const fs = require('node:fs');
const path = require('path');
const { get } = require('lodash');
const { getCACertificates } = require('@usebruno/requests');
const { preferencesUtil } = require('../../store/preferences');
const { getBrunoConfig } = require('../../store/bruno-config');
const { getCachedSystemProxy } = require('../../store/system-proxy');
const { interpolateString, interpolateObject } = require('./interpolate-string');

/**
 * Gets certificates and proxy configuration for a request
 */
const getCertsAndProxyConfig = async ({
  collectionUid,
  collection,
  request,
  envVars,
  runtimeVariables,
  processEnvVars,
  collectionPath,
  globalEnvironmentVariables
}) => {
  /**
   * @see https://github.com/usebruno/bruno/issues/211 set keepAlive to true, this should fix socket hang up errors
   * @see https://github.com/nodejs/node/pull/43522 keepAlive was changed to true globally on Node v19+
   */
  const httpsAgentRequestFields = { keepAlive: true };
  if (!preferencesUtil.shouldVerifyTls()) {
    httpsAgentRequestFields['rejectUnauthorized'] = false;
  }

  let caCertificates = '';
  let caCertificatesCount = { system: 0, root: 0, custom: 0, extra: 0 };

  // Only load CA certificates if SSL validation is enabled (otherwise they're unused)
  if (preferencesUtil.shouldVerifyTls()) {
    let caCertFilePath = preferencesUtil.shouldUseCustomCaCertificate() && preferencesUtil.getCustomCaCertificateFilePath();
    let caCertificatesData = getCACertificates({
      caCertFilePath,
      shouldKeepDefaultCerts: preferencesUtil.shouldKeepDefaultCaCertificates()
    });

    caCertificates = caCertificatesData.caCertificates;
    caCertificatesCount = caCertificatesData.caCertificatesCount;
  }

  // configure HTTPS agent with aggregated CA certificates
  httpsAgentRequestFields['caCertificatesCount'] = caCertificatesCount;
  httpsAgentRequestFields['ca'] = caCertificates || [];

  const { promptVariables } = collection;
  const collectionVariables = request.collectionVariables || {};
  const folderVariables = request.folderVariables || {};
  const requestVariables = request.requestVariables || {};

  const brunoConfig = getBrunoConfig(collectionUid, collection);
  const interpolationOptions = {
    globalEnvironmentVariables,
    collectionVariables,
    envVars,
    folderVariables,
    requestVariables,
    runtimeVariables,
    promptVariables,
    processEnvVars
  };

  // client certificate config
  const clientCertConfig = get(brunoConfig, 'clientCertificates.certs', []);

  for (let clientCert of clientCertConfig) {
    const domain = interpolateString(clientCert?.domain, interpolationOptions);
    const type = clientCert?.type || 'cert';
    if (domain) {
      const hostRegex = '^(https:\\/\\/|grpc:\\/\\/|grpcs:\\/\\/|ws:\\/\\/|wss:\\/\\/)?'
        + domain.replaceAll('.', '\\.').replaceAll('*', '.*');
      const requestUrl = interpolateString(request.url, interpolationOptions);
      if (requestUrl && requestUrl.match(hostRegex)) {
        if (type === 'cert') {
          try {
            let certFilePath = interpolateString(clientCert?.certFilePath, interpolationOptions);
            certFilePath = path.isAbsolute(certFilePath) ? certFilePath : path.join(collectionPath, certFilePath);
            let keyFilePath = interpolateString(clientCert?.keyFilePath, interpolationOptions);
            keyFilePath = path.isAbsolute(keyFilePath) ? keyFilePath : path.join(collectionPath, keyFilePath);

            httpsAgentRequestFields['cert'] = fs.readFileSync(certFilePath);
            httpsAgentRequestFields['key'] = fs.readFileSync(keyFilePath);
          } catch (err) {
            console.error('Error reading cert/key file', err);
            throw new Error('Error reading cert/key file' + err);
          }
        } else if (type === 'pfx') {
          try {
            let pfxFilePath = interpolateString(clientCert?.pfxFilePath, interpolationOptions);
            pfxFilePath = path.isAbsolute(pfxFilePath) ? pfxFilePath : path.join(collectionPath, pfxFilePath);
            httpsAgentRequestFields['pfx'] = fs.readFileSync(pfxFilePath);
          } catch (err) {
            console.error('Error reading pfx file', err);
            throw new Error('Error reading pfx file' + err);
          }
        }
        httpsAgentRequestFields['passphrase'] = interpolateString(clientCert.passphrase, interpolationOptions);
        break;
      }
    }
  }

