google_cds_store.go

// Copyright 2019-2020 Google LLC
//
// 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.

package google_cds_store

import (
	"context"
	"fmt"
	"peoplemath/models"
	"peoplemath/storage"

	"google.golang.org/api/iterator"

	"cloud.google.com/go/datastore"
)

const (
	// TeamKind - Datastore kind name for teams
	TeamKind = "Team"
	// PeriodKind - Datastore kind name for periods
	PeriodKind = "Period"
	// SettingsKind - Datastore kind name for settings
	SettingsKind = "Settings"
	// SettingsEntity - entity name for settings
	SettingsEntity = "Settings"
)

// StorageService using Google Cloud Datastore
type googleCDSStore struct {
	client *datastore.Client
}

func MakeGoogleCDSStore(ctx context.Context, projectID string) (storage.StorageService, error) {
	client, err := datastore.NewClient(ctx, projectID)
	if err != nil {
		return nil, fmt.Errorf("Could not create datastore client: %s", err)
	}
	return &googleCDSStore{client: client}, nil
}

func getTeamKey(teamID string) *datastore.Key {
	return datastore.NameKey(TeamKind, teamID, nil)
}

func getPeriodKey(teamKey *datastore.Key, periodID string) *datastore.Key {
	return datastore.NameKey(PeriodKind, periodID, teamKey)
}

func (s *googleCDSStore) GetAllTeams(ctx context.Context) ([]models.Team, error) {
	query := datastore.NewQuery(TeamKind).Order("DisplayName")
	iter := s.client.Run(ctx, query)
	result := []models.Team{}
	for {
		var t models.Team
		_, err := iter.Next(&t)
		if err == iterator.Done {
			break
		}
		if err != nil {
			return result, err
		}
		scrubLoadedTeam(&t)
		result = append(result, t)
	}
	return result, nil
}

func (s *googleCDSStore) GetTeam(ctx context.Context, teamID string) (models.Team, bool, error) {
	key := getTeamKey(teamID)
	var team models.Team
	err := s.client.Get(ctx, key, &team)
	if err == datastore.ErrNoSuchEntity {
		return team, false, nil
	}
	if err != nil {
		return team, true, err
	}
	scrubLoadedTeam(&team)
	return team, true, nil
}

func (s *googleCDSStore) CreateTeam(ctx context.Context, team models.Team) error {
	key := getTeamKey(team.ID)
	_, err := s.client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
		var empty models.Team
		if err := tx.Get(key, &empty); err != datastore.ErrNoSuchEntity {
			return fmt.Errorf("Expected no existing team '%s', found: %s", team.ID, err)
		}
		_, err := tx.Put(key, &team)
		return err
	})
	return err
}

func (s *googleCDSStore) UpdateTeam(ctx context.Context, team models.Team) error {
	key := getTeamKey(team.ID)
	_, err := s.client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
		var ignored models.Team
		if err := tx.Get(key, &ignored); err != nil {
			return fmt.Errorf("Could not retrieve team '%s': %s", team.ID, err)
		}
		_, err := tx.Put(key, &team)
		return err
	})
	return err
}

func (s *googleCDSStore) GetAllPeriods(ctx context.Context, teamID string) ([]models.Period, bool, error) {
	if _, ok, err := s.GetTeam(ctx, teamID); !ok || err != nil {
		return nil, false, err
	}
	teamKey := getTeamKey(teamID)
	query := datastore.NewQuery(PeriodKind).Ancestor(teamKey)
	iter := s.client.Run(ctx, query)
	result := []models.Period{}
	for {
		var p models.Period
		_, err := iter.Next(&p)
		if err == iterator.Done {
			break
		}
		if err != nil {
			return result, true, err
		}
		scrubLoadedPeriod(&p)
		result = append(result, p)
	}
	return result, true, nil
}

func (s *googleCDSStore) GetPeriod(ctx context.Context, teamID, periodID string) (models.Period, bool, error) {
	teamKey := getTeamKey(teamID)
	periodKey := getPeriodKey(teamKey, periodID)
	var period models.Period
	err := s.client.Get(ctx, periodKey, &period)
	if err == datastore.ErrNoSuchEntity {
		return period, false, nil
	}
	scrubLoadedPeriod(&period)
	return period, true, err
}

func (s *googleCDSStore) CreatePeriod(ctx context.Context, teamID string, period models.Period) error {
	teamKey := getTeamKey(teamID)
	periodKey := getPeriodKey(teamKey, period.ID)
	_, err := s.client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
		var empty models.Period
		if err := tx.Get(periodKey, &empty); err != datastore.ErrNoSuchEntity {
			return fmt.Errorf("Expected no period '%s' for team '%s': %s", period.ID, teamID, err)
		}
		_, err := tx.Put(periodKey, &period)
		return err
	})
	return err
}

func (s *googleCDSStore) UpdatePeriod(ctx context.Context, teamID string, period models.Period) error {
	teamKey := getTeamKey(teamID)
	periodKey := getPeriodKey(teamKey, period.ID)
	_, err := s.client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
		var ignored models.Period
		if err := tx.Get(periodKey, &ignored); err != nil {
			return fmt.Errorf("Could not retrieve period '%s' for team '%s': %s", period.ID, teamID, err)
		}
		_, err := tx.Put(periodKey, &period)
		return err
	})
	return err
}

func (s *googleCDSStore) GetSettings(ctx context.Context) (models.Settings, error) {
	key := datastore.NameKey(SettingsKind, SettingsEntity, nil)
	var result models.Settings
	err := s.client.Get(ctx, key, &result)
	if err == datastore.ErrNoSuchEntity {
		result = models.Settings{}
	} else if err != nil {
		return result, err
	}
	if result.ImproveURL == "" {
		result.ImproveURL = "https://github.com/google/peoplemath"
	}
	return result, nil
}

func (s *googleCDSStore) Close() error {
	return s.client.Close()
}

// Cloud Datastore does not save zero-length slices, so when retrieving entities with slice members,
// they may be nil. This function is to avoid clients having to deal with this.
// TODO Consider moving this function into the controller so it applies to all storage implementations.
func scrubLoadedPeriod(period *models.Period) {
	if period.People == nil {
		period.People = []models.Person{}
	}
	if period.Buckets == nil {
		period.Buckets = []models.Bucket{}
	}
	if period.SecondaryUnits == nil {
		period.SecondaryUnits = []models.SecondaryUnit{}
	}
	for i := range period.Buckets {
		if period.Buckets[i].Objectives == nil {
			period.Buckets[i].Objectives = []models.Objective{}
		}
		for j := range period.Buckets[i].Objectives {
			if period.Buckets[i].Objectives[j].Assignments == nil {
				period.Buckets[i].Objectives[j].Assignments = []models.Assignment{}
			}
			if period.Buckets[i].Objectives[j].Groups == nil {
				period.Buckets[i].Objectives[j].Groups = []models.ObjectiveGroup{}
			}
			if period.Buckets[i].Objectives[j].Tags == nil {
				period.Buckets[i].Objectives[j].Tags = []models.ObjectiveTag{}
			}
		}
	}
}

// Cloud Datastore does not save zero-length slices, so when retrieving entities with slice members,
// they may be nil. This function is to avoid clients having to deal with this.
// TODO Consider moving this function into the controller so it applies to all storage implementations.
func scrubLoadedTeam(team *models.Team) {
	if team.Permissions.Read.Allow == nil {
		team.Permissions.Read.Allow = []models.UserMatcher{}
	}
	if team.Permissions.Write.Allow == nil {
		team.Permissions.Write.Allow = []models.UserMatcher{}
	}
}