service backend

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

@@ -0,0 +1,131 @@
+package builderimp
+
+import (
+	"github.com/tech/sendico/pkg/db/repository/builder"
+	"github.com/tech/sendico/pkg/mservice"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+type unwindOpts = builder.UnwindOpts
+
+// UnwindOption is the same type defined in the builder package.
+type UnwindOption = builder.UnwindOption
+
+// NewUnwindOpts applies all UnwindOption's to a fresh unwindOpts.
+func NewUnwindOpts(opts ...UnwindOption) *unwindOpts {
+	cfg := &unwindOpts{}
+	for _, opt := range opts {
+		opt(cfg)
+	}
+	return cfg
+}
+
+type PipelineImp struct {
+	pipeline mongo.Pipeline
+}
+
+func (b *PipelineImp) Match(filter builder.Query) builder.Pipeline {
+	b.pipeline = append(b.pipeline, filter.BuildPipeline())
+	return b
+}
+
+func (b *PipelineImp) Lookup(from mservice.Type, localField, foreignField, as builder.Field) builder.Pipeline {
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.Lookup), Value: bson.D{
+		{Key: string(builder.MKFrom), Value: from},
+		{Key: string(builder.MKLocalField), Value: localField.Build()},
+		{Key: string(builder.MKForeignField), Value: foreignField.Build()},
+		{Key: string(builder.MKAs), Value: as.Build()},
+	}}})
+	return b
+}
+
+func (b *PipelineImp) LookupWithPipeline(
+	from mservice.Type,
+	nested builder.Pipeline,
+	as builder.Field,
+	let *map[string]builder.Field,
+) builder.Pipeline {
+	lookupStage := bson.D{
+		{Key: string(builder.MKFrom), Value: from},
+		{Key: string(builder.MKPipeline), Value: nested.Build()},
+		{Key: string(builder.MKAs), Value: as.Build()},
+	}
+
+	// only add "let" if provided and not empty
+	if let != nil && len(*let) > 0 {
+		letDoc := bson.D{}
+		for varName, fld := range *let {
+			letDoc = append(letDoc, bson.E{Key: varName, Value: fld.Build()})
+		}
+		lookupStage = append(lookupStage, bson.E{Key: string(builder.MKLet), Value: letDoc})
+	}
+
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.Lookup), Value: lookupStage}})
+	return b
+}
+
+func (b *PipelineImp) Unwind(path builder.Field, opts ...UnwindOption) builder.Pipeline {
+	cfg := NewUnwindOpts(opts...)
+
+	var stageValue interface{}
+	// if no options, shorthand
+	if !cfg.PreserveNullAndEmptyArrays && cfg.IncludeArrayIndex == "" {
+		stageValue = path.Build()
+	} else {
+		d := bson.D{{Key: string(builder.MKPath), Value: path.Build()}}
+		if cfg.PreserveNullAndEmptyArrays {
+			d = append(d, bson.E{Key: string(builder.MKPreserveNullAndEmptyArrays), Value: true})
+		}
+		if cfg.IncludeArrayIndex != "" {
+			d = append(d, bson.E{Key: string(builder.MKIncludeArrayIndex), Value: cfg.IncludeArrayIndex})
+		}
+		stageValue = d
+	}
+
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.Unwind), Value: stageValue}})
+	return b
+}
+
+func (b *PipelineImp) Count(field builder.Field) builder.Pipeline {
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.Count), Value: field.Build()}})
+	return b
+}
+
+func (b *PipelineImp) Group(groupBy builder.Alias, accumulators ...builder.GroupAccumulator) builder.Pipeline {
+	groupDoc := groupBy.Build()
+	for _, acc := range accumulators {
+		groupDoc = append(groupDoc, acc.Build()...)
+	}
+
+	b.pipeline = append(b.pipeline, bson.D{
+		{Key: string(builder.Group), Value: groupDoc},
+	})
+	return b
+}
+
+func (b *PipelineImp) Project(projections ...builder.Projection) builder.Pipeline {
+	projDoc := bson.D{}
+	for _, pr := range projections {
+		projDoc = append(projDoc, pr.Build()...)
+	}
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.Project), Value: projDoc}})
+	return b
+}
+
+func (b *PipelineImp) ReplaceRoot(newRoot builder.Expression) builder.Pipeline {
+	b.pipeline = append(b.pipeline, bson.D{{Key: string(builder.ReplaceRoot), Value: bson.D{
+		{Key: string(builder.MKNewRoot), Value: newRoot.Build()},
+	}}})
+	return b
+}
+
+func (b *PipelineImp) Build() mongo.Pipeline {
+	return b.pipeline
+}
+
+func NewPipelineImp() builder.Pipeline {
+	return &PipelineImp{
+		pipeline: mongo.Pipeline{},
+	}
+}