[feat] basic gomap implementation

source_go_map.go

@@ -1,11 +1,236 @@
 package croconf
 
+import (
+	"fmt"
+)
+
 type SourceGoMap struct {
 	values map[string]interface{}
 }
 
-func NewGoMapSource(values map[string]interface{}) (*SourceGoMap, error) {
-	return &SourceGoMap{values: values}, nil
+func NewGoMapSource(values map[string]interface{}) *SourceGoMap {
+	return &SourceGoMap{values: values}
 }
 
 // TODO: implement something like https://github.com/mitchellh/mapstructure
+
+func (sm *SourceGoMap) GetName() string {
+	return "go map"
+}
+
+func (sm *SourceGoMap) Initialize() error { return nil }
+
+func (sm *SourceGoMap) Lookup(name string) (interface{}, bool) {
+	res, ok := sm.values[name]
+	return res, ok
+}
+
+func (sm *SourceGoMap) From(name string) *gomapBinding {
+	return &gomapBinding{
+		source: sm,
+		name:   name,
+		lookup: func() (interface{}, error) {
+			raw, ok := sm.Lookup(name)
+			if !ok {
+				return nil, NewBindFieldMissingError(sm.GetName(), name)
+			}
+			return raw, nil
+		},
+	}
+}
+
+type gomapBinding struct {
+	source Source
+	lookup func() (interface{}, error)
+	name   string
+}
+
+func (mb *gomapBinding) GetSource() Source {
+	return mb.source
+}
+
+func (mb *gomapBinding) From(name string) *gomapBinding {
+	return &gomapBinding{
+		source: mb.source,
+		name:   mb.name + "." + name,
+		lookup: func() (interface{}, error) {
+			raw, err := mb.lookup()
+			if err != nil {
+				return nil, err
+			}
+
+			data, ok := raw.(map[string]interface{})
+			if !ok {
+				return nil, fmt.Errorf("key=%s must be of a map[string]interface{} type", mb.name)
+			}
+
+			// TODO: cache this, so we don't parse sub-configs multiple times
+			submap := NewGoMapSource(data)
+
+			rawEl, ok := submap.Lookup(name)
+			if !ok {
+				return nil, NewBindFieldMissingError(submap.GetName(), name)
+			}
+			return rawEl, nil
+		},
+	}
+}
+
+func (mb *gomapBinding) BindStringValueTo(dest *string) func() error {
+	return func() error {
+		raw, err := mb.lookup()
+		if err != nil {
+			return err
+		}
+
+		val, ok := raw.(string)
+		if !ok {
+			return fmt.Errorf("failed cast value for key=%s as a string", mb.name)
+		}
+		*dest = val
+		return nil
+
+	}
+}
+
+func (mb *gomapBinding) BindIntValue() func(bitSize int) (int64, error) {
+	return func(bitSize int) (int64, error) {
+		raw, err := mb.lookup()
+		if err != nil {
+			return 0, NewBindFieldMissingError(mb.source.GetName(), mb.name)
+		}
+
+		var val int64
+		switch bitSize {
+		case 0:
+			v, ok := raw.(int)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a int", mb.name)
+			}
+			val = int64(v)
+
+		case 8:
+			v, ok := raw.(int8)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a int8", mb.name)
+			}
+			val = int64(v)
+
+		case 16:
+			v, ok := raw.(int16)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a int16", mb.name)
+			}
+			val = int64(v)
+
+		case 32:
+			v, ok := raw.(int32)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a int32", mb.name)
+			}
+			val = int64(v)
+
+		case 64:
+			v, ok := raw.(int64)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a int64", mb.name)
+			}
+			val = v
+		}
+
+		return val, nil
+	}
+}
+
+func (mb *gomapBinding) BindUintValue() func(bitSize int) (uint64, error) {
+	return func(bitSize int) (uint64, error) {
+		raw, err := mb.lookup()
+		if err != nil {
+			return 0, NewBindFieldMissingError(mb.source.GetName(), mb.name)
+		}
+
+		var val uint64
+		switch bitSize {
+		case 0:
+			v, ok := raw.(uint)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a uint", mb.name)
+			}
+			val = uint64(v)
+
+		case 8:
+			v, ok := raw.(uint8)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a uint8", mb.name)
+			}
+			val = uint64(v)
+
+		case 16:
+			v, ok := raw.(uint16)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a uint16", mb.name)
+			}
+			val = uint64(v)
+
+		case 32:
+			v, ok := raw.(uint32)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a uint32", mb.name)
+			}
+			val = uint64(v)
+
+		case 64:
+			v, ok := raw.(uint64)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a uint64", mb.name)
+			}
+			val = v
+		}
+
+		return val, nil
+	}
+}
+
+func (mb *gomapBinding) BindFloatValue() func(bitSize int) (float64, error) {
+	return func(bitSize int) (float64, error) {
+		raw, err := mb.lookup()
+		if err != nil {
+			return 0, NewBindFieldMissingError(mb.source.GetName(), mb.name)
+		}
+
+		var val float64
+		switch bitSize {
+		case 32:
+			v, ok := raw.(float32)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a float32", mb.name)
+			}
+			val = float64(v)
+
+		case 64:
+			v, ok := raw.(float64)
+			if !ok {
+				return 0, fmt.Errorf("failed cast value for key=%s as a float64", mb.name)
+			}
+			val = v
+		}
+
+		return val, nil
+	}
+}
+
+func (mb *gomapBinding) BindBoolValueTo(dest *bool) func() error {
+	return func() error {
+		raw, err := mb.lookup()
+		if err != nil {
+			return err
+		}
+
+		v, ok := raw.(bool)
+		if !ok {
+			return fmt.Errorf("failed cast value for key=%s as a bool", mb.name)
+		}
+		*dest = v
+		return nil
+	}
+}