From a14bd11b0c03e4d9a0a93288da21c79def40d264 Mon Sep 17 00:00:00 2001
From: sanjid133 <sanjid133@gmail.com>
Date: Tue, 6 Aug 2019 17:22:41 +0600
Subject: [PATCH] Verfiy latest receipt

---
 appstore/model.go     | 10 ++++++++++
 appstore/validator.go | 31 ++++++++++++++++---------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/appstore/model.go b/appstore/model.go
index 19182fa..a6f0f4f 100644
--- a/appstore/model.go
+++ b/appstore/model.go
@@ -151,6 +151,16 @@ type (
 		IsRetryable        bool                 `json:"is-retryable,omitempty"`
 	}
 
+	// The IAPLatestResponse type has the response properties
+	// If you use latest_receipt as token to verify, response should be like following struct
+	IAPLatestResponse struct {
+		Status                   int    `json:"status"`
+		Receipt                  InApp  `json:"receipt"`
+		LatestReceiptInfo        InApp  `json:"latest_receipt_info,omitempty"`
+		LatestExpiredReceiptInfo InApp  `json:"latest_expired_receipt_info,omitempty"`
+		LatestReceipt            string `json:"latest_receipt,omitempty"`
+	}
+
 	// The HttpStatusResponse struct contains the status code returned by the store
 	// Used as a workaround to detect when to hit the production appstore or sandbox appstore regardless of receipt type
 	StatusResponse struct {
diff --git a/appstore/validator.go b/appstore/validator.go
index dee06bc..077dc7d 100644
--- a/appstore/validator.go
+++ b/appstore/validator.go
@@ -105,70 +105,71 @@ func NewWithClient(client *http.Client) *Client {
 }
 
 // Verify sends receipts and gets validation result
-func (c *Client) Verify(ctx context.Context, reqBody IAPRequest, result interface{}) error {
+func (c *Client) Verify(ctx context.Context, reqBody IAPRequest, result interface{}) (Environment, error) {
 	b := new(bytes.Buffer)
 	if err := json.NewEncoder(b).Encode(reqBody); err != nil {
-		return err
+		return "", err
 	}
 
 	req, err := http.NewRequest("POST", c.ProductionURL, b)
 	if err != nil {
-		return err
+		return "", err
 	}
 	req.Header.Set("Content-Type", ContentType)
 	req = req.WithContext(ctx)
 	resp, err := c.httpCli.Do(req)
 	if err != nil {
-		return err
+		return "", err
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode >= 500 {
-		return fmt.Errorf("Received http status code %d from the App Store: %w", resp.StatusCode, ErrAppStoreServer)
+		return "", fmt.Errorf("Received http status code %d from the App Store: %w", resp.StatusCode, ErrAppStoreServer)
 	}
 	return c.parseResponse(resp, result, ctx, reqBody)
 }
 
-func (c *Client) parseResponse(resp *http.Response, result interface{}, ctx context.Context, reqBody IAPRequest) error {
+func (c *Client) parseResponse(resp *http.Response, result interface{}, ctx context.Context, reqBody IAPRequest) (Environment, error) {
 	// Read the body now so that we can unmarshal it twice
 	buf, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return err
+		return "", err
 	}
 
 	err = json.Unmarshal(buf, &result)
 	if err != nil {
-		return err
+		return "", err
 	}
 
 	// https://developer.apple.com/library/content/technotes/tn2413/_index.html#//apple_ref/doc/uid/DTS40016228-CH1-RECEIPTURL
 	var r StatusResponse
 	err = json.Unmarshal(buf, &r)
 	if err != nil {
-		return err
+		return "", err
 	}
 	if r.Status == 21007 {
 		b := new(bytes.Buffer)
 		if err := json.NewEncoder(b).Encode(reqBody); err != nil {
-			return err
+			return "", err
 		}
 
 		req, err := http.NewRequest("POST", c.SandboxURL, b)
 		if err != nil {
-			return err
+			return "", err
 		}
 		req.Header.Set("Content-Type", ContentType)
 		req = req.WithContext(ctx)
 		resp, err := c.httpCli.Do(req)
 		if err != nil {
-			return err
+			return "", err
 		}
 		defer resp.Body.Close()
 		if resp.StatusCode >= 500 {
-			return fmt.Errorf("Received http status code %d from the App Store Sandbox: %w", resp.StatusCode, ErrAppStoreServer)
+			return Sandbox, fmt.Errorf("Received http status code %d from the App Store Sandbox: %w", resp.StatusCode, ErrAppStoreServer)
 		}
 
-		return json.NewDecoder(resp.Body).Decode(result)
+		// 21007 is found when the receipt is from the test environment
+		return Sandbox, json.NewDecoder(resp.Body).Decode(result)
 	}
 
-	return nil
+	return Production, nil
 }