Introducing basic CQRS

Makefile

@@ -44,6 +44,10 @@ lint:
 	@./scripts/lint.sh trainings
 	@./scripts/lint.sh users
 
+.PHONY: fmt
+fmt:
+	goimports -l -w internal/
+
 .PHONY: mycli
 mycli:
 	mycli -u ${MYSQL_USER} -p ${MYSQL_PASSWORD} ${MYSQL_DATABASE}

README.md

@@ -22,7 +22,8 @@ No application is perfect from the beginning. With over a dozen coming articles,
 7. [**Repository pattern: painless way to simplify your Go service logic**](https://threedots.tech/post/repository-pattern-in-go/?utm_source=github.com) _[[v2.2]](https://github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/releases/tag/v2.2)_
 8. [**4 practical principles of high-quality database integration tests in Go**](https://threedots.tech/post/database-integration-testing/?utm_source=github.com) _[[v2.3]](https://github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/releases/tag/v2.3)_
 9. [**Introducing Clean Architecture by refactoring a Go project**](https://threedots.tech/post/introducing-clean-architecture/?utm_source=github.com) _[[v2.4]](https://github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/releases/tag/v2.4)_
-10. *More articles are on the way!*
+10. [**Introducing basic CQRS by refactoring**](https://threedots.tech/post/basic-cqrs-in-go/?utm_source=github.com) _[[v2.5]](https://github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/releases/tag/v2.5)_
+11. *More articles are on the way!*
 
 ### Directories
 

api/openapi/trainings.yml

@@ -99,6 +99,33 @@ paths:
               schema:
                 $ref: '#/components/schemas/Error'
 
+  /trainings/{trainingUUID}/request-reschedule:
+    put:
+      operationId: requestRescheduleTraining
+      requestBody:
+        description: todo
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/PostTraining'
+      parameters:
+        - in: path
+          name: trainingUUID
+          schema:
+            type: string
+            format: uuid
+          required: true
+          description: todo
+      responses:
+        '204':
+          description: todo
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
 
   /trainings/{trainingUUID}/approve-reschedule:
     put:

internal/common/logs/cqrs.go

@@ -0,0 +1,15 @@
+package logs
+
+import (
+	"github.com/sirupsen/logrus"
+)
+
+func LogCommandExecution(commandName string, cmd interface{}, err error) {
+	log := logrus.WithField("cmd", cmd)
+
+	if err == nil {
+		log.Info(commandName + " command succeeded")
+	} else {
+		log.WithError(err).Error(commandName + " command failed")
+	}
+}

internal/trainer/adapters/dates_firestore_repository.go

@@ -2,9 +2,11 @@ package adapters
 
 import (
 	"context"
+	"sort"
 	"time"
 
-	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/app"
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/app/query"
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/domain/hour"
 
 	"cloud.google.com/go/firestore"
 	"google.golang.org/api/iterator"
@@ -24,16 +26,15 @@ type HourModel struct {
 
 type DatesFirestoreRepository struct {
 	firestoreClient *firestore.Client
+	factoryConfig   hour.FactoryConfig
 }
 
-func NewDatesFirestoreRepository(firestoreClient *firestore.Client) DatesFirestoreRepository {
+func NewDatesFirestoreRepository(firestoreClient *firestore.Client, factoryConfig hour.FactoryConfig) DatesFirestoreRepository {
 	if firestoreClient == nil {
 		panic("missing firestoreClient")
 	}
 
-	return DatesFirestoreRepository{
-		firestoreClient: firestoreClient,
-	}
+	return DatesFirestoreRepository{firestoreClient, factoryConfig}
 }
 
 func (d DatesFirestoreRepository) trainerHoursCollection() *firestore.CollectionRef {
@@ -44,14 +45,14 @@ func (d DatesFirestoreRepository) DocumentRef(dateTimeToUpdate time.Time) *fires
 	return d.trainerHoursCollection().Doc(dateTimeToUpdate.Format("2006-01-02"))
 }
 
