add sentiment analaysis mvp

sentiment/handler/sentiment.go

@@ -0,0 +1,34 @@
+package handler
+
+import (
+	"context"
+
+	"github.com/cdipaolo/sentiment"
+	"github.com/micro/micro/v3/service/errors"
+	pb "github.com/micro/services/sentiment/proto"
+)
+
+type Sentiment struct {
+	Model *sentiment.Models
+}
+
+func (e *Sentiment) Analyze(ctx context.Context, req *pb.Request, rsp *pb.Response) error {
+	if len(req.Text) == 0 {
+		return errors.BadRequest("sentiment.analyze", "text is blank")
+	}
+
+	if len(req.Lang) == 0 {
+		req.Lang = "english"
+	}
+
+	if req.Lang != "english" {
+		return errors.BadRequest("sentiment.analyze", "only support english")
+	}
+
+	an := e.Model.SentimentAnalysis(req.Text, sentiment.English)
+	rsp.Score = float64(an.Score)
+
+	// TODO: more complex word scoring
+
+	return nil
+}