import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { mkdirSync, writeFileSync, existsSync } from "node:fs";
import { resolve, join } from "node:path";
import type { Config } from "../config.js";
import {
generatePrefab,
getPrefabSubdirectory,
getPrefabFilename,
type PrefabType,
type ComponentDef,
} from "../templates/prefab.js";
import { validateFilename } from "../utils/safe-path.js";
export function registerPrefabCreate(server: McpServer, config: Config): void {
server.registerTool(
"prefab_create",
{
description:
"Create a new Entity Template (.et) prefab file for an Arma Reforger mod. Generates a properly structured prefab with components in valid Enfusion text serialization format.",
inputSchema: {
name: z
.string()
.min(1)
.describe("Prefab name (e.g., 'MySpawnPoint', 'CustomVehicle')"),
prefabType: z
.enum([
"character",
"vehicle",
"weapon",
"spawnpoint",
"gamemode",
"interactive",
"generic",
])
.describe(
"Prefab template type. Determines the root entity type, default components, and file location."
),
parentPrefab: z
.string()
.optional()
.describe(
"Parent prefab to inherit from (e.g., '{GUID}Prefabs/Weapons/AK47.et'). Omit to create a standalone prefab."
),
components: z
.array(
z.object({
type: z.string().describe("Component class name (e.g., 'RigidBody', 'MeshObject')"),
properties: z
.record(z.string())
.optional()
.describe("Component property key-value pairs"),
})
)
.optional()
.describe("Additional components to add beyond the defaults for this prefab type"),
description: z
.string()
.optional()
.describe(
"Description for the prefab. Used as the display name in Game Master."
),
projectPath: z
.string()
.optional()
.describe("Addon root path. Uses configured default if omitted."),
},
},
async ({ name, prefabType, parentPrefab, components, description, projectPath }) => {
const basePath = projectPath || config.projectPath;
try {
validateFilename(name);
const content = generatePrefab({
name,
prefabType: prefabType as PrefabType,
parentPrefab,
components: components as ComponentDef[] | undefined,
description,
});
if (basePath) {
const subdir = getPrefabSubdirectory(prefabType as PrefabType);
const filename = getPrefabFilename(name);
const targetDir = resolve(basePath, subdir);
const targetPath = join(targetDir, filename);
mkdirSync(targetDir, { recursive: true });
if (existsSync(targetPath)) {
return {
content: [
{
type: "text",
text: `File already exists: ${subdir}/${filename}\n\nGenerated content (not written):\n\n\`\`\`\n${content}\n\`\`\``,
},
],
};
}
writeFileSync(targetPath, content, "utf-8");
return {
content: [
{
type: "text",
text: `Prefab created: ${subdir}/${filename}\n\n\`\`\`\n${content}\n\`\`\``,
},
],
};
}
return {
content: [
{
type: "text",
text: `Generated prefab (no project path configured — not written to disk):\n\n\`\`\`\n${content}\n\`\`\`\n\nSet ENFUSION_PROJECT_PATH to write files automatically.`,
},
],
};
} catch (e) {
const msg = e instanceof Error ? e.message : String(e);
return {
content: [{ type: "text", text: `Error creating prefab: ${msg}` }],
};
}
}
);
}