-func (d DatesFirestoreRepository) GetDates(ctx context.Context, from time.Time, to time.Time) ([]app.Date, error) {
+func (d DatesFirestoreRepository) AvailableHours(ctx context.Context, from time.Time, to time.Time) ([]query.Date, error) {
 	iter := d.
 		trainerHoursCollection().
 		Where("Date", ">=", from).
 		Where("Date", "<=", to).
 		Documents(ctx)
 
-	var dates []app.Date
+	var dates []query.Date
 
 	for {
 		doc, err := iter.Next()
@@ -69,31 +70,73 @@ func (d DatesFirestoreRepository) GetDates(ctx context.Context, from time.Time,
 		dates = append(dates, dateModelToApp(date))
 	}
 
+	dates = addMissingDates(dates, from, to)
+	for i, date := range dates {
+		date = d.setDefaultAvailability(date)
+		sort.Slice(date.Hours, func(i, j int) bool { return date.Hours[i].Hour.Before(date.Hours[j].Hour) })
+		dates[i] = date
+	}
+	sort.Slice(dates, func(i, j int) bool { return dates[i].Date.Before(dates[j].Date) })
+
 	return dates, nil
 }
 
-func dateModelToApp(dm DateModel) app.Date {
-	var hours []app.Hour
+// setDefaultAvailability adds missing hours to Date model if they were not set
+func (d DatesFirestoreRepository) setDefaultAvailability(date query.Date) query.Date {
+HoursLoop:
+	for h := d.factoryConfig.MinUtcHour; h <= d.factoryConfig.MaxUtcHour; h++ {
+		hour := time.Date(date.Date.Year(), date.Date.Month(), date.Date.Day(), h, 0, 0, 0, time.UTC)
+
+		for i := range date.Hours {
+			if date.Hours[i].Hour.Equal(hour) {
+				continue HoursLoop
+			}
+		}
+		newHour := query.Hour{
+			Available: false,
+			Hour:      hour,
+		}
+
+		date.Hours = append(date.Hours, newHour)
+	}
+
+	return date
+}
+
+func addMissingDates(dates []query.Date, from time.Time, to time.Time) []query.Date {
+	for day := from.UTC(); day.Before(to) || day.Equal(to); day = day.AddDate(0, 0, 1) {
+		found := false
+		for _, date := range dates {
+			if date.Date.Equal(day) {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			date := query.Date{
+				Date: day,
+			}
+			dates = append(dates, date)
+		}
+	}
+
+	return dates
+}
+
+func dateModelToApp(dm DateModel) query.Date {
+	var hours []query.Hour
 	for _, h := range dm.Hours {
-		hours = append(hours, app.Hour{
+		hours = append(hours, query.Hour{
 			Available:            h.Available,
 			HasTrainingScheduled: h.HasTrainingScheduled,
 			Hour:                 h.Hour,
 		})
 	}
 
-	return app.Date{
+	return query.Date{
 		Date:         dm.Date,
 		HasFreeHours: dm.HasFreeHours,
 		Hours:        hours,
 	}
 }
-
-func (d DatesFirestoreRepository) CanLoadFixtures(ctx context.Context, daysToSet int) (bool, error) {
-	documents, err := d.trainerHoursCollection().Limit(daysToSet).Documents(ctx).GetAll()
-	if err != nil {
-		return false, err
-	}
-
-	return len(documents) < daysToSet, nil
-}

internal/trainer/adapters/hour_mysql_repository.go

@@ -79,10 +79,28 @@ func (m MySQLHourRepository) getOrCreateHour(
 	return domainHour, nil
 }
 
