fix(dbmanager): resolve deadlock in adapter getter methods

Fixes deadlock caused by calling public methods (Bun, GORM, Native)
while holding a write lock. The public methods attempt to acquire
their own locks, causing the goroutine to freeze.

Solution: Call provider methods directly within the adapter getters
since they already hold the necessary write lock.

pkg/dbmanager/connection.go

@@ -3,6 +3,7 @@ package dbmanager
 import (
 	"context"
 	"database/sql"
+	"fmt"
 	"sync"
 	"time"
 
@@ -159,6 +160,9 @@ func (c *sqlConnection) Close() error {
 
 // HealthCheck verifies the connection is alive
 func (c *sqlConnection) HealthCheck(ctx context.Context) error {
+	if c == nil {
+		return fmt.Errorf("connection is nil")
+	}
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -188,6 +192,9 @@ func (c *sqlConnection) Reconnect(ctx context.Context) error {
 
 // Native returns the native *sql.DB connection
 func (c *sqlConnection) Native() (*sql.DB, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.nativeDB != nil {
 		defer c.mu.RUnlock()
@@ -219,6 +226,9 @@ func (c *sqlConnection) Native() (*sql.DB, error) {
 
 // Bun returns a Bun ORM instance wrapping the native connection
 func (c *sqlConnection) Bun() (*bun.DB, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.bunDB != nil {
 		defer c.mu.RUnlock()
@@ -249,6 +259,9 @@ func (c *sqlConnection) Bun() (*bun.DB, error) {
 
 // GORM returns a GORM instance wrapping the native connection
 func (c *sqlConnection) GORM() (*gorm.DB, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.gormDB != nil {
 		defer c.mu.RUnlock()
@@ -283,6 +296,9 @@ func (c *sqlConnection) GORM() (*gorm.DB, error) {
 
 // Database returns the common.Database interface using the configured default ORM
 func (c *sqlConnection) Database() (common.Database, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	defaultORM := c.config.DefaultORM
 	c.mu.RUnlock()
@@ -307,6 +323,9 @@ func (c *sqlConnection) MongoDB() (*mongo.Client, error) {
 
 // Stats returns connection statistics
 func (c *sqlConnection) Stats() *ConnectionStats {
+	if c == nil {
+		return nil
+	}
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
@@ -336,6 +355,9 @@ func (c *sqlConnection) Stats() *ConnectionStats {
 
 // getBunAdapter returns or creates the Bun adapter
 func (c *sqlConnection) getBunAdapter() (common.Database, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.bunAdapter != nil {
 		defer c.mu.RUnlock()
@@ -350,17 +372,28 @@ func (c *sqlConnection) getBunAdapter() (common.Database, error) {
 		return c.bunAdapter, nil
 	}
 
-	bunDB, err := c.Bun()
-	if err != nil {
-		return nil, err
+	// Double-check bunDB exists (while already holding write lock)
+	if c.bunDB == nil {
+		// Get native connection first
+		native, err := c.provider.GetNative()
+		if err != nil {
+			return nil, NewConnectionError(c.name, "get bun", err)
+		}
+
+		// Create Bun DB wrapping the same sql.DB
+		dialect := c.getBunDialect()
+		c.bunDB = bun.NewDB(native, dialect)
 	}
 
-	c.bunAdapter = database.NewBunAdapter(bunDB)
+	c.bunAdapter = database.NewBunAdapter(c.bunDB)
 	return c.bunAdapter, nil
 }
 
 // getGORMAdapter returns or creates the GORM adapter
 func (c *sqlConnection) getGORMAdapter() (common.Database, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.gormAdapter != nil {
 		defer c.mu.RUnlock()
@@ -375,17 +408,33 @@ func (c *sqlConnection) getGORMAdapter() (common.Database, error) {
 		return c.gormAdapter, nil
 	}
 
-	gormDB, err := c.GORM()
-	if err != nil {
-		return nil, err
+	// Double-check gormDB exists (while already holding write lock)
+	if c.gormDB == nil {
+		// Get native connection first
+		native, err := c.provider.GetNative()
+		if err != nil {
+			return nil, NewConnectionError(c.name, "get gorm", err)
+		}
+
+		// Create GORM DB wrapping the same sql.DB
+		dialector := c.getGORMDialector(native)
+		db, err := gorm.Open(dialector, &gorm.Config{})
+		if err != nil {
+			return nil, NewConnectionError(c.name, "initialize gorm", err)
+		}
+
+		c.gormDB = db
 	}
 
-	c.gormAdapter = database.NewGormAdapter(gormDB)
+	c.gormAdapter = database.NewGormAdapter(c.gormDB)
 	return c.gormAdapter, nil
 }
 
