77 lines
2.6 KiB
Go
77 lines
2.6 KiB
Go
 
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package processor
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import (
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"context"
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"errors"
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"github.com/google/uuid"
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)
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var (
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// ErrVoucherProviderRejected is what an adapter wraps when the provider definitely
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// will not issue the voucher: out of stock, the product retired, the request
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// refused. The redemption fails and the EnakPoint go back.
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ErrVoucherProviderRejected = errors.New("voucher provider refused")
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// ErrVoucherProviderNotFound is what an adapter's Lookup wraps when the provider
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// has no record of the redemption: the issue request never reached it.
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ErrVoucherProviderNotFound = errors.New("voucher provider has no such redemption")
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)
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// VoucherIssueRequest is one redemption of an EXTERNAL voucher sent to its provider.
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type VoucherIssueRequest struct {
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// The provider's idempotency key: asking twice for the same redemption must give
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// the same voucher, never a second one (docs/rfc-enakgame.md §7.5).
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RedemptionID uuid.UUID
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// The provider's own reference of the product, from vouchers.provider_ref.
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ProviderRef *string
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VoucherID uuid.UUID
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FaceValue int64
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CustomerID uuid.UUID
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}
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// VoucherIssue is what a provider handed out.
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type VoucherIssue struct {
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Code string
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// The provider's reference of this issue, for support and reconciliation.
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Ref string
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}
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// VoucherProvider issues EXTERNAL vouchers (EG-801). Adapters classify every outcome
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// through the error they return:
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//
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// - nil: issued.
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// - wrapping ErrVoucherProviderRejected: definitely not issued, and never will be.
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// - wrapping ErrVoucherProviderNotFound (Lookup only): the provider never got it.
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// - anything else, a timeout above all: unknown. The redemption stays PENDING and
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// the recovery job asks again.
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type VoucherProvider interface {
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Issue(ctx context.Context, req VoucherIssueRequest) (*VoucherIssue, error)
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Lookup(ctx context.Context, req VoucherIssueRequest) (*VoucherIssue, error)
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}
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// VoucherProviders are the adapters by the name vouchers.provider holds.
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type VoucherProviders map[string]VoucherProvider
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// voucherIssueOutcome is how one call to a provider ended.
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type voucherIssueOutcome int
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const (
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voucherIssued voucherIssueOutcome = iota
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voucherRejected
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voucherUnknown
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voucherNotFound
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)
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func classifyVoucherIssue(issue *VoucherIssue, err error) voucherIssueOutcome {
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switch {
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case err == nil && issue != nil && issue.Code != "":
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return voucherIssued
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case errors.Is(err, ErrVoucherProviderRejected):
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return voucherRejected
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case errors.Is(err, ErrVoucherProviderNotFound):
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return voucherNotFound
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}
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// An error of any other kind, or a success without a code, settles nothing.
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return voucherUnknown
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}
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