import { Bus, Context } from "./types.js";
import {
CallToolResult,
ServerNotification,
ServerRequest,
} from "@modelcontextprotocol/sdk/types.js";
import { RequestHandlerExtra } from "@modelcontextprotocol/sdk/shared/protocol.js";
import { strip_internal_fields } from "./events.js";
export type Handler = (reply_payload: any) => CallToolResult;
export type ToolFn<S> = (
args: S,
extra: RequestHandlerExtra<ServerRequest, ServerNotification>,
) => Promise<CallToolResult>;
export function build_channel<S>(
{ bus, id_generator, log }: Context,
event_name: string,
handler: Handler,
) {
const fn: ToolFn<S> = async (
_args: S,
_extra: RequestHandlerExtra<ServerRequest, ServerNotification>,
) => {
const request_id = id_generator.generate();
// const event_name = `get-selected-cell`;
const reply_name = `${event_name}.${request_id}`;
bus.send_to_extension({
__event: event_name,
__request_id: request_id,
..._args,
});
log.debug(`[${event_name}] emitted, waiting for reply @${reply_name}`);
const p: Promise<CallToolResult> = new Promise((resolve, _reject) => {
log.debug(`[${event_name}] waiting for response @${reply_name}`);
bus.on_reply_from_extension(reply_name, (reply: Record<string, any>) => {
// bus.on(reply_name, (args) => {
log.debug(`[${reply_name}] received response`, reply);
const data = strip_internal_fields(reply);
const response = handler(data);
resolve(response);
});
});
return p;
};
return fn;
}
export function default_tool(name: string, context: Context) {
const fn = build_channel(context, name, (reply) => {
const response: CallToolResult = {
content: [
{
type: "text",
text: JSON.stringify(reply),
},
],
};
return response;
});
return fn;
}
