////////////////////////////////////////////////////////////////////////////
//
// Copyright 2017 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////


'use strict';

var Realm = require('realm');
var TestCase = require('./asserts');

function uuid() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
    var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

function createUsersWithTestRealms(count) {
  const createUserWithTestRealm = () => {
    return Realm.Sync.User.register('http://localhost:9080', uuid(), 'password')
      .then(user => {
        new Realm({sync: {user, url: 'realm://localhost:9080/~/test'}}).close();
        return user;
      });
  };

  return Promise.all(Array.from({length: count}, createUserWithTestRealm));
}

function wait(t) {
   return new Promise(resolve => setTimeout(resolve, t));
}

function repeatUntil(fn, predicate) {
    let retries = 0
    function check() {
        if (retries > 3) {
            return Promise.reject(new Error("operation timed out"));
        }
        ++retries;
        return fn().then(x => predicate(x) ? x : wait(100).then(check));
    }
    return check;
}

function subscribe(results) {
  const subscription = results.subscribe()
  return new Promise((resolve, reject) => {
      subscription.addListener((subscription, state) => {
          if (state == Realm.Sync.SubscriptionState.Complete) {
              resolve();
          }
          else if (state == Realm.Sync.SubscriptionState.Error) {
              reject();
          }
      });
      setTimeout(() => reject("listener never called"), 5000);
  });
}

function waitForUpload(realm) {
    let session = realm.syncSession;
    return new Promise(resolve => {
        let callback = (transferred, total) => {
            if (transferred === total) {
                session.removeProgressNotification(callback);
                resolve(realm);
            }
        }
        session.addProgressNotification('upload', 'forCurrentlyOutstandingWork', callback);
    });
}

module.exports = {
    testApplyAndGetGrantedPermissions() {
      return createUsersWithTestRealms(1)
        .then(([user]) => {
          return user.applyPermissions({ userId: `${user.identity}` }, `/${user.identity}/test`, 'read')
            .then(repeatUntil(() => user.getGrantedPermissions('any'),
                              permissions => permissions.length > 1))
            .then(permissions => {
              TestCase.assertEqual(permissions[0].path, `/${user.identity}/test`);
              TestCase.assertEqual(permissions[0].mayRead, true);
              TestCase.assertEqual(permissions[0].mayWrite, false);
              TestCase.assertEqual(permissions[0].mayManage, false);
            });
        });
    },

    testOfferPermissions() {
      return createUsersWithTestRealms(2)
        .then(([user1, user2]) => {
          return user1.offerPermissions(`/${user1.identity}/test`, 'read')
            .then(token => user2.acceptPermissionOffer(token))
            .then(realmUrl => {
              TestCase.assertEqual(realmUrl, `/${user1.identity}/test`);
              return realmUrl;
            })
            .then(repeatUntil(() => user2.getGrantedPermissions('any'),
                              permissions => permissions.length > 1))
            .then(permissions => {
              TestCase.assertEqual(permissions[2].path, `/${user1.identity}/test`);
              TestCase.assertEqual(permissions[2].mayRead, true);
              TestCase.assertEqual(permissions[2].mayWrite, false);
              TestCase.assertEqual(permissions[2].mayManage, false);
            });
        });
    },

    testInvalidatePermissionOffer() {
      let user1, user2, token;
      return createUsersWithTestRealms(2)
        .then(users => {
            user1 = users[0];
            user2 = users[1];
            return user1.offerPermissions(`/${user1.identity}/test`, 'read');
        })
        .then(t => { token = t; return user1.invalidatePermissionOffer(token); })
        // Since we don't yet support notification when the invalidation has gone through,
        // wait for a bit and hope the server is done processing.
        .then(wait(100))
        .then(() => user2.acceptPermissionOffer(token))
        // We want the call to fail, i.e. the catch() below should be called.
        .then(() => { throw new Error("User was able to accept an invalid permission offer token"); })
        .catch(error => {
          try {
            TestCase.assertEqual(error.message, 'The permission offer is expired.');
            TestCase.assertEqual(error.statusCode, 701);
          }
          catch (e) {
            throw new Error(e);
          }
        });
    },

    testObjectPermissions() {
      let config = (user, url) => {
        return {
          schema: [
            Realm.Permissions.Permission,
            Realm.Permissions.User,
            Realm.Permissions.Role,
            {
              name: 'Object',
              properties: {
                value: 'int',
                permissions: '__Permission[]'
              }
            }
          ],
          sync: {user, url, partial: true}
        };
      };
      let owner, otherUser
      return Realm.Sync.User.register('http://localhost:9080', uuid(), 'password')
        .then(user => {
          owner = user;
          new Realm({sync: {user, url: 'realm://localhost:9080/~/test'}}).close();
          return Realm.Sync.User.register('http://localhost:9080', uuid(), 'password')
        })
        .then(user => {
          otherUser = user;
          return owner.applyPermissions({userId: otherUser.identity}, `/${owner.identity}/test`, 'read')
        })
        .then(() => {
          let realm = new Realm(config(owner, 'realm://localhost:9080/~/test'));
          realm.write(() => {
            let user = realm.create(Realm.Permissions.User, {id: otherUser.identity})
            let role = realm.create(Realm.Permissions.Role, {name: 'reader'})
            role.members.push(user)

            let obj1 = realm.create('Object', {value: 1})
            let obj2 = realm.create('Object', {value: 2})
            obj2.permissions.push(realm.create(Realm.Permissions.Permission,
                                               {role: role, canRead: true, canUpdate: false}))
          });
          return waitForUpload(realm).then(() => realm.close());
        })
        .then(() => Realm.open(config(otherUser, `realm://localhost:9080/${owner.identity}/test`)))
        .then((realm) => subscribe(realm.objects('Object')).then(() => realm))
        .then((realm) => {
          // Should have full access to the Realm as a whole
          TestCase.assertSimilar('object', realm.privileges(),
                                 {read: true, update: true, modifySchema: true, setPermissions: true});
          TestCase.assertSimilar('object', realm.privileges('Object'),
                                 {read: true, update: true, create: true, subscribe: true, setPermissions: true});
          // Verify that checking via constructor works too
          TestCase.assertSimilar('object', realm.privileges(Realm.Permissions.User),
                                 {read: true, update: true, create: true, subscribe: true, setPermissions: true});

          // Should only be able to see the second object
          let results = realm.objects('Object')
          TestCase.assertEqual(results.length, 1);
          TestCase.assertEqual(results[0].value, 2);
          TestCase.assertSimilar('object', realm.privileges(results[0]),
                                 {read: true, update: false, delete: false, setPermissions: false});
          realm.close();
        });
    }
}