import { INestApplication } from "@nestjs/common";
import request from "supertest";
import { buildTestApp } from "./app.harness";

/**
 * MCP controller integration tests.
 *
 * The MCP endpoint speaks the Model Context Protocol (streamable HTTP
 * transport).  We test:
 *  - that the endpoint is reachable and returns a recognised MCP response
 *  - that tool invocations for read-only, non-browser tools work end-to-end
 *  - that tools with bad inputs return error payloads (not HTTP 5xx)
 *
 * Browser-dependent tools (open_url, exec_code) require a live Playwright
 * session and are not covered here.
 */
describe("McpController", () => {
  let app: INestApplication;

  beforeAll(async () => {
    app = await buildTestApp();
  });

  afterAll(async () => {
    await app.close();
  });

  /** Parse the JSON-RPC payload from an SSE response body. */
  function parseSse(text: string): Record<string, unknown> {
    const match = text.match(/^data:\s*(.+)$/m);
    if (!match) throw new Error(`No SSE data line found in: ${text}`);
    return JSON.parse(match[1]) as Record<string, unknown>;
  }

  /** Send a single MCP tool call and return the parsed response body. */
  async function mcpCall(toolName: string, args: Record<string, unknown> = {}) {
    const res = await request(app.getHttpServer())
      .post("/mcp")
      .set("Content-Type", "application/json")
      .set("Accept", "application/json, text/event-stream")
      .send({
        jsonrpc: "2.0",
        id: 1,
        method: "tools/call",
        params: { name: toolName, arguments: args },
      });
    return { status: res.status, rpc: parseSse(res.text) };
  }

  // ── Connectivity ───────────────────────────────────────────────────────────

  describe("POST /mcp — connectivity", () => {
    it("is reachable and returns a non-5xx status", async () => {
      const res = await request(app.getHttpServer())
        .post("/mcp")
        .set("Content-Type", "application/json")
        .set("Accept", "application/json, text/event-stream")
        .send({
          jsonrpc: "2.0",
          id: 1,
          method: "initialize",
          params: {
            protocolVersion: "2024-11-05",
            capabilities: {},
            clientInfo: { name: "test", version: "0" },
          },
        });
      expect(res.status).toBe(200);
    });
  });

  // ── list_keys tool (removed) ──────────────────────────────────────────────

  describe("list_keys", () => {
    it("returns MCP error for removed tool", async () => {
      const { status, rpc } = await mcpCall("list_keys");
      expect(status).toBe(200);
      const result = rpc.result as { isError: boolean; content?: { text: string }[] };
      expect(result.isError).toBe(true);
    });
  });

  // ── list_sessions tool ─────────────────────────────────────────────────────

  describe("list_sessions", () => {
    it("returns a paginated result with a data array", async () => {
      const { status, rpc } = await mcpCall("list_sessions");
      expect(status).toBe(200);
      const result = rpc.result as { content: { text: string }[] };
      const body = JSON.parse(result.content[0].text) as {
        data: unknown[];
        total: number;
      };
      expect(Array.isArray(body.data)).toBe(true);
      expect(typeof body.total).toBe("number");
    });
  });

  // ── list_environments tool ─────────────────────────────────────────────────

  describe("list_environments", () => {
    it("returns a paginated result with a data array", async () => {
      const { status, rpc } = await mcpCall("list_environments");
      expect(status).toBe(200);
      const result = rpc.result as { content: { text: string }[] };
      const body = JSON.parse(result.content[0].text) as {
        data: unknown[];
        total: number;
      };
      expect(Array.isArray(body.data)).toBe(true);
      expect(typeof body.total).toBe("number");
    });
  });

  // ── create_environment tool ────────────────────────────────────────────────

  describe("create_environment", () => {
    it("creates an environment via MCP", async () => {
      const { status, rpc } = await mcpCall("create_environment", {
        name: "mcp-test-env",
        urls: { id_url: "https://id.example.com" },
      });
      expect(status).toBe(200);
      const result = rpc.result as { content: { text: string }[] };
      const created = JSON.parse(result.content[0].text) as { name: string };
      expect(created.name).toBe("mcp-test-env");
    });
  });

  // ── delete_session tool with unknown id ────────────────────────────────────

  describe("delete_session", () => {
    it("returns an MCP error result for a non-existent session id", async () => {
      const { status, rpc } = await mcpCall("delete_session", { id: 999999 });
      expect(status).toBe(200);
      // MCP wraps service errors as isError:true content, not HTTP errors
      const result = rpc.result as { isError: boolean };
      expect(result.isError).toBe(true);
    });
  });
});