Implement main game as a mod

common/mod_loader.ts

@@ -0,0 +1,89 @@
+// registers mods' data, the same way on the server and on clients
+import { BlockRegistry, EverythingRegistry, ItemRegistry } from "./everything_registry.ts";
+import {
+	block_from_json,
+	BlockJson,
+	grid_recipe_from_json,
+	GridRecipe,
+	item_from_json,
+	ItemJson,
+	OreJson,
+	RecipeJson,
+} from "./mod_data.ts";
+import { register_block_item } from "./utils.ts";
+
+// everything a mod's json files hold, merged into one file by the build (build/mods/<id>/<hash>/data.json)
+export interface ModData {
+	blocks: BlockJson[];
+	items: ItemJson[];
+	recipes: RecipeJson[];
+	ores: OreJson[];
+}
+
+// a mod as the server lists it to clients, in load order. paths are relative to the site root
+export interface ModListing {
+	id: string;
+	name: string;
+	version: string;
+	hash: string;
+	data: string;
+	client?: string;
+	worldgen?: string;
+}
+
+export class RecipeBook {
+	shaped: GridRecipe[] = [];
+	furnace = new Map<string, { output: { id: string; count: number }; cook_time: number }>();
+	fuel = new Map<string, number>();
+	ores: OreJson[] = [];
+}
+
+export class ModLoadError extends Error {
+	constructor(mod: string, message: string) {
+		super(`${mod}: ${message}`);
+		this.name = "ModLoadError";
+	}
+}
+
+// registers every mod's blocks, items and recipes, in the order given (dependencies first)
+export function register_mod_data(mods: { id: string; data: ModData }[]): RecipeBook {
+	const recipes = new RecipeBook();
+
+	for (const { id, data } of mods) {
+		const fail = (message: string): never => {
+			throw new ModLoadError(id, message);
+		};
+		try {
+			for (const json of data.blocks) {
+				const { block, has_item } = block_from_json(json);
+				EverythingRegistry.register<BlockRegistry>("blocks", block.id, block);
+				if (has_item) {
+					register_block_item(block);
+				}
+			}
+			for (const json of data.items) {
+				EverythingRegistry.register<ItemRegistry>("items", json.id, item_from_json(json));
+			}
+		} catch (e) {
+			fail((e as Error).message);
+		}
+
+		for (const recipe of data.recipes) {
+			switch (recipe.type) {
+				case "shaped":
+					recipes.shaped.push(grid_recipe_from_json(recipe));
+					break;
+				case "furnace":
+					if (recipes.furnace.has(recipe.input)) fail(`two furnace recipes for ${recipe.input}`);
+					recipes.furnace.set(recipe.input, { output: recipe.output, cook_time: recipe.cook_time });
+					break;
+				case "fuel":
+					recipes.fuel.set(recipe.item, recipe.burn_time);
+					break;
+			}
+		}
+		recipes.ores.push(...data.ores);
+	}
+
+	return recipes;
+}