Merge pull request #6 from CS3219-AY2425S1/titus/add-id-ref

feat: add question id, ref, createdAt

Author: solomonng2001

services/question-service/handlers/create.go

@@ -1,11 +1,16 @@
 package handlers
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
+	"log"
 	"net/http"
 	"question-service/models"
 	"question-service/utils"
+
+	"cloud.google.com/go/firestore"
+	"google.golang.org/api/iterator"
 )
 
 func (s *Service) CreateQuestion(w http.ResponseWriter, r *http.Request) {
@@ -18,23 +23,71 @@ func (s *Service) CreateQuestion(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Update database
-	docRef, _, err := s.Client.Collection("questions").Add(ctx, map[string]interface{}{
-		"title":       question.Title,
-		"description": question.Description,
-		"complexity":  question.Complexity,
-		"categories":  question.Categories,
+	// Validation
+	// TODO: Duplicate checking for question name
+
+	// Reference to the document where we store the last ID
+	counterDocRef := s.Client.Collection("counters").Doc("questions")
+
+	// Firestore transaction to implement auto-increment
+	err := s.Client.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
+		doc, err := tx.Get(counterDocRef)
+		if err != nil {
+			return err
+		}
+
+		// Get the current value of the counter
+		currentCounter := doc.Data()["count"].(int64)
+		newCounter := currentCounter + 1
+
+		// Update the counter in Firestore
+		if err := tx.Set(counterDocRef, map[string]interface{}{
+			"count": newCounter,
+		}); err != nil {
+			return err
+		}
+
+		// Use the newCounter as the ID for the new document
+		docRef, _, err := s.Client.Collection("questions").Add(ctx, map[string]interface{}{
+			"id":          newCounter,
+			"title":       question.Title,
+			"description": question.Description,
+			"complexity":  question.Complexity,
+			"categories":  question.Categories,
+			"createdAt":   firestore.ServerTimestamp,
+		})
+		if err != nil {
+			http.Error(w, "Error adding question", http.StatusInternalServerError)
+			return err
+		}
+
+		// Get data
+		doc, err = docRef.Get(ctx)
+		if err != nil {
+			if err != iterator.Done {
+				http.Error(w, "Question not found", http.StatusNotFound)
+				return err
+			}
+			http.Error(w, "Failed to get question", http.StatusInternalServerError)
+			return err
+		}
+
+		// Map data
+		question.DocRefID = doc.Ref.ID
+		if err := doc.DataTo(&question); err != nil {
+			http.Error(w, "Failed to map question data", http.StatusInternalServerError)
+			return err
+		}
+
+		return nil
 	})
 	if err != nil {
-		http.Error(w, "Error adding question", http.StatusInternalServerError)
+		log.Fatalf("Trasaction failed: %v", err)
 		return
 	}
 
-	// Map data
-	question.ID = docRef.ID
-
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(question)
 
-	fmt.Fprintf(w, "Question with ID %s created successfully", question.ID)
+	fmt.Fprintf(w, "Question with ID %s created successfully", question.DocRefID)
 }

services/question-service/handlers/delete.go

@@ -13,10 +13,14 @@ func (s *Service) DeleteQuestion(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 
 	// Parse request
-	id := chi.URLParam(r, "id")
+	docRefID := chi.URLParam(r, "docRefID")
 
+	// Reference document
+	docRef := s.Client.Collection("questions").Doc(docRefID)
+
+	// Validation
 	// Check if exists
-	_, err := s.Client.Collection("questions").Doc(id).Get(ctx)
+	_, err := docRef.Get(ctx)
 	if err != nil {
 		if status.Code(err) == codes.NotFound {
 			http.Error(w, "Question not found", http.StatusNotFound)
@@ -27,11 +31,11 @@ func (s *Service) DeleteQuestion(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Update database
-	_, err = s.Client.Collection("questions").Doc(id).Delete(ctx)
+	_, err = docRef.Delete(ctx)
 	if err != nil {
 		http.Error(w, "Error deleting question", http.StatusInternalServerError)
 		return
 	}
 
-	fmt.Fprintf(w, "Question with ID %s deleted successfully", id)
+	fmt.Fprintf(w, "Question with ID %s deleted successfully", docRefID)
 }

services/question-service/handlers/list.go

@@ -27,7 +27,7 @@ func (s *Service) ListQuestions(w http.ResponseWriter, r *http.Request) {
 
