init commit

Backend/models/booking.go

@@ -0,0 +1,62 @@
+package models
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+)
+
+type Booking struct {
+	CradID      string `json:"cradID"`
+	ReaderID    string `json:"readerID"`
+	BookingType int `json:"bookingTyp"`
+}
+
+type SameBookingError struct{}
+
+func (e SameBookingError) Error() string {
+	return "the same booking already exists!"
+}
+
+func VerifyBooking(b Booking) bool {
+	if b.CradID == "" || b.ReaderID == "" || b.BookingType == 0 {
+		return false
+	}
+	return true
+}
+
+func InsertBooking(b Booking, db *sql.DB) error {
+	if !checkLastBooking(b, db) {
+		return fmt.Errorf("the same booking already exists")
+    }
+	stmt, err := db.Prepare((`INSERT INTO zeiten (card_id, reader_id, booking_type) VALUES ($1, $2, $3)`))
+	if err != nil {
+		return err
+	}
+	_, err = stmt.Query(b.CradID, b.ReaderID, b.BookingType)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func checkLastBooking(b Booking, db *sql.DB) bool {
+	var booking_type int
+	stmt, err := db.Prepare((`SELECT booking_type FROM "zeiten" WHERE "card_id" = $1 ORDER BY "logged_time" DESC LIMIT 1;`))
+	if err != nil {
+		log.Fatalf("Error preparing query: %v", err)
+        return false
+    }
+	err = stmt.QueryRow(b.CradID).Scan(&booking_type)
+	if err == sql.ErrNoRows {
+		return true
+	}
+	if err!= nil {
+        log.Println("Error checking last booking: ", err)
+        return false
+    }
+	if booking_type == b.BookingType {
+		return false
+	}
+	return true
+}