  /**
   * Proxy configuration
   *
   * New format:
   * - disabled: boolean (optional, defaults to false)
   * - inherit: boolean (required)
   * - config: { protocol, hostname, port, auth, bypassProxy }
   *
   * When collection proxy has inherit=false and disabled=false, use collection-specific proxy
   * When collection proxy has inherit=true, inherit from global preferences
   * When disabled=true, proxy is disabled
   *
   * Below logic calculates the proxyMode and proxyConfig to be used for the request
   */
  let proxyMode = 'off';
  let proxyConfig = {};
  let proxyModeReason = '';

  const collectionProxyConfig = get(brunoConfig, 'proxy', {});
  const collectionProxyDisabled = get(collectionProxyConfig, 'disabled', false);
  const collectionProxyInherit = get(collectionProxyConfig, 'inherit', true);
  const collectionProxyConfigData = get(collectionProxyConfig, 'config', collectionProxyConfig);

  if (!collectionProxyDisabled && !collectionProxyInherit) {
    // Use collection-specific proxy
    proxyConfig = collectionProxyConfigData;
    proxyMode = 'on';
  } else if (!collectionProxyDisabled && collectionProxyInherit) {
    // Inherit from global preferences
    const globalProxy = preferencesUtil.getGlobalProxyConfig();
    const globalDisabled = get(globalProxy, 'disabled', false);
    const globalProxySource = get(globalProxy, 'source', 'manual');
    const globalProxyConfigData = get(globalProxy, 'config', {});

    if (!globalDisabled) {
      if (globalProxySource === 'pac') {
        proxyMode = 'pac';
        proxyConfig = {
          pac: globalProxy.pac ?? {}
        };
      } else if (globalProxySource === 'inherit') {
        proxyMode = 'system';
        const systemProxyConfig = await getCachedSystemProxy();
        proxyConfig = systemProxyConfig || { http_proxy: null, https_proxy: null, no_proxy: null, pac_url: null, source: 'cache-miss' };
      } else {
        // source === 'manual'
        proxyConfig = globalProxyConfigData;
        proxyMode = 'on';
      }
    } else {
      proxyModeReason = 'App-level proxy is disabled';
    }
  } else {
    proxyModeReason = 'Collection-level proxy is disabled';
  }

  return { proxyMode, proxyModeReason, proxyConfig, httpsAgentRequestFields, interpolationOptions };
};

/**
 * Builds the certsAndProxyConfig object for bru.sendRequest
 * This allows bru.sendRequest to use the same proxy/certs config as the main request
 */
const buildCertsAndProxyConfig = async ({
  collectionUid,
  collection,
  collectionPath,
  envVars,
  runtimeVariables,
  processEnvVars,
  request
}) => {
  const brunoConfig = getBrunoConfig(collectionUid, collection);

  // Build interpolation options (same pattern as getCertsAndProxyConfig)
  const globalEnvironmentVariables = collection.globalEnvironmentVariables || {};
  const { promptVariables } = collection;
  const collectionVariables = request?.collectionVariables || {};
  const folderVariables = request?.folderVariables || {};
  const requestVariables = request?.requestVariables || {};

  const interpolationOptions = {
    globalEnvironmentVariables,
    collectionVariables,
    envVars,
    folderVariables,
    requestVariables,
    runtimeVariables,
    promptVariables,
    processEnvVars
  };

  // Build options for getHttpHttpsAgents
  const options = {
    noproxy: false,
    shouldVerifyTls: preferencesUtil.shouldVerifyTls(),
    shouldUseCustomCaCertificate: preferencesUtil.shouldUseCustomCaCertificate(),
    customCaCertificateFilePath: preferencesUtil.getCustomCaCertificateFilePath(),
    shouldKeepDefaultCaCertificates: preferencesUtil.shouldKeepDefaultCaCertificates(),
    cacheSslSession: preferencesUtil.isSslSessionCachingEnabled()
  };

  // Get client certificates from bruno config and interpolate
  const rawClientCertificates = get(brunoConfig, 'clientCertificates');
  const clientCertificates = rawClientCertificates
    ? interpolateObject(rawClientCertificates, interpolationOptions)
    : undefined;

  // Get proxy config from bruno config and interpolate
  const collectionProxyConfig = get(brunoConfig, 'proxy', {});
  const collectionLevelProxy = interpolateObject(collectionProxyConfig, interpolationOptions);

  // Get app-level proxy config from global preferences
  const appLevelProxyConfig = preferencesUtil.getGlobalProxyConfig();

  // Get system proxy config
  const systemProxyConfig = await getCachedSystemProxy();

  return {
    collectionPath,
    options,
    clientCertificates,
    collectionLevelProxy,
    appLevelProxyConfig,
    systemProxyConfig
  };
};

module.exports = { getCertsAndProxyConfig, buildCertsAndProxyConfig };