Various little nation improvements 🤖 (#3082)

## Description:

- Maybe greet nearby players with a 👋 emoji in the earlygame (make
nations feel a little bit more lively)
- Destroying a transport ship / capturing a trade ship of a nation now
updates the relation (mainly on higher difficulties)
- On hard difficulty: Only lift embargos if we have a friendly relation.
On impossible difficulty: Don't lift embargos
- Improve totalPlayers calculation and return value of
`hasTooManyAlliances` in `NationAllianceBehavior`

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

FloPinguin

src/core/execution/NationExecution.ts

@@ -360,7 +360,15 @@ export class NationExecution implements Execution {
         player.addEmbargo(other, false);
       } else if (
         player.relation(other) >= Relation.Neutral &&
-        player.hasEmbargoAgainst(other)
+        player.hasEmbargoAgainst(other) &&
+        this.mg.config().gameConfig().difficulty !== Difficulty.Hard &&
+        this.mg.config().gameConfig().difficulty !== Difficulty.Impossible
+      ) {
+        player.stopEmbargo(other);
+      } else if (
+        player.relation(other) >= Relation.Friendly &&
+        player.hasEmbargoAgainst(other) &&
+        this.mg.config().gameConfig().difficulty !== Difficulty.Impossible
       ) {
         player.stopEmbargo(other);
       }

src/core/execution/nation/NationAllianceBehavior.ts

@@ -143,10 +143,16 @@ export class NationAllianceBehavior {
       return false;
     }
 
-    const totalPlayers = this.game.players().length;
+    const totalPlayers = this.game
+      .players()
+      .filter((p) => p.type() !== PlayerType.Bot).length;
     const otherPlayerAlliances = otherPlayer.alliances().length;
 
-    return otherPlayerAlliances >= totalPlayers * 0.5;
+    if (difficulty !== Difficulty.Hard) {
+      return otherPlayerAlliances >= totalPlayers * 0.5;
+    } else {
+      return otherPlayerAlliances >= totalPlayers * 0.25;
+    }
   }
 
   private isConfused(): boolean {

src/core/execution/nation/NationEmojiBehavior.ts

@@ -42,6 +42,7 @@ export const EMOJI_BORED = (["🥱"] as const).map(emojiId);
 export const EMOJI_HANDSHAKE = (["🤝"] as const).map(emojiId);
 export const EMOJI_DONATION_OK = (["👍"] as const).map(emojiId);
 export const EMOJI_DONATION_TOO_SMALL = (["❓", "🥱"] as const).map(emojiId);
+export const EMOJI_GREET = (["👋"] as const).map(emojiId);
 
 export class NationEmojiBehavior {
   private readonly lastEmojiSent = new Map<Player, Tick>();
@@ -63,6 +64,7 @@ export class NationEmojiBehavior {
     this.charmAllies();
     this.annoyTraitors();
     this.findRat();
+    this.greetNearbyPlayers();
   }
 
   private checkOverwhelmedByAttacks(): void {
@@ -203,6 +205,22 @@ export class NationEmojiBehavior {
     this.sendEmoji(smallPlayer, EMOJI_RAT);
   }
 
+  private greetNearbyPlayers(): void {
+    if (this.game.ticks() > 600) return; // Only in the first minute
+    if (!this.random.chance(250)) return;
+
+    const nearbyHumans = this.player
+      .neighbors()
+      .filter(
+        (p): p is Player => p.isPlayer() && p.type() === PlayerType.Human,
+      );
+
+    if (nearbyHumans.length === 0) return;
+
+    const neighbor = this.random.randElement(nearbyHumans);
+    this.sendEmoji(neighbor, EMOJI_GREET);
+  }
+
   maybeSendEmoji(
     otherPlayer: Player | typeof AllPlayers,
     emojisList: number[],

src/core/execution/nation/NationWarshipBehavior.ts

@@ -99,7 +99,11 @@ export class NationWarshipBehavior {
       if (!ship.isActive()) {
         // Distinguish between arrival/retreat and enemy destruction
         if (ship.wasDestroyedByEnemy() && ship.destroyer() !== undefined) {
-          this.maybeRetaliateWithWarship(ship.tile(), ship.destroyer()!);
+          this.maybeRetaliateWithWarship(
+            ship.tile(),
+            ship.destroyer()!,
+            "transport",
+          );
         }
         this.trackedTransportShips.delete(ship);
       }
@@ -121,13 +125,17 @@ export class NationWarshipBehavior {
       }
       if (ship.owner().id() !== this.player.id()) {
         // Ship was ours and is now owned by someone else -> captured
-        this.maybeRetaliateWithWarship(ship.tile(), ship.owner());
+        this.maybeRetaliateWithWarship(ship.tile(), ship.owner(), "trade");
         this.trackedTradeShips.delete(ship);
       }
     }
   }
 
-  private maybeRetaliateWithWarship(tile: TileRef, enemy: Player): void {
+  private maybeRetaliateWithWarship(
+    tile: TileRef,
+    enemy: Player,
+    reason: "trade" | "transport",
+  ): void {
     // Don't send too many warships
     if (this.player.units(UnitType.Warship).length >= 10) {
       return;
@@ -148,6 +156,7 @@ export class NationWarshipBehavior {
         new ConstructionExecution(this.player, UnitType.Warship, tile),
       );
       this.emojiBehavior.maybeSendEmoji(enemy, EMOJI_WARSHIP_RETALIATION);
+      this.player.updateRelation(enemy, reason === "trade" ? -7.5 : -15);
     }
   }