dapp-config.js

const path = require("path");
const fs = require("fs");
const dappSchema = require('./dapp-schema');
const fm = require('front-matter');

class DAppConfig {
  constructor(config, logger) {
    this.configurations = {};
    this.appConfig = config;
    this.logger = logger;

    this.validate();
  }

  validate() {
    const exitError = msg => {
      this.logger.error(msg);
      process.exit(1);
    };

    this.appConfig.VALID_DAPPS.forEach(dapp => {
      if (!fs.existsSync(`./dapps/${dapp}`)) exitError(`Folder ./dapps/${dapp} does not exist`);
      if (!fs.existsSync(`./dapps/${dapp}/config.js`)) exitError(`Config ./dapps/${dapp}/config.js does not exist`);

      const dappConfig = require(`./dapps/${dapp}/config.js`);
      
      const result = dappSchema.validate(dappConfig);
      if (result.error) exitError(result.error);

      // TODO: improve this
      if(!fs.existsSync(`./dapps/${dapp}/${dappConfig.templates.subscribe}`)) exitError(`Template ./dapps/${dapp}/${dappConfig.templates.subscribe} does not exist`);
      
      Object.keys(dappConfig.templates.contracts).forEach(contract => {
        Object.values(dappConfig.templates.contracts[contract]).forEach(event => {
          if(!fs.existsSync(`./dapps/${dapp}/${event.template}`)) exitError(`Template ./dapps/${dapp}/${event.template} does not exist`);
        });
      });
    });
  }

  isDapp(dappId) {
    return this.appConfig.VALID_DAPPS.indexOf(dappId) > -1;
  }

  getDapps() {
    return this.appConfig.VALID_DAPPS;
  }

  config(dappId) {
    if (this.configurations[dappId]) {
      return this.configurations[dappId];
    }

    this.configurations[dappId] = require("./" + path.join("./dapps/", dappId, "config.js"));

    return this.configurations[dappId];
  }

  contracts(dappId) {
    const dappConfig = this.config(dappId);
    return Object.keys(dappConfig.templates.contracts);
  }

  ABI(dappId, contract) {
    const dappConfig = this.config(dappId);
    const ABI = Object.values(dappConfig.templates.contracts[contract])
      .map(x => x.ABI)
      .reduce((accum, curr) => {
        if (accum.find(x => x.name === curr.name)) return accum;
        return [...accum, curr];
      }, []);
    return ABI;
  }

  template(dappId, templateName) {
    const dappConfig = this.config(dappId);
    return dappConfig.templates[templateName];
  }

  eventConfig(dappId, contract, eventName) {
    const dappConfig = this.config(dappId);
    return Object.values(dappConfig.templates.contracts[contract]).filter(
      x => x.ABI.name === eventName && x.ABI.type === "event"
    );
  }

  getEmailTemplate(dappId, template) {
    const file = fs.readFileSync(path.join("./dapps", dappId, template)).toString();
    const content = fm(file);
    const subject = content.attributes.subject || template;
    const body = content.body;
    const html = content.attributes.html ? !!content.attributes.html : true;
    return { subject, body, html };
  }

  getVariables(dappId, extraData) {
    const dappConfig = this.config(dappId);
    return Object.assign(dappConfig.templates.variables || {}, extraData);
  }
}

module.exports = DAppConfig;