api for initial widgets

widgets/expenses.go

@@ -0,0 +1,55 @@
+package widgets
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/jacobmveber-01839764/BudgetBuddy/db"
+	"github.com/jacobmveber-01839764/BudgetBuddy/money"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+func GetMonthExpenses(w http.ResponseWriter, r *http.Request) {
+	// get session key from request
+	session := r.Header.Get("x-session-key")
+
+	// get collection handle from db
+	var userCollection = db.Client.Database("budgetbuddy").Collection("users")
+
+	var user = db.UserSchema{}
+
+	err := userCollection.FindOne(context.Background(), bson.D{primitive.E{Key: "session", Value: session}}).Decode(&user)
+	if err != nil {
+		w.WriteHeader(http.StatusUnauthorized)
+		fmt.Fprintf(w, "{\"error\":\"invalid session key\"}")
+		return
+	}
+
+	if user.Expenses == nil {
+		user.Expenses = make([]db.Transaction, 0)
+	}
+
+	total := money.Money{}
+	total.Currency = user.Balance.Currency
+
+	for i := 0; i < len(user.Expenses); i++ {
+		// stop if/when we get past a month ago
+		if user.Expenses[i].Timestamp < time.Now().Add(-30*24*time.Hour).Unix() {
+			break
+		}
+		total = money.Add(total, user.Expenses[i].Amount)
+	}
+
+	ret, err := json.Marshal(total)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprintf(w, "{\"error\":\"problem marshalling response\"}")
+		return
+	}
+
+	w.Write(ret)
+}