import { z } from "zod";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
import {
  textResource,
  textResourceUri,
  blobResourceUri,
  blobResource,
} from "../resources/templates.js";

// Tool input schema
const GetResourceLinksSchema = z.object({
  count: z
    .number()
    .min(1)
    .max(10)
    .default(3)
    .describe("Number of resource links to return (1-10)"),
});

// Tool configuration
const name = "get-resource-links";
const config = {
  title: "Get Resource Links Tool",
  description:
    "Returns up to ten resource links that reference different types of resources",
  inputSchema: GetResourceLinksSchema,
};

/**
 * Registers the 'get-resource-reference' tool with the provided McpServer instance.
 *
 * The registered tool retrieves a specified number of resource links and their metadata.
 * Resource links are dynamically generated as either text or binary blob resources,
 * based on their ID being even or odd.

 * The response contains a "text" introductory block and multiple "resource_link" blocks.
 *
 * @param {McpServer} server - An instance of the McpServer on which the tool will be registered.
 */
export const registerGetResourceLinksTool = (server: McpServer) => {
  server.registerTool(name, config, async (args): Promise<CallToolResult> => {
    const { count } = GetResourceLinksSchema.parse(args);

    // Add intro text content block
    const content: CallToolResult["content"] = [];
    content.push({
      type: "text",
      text: `Here are ${count} resource links to resources available in this server:`,
    });

    // Create resource link content blocks
    for (let resourceId = 1; resourceId <= count; resourceId++) {
      // Get resource uri for text or blob resource based on odd/even resourceId
      const isOdd = resourceId % 2 === 0;
      const uri = isOdd
        ? textResourceUri(resourceId)
        : blobResourceUri(resourceId);

      // Get resource based on the resource type
      const resource = isOdd
        ? textResource(uri, resourceId)
        : blobResource(uri, resourceId);

      content.push({
        type: "resource_link",
        uri: resource.uri,
        name: `${isOdd ? "Text" : "Blob"} Resource ${resourceId}`,
        description: `Resource ${resourceId}: ${
          resource.mimeType === "text/plain"
            ? "plaintext resource"
            : "binary blob resource"
        }`,
        mimeType: resource.mimeType,
      });
    }

    return { content };
  });
};