port spawns on coast

src/core/execution/PortExecution.ts

@@ -1,4 +1,6 @@
-import { AllPlayers, Cell, Execution, MutableGame, MutablePlayer, PlayerID, UnitType } from "../game/Game";
+import { BuildValidator } from "../game/BuildValidator";
+import { AllPlayers, BuildItem, BuildItems, Cell, Execution, MutableGame, MutablePlayer, PlayerID, UnitType } from "../game/Game";
+import { bfs, dist, manhattanDist } from "../Util";
 
 export class PortExecution implements Execution {
 
@@ -18,7 +20,23 @@ export class PortExecution implements Execution {
     }
 
     tick(ticks: number): void {
-        this.player.addUnit(UnitType.Port, 0, this.mg.tile(this.cell))
+        const tile = this.mg.tile(this.cell)
+        if (!new BuildValidator(this.mg).canBuild(this.player, tile, BuildItems.Port)) {
+            console.warn(`player ${this.player} cannot build port at ${this.cell}`)
+            this.active = false
+            return
+        }
+        const spawns = Array.from(bfs(tile, dist(tile, 20)))
+            .filter(t => t.isOceanShore() && t.owner() == this.player)
+            .sort((a, b) => manhattanDist(a.cell(), tile.cell()) - manhattanDist(b.cell(), tile.cell()))
+
+        if (spawns.length == 0) {
+            console.warn(`cannot find spawn for port`)
+            this.active = false
+            return
+        }
+
+        this.player.addUnit(UnitType.Port, 0, spawns[0])
         this.active = false
     }