import { PROTECTED_RUNTIME_READER } from './runtime-reader-template.js';

export interface GuardScriptOptions {
  readonly failClosed?: boolean;
  readonly successOutput?: string;
  readonly denyProtocol?: 'cursor' | 'grok';
}

export function generateGuardScript(
  agentName: string,
  agentId: string,
  options: GuardScriptOptions = {},
): string {
  const failClosed = options.failClosed ?? false;
  const successOutput = options.successOutput ?? '';
  const denyProtocol = options.denyProtocol ?? '';
  return `#!/usr/bin/env node
'use strict';

// Elydora agent guard for ${agentName}. Generated by @elydora/sdk.
const crypto = require('node:crypto');
const fs = require('node:fs');
const path = require('node:path');
const os = require('node:os');

const AGENT_NAME = ${JSON.stringify(agentName)};
const AGENT_ID = ${JSON.stringify(agentId)};
const SUCCESS_OUTPUT = ${JSON.stringify(successOutput)};
const FAIL_CLOSED = ${JSON.stringify(failClosed)};
const DENY_PROTOCOL = ${JSON.stringify(denyProtocol)};
const ELYDORA_DIR = path.join(os.homedir(), '.elydora');
const CONFIG_PATH = path.join(ELYDORA_DIR, AGENT_ID, 'config.json');
const STATUS_CACHE_PATH = path.join(ELYDORA_DIR, AGENT_ID, 'status-cache.json');
const CACHE_TTL_MS = 60000;

${PROTECTED_RUNTIME_READER}

function validateStatus(value, source) {
  if (!['active', 'frozen', 'revoked'].includes(value)) {
    throw new Error(source + ' contains an invalid agent status');
  }
  return value;
}

function blockAgent(status) {
  const state = status === 'frozen' ? 'frozen' : 'revoked';
  const message = 'Agent "' + AGENT_NAME + '" is ' + state + ' in Elydora.';
  if (DENY_PROTOCOL === 'cursor') {
    process.stdout.write(JSON.stringify({
      permission: 'deny',
      userMessage: message,
      agentMessage: message + ' Tool execution is blocked.',
    }) + '\\n');
  } else if (DENY_PROTOCOL === 'grok') {
    process.stdout.write(JSON.stringify({ decision: 'deny', reason: message }) + '\\n');
  }
  process.stderr.write('[Elydora guard] ' + message + ' Tool execution blocked.\\n');
  process.exitCode = 2;
}

function readStatusCache() {
  let raw;
  try {
    raw = readProtectedFile(
      STATUS_CACHE_PATH,
      'Status cache',
      MAX_PROTECTED_CONFIG_BYTES,
    ).toString('utf-8');
  } catch (error) {
    if (hasRuntimeErrorCode(error, 'ENOENT')) return undefined;
    throw new Error('Failed to read status cache: ' + error.message);
  }
  let cache;
  try {
    cache = JSON.parse(raw);
  } catch (error) {
    throw new Error('Status cache is invalid JSON: ' + error.message);
  }
  if (!cache || typeof cache !== 'object' || !Number.isFinite(cache.cached_at)) {
    throw new Error('Status cache has an invalid shape');
  }
  const age = Date.now() - cache.cached_at;
  if (age < 0) throw new Error('Status cache timestamp is in the future');
  return { status: validateStatus(cache.status, 'Status cache'), age };
}

function writeStatusCache(status) {
  writeProtectedJson(STATUS_CACHE_PATH, 'Status cache', {
    status,
    cached_at: Date.now(),
  });
}

async function readInput() {
  const chunks = [];
  for await (const chunk of process.stdin) chunks.push(chunk);
  const raw = Buffer.concat(chunks).toString('utf-8').trim();
  if (!raw) {
    if (FAIL_CLOSED) throw new Error('Hook input is empty');
    process.stderr.write('[Elydora guard] Hook input is empty; enforcement continued in fail-open mode.\\n');
    return;
  }
  try {
    JSON.parse(raw);
  } catch (error) {
    if (FAIL_CLOSED) throw new Error('Hook input is invalid JSON: ' + error.message);
    process.stderr.write('[Elydora guard] Hook input is invalid JSON; enforcement continued in fail-open mode: ' + error.message + '\\n');
  }
}

function readConfig() {
  const raw = readProtectedFile(
    CONFIG_PATH,
    'Agent config',
    MAX_PROTECTED_CONFIG_BYTES,
  ).toString('utf-8');
  let config;
  try {
    config = JSON.parse(raw);
  } catch (error) {
    throw new Error('Agent config is invalid JSON: ' + error.message);
  }
  if (!config || typeof config !== 'object') throw new Error('Agent config must be an object');
  if (config.agent_id !== AGENT_ID
      || (config.agent_name !== undefined && config.agent_name !== AGENT_NAME)) {
    throw new Error('Agent config identity does not match the generated guard');
  }
  return config;
}

async function main() {
  await readInput();
  let config;
  try {
    config = readConfig();
  } catch (error) {
    if (FAIL_CLOSED) throw new Error('Failed to read agent config: ' + error.message);
    process.stderr.write('[Elydora guard] Failed to read agent config: ' + error.message + '\\n');
    return;
  }

  try {
    const cache = readStatusCache();
    if (cache && cache.age < CACHE_TTL_MS) {
      if (cache.status !== 'active') blockAgent(cache.status);
      return;
    }
  } catch (error) {
    if (FAIL_CLOSED) throw error;
    process.stderr.write('[Elydora guard] ' + error.message + '\\n');
  }

  const baseUrl = String(config.base_url || 'https://api.elydora.com').replace(/\\\/+$/, '');
  const token = config.token || '';
  const controller = new AbortController();
  const timeout = setTimeout(() => controller.abort(), 3000);
  try {
    const headers = { Accept: 'application/json' };
    if (token) headers.Authorization = 'Bearer ' + token;
    const response = await fetch(baseUrl + '/v1/agents/' + encodeURIComponent(AGENT_ID), {
      headers,
      signal: controller.signal,
    });
    if (!response.ok) throw new Error('Agent status API returned HTTP ' + response.status);
    const data = await response.json();
    const status = validateStatus(data && data.agent && data.agent.status, 'Agent status API');
    writeStatusCache(status);
    if (status !== 'active') blockAgent(status);
  } catch (error) {
    if (FAIL_CLOSED) throw new Error('Failed to resolve agent status: ' + error.message);
    process.stderr.write('[Elydora guard] Failed to resolve agent status: ' + error.message + '\\n');
  } finally {
    clearTimeout(timeout);
  }
}

main().then(() => {
  if ((!process.exitCode || process.exitCode === 0) && SUCCESS_OUTPUT) {
    process.stdout.write(SUCCESS_OUTPUT);
  }
}).catch((error) => {
  process.stderr.write('[Elydora guard] ' + (error.stack || error.message || String(error)) + '\\n');
  process.exitCode = 1;
});
`;
}