// here be dragons
// TODO: this is horrible and needs to be refactored ASAP
let utils = require('../utils/utils.js');
let fs = require('../core/fs.js');

class Npm {

  constructor(options) {
    this.logger = options.logger;
  }

  downloadFromGit(registryJSON, packageName, version, returnContent, callback) {
    let repoName = registryJSON.repository.url.replace("git+https://github.com/", "").replace(".git","");
    let gitHead = registryJSON.gitHead;

    if (!gitHead) {
      this.logger.error("Could not download " + packageName + " " + version);
      return callback("error");
    }

    let fileLocation = "https://raw.githubusercontent.com/" + repoName + "/" + gitHead + "/dist/web3.min.js";

    let packageDirectory = './.embark/versions/' + packageName + '/' + version + '/';
    if (fs.existsSync(packageDirectory + "/" + packageName + ".js")) {
      if (returnContent) {
        let distFile = packageDirectory + packageName + ".js";
        callback(null, fs.readFileSync(distFile).toString());
      } else {
        callback(null, packageDirectory);
      }
    } else {
      fs.mkdirpSync(packageDirectory);
      this.logger.info("downloading " + packageName + " " + version + "....");

      utils.downloadFile(fileLocation, packageDirectory + "/" + packageName + ".js", function() {
        utils.extractTar(packageDirectory + "/" + packageName + ".js", packageDirectory, function() {
          if (returnContent) {
            let distFile = packageDirectory + packageName + ".js";
            callback(null, fs.readFileSync(distFile).toString());
          } else {
            callback(null, packageDirectory);
          }
        });
      });
    }
  }

  downloadFromNpm(registryJSON, packageName, version, returnContent, callback) {
    let tarball = registryJSON.dist.tarball;

    let packageDirectory = './.embark/versions/' + packageName + '/' + version + '/';
    if (fs.existsSync(packageDirectory + "/downloaded_package.tgz")) {
      if (returnContent) {
        let distFile = packageDirectory + returnContent;
        callback(null, fs.readFileSync(distFile).toString());
      } else {
        callback(null, packageDirectory);
      }
    } else {
      fs.mkdirpSync(packageDirectory);
      this.logger.info("downloading " + packageName + " " + version + "....");

      utils.downloadFile(tarball, packageDirectory + "/downloaded_package.tgz", function() {
        utils.extractTar(packageDirectory + "/downloaded_package.tgz", packageDirectory, function() {
          if (returnContent) {
            let distFile = packageDirectory + returnContent;
            callback(null, fs.readFileSync(distFile).toString());
          } else {
            callback(null, packageDirectory);
          }
        });
      });
    }
  }

  // TODO: callback should accept an error
  getPackageVersion(packageName, version, returnContent, getFromGit, callback) {
    let self = this;
    let npmRegistry = "https://registry.npmjs.org/" + packageName + "/" + version;
    let packageDirectory = './.embark/versions/' + packageName + '/' + version + '/';

    if (fs.existsSync(packageDirectory)) {
      let content;
      if (getFromGit && returnContent) {
        let distFile = packageDirectory + packageName + ".js";
        content = fs.readFileSync(distFile).toString();
      } else if (returnContent) {
        let distFile = packageDirectory + returnContent;
        content = fs.readFileSync(distFile).toString();
      } else {
        content = packageDirectory;
      }
      return callback(null, content);
    }

    utils.httpsGet(npmRegistry, function (err, body) {
      if (err) {
        if (err.code === 'ENOTFOUND') {
          return callback("can't reach " + err.hostname + " to download " + packageName + " " + version + " - are you connected to the internet?");
        }
        return callback(err);
      }
      let registryJSON = JSON.parse(body);

      if (getFromGit) {
        self.downloadFromGit(registryJSON, packageName, version, returnContent, callback);
      } else {
        self.downloadFromNpm(registryJSON, packageName, version, returnContent, callback);
      }
    });
  }
}

module.exports = Npm;