tsk-8: Create Message endpoint (#15)

Closes #8

Reviewed-on: phoenix/textsender-api#15
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/handler/message.go

@@ -0,0 +1,72 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/google/uuid"
+
+	"git.kundeng.us/phoenix/textsender-api/internal/store"
+	"git.kundeng.us/phoenix/textsender-models/pkg/message"
+)
+
+type RequestAddMessage struct {
+	Content string    `json:"content"`
+	UserId  uuid.UUID `json:"user_id"`
+}
+
+type AddMessageResponse struct {
+	Message string            `json:"message"`
+	Data    []message.Message `json:"data"`
+}
+
+type MessageHandler struct {
+	MessageStore store.MessageStore
+}
+
+func NewMessageHandler(str store.MessageStore) *MessageHandler {
+	return &MessageHandler{MessageStore: str}
+}
+
+func (m *MessageHandler) AddMessage(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var req RequestAddMessage
+	if err := ExtractFromRequest(r, &req); err != nil {
+		http.Error(w, "Invalid JSON: "+err.Error(), http.StatusBadRequest)
+	}
+	defer r.Body.Close()
+
+	newMessage := message.Message{Content: req.Content, UserId: req.UserId}
+
+	var statusCode int
+	var resp AddMessageResponse
+
+	ctx := r.Context()
+
+	if exists, err := m.MessageStore.MessageExists(ctx, &newMessage); err != nil {
+		fmt.Println("Error: ", err)
+		statusCode = http.StatusInternalServerError
+		resp.Message = err.Error()
+	} else {
+		if exists {
+			statusCode = http.StatusBadRequest
+			resp.Message = "Cannot create message"
+		} else {
+			if err = m.MessageStore.CreateMessage(ctx, &newMessage); err != nil {
+				fmt.Println("Error:", err)
+				statusCode = http.StatusInternalServerError
+				resp.Message = err.Error()
+			} else {
+				statusCode = http.StatusCreated
+				resp.Message = "Message created"
+				resp.Data = append(resp.Data, newMessage)
+			}
+		}
+	}
+
+	RespondWithJSON(w, statusCode, &resp)
+}