Implement `CheckIBDUsername` for `UserService`

3 files changed, 84 insertions, 4 deletions

diff --git a/backend/internal/ibd/check_ibd_username.go b/backend/internal/ibd/check_ibd_username.go
new file mode 100644
index 0000000..03d2640
--- /dev/null
+++ b/backend/internal/ibd/check_ibd_username.go
@@ -0,0 +1,59 @@
+package ibd
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+const (
+	checkUsernameUrl = "https://sso.accounts.dowjones.com/getuser"
+)
+
+func (c *Client) CheckIBDUsername(ctx context.Context, username string) (bool, error) {
+	cfg, err := c.getLoginPage(ctx)
+	if err != nil {
+		return false, err
+	}
+
+	return c.checkIBDUsername(ctx, cfg, username)
+}
+
+func (c *Client) checkIBDUsername(ctx context.Context, cfg *authConfig, username string) (bool, error) {
+	body := map[string]string{
+		"username": username,
+		"csrf":     cfg.ExtraParams.Csrf,
+	}
+	bodyJson, err := json.Marshal(body)
+	if err != nil {
+		return false, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, checkUsernameUrl, bytes.NewReader(bodyJson))
+	if err != nil {
+		return false, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-REMOTE-USER", username)
+	req.Header.Set("X-REQUEST-EDITIONID", "IBD-EN_US")
+	req.Header.Set("X-REQUEST-SCHEME", "https")
+
+	resp, err := c.Do(req)
+	if err != nil {
+		return false, err
+	}
+
+	if resp.Result.StatusCode == http.StatusUnauthorized {
+		return false, nil
+	} else if resp.Result.StatusCode != http.StatusOK {
+		return false, fmt.Errorf(
+			"unexpected status code %d: %s",
+			resp.Result.StatusCode,
+			resp.Result.Content,
+		)
+	}
+	return true, nil
+}
diff --git a/backend/internal/server/idb/user/v1/user.go b/backend/internal/server/idb/user/v1/user.go
index 9550b06..8e5f16a 100644
--- a/backend/internal/server/idb/user/v1/user.go
+++ b/backend/internal/server/idb/user/v1/user.go
@@ -6,6 +6,7 @@ import (
 
 	pb "github.com/ansg191/ibd-trader-backend/api/gen/idb/user/v1"
 	"github.com/ansg191/ibd-trader-backend/internal/database"
+	"github.com/ansg191/ibd-trader-backend/internal/ibd"
 
 	"github.com/mennanov/fmutils"
 	"google.golang.org/grpc/codes"
@@ -16,11 +17,12 @@ import (
 type Server struct {
 	pb.UnimplementedUserServiceServer
 
-	db database.UserStore
+	db     database.UserStore
+	client *ibd.Client
 }
 
-func New(db database.UserStore) *Server {
-	return &Server{db: db}
+func New(db database.UserStore, client *ibd.Client) *Server {
+	return &Server{db: db, client: client}
 }
 
 func (u *Server) CreateUser(ctx context.Context, request *pb.CreateUserRequest) (*pb.CreateUserResponse, error) {
@@ -92,3 +94,20 @@ func (u *Server) UpdateUser(ctx context.Context, request *pb.UpdateUserRequest)
 		User: newUser,
 	}, nil
 }
+
+func (u *Server) CheckIBDUsername(ctx context.Context, req *pb.CheckIBDUsernameRequest) (*pb.CheckIBDUsernameResponse, error) {
+	username := req.IbdUsername
+	if username == "" {
+		return nil, status.Errorf(codes.InvalidArgument, "username cannot be empty")
+	}
+
+	// Check if the username exists
+	exists, err := u.client.CheckIBDUsername(ctx, username)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "unable to check username: %v", err)
+	}
+
+	return &pb.CheckIBDUsernameResponse{
+		Exists: exists,
+	}, nil
+}
diff --git a/backend/internal/server/server.go b/backend/internal/server/server.go
index 133deb7..c46a629 100644
--- a/backend/internal/server/server.go
+++ b/backend/internal/server/server.go
@@ -10,6 +10,7 @@ import (
 	spb "github.com/ansg191/ibd-trader-backend/api/gen/idb/stock/v1"
 	upb "github.com/ansg191/ibd-trader-backend/api/gen/idb/user/v1"
 	"github.com/ansg191/ibd-trader-backend/internal/database"
+	"github.com/ansg191/ibd-trader-backend/internal/ibd"
 	"github.com/ansg191/ibd-trader-backend/internal/leader/manager/ibd/scrape"
 	"github.com/ansg191/ibd-trader-backend/internal/redis/taskqueue"
 	"github.com/ansg191/ibd-trader-backend/internal/server/idb/stock/v1"
@@ -31,6 +32,7 @@ func New(
 	port uint16,
 	db database.Database,
 	rClient *redis.Client,
+	client *ibd.Client,
 ) (*Server, error) {
 	scrapeQueue, err := taskqueue.New(
 		ctx,
@@ -43,7 +45,7 @@ func New(
 	}
 
 	s := grpc.NewServer()
-	upb.RegisterUserServiceServer(s, user.New(db))
+	upb.RegisterUserServiceServer(s, user.New(db, client))
 	spb.RegisterStockServiceServer(s, stock.New(db, scrapeQueue))
 	longrunningpb.RegisterOperationsServer(s, newOperationServer(scrapeQueue))
 	reflection.Register(s)