import fs, { writeFile, unlink } from 'fs-extra';
import axios from 'axios';
import { Message } from 'eris';
import { AccountInterface } from '../models';
import { Command, RichEmbed } from '../class';
import { Client } from '..';
import { parseCertificate } from '../functions';

export default class CWG_Create extends Command {
  public urlRegex: RegExp;

  constructor(client: Client) {
    super(client);
    this.name = 'create';
    this.description = 'Bind a domain to the CWG';
    this.usage = `${this.client.config.prefix}cwg create [User ID | Username] [Domain] [Port] <Cert Chain> <Private Key> || Use snippets raw URL`;
    this.permissions = { roles: ['525441307037007902'] };
    this.aliases = ['bind'];
    this.enabled = true;
    this.urlRegex = /^[a-zA-Z0-9\-._~:/?#[\]@!$&'()*+,;=]+$/;
  }

  public async run(message: Message, args: string[]) {
    /*
    args[0] should be the user's ID OR account username; required
    args[1] should be the domain; required
    args[2] should be the port; required
    args[3] should be the path to the x509 certificate; not required
    args[4] should be the path to the x509 key; not required
    */
    try {
      if (!args[2]) return this.client.commands.get('help').run(message, ['cwg', this.name]);

      let certs: { cert: string, key: string };

      if (!this.urlRegex.test(args[1])) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Invalid URL***`);
      if (Number(args[2]) <= 1024 || Number(args[2]) >= 65535) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Port must be greater than 1024 and less than 65535***`);
      if (!args[1].endsWith('.cloud.libraryofcode.org') && !args[4]) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Certificate Chain and Private Key are required for custom domains***`);

      const account = await this.client.db.Account.findOne({ $or: [{ username: args[0] }, { userID: args[0] }] });
      if (!account) return message.channel.createMessage(`${this.client.stores.emojis.error} Cannot locate account, please try again.`);

      if (await this.client.db.Domain.exists({ domain: args[1] })) return message.channel.createMessage(`${this.client.stores.emojis.error} ***This domain already exists***`);

      if (await this.client.db.Domain.exists({ port: Number(args[2]) })) {
        let answer: Message;
        try {
          answer = await this.client.util.messageCollector(
            message,
            `***${this.client.stores.emojis.error} ***This port is already binded to a domain. Do you wish to continue? (y/n)***`,
            30000, true, ['y', 'n'], (msg) => msg.author.id === message.author.id && msg.channel.id === message.channel.id,
          );
        } catch (error) {
          return message.channel.createMessage(`${this.client.stores.emojis.error} ***Bind request cancelled***`);
        }
        if (answer.content === 'n') return message.channel.createMessage(`${this.client.stores.emojis.error} ***Bind request cancelled***`);
      }

      const edit = await message.channel.createMessage(`${this.client.stores.emojis.loading} ***Binding domain...***`);

      if (!args[1].endsWith('.cloud.libraryofcode.org')) {
        const urls = args.slice(3, 5);
        if (urls.some((l) => !l.includes('snippets.cloud.libraryofcode.org/raw/'))) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Invalid snippets URL***`);

        const tasks = urls.map((l) => axios({ method: 'GET', url: l }));
        const response = await Promise.all(tasks);
        const certAndPrivateKey: string[] = response.map((r) => r.data);

        if (!this.isValidCertificateChain(certAndPrivateKey[0])) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Invalid Certificate Chain***`);
        if (!this.isValidPrivateKey(certAndPrivateKey[1])) return message.channel.createMessage(`${this.client.stores.emojis.error} ***Invalid Private Key***`);

        certs = { cert: certAndPrivateKey[0], key: certAndPrivateKey[1] };
      }

      const domain = await this.createDomain(account, args[1], Number(args[2]), certs);

      const tasks = [message.delete(), this.client.util.exec('systemctl reload nginx')];
      // @ts-ignore
      await Promise.all(tasks);

      const embed = new RichEmbed()
        .setTitle('Domain Creation')
        .setColor(3066993)
        .addField('Account Username', account.username, true)
        .addField('Account ID', account.id, true)
        .addField('Engineer', `<@${message.author.id}>`, true)
        .addField('Domain', domain.domain, true)
        .addField('Port', String(domain.port), true);

