Implement features endpoint

server/handler/features.go

@@ -0,0 +1,26 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/go-chi/chi"
+	"github.com/src-d/code-annotation/server/repository"
+	"github.com/src-d/code-annotation/server/serializer"
+)
+
+// GetFeatures returns a function that returns a *serializer.Response
+// with the list of features for blobId
+func GetFeatures(repo *repository.Features) RequestProcessFunc {
+	return func(r *http.Request) (*serializer.Response, error) {
+		blobID := chi.URLParam(r, "blobId")
+
+		// in the future it should take file by blobID from DB
+		// and make API request to ML system
+		features, err := repo.GetAll(blobID)
+		if err != nil {
+			return nil, err
+		}
+
+		return serializer.NewFeaturesResponse(features), nil
+	}
+}

server/model/models.go

@@ -48,6 +48,12 @@ type File struct {
 	Hash         string
 }
 
+// Feature represents one name-value feature of file
+type Feature struct {
+	Name   string
+	Weight float64
+}
+
 // Role represents the position of a app User
 type Role string
 

server/repository/features.go

@@ -0,0 +1,44 @@
+package repository
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/src-d/code-annotation/server/model"
+)
+
+// Features repository
+type Features struct {
+	db *sql.DB
+}
+
+// NewFeatures returns a new Features repository
+func NewFeatures(db *sql.DB) *Features {
+	return &Features{db: db}
+}
+
+const selectFeaturesSQL = `SELECT name, weight FROM features WHERE blob_id=$1`
+
+// GetAll returns a list of all features for blobID
+func (repo *Features) GetAll(blobID string) ([]*model.Feature, error) {
+	rows, err := repo.db.Query(selectFeaturesSQL, blobID)
+	if err != nil {
+		return nil, fmt.Errorf("Error getting features from the DB: %v", err)
+	}
+	defer rows.Close()
+
+	results := make([]*model.Feature, 0)
+
+	for rows.Next() {
+		var f model.Feature
+		rows.Scan(&f.Name, &f.Weight)
+
+		results = append(results, &f)
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("DB error: %v", err)
+	}
+
+	return results, nil
+}

server/router.go

@@ -29,6 +29,7 @@ func Router(
 	experimentRepo := repository.NewExperiments(db)
 	assignmentRepo := repository.NewAssignments(db)
 	filePairRepo := repository.NewFilePairs(db)
+	featureRepo := repository.NewFeatures(db)
 
 	// cors options
 	corsOptions := cors.Options{
@@ -63,6 +64,8 @@ func Router(
 
 			r.Get("/file-pairs/{pairId}", handler.Get(handler.GetFilePairDetails(filePairRepo)))
 		})
+
+		r.Get("/features/{blobId}", handler.Get(handler.GetFeatures(featureRepo)))
 	})
 
 	r.Get("/static/*", handler.FrontendStatics(staticsPath, false))

server/serializer/serializers.go

@@ -130,6 +130,20 @@ func NewUserResponse(u *model.User) *Response {
 	return newResponse(userResponse{u.ID, u.Login, u.Username, u.AvatarURL})
 }
 
+type featureResponse struct {
+	Name   string  `json:"name"`
+	Weight float64 `json:"weight"`
+}
+
+// NewFeaturesResponse returns a Response for the passed Features
+func NewFeaturesResponse(fs []*model.Feature) *Response {
+	features := make([]featureResponse, len(fs))
+	for i, f := range fs {
+		features[i] = featureResponse(*f)
+	}
+	return newResponse(features)
+}
+
 type countResponse struct {
 	Count int `json:"count"`
 }