosions);
+
+        // 4.1. existing bombs evolution
+        Set<Cell> blastedCells0 = this.blastedCells();
+        List<Bomb> explodingBombs = this.filterExplodingBombs(this.bombs, blastedCells0);
+        List<Bomb> bombs = this.bombs.stream().filter(b -> !explodingBombs.contains(b)).collect(Collectors.toList());
+
+        // 4.2. subsequent explosions addition
+        explodingBombs.forEach(b -> explosions1.addAll(b.explosion()));
+
+        // 4.3. newly dropped bombs addition
+        Set<PlayerID> topPriorityBombDropEvents = discardConflictingBombDropEvents(bombDropEvents);
+        bombs.addAll(GameState.newlyDroppedBombs(this.players, topPriorityBombDropEvents, this.bombs));
+
+        // 5. players evolution
+        Map<PlayerID, Bonus> playerBonuses = mapPlayersToBonuses(consumedBonuses);
+        Set<Cell> bombedCells1 = GameState.bombedCells(bombs).keySet();
+        List<Player> players1 = GameState.nextPlayers(
+                this.players, playerBonuses, bombedCells1, board1, blastedCells1, speedChangeEvents);
+
+        return new GameState(this.ticks, board1, players1, bombs, explosions1, blasts1);
     }
 
     /**
@@ -324,4 +353,85 @@ public final class GameState {
                 .get();
     }
 
+    /**
+     * Returns a mapping of players from their location.
+     *
+     * @param players a list of players to map
+     * @return the location->player mapping
+     */
+    private Map<Cell, List<PlayerID>> mapPlayersCells(List<Player> players) {
+        return players.stream()
+                .collect(
+                        Collectors.groupingBy(p -> p.position().containingCell(),
+                                Collectors.mapping(Player::id, Collectors.toList())));
+    }
+
+    /**
+     * Returns a mapping of top-priority player from their location.
+     * Conflicts are resolved using the current turn's players priority order.
+     *
+     * @param players a list of players to map
+     * @return the location->top-priority player mapping
+     */
+    private Map<Cell, PlayerID> mapTopPriorityPlayerCells(List<Player> players) {
+        return this.mapPlayersCells(players).entrySet().stream()
+                .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        e -> resolveConflict(e.getValue())));
+    }
+
+    /**
+     * Returns a mapping of location of consumed bonuses and their top-priority claimant.
+     *
+     * @return the bonus-location->player mapping
+     */
+    private Map<Cell, PlayerID> consumedBonuses() {
+        return this.mapTopPriorityPlayerCells(
+                this.alivePlayers().stream()
+                        .filter(p -> p.position().isCentral())
+                        .filter(p -> this.board.blockAt(p.position().containingCell()).isBonus())
+                        .collect(Collectors.toList()));
+    }
+
+    /**
+     * Returns a mapping of players and their newly acquired bonus.
+     *
+     * @param consumedBonuses a mapping of bonus location and their claimants
+     * @return the player->bonus mapping
+     */
+    private Map<PlayerID, Bonus> mapPlayersToBonuses(Map<Cell, PlayerID> consumedBonuses) {
+        return consumedBonuses.entrySet().stream()
+                .collect(Collectors.toMap(
+                        Map.Entry::getValue,
+                        e -> this.board.blockAt(e.getKey()).associatedBonus()));
+    }
+
+    /**
+     * Returns a conflict-free set a player bomb dropping events.
+     *
+     * @param bombDropEvents the bomb drop events to filter
+     * @return the conflict-free set of bomb drop events
+     */
+    private Set<PlayerID> discardConflictingBombDropEvents(Set<PlayerID> bombDropEvents) {
+        return EnumSet.copyOf(
+                this.mapTopPriorityPlayerCells(
+                        this.alivePlayers().stream()
+                                .filter(bombDropEvents::contains)
+                                .collect(Collectors.toList())
+                ).values());
+    }
+
+    /**
+     * Returns a list of exploding bombs (reached by a blast or consumed fuse).
+     *
+     * @param bombs        the list of bombs
+     * @param blastedCells the set of blasted cells
+     * @return the list of exploding bombs
+     */
+    private List<Bomb> filterExplodingBombs(List<Bomb> bombs, Set<Cell> blastedCells) {
+        return bombs.stream()
+                .filter(b -> blastedCells.contains(b.position()) || b.fuseLength() == 0)
+                .collect(Collectors.toList());
+    }
+
 }