issue-9: finishing keybinding service and implemented controller

Have now got rebinding keys working with the "rebind" command.
Still need to make sure key names are correct and implement rebinding
as part of an RC file and add bindings for the table.

internal/dynamo-browse/services/keybindings/errors.go

@@ -0,0 +1,14 @@
+package keybindings
+
+import (
+	"fmt"
+)
+
+type KeyAlreadyBoundError struct {
+	Key                 string
+	ExistingBindingName string
+}
+
+func (e KeyAlreadyBoundError) Error() string {
+	return fmt.Sprintf("key '%v' already bound to '%v'", e.Key, e.ExistingBindingName)
+}

internal/dynamo-browse/services/keybindings/service.go

@@ -1,6 +1,11 @@
 package keybindings
 
-import "reflect"
+import (
+	"github.com/charmbracelet/bubbles/key"
+	"github.com/pkg/errors"
+	"reflect"
+	"strings"
+)
 
 type Service struct {
 	keyBindingValue reflect.Value
@@ -17,16 +22,95 @@ func NewService(keyBinding any) *Service {
 	}
 }
 
-func (s *Service) Rebind(name string, key string) error {
+func (s *Service) Rebind(newKey string, name string, force bool) error {
+	// Check if there already exists a binding
+	if !force {
+		var foundBinding = ""
+		s.walkBindingFields(func(bindingName string, binding key.Binding) bool {
+			for _, key := range binding.Keys() {
+				if key == newKey {
+					foundBinding = bindingName
+					return false
+				}
+			}
+			return true
+		})
 
-}
-
-func (s *Service) findFieldForBinding(name string) reflect.Value {
-
-}
-
-func (s *Service) findFieldForBindingInGroup(group reflect.Value, name string) reflect.Value {
-	for i := 0; i < group.NumField(); i++ {
-		group.Field(i).Type().
+		if foundBinding != "" {
+			return KeyAlreadyBoundError{Key: newKey, ExistingBindingName: foundBinding}
+		}
 	}
+
+	// Rebind
+	binding := s.findFieldForBinding(name)
+	if binding == nil {
+		return errors.Errorf("invalid binding: %v", name)
+	}
+
+	*binding = key.NewBinding(key.WithKeys(newKey))
+	return nil
+}
+
+func (s *Service) findFieldForBinding(name string) *key.Binding {
+	return s.findFieldForBindingInGroup(s.keyBindingValue, name)
+}
+
+func (s *Service) findFieldForBindingInGroup(group reflect.Value, name string) *key.Binding {
+	bindingName, bindingSuffix, _ := strings.Cut(name, ".")
+
+	groupType := group.Type()
+	for i := 0; i < group.NumField(); i++ {
+		fieldType := groupType.Field(i)
+
+		keymapTag := fieldType.Tag.Get("keymap")
+		if keymapTag != bindingName {
+			continue
+		}
+
+		if fieldType.Type.Kind() == reflect.Pointer && fieldType.Type.Elem().Kind() == reflect.Struct {
+			return s.findFieldForBindingInGroup(group.Field(i).Elem(), bindingSuffix)
+		}
+
+		binding, isBinding := group.Field(i).Addr().Interface().(*key.Binding)
+		if !isBinding {
+			return nil
+		}
+		return binding
+	}
+	return nil
+}
+
+func (s *Service) walkBindingFields(fn func(name string, binding key.Binding) bool) {
+	s.walkBindingFieldsInGroup(s.keyBindingValue, "", fn)
+}
+
+func (s *Service) walkBindingFieldsInGroup(group reflect.Value, prefix string, fn func(name string, binding key.Binding) bool) bool {
+	groupType := group.Type()
+	for i := 0; i < group.NumField(); i++ {
+		fieldType := groupType.Field(i)
+
+		keymapTag := fieldType.Tag.Get("keymap")
+
+		var fullName string
+		if prefix != "" {
+			fullName = prefix + "." + keymapTag
+		} else {
+			fullName = keymapTag
+		}
+
+		if fieldType.Type.Kind() == reflect.Pointer && fieldType.Type.Elem().Kind() == reflect.Struct {
+			if !s.walkBindingFieldsInGroup(group.Field(i).Elem(), fullName, fn) {
+				return false
+			}
+		}
+
+		binding, isBinding := group.Field(i).Addr().Interface().(*key.Binding)
+		if !isBinding {
+			continue
+		}
+		if !fn(fullName, *binding) {
+			return false
+		}
+	}
+	return true
 }