feat: new system

internal/cli/codec.go

@@ -6,33 +6,19 @@ import (
 	"git.maximhutz.com/max/lambda/pkg/codec"
 )
 
-type Codec interface {
-	codec.Codec[Repr, Repr]
-
+type Conversion interface {
 	InType() string
 	OutType() string
+
+	Run(Repr) (Repr, error)
 }
 
-type convertedCodec[T, U any] struct {
+type forwardCodec[T, U any] struct {
 	codec           codec.Codec[T, U]
 	inType, outType string
 }
 
-func (c convertedCodec[T, U]) Decode(r Repr) (Repr, error) {
-	u, ok := r.Data().(U)
-	if !ok {
-		return nil, fmt.Errorf("could not parse '%v' as '%s'", r, c.inType)
-	}
-
-	t, err := c.codec.Decode(u)
-	if err != nil {
-		return nil, err
-	}
-
-	return NewRepr(c.outType, t), nil
-}
-
-func (c convertedCodec[T, U]) Encode(r Repr) (Repr, error) {
+func (c forwardCodec[T, U]) Run(r Repr) (Repr, error) {
 	t, ok := r.Data().(T)
 	if !ok {
 		return nil, fmt.Errorf("could not parse '%v' as '%s'", t, c.outType)
@@ -46,10 +32,36 @@ func (c convertedCodec[T, U]) Encode(r Repr) (Repr, error) {
 	return NewRepr(c.inType, u), nil
 }
 
-func (c convertedCodec[T, U]) InType() string { return c.inType }
+func (c forwardCodec[T, U]) InType() string { return c.inType }
 
-func (c convertedCodec[T, U]) OutType() string { return c.outType }
+func (c forwardCodec[T, U]) OutType() string { return c.outType }
 
-func ConvertCodec[T, U any](e codec.Codec[T, U], inType, outType string) Codec {
-	return convertedCodec[T, U]{e, inType, outType}
+type backwardCodec[T, U any] struct {
+	codec           codec.Codec[T, U]
+	inType, outType string
+}
+
+func (c backwardCodec[T, U]) Run(r Repr) (Repr, error) {
+	u, ok := r.Data().(U)
+	if !ok {
+		return nil, fmt.Errorf("could not parse '%v' as '%s'", r, c.inType)
+	}
+
+	t, err := c.codec.Decode(u)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewRepr(c.outType, t), nil
+}
+
+func (c backwardCodec[T, U]) InType() string { return c.outType }
+
+func (c backwardCodec[T, U]) OutType() string { return c.inType }
+
+func ConvertCodec[T, U any](e codec.Codec[T, U], inType, outType string) []Conversion {
+	return []Conversion{
+		forwardCodec[T, U]{e, inType, outType},
+		backwardCodec[T, U]{e, inType, outType},
+	}
 }

internal/registry/converter.go

@@ -0,0 +1,27 @@
+package registry
+
+import (
+	"git.maximhutz.com/max/lambda/internal/cli"
+)
+
+type Converter struct {
+	data map[string][]cli.Conversion
+}
+
+func NewConverter() *Converter {
+	return &Converter{data: map[string][]cli.Conversion{}}
+}
+
+func (g *Converter) Add(c cli.Conversion) {
+	conversionsFromIn, ok := g.data[c.InType()]
+	if !ok {
+		conversionsFromIn = []cli.Conversion{}
+	}
+
+	conversionsFromIn = append(conversionsFromIn, c)
+	g.data[c.InType()] = conversionsFromIn
+}
+
+func (g *Converter) ConversionsFrom(t string) []cli.Conversion {
+	return g.data[t]
+}

internal/registry/registry.go

@@ -8,20 +8,23 @@ import (
 
 type Registry struct {
 	marshalers map[string]cli.Marshaler
-	codecs     []cli.Codec
+	converter  *Converter
 	engines    map[string]cli.Engine
 }
 
 func New() *Registry {
 	return &Registry{
 		marshalers: map[string]cli.Marshaler{},
-		codecs:     []cli.Codec{},
+		converter:  NewConverter(),
 		engines:    map[string]cli.Engine{},
 	}
 }
 
-func (r *Registry) AddCodec(c cli.Codec) error {
-	r.codecs = append(r.codecs, c)
+func (r *Registry) AddConversions(conversions ...cli.Conversion) error {
+	for _, conversion := range conversions {
+		r.converter.Add(conversion)
+	}
+
 	return nil
 }
 
@@ -52,8 +55,31 @@ func (r *Registry) GetEngine(name string) (cli.Engine, error) {
 	return e, nil
 }
 
+func (r *Registry) GetDefaultEngine(id string) (cli.Engine, error) {
+	for _, engine := range r.engines {
+		if engine.InType() == id {
+			return engine, nil
+		}
+	}
+
+	return nil, fmt.Errorf("no engine for '%s'", id)
+}
+
 func (r *Registry) ConvertTo(repr cli.Repr, outType string) (cli.Repr, error) {
-	panic("")
+	path, err := r.ConversionPath(repr.Id(), outType)
+	if err != nil {
+		return nil, err
+	}
+
+	result := repr
+	for _, conversion := range path {
+		result, err = conversion.Run(result)
+		if err != nil {
+			return nil, fmt.Errorf("converting '%s' to '%s': %w", conversion.InType(), conversion.OutType(), err)
+		}
+	}
+
+	return result, err
 }
 
 func (r *Registry) Marshal(repr cli.Repr) (string, error) {
@@ -73,3 +99,52 @@ func (r *Registry) Unmarshal(s string, outType string) (cli.Repr, error) {
 
 	return m.Decode(s)
 }
+
+func reverse[T any](list []T) []T {
+	if list == nil {
+		return list
+	}
+
+	reversed := []T{}
+
+	for i := len(list) - 1; i >= 0; i-- {
+		reversed = append(reversed, list[i])
+	}
+
+	return reversed
+}
+
+func (r *Registry) ConversionPath(from, to string) ([]cli.Conversion, error) {
+	backtrack := map[string]cli.Conversion{}
+	iteration := []string{from}
+	for len(iteration) > 0 {
+		nextIteration := []string{}
+
+		for _, item := range iteration {
+			for _, conversion := range r.converter.ConversionsFrom(item) {
+				if _, ok := backtrack[conversion.OutType()]; ok {
+					continue
+				}
+
+				nextIteration = append(nextIteration, conversion.OutType())
+				backtrack[conversion.OutType()] = conversion
+			}
+		}
+
+		iteration = nextIteration
+	}
+
+	reversedPath := []cli.Conversion{}
+	current := to
+	for current != from {
+		conversion, ok := backtrack[current]
+		if !ok {
+			return nil, fmt.Errorf("no valid conversion from '%s' to '%s'", from, to)
+		}
+
+		reversedPath = append(reversedPath, conversion)
+		current = conversion.InType()
+	}
+
+	return reverse(reversedPath), nil
+}