Stand up DB migrations now that the app is mature enough (#229)

Author: dkhalife

apiserver/internal/migrations/001_initial_schema.go

@@ -0,0 +1,66 @@
+package migrations
+
+import (
+	"context"
+
+	"dkhalife.com/tasks/core/internal/models"
+	"gorm.io/gorm"
+)
+
+func init() {
+	Register(&InitialSchemaMigration{})
+}
+
+type InitialSchemaMigration struct{}
+
+func (m *InitialSchemaMigration) Version() int {
+	return 1
+}
+
+func (m *InitialSchemaMigration) Name() string {
+	return "initial_schema"
+}
+
+func (m *InitialSchemaMigration) Up(ctx context.Context, db *gorm.DB) error {
+	tables := []interface{}{
+		&models.User{},
+		&models.UserPasswordReset{},
+		&models.AppToken{},
+		&models.Label{},
+		&models.Task{},
+		&models.TaskLabel{},
+		&models.TaskHistory{},
+		&models.NotificationSettings{},
+		&models.Notification{},
+	}
+
+	for _, table := range tables {
+		if err := db.WithContext(ctx).AutoMigrate(table); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (m *InitialSchemaMigration) Down(ctx context.Context, db *gorm.DB) error {
+	tables := []string{
+		"notifications",
+		"notification_settings",
+		"task_histories",
+		"task_labels",
+		"tasks",
+		"labels",
+		"app_tokens",
+		"user_password_resets",
+		"users",
+	}
+
+	for _, table := range tables {
+		if err := db.WithContext(ctx).Exec("DROP TABLE IF EXISTS " + table + " CASCADE").Error; err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

apiserver/internal/migrations/base.go

@@ -0,0 +1,84 @@
+package migrations
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sort"
+	"sync"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+type Migration interface {
+	Version() int
+	Name() string
+	Up(ctx context.Context, db *gorm.DB) error
+	Down(ctx context.Context, db *gorm.DB) error
+}
+
+type SchemaVersion struct {
+	Version   int       `gorm:"primaryKey"`
+	Name      string    `gorm:"size:255;not null"`
+	AppliedAt time.Time `gorm:"not null"`
+}
+
+func (SchemaVersion) TableName() string {
+	return "schema_versions"
+}
+
+var (
+	registry     = make(map[int]Migration)
+	registryLock sync.RWMutex
+)
+
+func Register(m Migration) {
+	registryLock.Lock()
+	defer registryLock.Unlock()
+
+	version := m.Version()
+	if existing, ok := registry[version]; ok {
+		panic(fmt.Sprintf("migration version %d already registered by %q, cannot register %q",
+			version, existing.Name(), m.Name()))
+	}
+	registry[version] = m
+	log.Printf("Registered migration %d: %s", version, m.Name())
+}
+
+func GetMigrations() []Migration {
+	registryLock.RLock()
+	defer registryLock.RUnlock()
+
+	migrations := make([]Migration, 0, len(registry))
+	for _, m := range registry {
+		migrations = append(migrations, m)
+	}
+
+	sort.Slice(migrations, func(i, j int) bool {
+		return migrations[i].Version() < migrations[j].Version()
+	})
+
+	return migrations
+}
+
+func GetMigration(version int) (Migration, bool) {
+	registryLock.RLock()
+	defer registryLock.RUnlock()
+
+	m, ok := registry[version]
+	return m, ok
+}
+
+func GetLatestVersion() int {
+	registryLock.RLock()
+	defer registryLock.RUnlock()
+
+	latest := 0
+	for version := range registry {
+		if version > latest {
+			latest = version
+		}
+	}
+	return latest
+}