      const cert = await parseCertificate(this.client, domain.x509.cert);

      embed.addField('Certificate Issuer', cert.issuer.organizationName, true)
        .addField('Certificate Subject', cert.subject.commonName, true)
        .setFooter(this.client.user.username, this.client.user.avatarURL)
        .setTimestamp(new Date(message.timestamp));

      const completed = [
        edit.edit(`***${this.client.stores.emojis.success} Successfully binded ${domain.domain} to port ${domain.port} for ${account.userID}.***`),
        this.client.createMessage('580950455581147146', { embed }),
        this.client.getDMChannel(account.userID).then((r) => r.createMessage({ embed })),
        this.client.util.transport.sendMail({
          to: account.emailAddress,
          from: 'Library of Code sp-us | Support Team <help@libraryofcode.org>',
          subject: 'Your domain has been binded',
          html: `
            <h1>Library of Code sp-us | Cloud Services</h1>
            <p>Hello, this is an email informing you that a new domain under your account has been binded.
            Information is below.</p>
            <b>Domain:</b> ${domain.domain}<br>
            <b>Port:</b> ${domain.port}<br>
            <b>Certificate Issuer:</b> ${cert.issuer.organizationName}<br>
            <b>Certificate Subject:</b> ${cert.subject.commonName}<br>
            <b>Responsible Engineer:</b> ${message.author.username}#${message.author.discriminator}<br><br>
  
            If you have any questions about additional setup, you can reply to this email or send a message in #cloud-support in our Discord server.<br>
  
            <b><i>Library of Code sp-us | Support Team</i></b>
            `,
        }),
      ];

      if (!domain.domain.includes('cloud.libraryofcode.org')) {
        const content = `__**DNS Record Setup**__\nYou recently a binded a custom domain to your Library of Code sp-us Account. You'll have to update your DNS records. We've provided the records below.\n\n\`${domain.domain} IN CNAME cloud.libraryofcode.org AUTO/500\`\nThis basically means you need to make a CNAME record with the key/host of ${domain.domain} and the value/point to cloud.libraryofcode.org. If you have any questions, don't hesitate to ask us.`;
        completed.push(this.client.getDMChannel(account.userID).then((r) => r.createMessage(content)));
      }

      return Promise.all(completed);
    } catch (err) {
      await fs.unlink(`/etc/nginx/sites-available/${args[1]}`);
      await fs.unlink(`/etc/nginx/sites-enabled/${args[1]}`);
      await this.client.db.Domain.deleteMany({ domain: args[1] });
      return this.client.util.handleError(err, message, this);
    }
  }

  /**
   * This function binds a domain to a port on the CWG.
   * @param account The account of the user.
   * @param subdomain The domain to use. `mydomain.cloud.libraryofcode.org`
   * @param port The port to use, must be between 1024 and 65535.
   * @param x509Certificate The contents the certificate and key files.
   * @example await CWG.createDomain(account, 'mydomain.cloud.libraryofcode.org', 6781);
   */
  public async createDomain(account: AccountInterface, domain: string, port: number, x509Certificate: { cert?: string, key?: string }) {
    try {
      if (port <= 1024 || port >= 65535) throw new RangeError(`Port range must be between 1024 and 65535, received ${port}.`);
      if (await this.client.db.Domain.exists({ domain })) throw new Error(`Domain ${domain} already exists in the database.`);
      if (!await this.client.db.Account.exists({ userID: account.userID })) throw new Error(`Cannot find account ${account.userID}.`);
      let x509: { cert: string, key: string };
      if (x509Certificate) {
        x509 = await this.createCertAndPrivateKey(domain, x509Certificate.cert, x509Certificate.key);
      } else {
        x509 = {
          cert: '/etc/ssl/private/cloud-libraryofcode-org.chain.crt',
          key: '/etc/ssl/private/cloud-libraryofcode-org.key',
        };
      }
      let cfg = await fs.readFile('/opt/CloudServices/src/static/nginx.conf', { encoding: 'utf8' });
      cfg = cfg.replace(/\[DOMAIN]/g, domain);
      cfg = cfg.replace(/\[PORT]/g, String(port));
      cfg = cfg.replace(/\[CERTIFICATE]/g, x509.cert);
      cfg = cfg.replace(/\[KEY]/g, x509.key);
      await fs.writeFile(`/etc/nginx/sites-available/${domain}`, cfg, { encoding: 'utf8' });
      await fs.symlink(`/etc/nginx/sites-available/${domain}`, `/etc/nginx/sites-enabled/${domain}`);
      const entry = new this.client.db.Domain({
        account,
        domain,
        port,
        x509,
        enabled: true,
      });
      if (domain.includes('cloud.libraryofcode.org')) {
        const dmn = domain.split('.');
        await axios({
          method: 'post',
          url: 'https://api.cloudflare.com/client/v4/zones/5e82fc3111ed4fbf9f58caa34f7553a7/dns_records',
          headers: { Authorization: `Bearer ${this.client.config.cloudflare}`, 'Content-Type': 'application/json' },
          data: JSON.stringify({ type: 'CNAME', name: `${dmn[0]}.${dmn[1]}`, content: 'cloud.libraryofcode.org', proxied: false }),
        });
      }
      return entry.save();
    } catch (error) {
      const tasks = [fs.unlink(`/etc/nginx/sites-enabled/${domain}`), fs.unlink(`/etc/nginx/sites-available/${domain}`), this.client.db.Domain.deleteMany({ domain })];
      await Promise.allSettled(tasks);
      throw error;
    }
  }

