fix: add default maxToken value of watsonxai backend (#1209)

Signed-off-by: yanweili <yanweili@ibm.com>
Co-authored-by: yanweili <yanweili@ibm.com>
Signed-off-by: AlexsJones <alexsimonjones@gmail.com>

pkg/ai/watsonxai.go

@@ -1,10 +1,10 @@
 package ai
 
 import (
-	"os"
-	"fmt"
 	"context"
 	"errors"
+	"fmt"
+	"os"
 
 	wx "github.com/IBM/watsonx-go/pkg/models"
 )
@@ -24,18 +24,23 @@ type WatsonxAIClient struct {
 
 const (
 	modelMetallama = "ibm/granite-13b-chat-v2"
+	maxTokens      = 2048
 )
 
 func (c *WatsonxAIClient) Configure(config IAIConfig) error {
-	if(config.GetModel() == "") {
-		c.model = config.GetModel()
-	} else {
+	if config.GetModel() == "" {
 		c.model = modelMetallama
+	} else {
+		c.model = config.GetModel()
+	}
+	if config.GetMaxTokens() == 0 {
+		c.maxNewTokens = maxTokens
+	} else {
+		c.maxNewTokens = config.GetMaxTokens()
 	}
 	c.temperature = config.GetTemperature()
 	c.topP = config.GetTopP()
 	c.topK = config.GetTopK()
-	c.maxNewTokens = config.GetMaxTokens()
 
 	// WatsonxAPIKeyEnvVarName    = "WATSONX_API_KEY"
 	// WatsonxProjectIDEnvVarName = "WATSONX_PROJECT_ID"
@@ -75,7 +80,6 @@ func (c *WatsonxAIClient) GetCompletion(ctx context.Context, prompt string) (str
 	if result.Text == "" {
 		return "", errors.New("Expected a result, but got an empty string")
 	}
-
 	return result.Text, nil
 }