From ae2efec4fa83a3ff0ada436e70963cd9c17b1ad4 Mon Sep 17 00:00:00 2001
From: AswinT22 <42780141+AswinT22@users.noreply.github.com>
Date: Mon, 27 Apr 2020 07:53:28 +0530
Subject: [PATCH] update

---
 utils/candlestickPatternUtils.js | 41 +++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/utils/candlestickPatternUtils.js b/utils/candlestickPatternUtils.js
index bd91f7c..e80b7d9 100644
--- a/utils/candlestickPatternUtils.js
+++ b/utils/candlestickPatternUtils.js
@@ -1,4 +1,43 @@
-module.exports.isHammer= function (row) {
+const fs = require('fs');
+const csv = require('csv-parser');
+const path = require('path');
+const csvWriter = require('csv-write-stream');
+const stringUtils = require(path.join(__dirname,"stringUtils"));
+const chartUtils = require(path.join(__dirname,"chartUtils"));
+
+module.exports.filterHammerAndWrite = function (inputFilePath, outputFilePath, render) {
+    // using streams to handle large datasets
+    var writer = csvWriter();
+    writer.pipe(fs.createWriteStream(outputFilePath, {flags: 'a'}));
+    
+    var map = {};// handle duplicates
+    console.log("Identifying hammer candlestick pattern.....");
+    fs.createReadStream(inputFilePath)
+    .on('error', (err) => {
+        console.log(err);
+    })
+    .pipe(csv())
+    .on('data', (row) => {
+        var hash = stringUtils.stringToHash(row.Date);
+        if (hash in map) {
+            // Duplicates
+            return
+        }
+        map[hash] = 1
+        if(isHammer(row)) {
+                writer.write(row);
+        }
+    })
+    .on('end',  () => {
+        writer.end();
+        console.log("Find the filtered csv at",  outputFilePath);
+        if (render) {
+            chartUtils.renderChart(outputFilePath, "filtered-hammer-chart");
+        }
+    });
+}
+
+function isHammer(row) {
     // defining these to perform checks later, if required any
     const close = parseFloat(row.close);
     const open = parseFloat(row.open);