+const mySQLDeadlockErrorCode = 1213
+
 func (m MySQLHourRepository) UpdateHour(
 	ctx context.Context,
 	hourTime time.Time,
 	updateFn func(h *hour.Hour) (*hour.Hour, error),
+) error {
+	for {
+		err := m.updateHour(ctx, hourTime, updateFn)
+
+		if val, ok := err.(*mysql.MySQLError); ok && val.Number == mySQLDeadlockErrorCode {
+			continue
+		}
+
+		return err
+	}
+}
+
+func (m MySQLHourRepository) updateHour(
+	ctx context.Context,
+	hourTime time.Time,
+	updateFn func(h *hour.Hour) (*hour.Hour, error),
 ) (err error) {
 	tx, err := m.db.Beginx()
 	if err != nil {

internal/trainer/adapters/hour_repository_test.go

@@ -290,10 +290,10 @@ var testHourFactory = hour.MustNewFactory(hour.FactoryConfig{
 })
 
 func newFirebaseRepository(t *testing.T, ctx context.Context) *adapters.FirestoreHourRepository {
-	firebaseClient, err := firestore.NewClient(ctx, os.Getenv("GCP_PROJECT"))
+	firestoreClient, err := firestore.NewClient(ctx, os.Getenv("GCP_PROJECT"))
 	require.NoError(t, err)
 
-	return adapters.NewFirestoreHourRepository(firebaseClient, testHourFactory)
+	return adapters.NewFirestoreHourRepository(firestoreClient, testHourFactory)
 }
 
 func newMySQLRepository(t *testing.T) *adapters.MySQLHourRepository {

internal/trainer/app/app.go

@@ -0,0 +1,24 @@
+package app
+
+import (
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/app/command"
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/app/query"
+)
+
+type Application struct {
+	Commands Commands
+	Queries  Queries
+}
+
+type Commands struct {
+	CancelTraining   command.CancelTrainingHandler
+	ScheduleTraining command.ScheduleTrainingHandler
+
+	MakeHoursAvailable   command.MakeHoursAvailableHandler
+	MakeHoursUnavailable command.MakeHoursUnavailableHandler
+}
+
+type Queries struct {
+	HourAvailability      query.HourAvailabilityHandler
+	TrainerAvailableHours query.AvailableHoursHandler
+}

internal/trainer/app/command/cancel_training.go

@@ -0,0 +1,34 @@
+package command
+
+import (
+	"context"
+	"time"
+
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/common/errors"
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/domain/hour"
+)
+
+type CancelTrainingHandler struct {
+	hourRepo hour.Repository
+}
+
+func NewCancelTrainingHandler(hourRepo hour.Repository) CancelTrainingHandler {
+	if hourRepo == nil {
+		panic("nil hourRepo")
+	}
+
+	return CancelTrainingHandler{hourRepo: hourRepo}
+}
+
+func (h CancelTrainingHandler) Handle(ctx context.Context, hourToCancel time.Time) error {
+	if err := h.hourRepo.UpdateHour(ctx, hourToCancel, func(h *hour.Hour) (*hour.Hour, error) {
+		if err := h.CancelTraining(); err != nil {
+			return nil, err
+		}
+		return h, nil
+	}); err != nil {
+		return errors.NewSlugError(err.Error(), "unable-to-update-availability")
+	}
+
+	return nil
+}

internal/trainer/app/command/make_hours_available.go

@@ -0,0 +1,36 @@
+package command
+
+import (
+	"context"
+	"time"
+
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/common/errors"
+	"github.com/ThreeDotsLabs/wild-workouts-go-ddd-example/internal/trainer/domain/hour"
+)
+
+type MakeHoursAvailableHandler struct {
+	hourRepo hour.Repository
+}
+
+func NewMakeHoursAvailableHandler(hourRepo hour.Repository) MakeHoursAvailableHandler {
+	if hourRepo == nil {
+		panic("hourRepo is nil")
+	}
+
+	return MakeHoursAvailableHandler{hourRepo: hourRepo}
+}
+
+func (c MakeHoursAvailableHandler) Handle(ctx context.Context, hours []time.Time) error {
+	for _, hourToUpdate := range hours {
+		if err := c.hourRepo.UpdateHour(ctx, hourToUpdate, func(h *hour.Hour) (*hour.Hour, error) {
+			if err := h.MakeAvailable(); err != nil {
+				return nil, err
+			}
+			return h, nil
+		}); err != nil {
+			return errors.NewSlugError(err.Error(), "unable-to-update-availability")
+		}
+	}
+
+	return nil
+}