'use strict';
/*global Promise*/

var Challenge = module.exports;

// IMPORTANT
//
// These are all PROMISIFIED by Greenlock in such a way that
// it doesn't matter whether you return synchronously, asynchronously,
// or even node-style callback thunk.
//
// Typically you should be using a promise or async function,
// but choose whichever makes sense for you.
Challenge.create = function (config) {
  // If your implementation needs config options, set them. Otherwise, don't bother (duh).

  var challenger = {};

  // Note: normally you'd implement these right here, but for the sake of
  // documentation I've abstracted them out "Table of Contents"-style.

  // call out to set the challenge, wherever
  challenger.set = function (opts, cb) {
    var ch = opts.challenge;
    if ('http-01' === ch.type) {
      return Challenge._setHttp(opts, cb);
    } else if ('dns-01' === ch.type) {
      return Challenge._setDns(opts, cb);
    } else {
      return Challenge._setAny(opts, cb);
    }
  };

  // call out to remove the challenge, wherever
  challenger.remove = function (opts) {
    var ch = opts.challenge;
    if ('http-01' === ch.type) {
      return Challenge._removeHttp(opts);
    } else if ('dns-01' === ch.type) {
      return Challenge._removeDns(opts);
    } else {
      return Challenge._removeAny(opts);
    }
  };

  // only really useful for http,
  // but probably not so much in this context...
  // (though you can test it and it'll work)
  challenger.get = function (opts) {
    var ch = opts.challenge;
    if ('http-01' === ch.type) {
      return Challenge._getHttp(opts);
    } else if ('dns-01' === ch.type) {
      return Challenge._getDns(opts);
    } else {
      return Challenge._getAny(opts);
    }
  };

  // Whatever you set to 'options' will be merged into 'opts' just before each call
  // (for convenience, so you don't have to merge it yourself).
  challenger.options = { debug: config.debug };

  return challenger;
};

// Show the user the token and key and wait for them to be ready to continue
Challenge._setHttp = function (args, cb) {
  // Using a node-style callback "thunk" in this example, because that makes

  var ch = args.challenge;
  console.info("[ACME http-01 '" + ch.altname + "' CHALLENGE]");
  console.info("Your mission (since you chose to accept it):");
  console.info("First, you must create a file with the following name and contents.");
  console.info("Then, by any means necessary, you cause that file to appear at the specified URL.");
  console.info("");
  console.info("\tFilename: " + ch.token);
  console.info("\tContents: " + ch.keyAuthorization);
  // TODO let acme-v2 handle generating this url
  console.info('\tURL: http://' + ch.altname + '/.well-known/acme-challenge/' + ch.token);
  console.info("");
  console.info("And, if you need additional information for debugging:");
  console.info("");
  console.info(JSON.stringify(httpChallengeToJson(ch), null, 2).replace(/^/gm, '\t'));
  console.info("");
  console.info("This message won't self-destruct, but you may press hit the any as soon as you're ready to continue...");
  console.info("");
  console.info("[Press the ANY key to continue...]");

  process.stdin.resume();
  process.stdin.once('data', function () {
    process.stdin.pause();
    cb(null);
  });
};

Challenge._setDns = function (args, cb) {
  // Using a node-style callback "thunk" in this example, because that makes

  var ch = args.challenge;
  console.info("[ACME dns-01 '" + ch.altname + "' CHALLENGE]");
  console.info("Your mission (since you chose to accept it):");
  console.info("First, you must create a DNS record with the following parameters:");
  console.info("");
  console.info(ch.dnsHost + "\tTXT\t" + ch.dnsKeyAuthorization + "\tTTL 60");
  console.info("");
  console.info("Next, wait, no... there is no next. That's it - but here's some stuff anyway:");
  console.info("");
  console.info(JSON.stringify(dnsChallengeToJson(ch), null, 2).replace(/^/gm, '\t'));
  console.info("");
  console.info("[Press the ANY key to continue...]");

  process.stdin.resume();
  process.stdin.once('data', function () {
    process.stdin.pause();
    cb(null);
  });
};

Challenge._setAny = function (args, cb) {
  var ch = args.challenge;
  console.info("[ACME " + ch.type + " '" + ch.altname + "' CHALLENGE]");
  console.info("There's no quippy pre-programmed response for this type of challenge.");
  console.info("I have no idea what you intend to do, but I'll tell you everything I know:");
  console.info("");
  console.info(JSON.stringify(ch, null, 2).replace(/^/gm, '\t'));
  console.info("");
  console.info("[Press the ANY key to continue...]");

  process.stdin.resume();
  process.stdin.on('data', function () {
    process.stdin.pause();
    cb(null);
  });
};

// might as well tell the user that whatever they were setting up has been checked
Challenge._removeHttp = function (args) {
  var ch = args.challenge;
  console.info("");
  console.info("Challenge for '" + ch.altname + "' complete. You can delete this file now:");
  console.info('\thttp://' + ch.altname + '/.well-known/acme-challenge/' + ch.token);
  console.info("");

  // this can return null or a Promise null
  // (or callback null, just like the set() above)
  return null;
};
Challenge._removeDns = function (args) {
  var ch = args.challenge;
  console.info("");
  console.info("Challenge for '" + ch.altname + "' complete. You can remove this record now:");
  console.info("\t" + ch.dnsHost + "\tTXT\t" + ch.dnsKeyAuthorization + "\tTTL 60");
  console.info("");

  // this can return null or a Promise null
  // (or callback null, just like the set() above)
  return null;
};
Challenge._removeAny = function (args) {
  var ch = args.challenge;
  console.info("");
  console.info("Challenge for '" + ch.altname + "' complete. You can now undo what you did.");
  console.info("");

  // this can return null or a Promise null
  // (or callback null, just like set() above)
  return null;
};

// nothing to do here, that's why it's manual
Challenge._get = function (args, cb) {
  console.info("");
  console.info("Woah! Hey, guess what!? That's right you guessed it:");
  console.info("It's time to painstakingly type out the ACME challenge response with your bear hands. Yes. Your bear hands.");
  process.stdout.write("> ");

  // Using a promise here just to show that Promises are support
  // (in fact, they're the default)
  return new Promise(function (resolve, reject) {
    process.stdin.resume();
    process.stdin.on('error', reject);
    process.stdin.on('data', function (chunk) {
      process.stdin.pause();
      var result = chunk.toString();
      try {
        result = JSON.parse(result);
      } catch(e) {
        args.keyAuthorization = result;
      }
      cb(null);
    });
  });
};

function httpChallengeToJson(ch) {
  return {
    type: ch.type
  , altname: ch.altname
  , identifier: ch.identifier
  , wildcard: false
  , expires: ch.expires
  , token: ch.token
  , thumbprint: ch.thumbprint
  , keyAuthorization: ch.keyAuthorization
  };
}

function dnsChallengeToJson(ch) {
  return {
    type: ch.type
  , altname: '*.example.com'
  , identifier: ch.identifier
  , wildcard: ch.wildcard
  , expires: ch.expires
  , token: ch.token
  , thumbprint: ch.thumbprint
  , keyAuthorization: ch.keyAuthorization
  , dnsHost: ch.dnsHost
  , dnsAuthorization: ch.dnsAuthorization
  };
}