import * as sdk from '@botpress/sdk';

type Json = Record<string, any>;

const rpcResponse = (body: string): Json => {

  const candidates = body

    .split('\n')

    .filter((line) => line.startsWith('data:'))

    .map((line) => line.slice(5).trim())

    .filter(Boolean);

  const raw = candidates.at(-1) ?? body;

  try {

    return JSON.parse(raw) as Json;

  } catch {

    throw new sdk.RuntimeError('OpenClasp returned an invalid MCP response');

  }

};

export const callOpenClaspTool = async <T = Json>(

  baseUrl: string,

  token: string,

  name: string,

  args: Json = {},

): Promise<T> => {

  if (!token) throw new sdk.RuntimeError('OpenClasp pairing is not complete');

  const response = await fetch(`${baseUrl.replace(/\/$/, '')}/mcp`, {

    method: 'POST',

    headers: {

      authorization: `Bearer ${token}`,

      accept: 'application/json, text/event-stream',

      'content-type': 'application/json',

      'mcp-protocol-version': '2025-06-18',

    },

    body: JSON.stringify({

      jsonrpc: '2.0',

      id: crypto.randomUUID(),

      method: 'tools/call',

      params: { name, arguments: args },

    }),

  });

  const payload = rpcResponse(await response.text());

  if (!response.ok || payload.error)

    throw new sdk.RuntimeError(

      String(payload.error?.message ?? `OpenClasp MCP HTTP ${response.status}`),

    );

  const result = payload.result as Json | undefined;

  if (result?.isError)

    throw new sdk.RuntimeError(String(result.content?.[0]?.text ?? 'OpenClasp tool failed'));

  const text = result?.content?.find((item: Json) => item.type === 'text')?.text;

  if (typeof text !== 'string') return result as T;

  try {

    return JSON.parse(text) as T;

  } catch {

    return text as T;

  }

};

export const sendMcpA2ARequest = async (value: Json): Promise<boolean> => {

  const a2a = value.a2a as Json | undefined;

  const endpoint = a2a?.endpoint;

  const bearerToken = a2a?.bearerToken;

  const request = a2a?.request ?? a2a?.requestTemplate;

  if (typeof endpoint !== 'string' || typeof bearerToken !== 'string' || !request) return false;

  const response = await fetch(endpoint, {

    method: 'POST',

    headers: {

      authorization: `Bearer ${bearerToken}`,

      'content-type': 'application/json',

      'A2A-Extensions': 'https://openclasp.dev/extensions/trust/v0.1',

    },

    body: JSON.stringify({

      jsonrpc: '2.0',

      id: crypto.randomUUID(),

      method: 'message/send',

      params: request.params ?? { message: request.message },

    }),

  });

  if (!response.ok)

    throw new sdk.RuntimeError(`Peer A2A endpoint returned HTTP ${response.status}`);

  return true;

};