/**
 * Smoke tests: v3 virtual agents — register a virtual Llm + a virtual
 * Agent through the same `_provider-register` payload, then verify mcpd
 * surfaces the agent as kind=virtual / status=active. Mirrors
 * virtual-llm.smoke.test.ts's in-process registrar pattern so we don't
 * need to mutate ~/.mcpctl/config.json or bounce systemd's mcplocal.
 *
 * Heartbeat-stale → inactive (90 s) and 4 h auto-deletion are covered by
 * the unit suite (mcpd virtual-agent-service.test.ts); waiting > 90 s in
 * smoke would balloon the suite duration.
 */
import { describe, it, expect, beforeAll, afterAll } from 'vitest';
import http from 'node:http';
import https from 'node:https';
import { mkdtempSync, rmSync, readFileSync, existsSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import {
  VirtualLlmRegistrar,
  type RegistrarPublishedProvider,
  type RegistrarPublishedAgent,
} from '../../src/providers/registrar.js';
import type { LlmProvider, CompletionResult } from '../../src/providers/types.js';

const MCPD_URL = process.env.MCPD_URL ?? 'https://mcpctl.ad.itaz.eu';
const SUFFIX = Date.now().toString(36);
const PROVIDER_NAME = `smoke-vagent-llm-${SUFFIX}`;
const AGENT_NAME = `smoke-vagent-${SUFFIX}`;

function makeFakeProvider(name: string, content: string): LlmProvider {
  return {
    name,
    async complete(): Promise<CompletionResult> {
      return {
        content,
        toolCalls: [],
        usage: { promptTokens: 1, completionTokens: 4, totalTokens: 5 },
        finishReason: 'stop',
      };
    },
    async listModels() { return []; },
    async isAvailable() { return true; },
  };
}

function healthz(url: string, timeoutMs = 5000): Promise<boolean> {
  return new Promise((resolve) => {
    const parsed = new URL(`${url.replace(/\/$/, '')}/healthz`);
    const driver = parsed.protocol === 'https:' ? https : http;
    const req = driver.get({
      hostname: parsed.hostname,
      port: parsed.port || (parsed.protocol === 'https:' ? 443 : 80),
      path: parsed.pathname,
      timeout: timeoutMs,
    }, (res) => { resolve((res.statusCode ?? 500) < 500); res.resume(); });
    req.on('error', () => resolve(false));
    req.on('timeout', () => { req.destroy(); resolve(false); });
  });
}

function readToken(): string | null {
  try {
    const path = join(process.env.HOME ?? '', '.mcpctl', 'credentials');
    if (!existsSync(path)) return null;
    const parsed = JSON.parse(readFileSync(path, 'utf-8')) as { token?: string };
    return parsed.token ?? null;
  } catch {
    return null;
  }
}

interface HttpResponse { status: number; body: string }

function httpRequest(method: string, urlStr: string, body: unknown): Promise<HttpResponse> {
  return new Promise((resolve, reject) => {
    const tokenRaw = readToken();
    const parsed = new URL(urlStr);
    const driver = parsed.protocol === 'https:' ? https : http;
    const headers: Record<string, string> = {
      Accept: 'application/json',
      ...(body !== undefined ? { 'Content-Type': 'application/json' } : {}),
      ...(tokenRaw !== null ? { Authorization: `Bearer ${tokenRaw}` } : {}),
    };
    const req = driver.request({
      hostname: parsed.hostname,
      port: parsed.port || (parsed.protocol === 'https:' ? 443 : 80),
      path: parsed.pathname + parsed.search,
      method,
      headers,
      timeout: 30_000,
    }, (res) => {
      const chunks: Buffer[] = [];
      res.on('data', (c: Buffer) => chunks.push(c));
      res.on('end', () => {
        resolve({ status: res.statusCode ?? 0, body: Buffer.concat(chunks).toString('utf-8') });
      });
    });
    req.on('error', reject);
    req.on('timeout', () => { req.destroy(); reject(new Error(`httpRequest timeout: ${method} ${urlStr}`)); });
    if (body !== undefined) req.write(JSON.stringify(body));
    req.end();
  });
}

interface AgentRow { id: string; name: string; kind?: string; status?: string; llm?: { name: string }; description?: string }

let mcpdUp = false;
let registrar: VirtualLlmRegistrar | null = null;
let tempDir: string;

