Refactor world bootstrap and allow empty startup worlds

apps/backend/Universe/Scenario/ScenarioValidationService.cs

@@ -0,0 +1,111 @@
+using SpaceGame.Api.Universe.Bootstrap;
+
+namespace SpaceGame.Api.Universe.Scenario;
+
+public sealed class ScenarioValidationService(IStaticDataProvider staticData)
+{
+    public ScenarioDefinition CreateEmptyScenario(
+      WorldGenerationOptions worldGenerationOptions,
+      IReadOnlyList<SolarSystemDefinition> systems)
+    {
+        if (systems.Count == 0)
+        {
+            throw new InvalidOperationException("World generation produced no systems.");
+        }
+
+        return new ScenarioDefinition
+        {
+            WorldGeneration = worldGenerationOptions,
+            InitialStations = [],
+            ShipFormations = [],
+            PatrolRoutes = [],
+        };
+    }
+
+    public void Validate(
+      ScenarioDefinition scenario,
+      IReadOnlySet<string> availableSystemIds)
+    {
+        foreach (var station in scenario.InitialStations)
+        {
+            ValidateSystemExists(station.SystemId, $"station '{station.Label}' system", availableSystemIds);
+            ValidateFactionId(station.FactionId, $"station '{station.Label}'");
+
+            foreach (var moduleId in station.StartingModules)
+            {
+                ValidateModuleId(moduleId, $"station '{station.Label}' starting module");
+            }
+        }
+
+        foreach (var formation in scenario.ShipFormations)
+        {
+            ValidateSystemExists(formation.SystemId, $"ship formation '{formation.ShipId}' system", availableSystemIds);
+            ValidateFactionId(formation.FactionId, $"ship formation '{formation.ShipId}' in system '{formation.SystemId}'");
+            ValidateShipId(formation.ShipId, $"ship formation in system '{formation.SystemId}'");
+
+            foreach (var itemId in formation.StartingInventory.Keys)
+            {
+                ValidateItemId(itemId, $"ship formation '{formation.ShipId}' starting inventory");
+            }
+        }
+
+        foreach (var route in scenario.PatrolRoutes)
+        {
+            ValidateSystemExists(route.SystemId, "patrol route system", availableSystemIds);
+        }
+    }
+
+    private static string GetRequiredFactionId(string? factionId, string context)
+    {
+        if (!string.IsNullOrWhiteSpace(factionId))
+        {
+            return factionId;
+        }
+
+        throw new InvalidOperationException($"Scenario {context} is missing a factionId.");
+    }
+
+    private static void ValidateSystemExists(
+      string systemId,
+      string context,
+      IReadOnlySet<string> availableSystemIds)
+    {
+        if (!availableSystemIds.Contains(systemId))
+        {
+            throw new InvalidOperationException($"Scenario {context} references unknown generated system '{systemId}'.");
+        }
+    }
+
+    private void ValidateFactionId(string? factionId, string context)
+    {
+        var requiredFactionId = GetRequiredFactionId(factionId, context);
+        if (!staticData.FactionDefinitions.ContainsKey(requiredFactionId))
+        {
+            throw new InvalidOperationException($"Scenario {context} references unknown faction '{requiredFactionId}'.");
+        }
+    }
+
+    private void ValidateModuleId(string moduleId, string context)
+    {
+        if (!staticData.ModuleDefinitions.ContainsKey(moduleId))
+        {
+            throw new InvalidOperationException($"Scenario {context} references unknown module '{moduleId}'.");
+        }
+    }
+
+    private void ValidateShipId(string shipId, string context)
+    {
+        if (!staticData.ShipDefinitions.ContainsKey(shipId))
+        {
+            throw new InvalidOperationException($"Scenario {context} references unknown ship '{shipId}'.");
+        }
+    }
+
+    private void ValidateItemId(string itemId, string context)
+    {
+        if (!staticData.ItemDefinitions.ContainsKey(itemId))
+        {
+            throw new InvalidOperationException($"Scenario {context} references unknown item '{itemId}'.");
+        }
+    }
+}