jordi fita mas e4636592c5 Add payment relation and use it to compute the booking’s cart
I had to add the payment concept separate from the booking, unlike other
eCommerce solutions that subsume the two into a single “order”, like
WooCommerce, because bookings should be done in a separate Camper
instance that will sync to the public instance, but the payment is done
by the public instance.  There will be a queue or something between
the public and the private instance to pass along the booking
information once the payment is complete, but the public instance still
needs to keep track of payments without creating bookings.

To compute the total for that payment i had to do the same as was doing
until now for the cart.  To prevent duplications, or having functions
with complex return types, i now create a “draft” payment while the
user is filling in the form, and compute the cart there; from Go i only
have to retrieve the data from the relation, that simplifies the work,
actually.

Since the payment is computed way before customers enter their details,
i can not have that data in the same payment relation, unless i allow
NULL values.  Allowing NULL values means that i can create a payment
without customer, thus i moved all customer details to a separate
relation.  It still allows payment without customer, but at least there
are no NULL values.

Draft payments should be removed after a time, but i believe this needs
to be done in a cronjob or similar, not in the Go application.

To update the same payment while filling the same booking form, i now
have a hidden field with the payment slug.  A competent developer would
have used a cookie or something like that; i am not competent.
2024-02-12 05:21:00 +01:00

192 lines
4.5 KiB
Go

package booking
import (
"context"
"strconv"
"time"
"dev.tandem.ws/tandem/camper/pkg/database"
"dev.tandem.ws/tandem/camper/pkg/locale"
)
type bookingCart struct {
Lines []*cartLine
Total string
Enabled bool
}
type cartLine struct {
Concept string
Units int
Subtotal string
}
func newBookingCart(ctx context.Context, conn *database.Conn, f *bookingForm, campsiteType string) (*bookingCart, error) {
cart := &bookingCart{
Total: "0.0",
}
if f.Dates == nil {
return cart, nil
}
arrivalDate, err := time.Parse(database.ISODateFormat, f.Dates.ArrivalDate.Val)
if err != nil {
return cart, nil
}
departureDate, err := time.Parse(database.ISODateFormat, f.Dates.DepartureDate.Val)
if err != nil {
return cart, nil
}
if f.Guests == nil {
return cart, nil
}
numAdults, err := strconv.Atoi(f.Guests.NumberAdults.Val)
if err != nil {
return cart, nil
}
numTeenagers, err := strconv.Atoi(f.Guests.NumberTeenagers.Val)
if err != nil {
return cart, nil
}
numChildren, err := strconv.Atoi(f.Guests.NumberChildren.Val)
if err != nil {
return cart, nil
}
numDogs := 0
if f.Guests.NumberDogs != nil {
numDogs, err = strconv.Atoi(f.Guests.NumberDogs.Val)
if err != nil {
return cart, nil
}
}
zonePreferences := ""
if f.Options != nil && f.Options.ZonePreferences != nil {
zonePreferences = f.Options.ZonePreferences.Val
}
optionMap := make(map[int]*campsiteTypeOption)
var typeOptions []*campsiteTypeOption
if f.Options != nil {
typeOptions = f.Options.Options
}
optionUnits := make([]*database.OptionUnits, 0, len(typeOptions))
for _, option := range typeOptions {
units, _ := strconv.Atoi(option.Input.Val)
if units < 1 {
continue
}
optionMap[option.ID] = option
optionUnits = append(optionUnits, &database.OptionUnits{
OptionID: option.ID,
Units: units,
})
}
paymentSlug, err := conn.DraftPayment(
ctx,
f.PaymentSlug.Val,
arrivalDate,
departureDate,
campsiteType,
numAdults,
numTeenagers,
numChildren,
numDogs,
zonePreferences,
optionUnits,
)
if err != nil {
return nil, err
}
f.PaymentSlug.Val = paymentSlug
row := conn.QueryRow(ctx, `
select payment_id
, departure_date - arrival_date
, to_price(subtotal_nights, decimal_digits)
, to_price(subtotal_adults, decimal_digits)
, to_price(subtotal_teenagers, decimal_digits)
, to_price(subtotal_children, decimal_digits)
, to_price(subtotal_dogs, decimal_digits)
, to_price(subtotal_tourist_tax, decimal_digits)
, to_price(total, decimal_digits)
from payment
join company using (company_id)
join currency using (currency_code)
where payment.slug = $1
`, paymentSlug)
var paymentID int
var numNights int
var nights string
var adults string
var teenagers string
var children string
var dogs string
var touristTax string
var total string
if err = row.Scan(&paymentID, &numNights, &nights, &adults, &teenagers, &children, &dogs, &touristTax, &total); err != nil {
if database.ErrorIsNotFound(err) {
return cart, nil
}
return nil, err
}
maybeAddLine := func(units int, subtotal string, concept string) {
if units > 0 && subtotal != "" {
cart.Lines = append(cart.Lines, &cartLine{
Concept: concept,
Units: units,
Subtotal: subtotal,
})
}
}
maybeAddLine(numNights, nights, locale.PgettextNoop("Night", "cart"))
maybeAddLine(numAdults, adults, locale.PgettextNoop("Adult", "cart"))
maybeAddLine(numTeenagers, teenagers, locale.PgettextNoop("Teenager", "cart"))
maybeAddLine(numChildren, children, locale.PgettextNoop("Child", "cart"))
maybeAddLine(numDogs, dogs, locale.PgettextNoop("Dog", "cart"))
rows, err := conn.Query(ctx, `
select campsite_type_option_id
, units
, to_price(subtotal, decimal_digits)
from payment_option
join payment using (payment_id)
join company using (company_id)
join currency using (currency_code)
where payment_id = $1
`, paymentID)
if err != nil {
return nil, err
}
defer rows.Close()
for rows.Next() {
var optionID int
var units int
var subtotal string
err = rows.Scan(&optionID, &units, &subtotal)
if err != nil {
return nil, err
}
option := optionMap[optionID]
if option == nil {
continue
}
maybeAddLine(units, subtotal, option.Label)
}
if rows.Err() != nil {
return nil, rows.Err()
}
maybeAddLine(numAdults, touristTax, locale.PgettextNoop("Tourist tax", "cart"))
if total != "0.0" {
cart.Total = total
cart.Enabled = f.Guests.Error == nil
}
return cart, nil
}