#!/usr/bin/env node
import { spawn } from 'node:child_process';
import { existsSync } from 'node:fs';
import { mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { createServer } from 'node:net';

const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const enabled = process.env.NIANCODE_OPENCODE_REAL_SMOKE === '1'
  || process.env.OPENCODE_REAL_SMOKE === '1';

function skip(reason) {
  console.log(`[opencode-real-smoke] skipped: ${reason}`);
  process.exit(0);
}

if (!enabled) {
  skip('set NIANCODE_OPENCODE_REAL_SMOKE=1 to launch a real opencode runtime');
}

function resolveOpencodeBin() {
  const explicit = process.env.NIANCODE_OPENCODE_BIN || process.env.OPENCODE_BIN;
  if (explicit) return explicit;

  const binName = process.platform === 'win32' ? 'opencode.cmd' : 'opencode';
  const localBin = join(repoRoot, 'node_modules', '.bin', binName);
  if (existsSync(localBin)) return localBin;
  return binName;
}

async function resolveConfigContent() {
  if (process.env.OPENCODE_CONFIG_CONTENT) return process.env.OPENCODE_CONFIG_CONTENT;
  if (process.env.OPENCODE_REAL_SMOKE_CONFIG) return process.env.OPENCODE_REAL_SMOKE_CONFIG;
  if (process.env.OPENCODE_REAL_SMOKE_CONFIG_FILE) {
    return await readFile(resolve(process.env.OPENCODE_REAL_SMOKE_CONFIG_FILE), 'utf8');
  }
  return null;
}

async function getFreePort() {
  return await new Promise((resolvePort, reject) => {
    const server = createServer();
    server.once('error', reject);
    server.listen(0, '127.0.0.1', () => {
      const address = server.address();
      const port = typeof address === 'object' && address ? address.port : null;
      server.close(() => {
        if (typeof port === 'number') {
          resolvePort(port);
          return;
        }
        reject(new Error('Unable to reserve a local smoke-test port'));
      });
    });
  });
}

function waitForListening(proc, timeoutMs) {
  return awaitableProcessOutput(proc, timeoutMs, (text) => {
    const match = text.match(/opencode server listening\s+on\s+(https?:\/\/[^\s]+)/);
    return match?.[1] ?? null;
  });
}

function awaitableProcessOutput(proc, timeoutMs, resolveFromText) {
  return new Promise((resolveUrl, reject) => {
    let settled = false;
    let stderr = '';
    const finish = (callback) => {
      if (settled) return;
      settled = true;
      clearTimeout(timer);
      callback();
    };
    const timer = setTimeout(() => {
      finish(() => reject(new Error(`Timed out waiting for opencode server after ${timeoutMs}ms${stderr ? `\n${stderr}` : ''}`)));
    }, timeoutMs);

    proc.stdout?.on('data', (chunk) => {
      const text = chunk.toString();
      process.stdout.write(text);
      const result = resolveFromText(text);
      if (result) finish(() => resolveUrl(result));
    });
    proc.stderr?.on('data', (chunk) => {
      const text = chunk.toString();
      stderr += text;
      process.stderr.write(text);
    });
    proc.on('error', (error) => finish(() => reject(error)));
    proc.on('exit', (code) => {
      finish(() => reject(new Error(`opencode exited before it became ready: ${code ?? 'unknown'}${stderr ? `\n${stderr}` : ''}`)));
    });
  });
}

function sessionIdOf(session) {
  if (!session || typeof session !== 'object') return null;
  const value = session.id ?? session.sessionID ?? session.sessionId;
  return typeof value === 'string' && value.trim() ? value : null;
}

async function requestJson(url, init = {}) {
  const response = await fetch(url, {
    ...init,
    headers: {
      'Content-Type': 'application/json',
      ...(init.headers ?? {}),
    },
  });
  if (!response.ok) {
    const body = await response.text().catch(() => '');
    throw new Error(`opencode request failed ${response.status} ${response.statusText}${body ? `\n${body}` : ''}`);
  }
  if (response.status === 204) return null;
  return await response.json();
}

async function createProjectDir() {
  if (process.env.OPENCODE_REAL_SMOKE_PROJECT) {
    return {
      path: resolve(process.env.OPENCODE_REAL_SMOKE_PROJECT),
      cleanup: async () => {},
    };
  }

  const path = await mkdtemp(join(tmpdir(), 'niancode-opencode-smoke-'));
  await writeFile(join(path, 'README.md'), '# Makelore opencode real-runtime smoke\n');
  return {
    path,
    cleanup: async () => {
      await rm(path, { recursive: true, force: true });
    },
  };
}

const configContent = await resolveConfigContent();
if (!configContent && process.env.OPENCODE_REAL_SMOKE_ALLOW_LOCAL_CONFIG !== '1') {
  skip('provide OPENCODE_CONFIG_CONTENT, OPENCODE_REAL_SMOKE_CONFIG, or OPENCODE_REAL_SMOKE_CONFIG_FILE');
}

JSON.parse(configContent ?? '{}');

const binPath = resolveOpencodeBin();
const port = Number(process.env.OPENCODE_REAL_SMOKE_PORT) || await getFreePort();
const startupTimeoutMs = Number(process.env.OPENCODE_REAL_SMOKE_STARTUP_TIMEOUT_MS) || 20_000;
const apiTimeoutMs = Number(process.env.OPENCODE_REAL_SMOKE_API_TIMEOUT_MS) || 60_000;
const project = await createProjectDir();
const proc = spawn(binPath, ['serve', '--hostname=127.0.0.1', `--port=${port}`], {
  env: {
    ...process.env,
    ...(configContent ? { OPENCODE_CONFIG_CONTENT: configContent } : {}),
  },
  stdio: ['ignore', 'pipe', 'pipe'],
  windowsHide: true,
  shell: process.platform === 'win32' && /\.cmd$/i.test(binPath),
});

try {
  const baseUrl = await waitForListening(proc, startupTimeoutMs);
  const directoryQuery = `directory=${encodeURIComponent(project.path)}`;
  const scopedHeaders = { 'x-opencode-directory': encodeURIComponent(project.path) };

  const sessions = await requestJson(`${baseUrl}/session?${directoryQuery}`, {
    signal: AbortSignal.timeout(apiTimeoutMs),
    headers: scopedHeaders,
  });
  if (!Array.isArray(sessions)) {
    throw new Error('Expected /session to return an array');
  }

  const session = await requestJson(`${baseUrl}/session?${directoryQuery}`, {
    method: 'POST',
    body: JSON.stringify({}),
    signal: AbortSignal.timeout(apiTimeoutMs),
    headers: scopedHeaders,
  });
  const sessionId = sessionIdOf(session);
  if (!sessionId) {
    throw new Error('Created opencode session did not include an id');
  }

  if (process.env.OPENCODE_REAL_SMOKE_PROMPT) {
    await requestJson(`${baseUrl}/session/${encodeURIComponent(sessionId)}/message?${directoryQuery}`, {
      method: 'POST',
      body: JSON.stringify({
        parts: [
          { type: 'text', text: process.env.OPENCODE_REAL_SMOKE_PROMPT },
        ],
      }),
      signal: AbortSignal.timeout(apiTimeoutMs),
      headers: scopedHeaders,
    });
  }

  console.log(`[opencode-real-smoke] ok: started ${baseUrl}, listed ${sessions.length} session(s), created ${sessionId}`);
} finally {
  proc.kill();
  await project.cleanup();
}