Xojo Plugin
Amazon Pay - Complete Checkout Session

Complete Checkout Session after the buyer returns to checkoutResultReturnUrl to finalize the paymentIntent.
Chilkat Xojo Plugin Downloads

Xojo Plugin
Dim success As Boolean
success = False

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Dim http As New Chilkat.Http

// Implements the following CURL command:

// curl "https://pay-api.amazon.com/:version/checkoutSessions/:checkoutSessionId/complete" \
// -X POST
// -H "authorization:Px2e5oHhQZ88vVhc0DO%2FsShHj8MDDg%3DEXAMPLESIGNATURE"
// -H "x-amz-pay-date:20201012T235046Z"
// -H "x-amz-pay-idempotency-key:AVLo5tI10BHgEk2jEXAMPLEKEY"
// -d '{
//     "chargeAmount": {
//         "amount": "14.00",
//         "currencyCode": "USD"
//     }
// }'

// Use the following online tool to generate HTTP code from a CURL command
// Convert a cURL Command to HTTP Source Code

// Use this online tool to generate code from sample JSON:
// Generate Code to Create JSON

// The following JSON is sent in the request body.

// {
//   "chargeAmount": {
//     "amount": "14.00",
//     "currencyCode": "USD"
//   }
// }

Dim json As New Chilkat.JsonObject
success = json.UpdateString("chargeAmount.amount","14.00")
success = json.UpdateString("chargeAmount.currencyCode","USD")

// Load your Amazon Pay private key.  
// There are many other ways to load private keys into the Chilkat private key object, such as from different formats,
// or from in-memory strings or bytes.
Dim privKey As New Chilkat.PrivateKey
success = privKey.LoadPemFile("C:/someDir/myAmazonPayPrivateKey.pem")
If (success = False) Then
    System.DebugLog(privKey.LastErrorText)
    Return
End If

// Provide your Amazon Pay private key and Public Key ID 
// Use your public key ID here.  It must be the one associated with the private key.
// Note: The SetAuthPrivateKey method was added in Chilkat v9.5.0.89
Dim publicKeyId As String
publicKeyId = "SANDBOX-AHEGSJCM3L2S637RBGABLAFW"
success = http.SetAuthPrivateKey(publicKeyId,privKey)
If (success = False) Then
    System.DebugLog(http.LastErrorText)
    Return
End If

// Note: When the private key is provided as shown above, Chilkat will automatically add the required x-amz-pay-* headers to the HTTP request,
// and will also sign the request.  Nothing more is needed.
// Chilkat automatically generates and adds the following headers:
// 
// x-amz-pay-date
// x-amz-pay-host
// x-amz-pay-region
// x-amz-pay-idempotency-key
// Authorization

http.Accept = "application/json"

// To use the live system, replace "sandbox" with "live" in the URL passed to HttpJson.
// Also, make sure to use the correct region: pay-api.amazon.com, pay-api.amazon.eu, or pay-api.amazon.jp
success = http.SetUrlVar("sessionId","62b7d028-6c7c-4a43-b077-3897dff27c5b")
Dim resp As New Chilkat.HttpResponse
success = http.HttpJson("POST","https://pay-api.amazon.eu/sandbox/v2/checkoutSessions/{$sessionId}/complete",json,"application/json",resp)
If (success = False) Then
    System.DebugLog(http.LastErrorText)
    Return
End If

Dim sbResponseBody As New Chilkat.StringBuilder
success = resp.GetBodySb(sbResponseBody)
Dim jResp As New Chilkat.JsonObject
success = jResp.LoadSb(sbResponseBody)
jResp.EmitCompact = False

// If the status code is not equal to 200, this will display error information.
System.DebugLog("Response Body:")
System.DebugLog(jResp.Emit())

Dim respStatusCode As Int32
respStatusCode = resp.StatusCode
System.DebugLog("Response Status Code = " + Str(respStatusCode))
If (respStatusCode <> 200) Then

    // A sample response body for the case where the session ID does not exist:
    // 	{
    // 	  "reasonCode": "ResourceNotFound",
    // 	  "message": "Resource you are trying to access is not available. Requested path '/sandbox/v2/checkoutSessions/bd504926-f659-4ad7-a1a9-9a747aaf5275'"
    // 	}