describe('virtual-agent smoke (v3)', () => {
  beforeAll(async () => {
    mcpdUp = await healthz(MCPD_URL);
    if (!mcpdUp) {
      // eslint-disable-next-line no-console
      console.warn(`\n  ○ virtual-agent smoke: skipped — ${MCPD_URL}/healthz unreachable.\n`);
      return;
    }
    if (readToken() === null) {
      mcpdUp = false;
      // eslint-disable-next-line no-console
      console.warn('\n  ○ virtual-agent smoke: skipped — no ~/.mcpctl/credentials.\n');
      return;
    }
    tempDir = mkdtempSync(join(tmpdir(), 'mcpctl-virtual-agent-smoke-'));
  }, 20_000);

  afterAll(async () => {
    if (registrar !== null) registrar.stop();
    if (tempDir !== undefined) rmSync(tempDir, { recursive: true, force: true });
    // Defensive cleanup: agent first (Llm.id has Restrict FK), then Llm.
    if (mcpdUp) {
      const agents = await httpRequest('GET', `${MCPD_URL}/api/v1/agents`, undefined);
      if (agents.status === 200) {
        const rows = JSON.parse(agents.body) as Array<{ id: string; name: string }>;
        const row = rows.find((r) => r.name === AGENT_NAME);
        if (row !== undefined) {
          await httpRequest('DELETE', `${MCPD_URL}/api/v1/agents/${row.id}`, undefined);
        }
      }
      const llms = await httpRequest('GET', `${MCPD_URL}/api/v1/llms`, undefined);
      if (llms.status === 200) {
        const rows = JSON.parse(llms.body) as Array<{ id: string; name: string }>;
        const row = rows.find((r) => r.name === PROVIDER_NAME);
        if (row !== undefined) {
          await httpRequest('DELETE', `${MCPD_URL}/api/v1/llms/${row.id}`, undefined);
        }
      }
    }
  });

  it('registrar publishes provider + agent in one round-trip and mcpd lists the agent kind=virtual / status=active', async () => {
    if (!mcpdUp) return;
    const token = readToken();
    if (token === null) return;

    const published: RegistrarPublishedProvider[] = [
      { provider: makeFakeProvider(PROVIDER_NAME, 'hi from virtual agent'), type: 'openai', model: 'fake-vagent', tier: 'fast' },
    ];
    const publishedAgents: RegistrarPublishedAgent[] = [
      {
        name: AGENT_NAME,
        llmName: PROVIDER_NAME,
        description: 'v3 virtual agent smoke',
        systemPrompt: 'You are a smoke test. Reply READY.',
        defaultParams: { temperature: 0 },
      },
    ];
    registrar = new VirtualLlmRegistrar({
      mcpdUrl: MCPD_URL,
      token,
      publishedProviders: published,
      publishedAgents,
      sessionFilePath: join(tempDir, 'session'),
      log: { info: () => {}, warn: () => {}, error: () => {} },
      heartbeatIntervalMs: 60_000,
    });
    await registrar.start();
    expect(registrar.getSessionId()).not.toBeNull();
    // Give the SSE handshake + atomic register a moment to settle.
    await new Promise((r) => setTimeout(r, 400));

    const res = await httpRequest('GET', `${MCPD_URL}/api/v1/agents`, undefined);
    expect(res.status).toBe(200);
    const rows = JSON.parse(res.body) as AgentRow[];
    const row = rows.find((r) => r.name === AGENT_NAME);
    expect(row, `${AGENT_NAME} must be present`).toBeDefined();
    expect(row!.kind).toBe('virtual');
    expect(row!.status).toBe('active');
    expect(row!.llm?.name).toBe(PROVIDER_NAME);
    expect(row!.description).toBe('v3 virtual agent smoke');
  }, 30_000);

  it('publisher disconnect flips the agent to status=inactive (paired with its Llm)', async () => {
    if (!mcpdUp) return;
    if (registrar !== null) {
      registrar.stop();
      registrar = null;
    }
    // unbindSession runs synchronously on the SSE close handler; mcpd
    // flips both the Llm and any agents owned by the session to
    // inactive. A short wait covers the request round-trip.
    await new Promise((r) => setTimeout(r, 400));

    const agents = await httpRequest('GET', `${MCPD_URL}/api/v1/agents`, undefined);
    expect(agents.status).toBe(200);
    const agentRow = (JSON.parse(agents.body) as AgentRow[]).find((r) => r.name === AGENT_NAME);
    expect(agentRow, `${AGENT_NAME} must still exist (deletion is GC-driven, not disconnect-driven)`).toBeDefined();
    expect(agentRow!.status).toBe('inactive');

    const llms = await httpRequest('GET', `${MCPD_URL}/api/v1/llms`, undefined);
    const llmRow = (JSON.parse(llms.body) as Array<{ name: string; status: string }>).find((r) => r.name === PROVIDER_NAME);
    expect(llmRow!.status).toBe('inactive');
  }, 30_000);
});