import path from 'path';
import { unlinkSync as rm, writeFileSync as writeFile, readFileSync as readFile } from 'fs';
import { sync as mkdirp } from 'mkdirp';
import { template as makeTemplate } from 'lodash';
import applicationConfigPath = require('application-config-path');
import eol from 'eol';
import {mktmp, numericHash} from './utils';

// Platform shortcuts
export const isMac = process.platform === 'darwin';
export const isLinux = process.platform === 'linux';
export const isWindows = process.platform === 'win32';

// Common paths
export const configDir = applicationConfigPath('devcert');
export const configPath: (...pathSegments: string[]) => string = path.join.bind(path, configDir);

const getFilteredDomains = (domains: string[]) =>
  Array.from(
    domains
      .sort((a, b) => b.length - a.length)
      .reduce((filteredList, domain) =>
        Array.from(filteredList)
          .reduce((matches, item) => {
            if (item.indexOf(domain) > -1) {
              matches.add(domain);
            } else if (domain.indexOf(item) === -1 && item.indexOf(domain) === -1) {
              matches.add(item);
              matches.add(domain);
            } else {
              matches.add(item);
            }

            return matches;
          }, new Set()
          ), new Set([domains[0]])
      )
  ).sort();

export const getStableDomainPath = (domains: string[]) =>
  domains.length === 1 ?
    domains[0] :
    'san-' + numericHash(getFilteredDomains(domains).join(''));
export const domainsDir = configPath('domains');
export const pathForDomain: (domain: string, ...pathSegments: string[]) => string = path.join.bind(path, domainsDir)

export const caVersionFile = configPath('devcert-ca-version');
export const opensslSerialFilePath = configPath('certificate-authority', 'serial');
export const opensslDatabaseFilePath = configPath('certificate-authority', 'index.txt');
export const caSelfSignConfig = path.join(__dirname, '../openssl-configurations/certificate-authority-self-signing.conf');

function generateSubjectAltNames(domains: string[]): string {
  return domains
    .reduce((dnsEntries, domain) =>
      dnsEntries.concat([
        `DNS.${dnsEntries.length + 1} = ${domain}`,
        `DNS.${dnsEntries.length + 2} = *.${domain}`,
      ]), [] as string[])
    .join("\r\n");
}

export function withDomainSigningRequestConfig(domains: string[], cb: (filepath: string) => void) {
  const domain = domains[0];
  const subjectAltNames = generateSubjectAltNames(domains);
  let tmpFile = mktmp();
  let source = readFile(path.join(__dirname, '../openssl-configurations/domain-certificate-signing-requests.conf'), 'utf-8');
  let template = makeTemplate(source);
  let result = template({domain, subjectAltNames});
  writeFile(tmpFile, eol.auto(result));
  cb(tmpFile);
  rm(tmpFile);
}

export function withDomainCertificateConfig(domains: string[], cb: (filepath: string) => void) {
  const domainPath = getStableDomainPath(domains);
  const subjectAltNames = generateSubjectAltNames(domains);
  let tmpFile = mktmp();
  let source = readFile(path.join(__dirname, '../openssl-configurations/domain-certificates.conf'), 'utf-8');
  let template = makeTemplate(source);
  let result = template({
    subjectAltNames,
    serialFile: opensslSerialFilePath,
    databaseFile: opensslDatabaseFilePath,
    domainDir: pathForDomain(domainPath)
  });
  writeFile(tmpFile, eol.auto(result));
  cb(tmpFile);
  rm(tmpFile);
}

  // confTemplate = confTemplate.replace(/DATABASE_PATH/, configPath('index.txt').replace(/\\/g, '\\\\'));
  // confTemplate = confTemplate.replace(/SERIAL_PATH/, configPath('serial').replace(/\\/g, '\\\\'));
  // confTemplate = eol.auto(confTemplate);

export const rootCADir = configPath('certificate-authority');
export const rootCAKeyPath = configPath('certificate-authority', 'private-key.key');
export const rootCACertPath = configPath('certificate-authority', 'certificate.cert');



// Exposed for uninstallation purposes.
export function getLegacyConfigDir(): string {
  if (isWindows && process.env.LOCALAPPDATA) {
    return path.join(process.env.LOCALAPPDATA, 'devcert', 'config');
  } else {
    let uid = process.getuid && process.getuid();
    let userHome = (isLinux && uid === 0) ? path.resolve('/usr/local/share') : require('os').homedir();
    return path.join(userHome, '.config', 'devcert');
  }
}

export function ensureConfigDirs() {
  mkdirp(configDir);
  mkdirp(domainsDir);
  mkdirp(rootCADir);
}

ensureConfigDirs();