    // Another sample failure response (status code = 422)
    // 	{
    // 	  "reasonCode": "InvalidCheckoutSessionStatus",
    // 	  "message": "You tried to call an operation on a Checkout Session that is in a state where that operation is not allowed"
    // 	}

    System.DebugLog("Failed.")
    Return
End If

// Sample JSON response:
// (Sample code for parsing the JSON response is shown below)

// {
//   "checkoutSessionId": "bd504926-f659-4ad7-a1a9-9a747aaf5275",
//   "webCheckoutDetails": null,
//   "chargePermissionType": "OneTime",
//   "recurringMetadata": null,
//   "productType": null,
//   "paymentDetails": null,
//   "merchantMetadata": null,
//   "supplementaryData": null,
//   "buyer": null,
//   "billingAddress": null,
//   "paymentPreferences": [
//     null
//   ],
//   "statusDetails": {
//     "state": "Completed",
//     "reasonCode": null,
//     "reasonDescription": null,
//     "lastUpdatedTimestamp": "20191015T204327Z"
//   },
//   "shippingAddress": null,
//   "platformId": null,
//   "chargePermissionId": "S01-5105180-3221187",
//   "chargeId": "S01-5105180-3221187-C056351",
//   "constraints": [
//     null
//   ],
//   "creationTimestamp": "20191015T204313Z",
//   "expirationTimestamp": null,
//   "storeId": null,
//   "deliverySpecifications": null,
//   "providerMetadata": null,
//   "releaseEnvironment": null
// }

// Sample code for parsing the JSON response...
// Use the following online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON

Dim nullVal As Boolean

Dim checkoutSessionId As String
checkoutSessionId = jResp.StringOf("checkoutSessionId")
Dim webCheckoutDetails As String
webCheckoutDetails = jResp.StringOf("webCheckoutDetails")
Dim chargePermissionType As String
chargePermissionType = jResp.StringOf("chargePermissionType")
Dim recurringMetadata As String
recurringMetadata = jResp.StringOf("recurringMetadata")
Dim productType As String
productType = jResp.StringOf("productType")
Dim paymentDetails As String
paymentDetails = jResp.StringOf("paymentDetails")
Dim merchantMetadata As String
merchantMetadata = jResp.StringOf("merchantMetadata")
Dim supplementaryData As String
supplementaryData = jResp.StringOf("supplementaryData")
Dim buyer As String
buyer = jResp.StringOf("buyer")
Dim billingAddress As String
billingAddress = jResp.StringOf("billingAddress")
Dim statusDetailsState As String
statusDetailsState = jResp.StringOf("statusDetails.state")
Dim statusDetailsReasonCode As String
statusDetailsReasonCode = jResp.StringOf("statusDetails.reasonCode")
Dim statusDetailsReasonDescription As String
statusDetailsReasonDescription = jResp.StringOf("statusDetails.reasonDescription")
Dim statusDetailsLastUpdatedTimestamp As String
statusDetailsLastUpdatedTimestamp = jResp.StringOf("statusDetails.lastUpdatedTimestamp")
Dim shippingAddress As String
shippingAddress = jResp.StringOf("shippingAddress")
Dim platformId As String
platformId = jResp.StringOf("platformId")
Dim chargePermissionId As String
chargePermissionId = jResp.StringOf("chargePermissionId")
Dim chargeId As String
chargeId = jResp.StringOf("chargeId")
Dim creationTimestamp As String
creationTimestamp = jResp.StringOf("creationTimestamp")
Dim expirationTimestamp As String
expirationTimestamp = jResp.StringOf("expirationTimestamp")
Dim storeId As String
storeId = jResp.StringOf("storeId")
Dim deliverySpecifications As String
deliverySpecifications = jResp.StringOf("deliverySpecifications")
Dim providerMetadata As String
providerMetadata = jResp.StringOf("providerMetadata")
Dim releaseEnvironment As String
releaseEnvironment = jResp.StringOf("releaseEnvironment")
Dim i As Int32
i = 0
Dim count_i As Int32
count_i = jResp.SizeOfArray("paymentPreferences")
While i < count_i
    jResp.I = i
    nullVal = jResp.IsNullOf("paymentPreferences[i]")
    i = i + 1
Wend
i = 0
count_i = jResp.SizeOfArray("constraints")
While i < count_i
    jResp.I = i
    nullVal = jResp.IsNullOf("constraints[i]")
    i = i + 1
Wend