Initial Stripe extension, that implements the standar stripe checkout…

… process, assuming an embedded form, and a given stripe price id.

Refactors `storage`, `handlersresponse`, `faucet` and `helpers` to  be new packages.
The min and max number of tokes is defined (should be paremtrized) and just aflat rate is allowed.
Adds the handlers:
- `/createCheckoutSession/{to}`
- `/createCheckoutSession/{to}/{amount}`
- `/sessionStatus/{session_id}`
- /webhook"
and the following env vars:
-STRIPEKEY
-STRIPEPRICEID
-STRIPEWEBHOOKSECRET
-STRIPEMINQUANTITY
-STRIPEMAXQUANTITY

.env.example

@@ -11,8 +11,18 @@ WAIT_PERIOD=10m
 DB_TYPE=pebble
 # base route for the API (default "/v2")
 BASE_ROUTE=/v2
-# authentication types to use (comma separated). Available: open, oauth
+# authentication types to use (comma separated). Available: open, oauth, stripe
 AUTH=open
+# stripe secret key
+STRIPE_KEY=
+# stripe price id
+STRIPE_PRICE_ID=
+# min number of tokens
+STRIPEMINQUANTITY=
+# max number of tokens
+STRIPEMAXQUANTITY=
+# stripe webhook secret
+STRIPE_WEBHOOK_SECRET=
 
 RESTART=unless-stopped
 

faucet/faucet.go

@@ -0,0 +1,74 @@
+package faucet
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/vocdoni/vocfaucet/storage"
+	"go.vocdoni.io/dvote/api"
+	vFaucet "go.vocdoni.io/dvote/api/faucet"
+	"go.vocdoni.io/dvote/crypto/ethereum"
+	"go.vocdoni.io/dvote/vochain"
+)
+
+type Faucet struct {
+	Signer     *ethereum.SignKeys
+	AuthTypes  map[string]uint64
+	WaitPeriod time.Duration
+	Storage    *storage.Storage
+}
+
+// prepareFaucetPackage prepares a Faucet package, including the signature, for the given address.
+// Returns the Faucet package as a marshaled json byte array, ready to be sent to the user.
+func (f *Faucet) prepareFaucetPackage(toAddr common.Address, authTypeName string) (*vFaucet.FaucetResponse, error) {
+	// check if the auth type is supported
+	if _, ok := f.AuthTypes[authTypeName]; !ok {
+		return nil, fmt.Errorf("auth type %s not supported", authTypeName)
+	}
+
+	// generate Faucet package
+	fpackage, err := vochain.GenerateFaucetPackage(f.Signer, toAddr, f.AuthTypes[authTypeName])
+	if err != nil {
+		return nil, api.ErrCantGenerateFaucetPkg.WithErr(err)
+	}
+	fpackageBytes, err := json.Marshal(vFaucet.FaucetPackage{
+		FaucetPayload: fpackage.Payload,
+		Signature:     fpackage.Signature,
+	})
+	if err != nil {
+		return nil, err
+	}
+	// send response
+	return &vFaucet.FaucetResponse{
+		Amount:        fmt.Sprint(f.AuthTypes[authTypeName]),
+		FaucetPackage: fpackageBytes,
+	}, nil
+}
+
+// PrepareFaucetPackageWithAmount prepares a Faucet package, including the signature, for the given address.
+// Returns the Faucet package as a marshaled json byte array, ready to be sent to the user.
+func (f *Faucet) PrepareFaucetPackageWithAmount(toAddr common.Address, amount uint64) (*vFaucet.FaucetResponse, error) {
+	if amount == 0 {
+		return nil, fmt.Errorf("invalid requested amount: %d", amount)
+	}
+
+	// generate Faucet package
+	fpackage, err := vochain.GenerateFaucetPackage(f.Signer, toAddr, amount)
+	if err != nil {
+		return nil, api.ErrCantGenerateFaucetPkg.WithErr(err)
+	}
+	fpackageBytes, err := json.Marshal(vFaucet.FaucetPackage{
+		FaucetPayload: fpackage.Payload,
+		Signature:     fpackage.Signature,
+	})
+	if err != nil {
+		return nil, err
+	}
+	// send response
+	return &vFaucet.FaucetResponse{
+		Amount:        fmt.Sprint(amount),
+		FaucetPackage: fpackageBytes,
+	}, nil
+}