Second checkpoint

internal/messaging/rabbitmq/parse_consumer.go

@@ -0,0 +1,118 @@
+package rabbitmq
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+
+	"github.com/google/uuid"
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+const (
+	// DatasetParseRoutingKey routes dataset attribute-table parse jobs.
+	DatasetParseRoutingKey = "dataset.parse"
+	// DatasetParseQueue receives dataset parse jobs.
+	DatasetParseQueue = "gis.datasets.parse"
+	// DatasetPropertiesRoutingKey routes plain-vector attribute-table extraction.
+	DatasetPropertiesRoutingKey = "dataset.properties"
+	// DatasetPropertiesQueue receives plain-vector properties jobs.
+	DatasetPropertiesQueue = "gis.datasets.properties"
+	// DatasetExtractRoutingKey routes dataset extraction (unpivot) jobs.
+	DatasetExtractRoutingKey = "dataset.extract"
+	// DatasetExtractQueue receives dataset extraction jobs.
+	DatasetExtractQueue = "gis.datasets.extract"
+	// DatasetConvertRoutingKey routes raster COG-conversion jobs.
+	DatasetConvertRoutingKey = "dataset.cog"
+	// DatasetConvertQueue receives raster COG-conversion jobs.
+	DatasetConvertQueue = "gis.datasets.cog"
+)
+
+// DatasetJob is the message body for a dataset job (parse or extract).
+type DatasetJob struct {
+	DatasetID uuid.UUID `json:"dataset_id"`
+}
+
+// DatasetJobPublisher publishes dataset parse/extract jobs; it implements
+// service.JobEnqueuer.
+type DatasetJobPublisher struct {
+	pub *Publisher
+}
+
+// NewDatasetJobPublisher returns a DatasetJobPublisher.
+func NewDatasetJobPublisher(pub *Publisher) *DatasetJobPublisher {
+	return &DatasetJobPublisher{pub: pub}
+}
+
+// EnqueueParse publishes a parse job for the given dataset.
+func (p *DatasetJobPublisher) EnqueueParse(ctx context.Context, datasetID uuid.UUID) error {
+	return p.publish(ctx, DatasetParseRoutingKey, datasetID)
+}
+
+// EnqueueProperties publishes a plain-vector properties-extraction job.
+func (p *DatasetJobPublisher) EnqueueProperties(ctx context.Context, datasetID uuid.UUID) error {
+	return p.publish(ctx, DatasetPropertiesRoutingKey, datasetID)
+}
+
+// EnqueueExtract publishes an extraction job for the given dataset.
+func (p *DatasetJobPublisher) EnqueueExtract(ctx context.Context, datasetID uuid.UUID) error {
+	return p.publish(ctx, DatasetExtractRoutingKey, datasetID)
+}
+
+// EnqueueConvert publishes a raster COG-conversion job for the given dataset.
+func (p *DatasetJobPublisher) EnqueueConvert(ctx context.Context, datasetID uuid.UUID) error {
+	return p.publish(ctx, DatasetConvertRoutingKey, datasetID)
+}
+
+func (p *DatasetJobPublisher) publish(ctx context.Context, routingKey string, datasetID uuid.UUID) error {
+	body, err := json.Marshal(DatasetJob{DatasetID: datasetID})
+	if err != nil {
+		return err
+	}
+	return p.pub.Publish(ctx, routingKey, body)
+}
+
+// DatasetProcessor runs the async dataset jobs; implemented by the service.
+type DatasetProcessor interface {
+	Parse(ctx context.Context, datasetID uuid.UUID) error
+	ExtractProperties(ctx context.Context, datasetID uuid.UUID) error
+	Extract(ctx context.Context, datasetID uuid.UUID) error
+	ConvertToCOG(ctx context.Context, datasetID uuid.UUID) error
+}
+
+// jobHandler dispatches a dataset job to one processor function.
+type jobHandler struct {
+	name string
+	fn   func(ctx context.Context, id uuid.UUID) error
+	log  *slog.Logger
+}
+
+func (h jobHandler) Handle(ctx context.Context, d amqp.Delivery) error {
+	var job DatasetJob
+	if err := json.Unmarshal(d.Body, &job); err != nil {
+		return fmt.Errorf("decode %s job: %w", h.name, err)
+	}
+	h.log.Info("processing dataset "+h.name, "dataset_id", job.DatasetID)
+	return h.fn(ctx, job.DatasetID)
+}
+
+// NewParseHandler returns a handler that parses datasets.
+func NewParseHandler(p DatasetProcessor, log *slog.Logger) Handler {
+	return jobHandler{name: "parse", fn: p.Parse, log: log}
+}
+
+// NewPropertiesHandler returns a handler that extracts a plain vector's table.
+func NewPropertiesHandler(p DatasetProcessor, log *slog.Logger) Handler {
+	return jobHandler{name: "properties", fn: p.ExtractProperties, log: log}
+}
+
+// NewExtractHandler returns a handler that extracts (unpivots) datasets.
+func NewExtractHandler(p DatasetProcessor, log *slog.Logger) Handler {
+	return jobHandler{name: "extract", fn: p.Extract, log: log}
+}
+
+// NewConvertHandler returns a handler that converts rasters to COGs.
+func NewConvertHandler(p DatasetProcessor, log *slog.Logger) Handler {
+	return jobHandler{name: "convert", fn: p.ConvertToCOG, log: log}
+}