Displaying transactions from cache when first entering wallet details.

src/js/services/wallet-history.service.js

@@ -0,0 +1,129 @@
+'use strict';
+
+(function(){
+
+  angular
+    .module('bitcoincom.services')
+    .factory('walletHistoryService', walletHistoryService);
+    
+    function walletHistoryService(configService, storageService, lodash, $log, txFormatService) {
+      // 8 Transactions fit on an iPhone Plus screen when in Wallet Details.
+      // Make it a little bit bigger so it doesn't have to load more immediately
+      var PAGE_SIZE = 50 / 1.5;
+      // How much to overlap on each end of the page, for mitigating inconsistent sort order.
+      var PAGE_OVERLAP_FRACTION = 0.5;
+
+      var SAFE_CONFIRMATIONS = 6;
+
+      var service = {
+        getCachedTxHistory: getCachedTxHistory,
+        updateTxHistoryByPage: updateTxHistoryByPage
+      };
+      return service;
+
+      /**
+       * @param {string} walletId
+       * @param {function(error, txs)} cb
+       */
+      function getCachedTxHistory(walletId, cb) {
+        storageService.getTxHistory(walletId, function onGetTxHistory(err, txHistoryString){
+          if (err) {
+            return cb(err);
+          }
+
+          if (!txHistoryString) {
+            return cb(null, txHistoryString);
+          }
+
+          try {
+            var txHistory = JSON.parse(txHistoryString);
+            return cb(null, txHistory);
+          } catch (e) {
+            $log.error('Failed to parse tx history.', e);
+            return cb(e);
+          }
+        });
+      }
+
+      function processNewTxs(wallet, txs) {
+        var now = Math.floor(Date.now() / 1000);
+        var txHistoryUnique = {};
+        var processedTxs = [];
+        wallet.hasUnsafeConfirmed = false;
+    
+        lodash.each(txs, function(tx) {
+          tx = txFormatService.processTx(wallet.coin, tx);
+    
+          // no future transactions...
+          if (tx.time > now)
+            tx.time = now;
+    
+          if (tx.confirmations >= SAFE_CONFIRMATIONS) {
+            tx.safeConfirmed = SAFE_CONFIRMATIONS + '+';
+          } else {
+            tx.safeConfirmed = false;
+            wallet.hasUnsafeConfirmed = true;
+          }
+    
+          if (tx.note) {
+            delete tx.note.encryptedEditedByName;
+            delete tx.note.encryptedBody;
+          }
+    
+          if (!txHistoryUnique[tx.txid]) {
+            processedTxs.push(tx);
+            txHistoryUnique[tx.txid] = true;
+          } else {
+            $log.debug('Ignoring duplicate TX in history: ' + tx.txid)
+          }
+        });
+
+        // Update notes?
+    
+        return processedTxs;
+      };
+
+      /**
+       * A small cache of up to the 50 most recent transactions
+       */
+      function saveTxHistory(processedTxs, walletId) {
+        storageService.setTxHistory(processedTxs, walletId, function onSetTxHistory(error){
+          // Looks like callback only gets called on error
+          $log.error('pagination Failed to save tx history.', error);
+        });
+        
+      }
+
+      // Only clear the cache once we have received new transactions from the server.
+      function updateTxHistoryByPage(wallet, getLatest, flushCacheOnNew, cb) {
+        var skip = 0;
+        var limit = Math.floor(PAGE_SIZE * (1 + PAGE_OVERLAP_FRACTION));
+
+        var opts = {
+          skip: skip,
+          limit: limit
+        };
+        wallet.getTxHistory(opts, function onTxHistory(err, txsFromServer) {
+          if (err) {
+            return cb(err);
+          }
+    
+          if (!txsFromServer.length) {
+            return cb(null, []);
+          }
+          
+          var processedTxs = processNewTxs(wallet, txsFromServer);
+
+          if (getLatest) {
+            console.log('pagination Saving retrieved txs.');
+            saveTxHistory(wallet, processedTxs);
+          }
+
+          return cb(null, processedTxs);
+        });
+      }
+
+    }
+
+
+})();