Notes Service (#12)

* Notes Service

* go mod tidy

* go mod tidy

notes/handler/handler.go

@@ -0,0 +1,161 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	"github.com/micro/micro/v3/service/store"
+	pb "github.com/micro/services/notes/proto"
+)
+
+const storePrefix = "notes/"
+
+// New returns an initialized notes handler
+func New() pb.NotesHandler {
+	return new(handler)
+}
+
+type handler struct{}
+
+// List all the notes
+func (h *handler) List(ctx context.Context, req *pb.ListRequest, rsp *pb.ListResponse) error {
+	// query the store
+	recs, err := store.Read("", store.Prefix(storePrefix))
+	if err != nil {
+		logger.Errorf("Error reading notes from the store: %v", err)
+		return errors.InternalServerError("notes.List.Unknown", "Error reading from the store")
+	}
+
+	// serialize the response
+	rsp.Notes = make([]*pb.Note, len(recs))
+	for i, r := range recs {
+		var note pb.Note
+		if err := json.Unmarshal(r.Value, &note); err != nil {
+			logger.Errorf("Error unmarshaling note: %v", err)
+			return errors.InternalServerError("notes.List.Unknown", "Error unmarshaling note")
+		}
+		rsp.Notes[i] = &note
+	}
+
+	return nil
+}
+
+// Create a note
+func (h *handler) Create(ctx context.Context, req *pb.CreateRequest, rsp *pb.CreateResponse) error {
+	// validate the request
+	if len(req.Title) == 0 {
+		return errors.BadRequest("notes.Create.MissingTitle", "Missing title")
+	}
+
+	// construct the note
+	note := &pb.Note{
+		Id:      uuid.New().String(),
+		Created: time.Now().Unix(),
+		Title:   req.Title,
+		Text:    req.Text,
+	}
+
+	// marshal the note to bytes
+	bytes, err := json.Marshal(note)
+	if err != nil {
+		logger.Errorf("Error marshaling note: %v", err)
+		return errors.InternalServerError("notes.Create.Unknown", "Error marshaling note")
+	}
+
+	// write to the store
+	key := storePrefix + note.Id
+	if err := store.Write(&store.Record{Key: key, Value: bytes}); err != nil {
+		logger.Errorf("Error writing to store: %v", err)
+		return errors.InternalServerError("notes.Create.Unknown", "Error writing to store")
+	}
+
+	// return the id
+	rsp.Id = note.Id
+	return nil
+}
+
+// Delete a note
+func (h *handler) Delete(ctx context.Context, req *pb.DeleteRequest, rsp *pb.DeleteResponse) error {
+	// validate the request
+	if len(req.Id) == 0 {
+		return errors.BadRequest("notes.Delete.MissingID", "Missing id")
+	}
+
+	// delete the note from the store
+	if err := store.Delete(storePrefix + req.Id); err == store.ErrNotFound {
+		return errors.NotFound("notes.Delete.InvalidID", "Note not found with this ID")
+	} else if err != nil {
+		logger.Errorf("Error deleting from the store: %v", err)
+		return errors.InternalServerError("notes.Delete.Unknown", "Error deleting from the store")
+	}
+
+	return nil
+}
+
+// Update a note
+func (h *handler) Update(ctx context.Context, req *pb.UpdateRequest, rsp *pb.UpdateResponse) error {
+	// validate the request
+	if len(req.Id) == 0 {
+		return errors.BadRequest("notes.Update.MissingID", "Missing id")
+	}
+	if len(req.Title) == 0 {
+		return errors.BadRequest("notes.Update.MissingTitle", "Missing title")
+	}
+
+	// read the note from the store
+	recs, err := store.Read(storePrefix + req.Id)
+	if err == store.ErrNotFound {
+		return errors.NotFound("notes.Update.InvalidID", "Note not found with this ID")
+	} else if err != nil {
+		logger.Errorf("Error reading from the store: %v", err)
+		return errors.InternalServerError("notes.Update.Unknown", "Error reading from the store")
+	}
+
+	// unmarshal the note
+	var note pb.Note
+	if err := json.Unmarshal(recs[0].Value, &note); err != nil {
+		logger.Errorf("Error unmarshaling note: %v", err)
+		return errors.InternalServerError("notes.Update.Unknown", "Error unmarshaling note")
+	}
+
+	// assign the new title and text
+	note.Title = req.Title
+	note.Text = req.Text
+
+	// marshal the note to bytes
+	bytes, err := json.Marshal(note)
+	if err != nil {
+		logger.Errorf("Error marshaling note: %v", err)
+		return errors.InternalServerError("notes.Update.Unknown", "Error marshaling note")
+	}
+
+	// write to the store
+	key := storePrefix + note.Id
+	if err := store.Write(&store.Record{Key: key, Value: bytes}); err != nil {
+		logger.Errorf("Error writing to store: %v", err)
+		return errors.InternalServerError("notes.Update.Unknown", "Error writing to store")
+	}
+
+	return nil
+}
+
+// UpdateStream updates a note every time an update is sent on the stream
+func (h *handler) UpdateStream(ctx context.Context, stream pb.Notes_UpdateStreamStream) error {
+	for {
+		uReq, err := stream.Recv()
+		if err == io.EOF {
+			return nil
+		} else if err != nil {
+			return errors.InternalServerError("notes.UpdateStream.Unknown", "Error reading from stream")
+		}
+
+		if err := h.Update(ctx, uReq, nil); err != nil {
+			return err
+		}
+	}
+}