repurchase detection

extension/content_scripts/notify.js

@@ -65,12 +65,36 @@ var TalerNotify;
     document.addEventListener("taler-contract", function (e) {
         // XXX: the merchant should just give us the parsed data ...
         var offer = JSON.parse(e.detail);
+        if (!offer.contract) {
+            console.error("contract field missing");
+            return;
+        }
+        var msg = {
+            type: "check-repurchase",
+            detail: {
+                contract: offer.contract
+            },
+        };
+        chrome.runtime.sendMessage(msg, function (resp) {
+            if (resp.error) {
+                console.error("wallet backend error", resp);
+                return;
+            }
+            if (resp.isRepurchase) {
+                console.log("doing repurchase");
+                console.assert(resp.existingFulfillmentUrl);
+                console.assert(resp.existingContractHash);
+                window.location.href = subst(resp.existingFulfillmentUrl, resp.existingContractHash);
+            }
+            else {
                 var uri = URI(chrome.extension.getURL("pages/confirm-contract.html"));
                 var params = {
                     offer: JSON.stringify(offer),
                     merchantPageUrl: document.location.href,
                 };
                 document.location.href = uri.query(params).href();
+            }
+        });
     });
     document.addEventListener('taler-execute-payment', function (e) {
         console.log("got taler-execute-payment in content page");

extension/content_scripts/notify.ts

@@ -77,12 +77,40 @@ namespace TalerNotify {
   document.addEventListener("taler-contract", function(e: CustomEvent) {
     // XXX: the merchant should just give us the parsed data ...
     let offer = JSON.parse(e.detail);
+
+    if (!offer.contract) {
+      console.error("contract field missing");
+      return;
+    }
+
+    let msg = {
+      type: "check-repurchase",
+      detail: {
+        contract: offer.contract
+      },
+    };
+
+    chrome.runtime.sendMessage(msg, (resp) => {
+      if (resp.error) {
+        console.error("wallet backend error", resp);
+        return;
+      }
+      if (resp.isRepurchase) {
+        console.log("doing repurchase");
+        console.assert(resp.existingFulfillmentUrl);
+        console.assert(resp.existingContractHash);
+        window.location.href = subst(resp.existingFulfillmentUrl,
+                                     resp.existingContractHash);
+
+      } else {
         let uri = URI(chrome.extension.getURL("pages/confirm-contract.html"));
         let params = {
           offer: JSON.stringify(offer),
           merchantPageUrl: document.location.href,
         };
         document.location.href = uri.query(params).href();
+      }
+    });
   });
 
 

extension/lib/wallet/db.ts

@@ -51,10 +51,21 @@ export function openTalerDb(): Promise<IDBDatabase> {
           db.createObjectStore("denoms", {keyPath: "denomPub"});
           const coins = db.createObjectStore("coins", {keyPath: "coinPub"});
           coins.createIndex("mintBaseUrl", "mintBaseUrl");
-          db.createObjectStore("transactions", {keyPath: "contractHash"});
+          const transactions = db.createObjectStore("transactions",
+                                                    {keyPath: "contractHash"});
+          transactions.createIndex("repurchase",
+                                   [
+                                     "contract.merchant_pub",
+                                     "contract.repurchase_correlation_id"
+                                   ]);
+
           db.createObjectStore("precoins",
                                {keyPath: "coinPub", autoIncrement: true});
-          const history = db.createObjectStore("history", {keyPath: "id", autoIncrement: true});
+          const history = db.createObjectStore("history",
+                                               {
+                                                 keyPath: "id",
+                                                 autoIncrement: true
+                                               });
           history.createIndex("timestamp", "timestamp");
           break;
       }

extension/lib/wallet/query.ts

@@ -287,6 +287,29 @@ class QueryRoot {
                   .then(() => promise);
   }
 
+  /**
+   * Get one object from a store by its key.
+   */
+  getIndexed(storeName, indexName, key): Promise<any> {
+    if (key === void 0) {
+      throw Error("key must not be undefined");
+    }
+
+    const {resolve, promise} = openPromise();
+
+    const doGetIndexed = (tx) => {
+      const req = tx.objectStore(storeName).index(indexName).get(key);
+      req.onsuccess = (r) => {
+        resolve(req.result);
+      };
+    };
+
+    this.addWork(doGetIndexed, storeName, false);
+    return Promise.resolve()
+                  .then(() => this.finish())
+                  .then(() => promise);
+  }
+
   /**
    * Finish the query, and start the query in the first place if necessary.
    */

extension/lib/wallet/types.ts

@@ -257,6 +257,13 @@ export namespace Amounts {
 }
 
 
+export interface CheckRepurchaseResult {
+  isRepurchase: boolean;
+  existingContractHash?: string;
+  existingFulfillmentUrl?: string;
+}
+
+
 export interface Notifier {
   notify();
 }

extension/lib/wallet/wallet.ts

@@ -32,6 +32,7 @@ import {Reserve} from "./types";
 import {CryptoApi} from "./cryptoApi";
 import {Coin} from "./types";
 import {PayCoinInfo} from "./types";
+import {CheckRepurchaseResult} from "./types";
 
 "use strict";
 
@@ -279,8 +280,9 @@ interface CoinPaySig {
 
 interface Transaction {
   contractHash: string;
-  contract: any;
+  contract: Contract;
   payReq: any;
+  merchantSig: string;
 }
 
 
@@ -512,6 +514,7 @@ export class Wallet {
       contractHash: offer.H_contract,
       contract: offer.contract,
       payReq: payReq,
+      merchantSig: offer.merchant_sig,
     };
 
     console.log("pay request");
@@ -926,4 +929,29 @@ export class Wallet {
       .iter("history", {indexName: "timestamp"})
       .reduce(collect, [])
   }
+
+  checkRepurchase(contract: Contract): Promise<CheckRepurchaseResult> {
+    if (!contract.repurchase_correlation_id) {
+      console.log("no repurchase: no correlation id");
+      return Promise.resolve({isRepurchase: false});
+    }
+    return Query(this.db)
+      .getIndexed("transactions",
+                  "repurchase",
+                  [contract.merchant_pub, contract.repurchase_correlation_id])
+      .then((result: Transaction) => {
+        console.log("db result", result);
+        let isRepurchase;
+        if (result) {
+          console.assert(result.contract.repurchase_correlation_id == contract.repurchase_correlation_id);
+          return {
+            isRepurchase: true,
+            existingContractHash: result.contractHash,
+            existingFulfillmentUrl: result.contract.fulfillment_url,
+          };
+        } else {
+          return {isRepurchase: false};
+        }
+      });
+  }
 }

extension/lib/wallet/wxMessaging.ts

@@ -22,6 +22,7 @@ import {Checkable} from "./checkable";
 import {AmountJson} from "./types";
 import Port = chrome.runtime.Port;
 import {Notifier} from "./types";
+import {Contract} from "./wallet";
 
 "use strict";
 
@@ -108,6 +109,10 @@ function makeHandlers(db: IDBDatabase,
       let amount = AmountJson.checked(detail.amount);
       return wallet.getReserveCreationInfo(detail.baseUrl, amount);
     },
+    ["check-repurchase"]: function(detail) {
+      let contract = Contract.checked(detail.contract);
+      return wallet.checkRepurchase(contract);
+    },
     ["get-history"]: function(detail) {
       // TODO: limit history length
       return wallet.getHistory();