 // getNativeAdapter returns or creates the native adapter
 func (c *sqlConnection) getNativeAdapter() (common.Database, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
 	c.mu.RLock()
 	if c.nativeAdapter != nil {
 		defer c.mu.RUnlock()
@@ -400,21 +449,31 @@ func (c *sqlConnection) getNativeAdapter() (common.Database, error) {
 		return c.nativeAdapter, nil
 	}
 
-	native, err := c.Native()
-	if err != nil {
-		return nil, err
+	// Double-check nativeDB exists (while already holding write lock)
+	if c.nativeDB == nil {
+		if !c.connected {
+			return nil, ErrConnectionClosed
+		}
+
+		// Get native connection from provider
+		db, err := c.provider.GetNative()
+		if err != nil {
+			return nil, NewConnectionError(c.name, "get native", err)
+		}
+
+		c.nativeDB = db
 	}
 
 	// Create a native adapter based on database type
 	switch c.dbType {
 	case DatabaseTypePostgreSQL:
-		c.nativeAdapter = database.NewPgSQLAdapter(native)
+		c.nativeAdapter = database.NewPgSQLAdapter(c.nativeDB)
 	case DatabaseTypeSQLite:
 		// For SQLite, we'll use the PgSQL adapter as it works with standard sql.DB
-		c.nativeAdapter = database.NewPgSQLAdapter(native)
+		c.nativeAdapter = database.NewPgSQLAdapter(c.nativeDB)
 	case DatabaseTypeMSSQL:
 		// For MSSQL, we'll use the PgSQL adapter as it works with standard sql.DB
-		c.nativeAdapter = database.NewPgSQLAdapter(native)
+		c.nativeAdapter = database.NewPgSQLAdapter(c.nativeDB)
 	default:
 		return nil, ErrUnsupportedDatabase
 	}
@@ -424,6 +483,7 @@ func (c *sqlConnection) getNativeAdapter() (common.Database, error) {
 
 // getBunDialect returns the appropriate Bun dialect for the database type
 func (c *sqlConnection) getBunDialect() schema.Dialect {
+
 	switch c.dbType {
 	case DatabaseTypePostgreSQL:
 		return database.GetPostgresDialect()

pkg/restheadspec/restheadspec.go

@@ -270,9 +270,14 @@ func ExampleWithBun(bunDB *bun.DB) {
 	SetupMuxRoutes(muxRouter, handler, nil)
 }
 
+// BunRouterHandler is an interface that both bunrouter.Router and bunrouter.Group implement
+type BunRouterHandler interface {
+	Handle(method, path string, handler bunrouter.HandlerFunc)
+}
+
 // SetupBunRouterRoutes sets up bunrouter routes for the RestHeadSpec API
-func SetupBunRouterRoutes(bunRouter *router.StandardBunRouterAdapter, handler *Handler) {
-	r := bunRouter.GetBunRouter()
+// Accepts bunrouter.Router or bunrouter.Group
+func SetupBunRouterRoutes(r BunRouterHandler, handler *Handler) {
 
 	// CORS config
 	corsConfig := common.DefaultCORSConfig()
@@ -450,17 +455,34 @@ func ExampleBunRouterWithBunDB(bunDB *bun.DB) {
 	// Create handler
 	handler := NewHandlerWithBun(bunDB)
 
-	// Create BunRouter adapter
-	routerAdapter := NewStandardBunRouter()
+	// Create bunrouter
+	bunRouter := bunrouter.New()
 
 	// Setup routes
-	SetupBunRouterRoutes(routerAdapter, handler)
-
-	// Get the underlying router for server setup
-	r := routerAdapter.GetBunRouter()
+	SetupBunRouterRoutes(bunRouter, handler)
 
 	// Start server
-	if err := http.ListenAndServe(":8080", r); err != nil {
+	if err := http.ListenAndServe(":8080", bunRouter); err != nil {
+		logger.Error("Server failed to start: %v", err)
+	}
+}
+
+// ExampleBunRouterWithGroup shows how to use SetupBunRouterRoutes with a bunrouter.Group
+func ExampleBunRouterWithGroup(bunDB *bun.DB) {
+	// Create handler with Bun adapter
+	handler := NewHandlerWithBun(bunDB)
+
+	// Create bunrouter
+	bunRouter := bunrouter.New()
+
+	// Create a route group with a prefix
+	apiGroup := bunRouter.NewGroup("/api")
+
+	// Setup RestHeadSpec routes on the group - routes will be under /api
+	SetupBunRouterRoutes(apiGroup, handler)
+
+	// Start server
+	if err := http.ListenAndServe(":8080", bunRouter); err != nil {
 		logger.Error("Server failed to start: %v", err)
 	}
 }