'use strict';

// IMPORTANT
// IMPORTANT
// IMPORTANT
//
// Ready? DON'T OVERTHINK IT!!! (Seriously, this is a huge problem)
//
// If you get confused, you're probably smart and thinking too deep.
//
// Want an explanation of how and why? Okay...
// https://coolaj86.com/articles/lets-encrypt-v2-step-by-step/
//
// But really, you probably don't want to know how and why (because then you'd be implementing your own from scratch)
//
// IMPORTANT
// IMPORTANT
// IMPORTANT
//
// If you want to create a storage strategy quick-and-easy, treat everything as either dumb strings or JSON blobs
// (just as is done here), don't try to do clever optimizations, 5th normal form, etc (you ain't gonna need it),
// but DO use the simple test provided by `greenlock-store-test`.
//
// IMPORTANT
// IMPORTANT
// IMPORTANT
//
// Don't get fancy. Don't overthink it.
// If you want to be fancy and clever, do that after you can pass `greenlock-store-test` the dumb way shown here.
//
// Also: please do contribute clarifying comments.


module.exports.create = function (opts) {
  // pass in database url, connection string, filepath,
  // or whatever it is you need to get your job done well



  // This is our in-memory storage.
  // We take it from the outside to make testing the dummy module easier.
  var cache = opts.cache || {};
  if (!cache.accounts) { cache.accounts = {}; }
  if (!cache.certificates) { cache.certificates = {}; }
  // Although we could have two collections of keypairs,
  // it's also fine to store both types together.
  if (!cache.keypairs) { cache.keypairs = {}; }



  var store = {};
  // any options you need per instance
  // (probably okay to leave empty)
  store.options = {};
  store.accounts = {};
  store.certificates = {};



  // Whenever a new keypair is used to successfully create an account, we need to save its keypair
  store.accounts.setKeypair = function (opts) {
    console.log('accounts.setKeypair:', opts.account, opts.email, opts.keypair);

    var id = opts.account.id || opts.email || 'default';
    var keypair = opts.keypair;

    cache.keypairs[id] = JSON.stringify({
      privateKeyPem: keypair.privateKeyPem
    , privateKeyJwk: keypair.privateKeyJwk
    });

    return null; // or Promise.resolve(null);
  };



  // We need a way to retrieve a prior account's keypair for renewals and additional ACME certificate "orders"
  store.accounts.checkKeypair = function (opts) {
    console.log('accounts.checkKeypair:', opts.account, opts.email);

    var id = opts.account.id || opts.email || 'default';
    var keyblob = cache.keypairs[id];

    if (!keyblob) { return null; }

    return JSON.parse(keyblob);
  };



  // We can optionally implement ACME account storage and retrieval
  // (to reduce API calls), but it's really not necessary.
  /*
    store.accounts.set = function (opts) {
      console.log('accounts.set:', opts);
      return null;
    };
    store.accounts.check = function (opts) {
      var id = opts.account.id || opts.email || 'default';
      console.log('accounts.check:', opts);
      return null;
    };
  */



  // The certificate keypairs (properly named privkey.pem, though sometimes sutpidly called cert.key)
  // https://community.letsencrypt.org/t/what-are-those-pem-files/18402
  // Certificate Keypairs must not be used for Accounts and vice-versamust not be the same as any account keypair
  //
  store.certificates.setKeypair = function (opts) {
    console.log('certificates.setKeypair:', opts.certificate, opts.subject, opts.keypair);

    // The ID is a string that doesn't clash between accounts and certificates.
    // That's all you need to know... unless you're doing something special (in which case you're on your own).
    var id = opts.certificate.kid || opts.certificate.id || opts.subject;
    var keypair = opts.keypair;

    cache.keypairs[id] = JSON.stringify({
      privateKeyPem: keypair.privateKeyPem
    , privateKeyJwk: keypair.privateKeyJwk
    });
    // Note: you can use the "keypairs" package to convert between
    // public and private for jwk and pem, as well as convert JWK <-> PEM

    return null;
  };



  // You won't be able to use a certificate without it's private key, gotta save it
  store.certificates.checkKeypair = function (opts) {
    console.log('certificates.checkKeypair:', opts.certificate, opts.subject);

    var id = opts.certificate.kid || opts.certificate.id || opts.subject;
    var keyblob = cache.keypairs[id];

    if (!keyblob) { return null; }

    return JSON.parse(keyblob);
  };



  // And you'll also need to save certificates. You may find the metadata useful to save
  // (perhaps to delete expired keys), but the same information can also be redireved from
  // the key using the "cert-info" package.
  store.certificates.set = function (opts) {
    console.log('certificates.set:', opts.certificate, opts.subject);

    var id = opts.certificate.id || opts.subject;
    var pems = opts.pems;
    cache.certificates[id] = JSON.stringify({
      cert: pems.cert
    , chain: pems.chain
    , subject: pems.subject
    , altnames: pems.altnames
    , issuedAt: pems.issuedAt   // a.k.a. NotBefore
    , expiresAt: pems.expiresAt // a.k.a. NotAfter
    });

    return null;
  };



  // This is actually the first thing to be called after approveDomins(),
  // but it's easiest to implement last since it's not useful until there
  // are certs that can actually be loaded from storage.
  store.certificates.check = function (opts) {
    console.log('certificates.check:', opts.certificate, opts.subject);

    var id = opts.certificate.id || opts.subject;
    var certblob = cache.certificates[id];

    if (!certblob) { return null; }

    return JSON.parse(certblob);
  };

  return store;
};