service backend

api/pkg/db/internal/mongo/repositoryimp/builderimp/alias.go

@@ -0,0 +1,102 @@
+package builderimp
+
+import (
+	"github.com/tech/sendico/pkg/db/repository/builder"
+	"go.mongodb.org/mongo-driver/bson"
+)
+
+type aliasImp struct {
+	lhs builder.Field
+	rhs any
+}
+
+func (a *aliasImp) Field() builder.Field {
+	return a.lhs
+}
+
+func (a *aliasImp) Build() bson.D {
+	return bson.D{{Key: a.lhs.Build(), Value: a.rhs}}
+}
+
+// 1. Null alias (_id: null)
+func NewNullAlias(lhs builder.Field) builder.Alias {
+	return &aliasImp{lhs: lhs, rhs: nil}
+}
+
+func NewAlias(lhs builder.Field, rhs any) builder.Alias {
+	return &aliasImp{lhs: lhs, rhs: rhs}
+}
+
+// 2. Simple alias (_id: "$taskRef")
+func NewSimpleAlias(lhs, rhs builder.Field) builder.Alias {
+	return &aliasImp{lhs: lhs, rhs: rhs.Build()}
+}
+
+// 3. Complex alias (_id: { aliasName: "$originalField", ... })
+type ComplexAlias struct {
+	lhs builder.Field
+	rhs []builder.Alias // Correcting handling of slice of aliases
+}
+
+func (a *ComplexAlias) Field() builder.Field {
+	return a.lhs
+}
+
+func (a *ComplexAlias) Build() bson.D {
+	fieldMap := bson.M{}
+
+	for _, alias := range a.rhs {
+		// Each alias.Build() still returns a bson.D
+		aliasDoc := alias.Build()
+
+		// 1. Marshal the ordered D into raw BSON bytes
+		raw, err := bson.Marshal(aliasDoc)
+		if err != nil {
+			panic("Failed to marshal alias document: " + err.Error())
+		}
+
+		// 2. Unmarshal those bytes into an unordered M
+		var docM bson.M
+		if err := bson.Unmarshal(raw, &docM); err != nil {
+			panic("Failed to unmarshal alias document: " + err.Error())
+		}
+
+		// Merge into our accumulator
+		for k, v := range docM {
+			fieldMap[k] = v
+		}
+	}
+
+	return bson.D{{Key: a.lhs.Build(), Value: fieldMap}}
+}
+
+func NewComplexAlias(lhs builder.Field, rhs []builder.Alias) builder.Alias {
+	return &ComplexAlias{lhs: lhs, rhs: rhs}
+}
+
+type aliasesImp struct {
+	aliases []builder.Alias
+}
+
+func (a *aliasesImp) Field() builder.Field {
+	if len(a.aliases) > 0 {
+		return a.aliases[0].Field()
+	}
+	return NewFieldImp("")
+}
+
+func (a *aliasesImp) Build() bson.D {
+	results := make([]bson.D, 0)
+	for _, alias := range a.aliases {
+		results = append(results, alias.Build())
+	}
+	aliases := bson.D{}
+	for _, r := range results {
+		aliases = append(aliases, r...)
+	}
+	return aliases
+}
+
+func NewAliases(aliases ...builder.Alias) builder.Alias {
+	return &aliasesImp{aliases: aliases}
+}