  public async createCertAndPrivateKey(domain: string, certChain: string, privateKey: string) {
    if (!this.isValidCertificateChain(certChain)) throw new Error('Invalid Certificate Chain');
    if (!this.isValidPrivateKey(privateKey)) throw new Error('Invalid Private Key');
    const path = `/opt/CloudServices/temp/${domain}`;
    const temp = [writeFile(`${path}.chain.crt`, certChain), writeFile(`${path}.key.pem`, privateKey)];
    const removeFiles = [unlink(`${path}.chain.crt`), unlink(`${path}.key.pem`)];
    await Promise.all(temp);
    if (!this.isMatchingPair(`${path}.chain.crt`, `${path}.key.pem`)) {
      await Promise.all(removeFiles);
      throw new Error('Certificate and Private Key do not match');
    }

    const tasks = [writeFile(`/etc/nginx/ssl/${domain}.chain.crt`, certChain), writeFile(`/etc/nginx/ssl/${domain}.key.pem`, privateKey)];
    await Promise.all(tasks);
    return { cert: `/etc/nginx/ssl/${domain}.chain.crt`, key: `/etc/nginx/ssl/${domain}.key.pem` };
  }

  public checkOccurance(text: string, query: string) {
    return (text.match(new RegExp(query, 'g')) || []).length;
  }

  public isValidCertificateChain(cert: string) {
    if (!cert.replace(/^\s+|\s+$/g, '').startsWith('-----BEGIN CERTIFICATE-----')) return false;
    if (!cert.replace(/^\s+|\s+$/g, '').endsWith('-----END CERTIFICATE-----')) return false;
    if (this.checkOccurance(cert.replace(/^\s+|\s+$/g, ''), '-----BEGIN CERTIFICATE-----') !== 2) return false;
    if (this.checkOccurance(cert.replace(/^\s+|\s+$/g, ''), '-----END CERTIFICATE-----') !== 2) return false;
    return true;
  }

  public isValidPrivateKey(key: string) {
    if (!key.replace(/^\s+|\s+$/g, '').startsWith('-----BEGIN PRIVATE KEY-----')) return false;
    if (!key.replace(/^\s+|\s+$/g, '').endsWith('-----END PRIVATE KEY-----')) return false;
    if (this.checkOccurance(key.replace(/^\s+|\s+$/g, ''), '-----BEGIN PRIVATE KEY-----') !== 1) return false;
    if (this.checkOccurance(key.replace(/^\s+|\s+$/g, ''), '-----END PRIVATE KEY-----') !== 1) return false;
    return true;
  }

  public async isMatchingPair(cert: string, privateKey: string) {
    const result: string = await this.client.util.exec(`${__dirname}/../bin/checkCertSignatures ${cert} ${privateKey}`);
    const { ok }: { ok: boolean } = JSON.parse(result);
    return ok;
  }
}