 		// Map data
 		var question models.Question
-		question.ID = doc.Ref.ID
+		question.DocRefID = doc.Ref.ID
 		if err := doc.DataTo(&question); err != nil {
 			http.Error(w, "Failed to parse question", http.StatusInternalServerError)
 			return

services/question-service/handlers/read.go

@@ -13,10 +13,13 @@ func (s *Service) ReadQuestion(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 
 	// Parse request
-	id := chi.URLParam(r, "id")
+	docRefID := chi.URLParam(r, "docRefID")
+
+	// Reference document
+	docRef := s.Client.Collection("questions").Doc(docRefID)
 
 	// Get data
-	doc, err := s.Client.Collection("questions").Doc(id).Get(ctx)
+	doc, err := docRef.Get(ctx)
 	if err != nil {
 		if err != iterator.Done {
 			http.Error(w, "Question not found", http.StatusNotFound)
@@ -28,7 +31,7 @@ func (s *Service) ReadQuestion(w http.ResponseWriter, r *http.Request) {
 
 	// Map data
 	var question models.Question
-	question.ID = doc.Ref.ID
+	question.DocRefID = doc.Ref.ID
 	if err := doc.DataTo(&question); err != nil {
 		http.Error(w, "Failed to map question data", http.StatusInternalServerError)
 		return

services/question-service/handlers/update.go

@@ -9,6 +9,7 @@ import (
 
 	"cloud.google.com/go/firestore"
 	"github.com/go-chi/chi/v5"
+	"google.golang.org/api/iterator"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -17,15 +18,19 @@ func (s *Service) UpdateQuestion(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 
 	// Parse request
-	id := chi.URLParam(r, "id")
+	docRefID := chi.URLParam(r, "docRefID")
 	var question models.Question
 	if err := utils.DecodeJSONBody(w, r, &question); err != nil {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}
 
+	// Reference document
+	docRef := s.Client.Collection("questions").Doc(docRefID)
+
+	// Validation
 	// Check if exists
-	_, err := s.Client.Collection("questions").Doc(id).Get(ctx)
+	_, err := docRef.Get(ctx)
 	if err != nil {
 		if status.Code(err) == codes.NotFound {
 			http.Error(w, "Question not found", http.StatusNotFound)
@@ -35,7 +40,7 @@ func (s *Service) UpdateQuestion(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Prepare the update data
+	// Prepare the update data.
 	updates := []firestore.Update{
 		{Path: "title", Value: question.Title},
 		{Path: "description", Value: question.Description},
@@ -44,17 +49,32 @@ func (s *Service) UpdateQuestion(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Update database
-	_, err = s.Client.Collection("questions").Doc(id).Update(ctx, updates)
+	_, err = docRef.Update(ctx, updates)
 	if err != nil {
 		http.Error(w, "Error updating question", http.StatusInternalServerError)
 		return
 	}
 
+	// Get data
+	doc, err := docRef.Get(ctx)
+	if err != nil {
+		if err != iterator.Done {
+			http.Error(w, "Question not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to get question", http.StatusInternalServerError)
+		return
+	}
+
 	// Map data
-	question.ID = id
+	question.DocRefID = doc.Ref.ID
+	if err := doc.DataTo(&question); err != nil {
+		http.Error(w, "Failed to map question data", http.StatusInternalServerError)
+		return
+	}
 
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(question)
 
-	fmt.Fprintf(w, "Question with ID %s updated successfully", id)
+	fmt.Fprintf(w, "Question with ID %s updated successfully", question.DocRefID)
 }

services/question-service/main.go

@@ -52,7 +52,7 @@ func main() {
 		r.Get("/", service.ListQuestions)
 		r.Post("/", service.CreateQuestion)
 
-		r.Route("/{id}", func(r chi.Router) {
+		r.Route("/{docRefID}", func(r chi.Router) {
 			r.Get("/", service.ReadQuestion)
 			r.Put("/", service.UpdateQuestion)
 			r.Delete("/", service.DeleteQuestion)

services/question-service/models/question.go

@@ -1,10 +1,16 @@
 package models
 
+import "time"
+
 // TODO: currently the Question model is a simplified model
 type Question struct {
-	ID          string   `json:"id"`
 	Title       string   `json:"title"`
 	Description string   `json:"description"`
 	Categories  []string `json:"categories"`
 	Complexity  string   `json:"complexity"`
+
+	// Special DB fields
+	ID        int64     `json:"id"`
+	DocRefID  string    `json:"docRefId"` // The firestore document reference ID
+	CreatedAt time.Time `json:"createdAt"`
 }