Complete instant diplomacy response parity

packages/logic/src/diplomacy/frontState.ts

@@ -0,0 +1,84 @@
+export interface FrontStateCity {
+    id: number;
+    nationId: number;
+    frontState: number;
+}
+
+export interface FrontStateDiplomacy {
+    fromNationId: number;
+    toNationId: number;
+    state: number;
+    term: number;
+}
+
+const collectAdjacentCities = (
+    cityIds: number[],
+    connections: ReadonlyMap<number, readonly number[]>,
+    bucket: Set<number>
+): void => {
+    for (const cityId of cityIds) {
+        for (const neighborId of connections.get(cityId) ?? []) {
+            bucket.add(neighborId);
+        }
+    }
+};
+
+export const buildNationFrontStatePatches = (options: {
+    cities: FrontStateCity[];
+    diplomacy: FrontStateDiplomacy[];
+    connections: ReadonlyMap<number, readonly number[]>;
+    nationIds: number[];
+}): Array<{ id: number; frontState: number }> => {
+    const cityIdsByNation = new Map<number, number[]>();
+    for (const city of options.cities) {
+        const list = cityIdsByNation.get(city.nationId) ?? [];
+        list.push(city.id);
+        cityIdsByNation.set(city.nationId, list);
+    }
+    const cityById = new Map(options.cities.map((city) => [city.id, city]));
+    const patches: Array<{ id: number; frontState: number }> = [];
+
+    for (const nationId of new Set(options.nationIds.filter((id) => id > 0))) {
+        const adjWar = new Set<number>();
+        const adjNeutral = new Set<number>();
+        const adjDeclaration = new Set<number>();
+
+        for (const entry of options.diplomacy) {
+            if (entry.fromNationId !== nationId) {
+                continue;
+            }
+            const targetCities = cityIdsByNation.get(entry.toNationId) ?? [];
+            if (entry.state === 0) {
+                collectAdjacentCities(targetCities, options.connections, adjWar);
+            } else if (entry.state === 1 && entry.term <= 5) {
+                collectAdjacentCities(targetCities, options.connections, adjDeclaration);
+            }
+        }
+
+        if (adjWar.size === 0 && adjDeclaration.size === 0) {
+            collectAdjacentCities(cityIdsByNation.get(0) ?? [], options.connections, adjNeutral);
+        }
+
+        for (const cityId of cityIdsByNation.get(nationId) ?? []) {
+            const city = cityById.get(cityId);
+            if (!city) {
+                continue;
+            }
+            let frontState = 0;
+            if (adjDeclaration.has(cityId)) {
+                frontState = 1;
+            }
+            if (adjNeutral.has(cityId)) {
+                frontState = 2;
+            }
+            if (adjWar.has(cityId)) {
+                frontState = 3;
+            }
+            if (city.frontState !== frontState) {
+                patches.push({ id: cityId, frontState });
+            }
+        }
+    }
+
+    return patches;
+};