GearBox/src/server/mcp/tools/items.ts

import type { db as prodDb } from "../../../db/index.ts";
import {
	createItem,
	deleteItem,
	getAllItems,
	getItemById,
	updateItem,
} from "../../services/item.service.ts";

type Db = typeof prodDb;

interface ToolResult {
	content: Array<{ type: "text"; text: string }>;
}

function textResult(data: unknown): ToolResult {
	return { content: [{ type: "text", text: JSON.stringify(data, null, 2) }] };
}

function errorResult(message: string): ToolResult {
	return {
		content: [{ type: "text", text: JSON.stringify({ error: message }) }],
	};
}

export const itemToolDefinitions = [
	{
		name: "list_items",
		description:
			"List all items in the gear collection, optionally filtered by category.",
		inputSchema: {
			type: "object" as const,
			properties: {
				categoryId: {
					type: "number",
					description: "Filter items by category ID",
				},
			},
		},
	},
	{
		name: "get_item",
		description: "Get a single item by its ID, including all details.",
		inputSchema: {
			type: "object" as const,
			properties: {
				id: { type: "number", description: "The item ID" },
			},
			required: ["id"],
		},
	},
	{
		name: "create_item",
		description:
			"Add a new item to the gear collection. Use this for items you've already decided on. For items you're still researching, use create_thread instead.",
		inputSchema: {
			type: "object" as const,
			properties: {
				name: { type: "string", description: "Item name" },
				categoryId: { type: "number", description: "Category ID" },
				weightGrams: { type: "number", description: "Weight in grams" },
				priceCents: { type: "number", description: "Price in cents" },
				notes: { type: "string", description: "Notes about the item" },
				productUrl: { type: "string", description: "URL to the product page" },
				imageFilename: {
					type: "string",
					description: "Filename of an uploaded image",
				},
				imageSourceUrl: {
					type: "string",
					description: "Original URL the image was fetched from",
				},
			},
			required: ["name", "categoryId"],
		},
	},
	{
		name: "update_item",
		description: "Update an existing item's fields.",
		inputSchema: {
			type: "object" as const,
			properties: {
				id: { type: "number", description: "The item ID to update" },
				name: { type: "string", description: "Item name" },
				categoryId: { type: "number", description: "Category ID" },
				weightGrams: { type: "number", description: "Weight in grams" },
				priceCents: { type: "number", description: "Price in cents" },
				notes: { type: "string", description: "Notes about the item" },
				productUrl: { type: "string", description: "URL to the product page" },
				imageFilename: {
					type: "string",
					description: "Filename of an uploaded image",
				},
				imageSourceUrl: {
					type: "string",
					description: "Original URL the image was fetched from",
				},
			},
			required: ["id"],
		},
	},
	{
		name: "delete_item",
		description: "Delete an item from the gear collection by ID.",
		inputSchema: {
			type: "object" as const,
			properties: {
				id: { type: "number", description: "The item ID to delete" },
			},
			required: ["id"],
		},
	},
];

export function registerItemTools(db: Db) {
	return {
		list_items: async (args: { categoryId?: number }): Promise<ToolResult> => {
			try {
				const items = getAllItems(db);
				if (args.categoryId) {
					return textResult(
						items.filter((i) => i.categoryId === args.categoryId),
					);
				}
				return textResult(items);
			} catch (err) {
				return errorResult((err as Error).message);
			}
		},

		get_item: async (args: { id: number }): Promise<ToolResult> => {
			try {
				const item = getItemById(db, args.id);
				if (!item) return errorResult(`Item ${args.id} not found`);
				return textResult(item);
			} catch (err) {
				return errorResult((err as Error).message);
			}
		},

		create_item: async (args: {
			name: string;
			categoryId: number;
			weightGrams?: number;
			priceCents?: number;
			notes?: string;
			productUrl?: string;
			imageFilename?: string;
			imageSourceUrl?: string;
		}): Promise<ToolResult> => {
			try {
				const item = createItem(db, args);
				return textResult(item);
			} catch (err) {
				return errorResult((err as Error).message);
			}
		},

		update_item: async (args: {
			id: number;
			name?: string;
			categoryId?: number;
			weightGrams?: number;
			priceCents?: number;
			notes?: string;
			productUrl?: string;
			imageFilename?: string;
			imageSourceUrl?: string;
		}): Promise<ToolResult> => {
			try {
				const { id, ...data } = args;
				const item = updateItem(db, id, data);
				if (!item) return errorResult(`Item ${id} not found`);
				return textResult(item);
			} catch (err) {
				return errorResult((err as Error).message);
			}
		},

		delete_item: async (args: { id: number }): Promise<ToolResult> => {
			try {
				const item = deleteItem(db, args.id);
				if (!item) return errorResult(`Item ${args.id} not found`);
				return textResult({ deleted: true, item });
			} catch (err) {
				return errorResult((err as Error).message);
			}
		},
	};
}