From 9cf422cdc17afae9e7e8d5fe03b1cfd0f8830821 Mon Sep 17 00:00:00 2001
From: Joshua Seigler <github@joshua.seigler.net>
Date: Thu, 7 Jul 2016 03:26:51 -0400
Subject: [PATCH] added candlesticks

---
 index.php       |   2 +-
 views/chart.php | 102 ++++++++++++++++++++++++++++++++----------------
 views/index.php |   4 +-
 3 files changed, 71 insertions(+), 37 deletions(-)

diff --git a/index.php b/index.php
index 87cab78..6c58891 100644
--- a/index.php
+++ b/index.php
@@ -18,7 +18,7 @@ $router->map('GET', '/', function() {
 });
 
 // map cryptocurrency stuff
-$router->map( 'GET', '/charts/[dark|light|sparkline:theme]/[a:curA]-[btc:curB]/[a:duration]/[svg|png:format]', function($theme, $curA, $curB, $duration, $format) {
+$router->map( 'GET', '/charts/[dark|light|sparkline|candlestick:theme]/[a:curA]-[btc:curB]/[a:duration]/[svg|png:format]', function($theme, $curA, $curB, $duration, $format) {
   require __DIR__ . '/views/chart.php';
   return renderChart(
     $theme,
diff --git a/views/chart.php b/views/chart.php
index 027c9aa..ec3e83c 100644
--- a/views/chart.php
+++ b/views/chart.php
@@ -20,6 +20,23 @@ function getJson($url) {
   return $result;
 }
 
+function getThemeVariable($variable, $defaults) {
+  if (!array_key_exists($variable, $defaults)) {
+    return null;
+  }
+  if (array_key_exists($variable, $_GET)) {
+    $toReturn = htmlspecialchars($_GET[$variable]);
+    if (1 === preg_match('/^[a-fA-F0-9]{3,6}/', $toReturn)) {
+      //this is an HTML color
+      return '#' . $toReturn;
+    } else {
+      return $toReturn;
+    }
+  } else {
+    return $defaults[$variable];
+  }
+}
+
 function renderChart(
   $theme,
   $currencyA,
@@ -29,21 +46,30 @@ function renderChart(
 ) {
 
   $durations = [
+    /*
+    valid resolutions in seconds:
+    300 5m
+    900 15m
+    1800 30m
+    7200 2h
+    14400 4h
+    86400 24h
+    */
     '1y'=> [
       'duration' => 60 * 60 * 24 * 365,
-      'resolution' => 86400 // 1d
+      'resolution' => 86400 // 24h
     ],
     '30d'=> [
       'duration' => 60 * 60 * 24 * 30,
-      'resolution' => 7200 // 2h
+      'resolution' => 14400 // 4h
     ],
     '7d'=> [
       'duration' => 60 * 60 * 24 * 7,
-      'resolution' => 1800 // 30m
+      'resolution' => 7200 // 2h
     ],
     '24h' => [
       'duration' => 60 * 60 * 24 * 1,
-      'resolution' => 300 // 15m
+      'resolution' => 900 // 15m
     ]
   ];
 
@@ -74,6 +100,17 @@ function renderChart(
       'fontSize'=>4,
       'yAxisEnabled'=>false,
       'xAxisEnabled'=>false
+    ],
+    'candlestick'=>[
+      'width' => 1000,
+      'height' => 300,
+      'barColor' => '#000',
+      'risingColor' => '#0D0',
+      'fallingColor' => '#D00',
+      'labelColor' => '#000',
+      'fontSize' => 15,
+      'yAxisEnabled'=>true,
+      'xAxisEnabled'=>false
     ]
   ];
 
@@ -124,19 +161,26 @@ function renderChart(
       $cacheTimeSeconds = max(60, end($poloniexJson)->date + $dataResolution - time() + 60);
     }
 
-    $chartData = [];
-
-    foreach ($poloniexJson as $item) {
-      $chartData[$item->date] = $item->weightedAverage;
-    }
-
     if ($format == 'svg') {
-      $chartOptions = array_replace($themes[$theme], ['lineColor'=>'@lineColor', 'markerColor'=>'@markerColor']);
+      $chartOptions = array_replace($themes[$theme], [
+        'lineColor'=>'@lineColor',
+        'markerColor'=>'@markerColor',
+        'risingColor'=>'@risingColor',
+        'fallingColor'=>'@fallingColor'
+      ]);
     } else {
       $chartOptions = $themes[$theme];
     }
 
-    $poloniexChart = new NeatCharts\LineChart($chartData, $chartOptions);
+    if ($theme == 'candlestick') {
+      $poloniexChart = new NeatCharts\CandlestickChart($poloniexJson, $chartOptions);
+    } else {
+      $chartData = [];
+      foreach ($poloniexJson as $item) {
+        $chartData[$item->date] = $item->weightedAverage;
+      }
+      $poloniexChart = new NeatCharts\LineChart($chartData, $chartOptions);
+    }
     $result = '<?xml version="1.0" standalone="no"?>' . PHP_EOL;
     $result .= $poloniexChart->render();
 
@@ -165,28 +209,18 @@ function renderChart(
   } else if ($format == 'svg') {
     header('Content-type: image/svg+xml; charset=utf-8');
     header('Content-Disposition: inline; filename="Dash-chart-' . gmdate('Y-m-d\THis+0', $startTime) . '--' . gmdate('Y-m-d\THis+0') . '.svg"');
-
-    if (array_key_exists('lineColor', $_GET)) {
-      $lineColor = htmlspecialchars($_GET['lineColor']);
-      if (1 === preg_match('/^[a-fA-F0-9]{3,6}/', $lineColor)) {
-        //this is an HTML color
-        $lineColor = '#' . $lineColor;
-      }
-    } else {
-      $lineColor = $themes[$theme]['lineColor'];
-    }
-
-    if (array_key_exists('markerColor', $_GET)) {
-      $markerColor = htmlspecialchars($_GET['markerColor']);
-      if (1 === preg_match('/^[a-fA-F0-9]{3,6}/', $markerColor)) {
-        //this is an HTML color
-        $markerColor = '#' . $markerColor;
-      }
-    } else {
-      $markerColor = $themes[$theme]['markerColor'];
-    }
-
-    echo str_replace(['@lineColor', '@markerColor'], [$lineColor, $markerColor], $result);
+    $result = str_replace([
+      '@lineColor',
+      '@markerColor',
+      '@risingColor',
+      '@fallingColor'
+    ], [
+      getThemeVariable('lineColor', $themes[$theme]),
+      getThemeVariable('markerColor', $themes[$theme]),
+      getThemeVariable('risingColor', $themes[$theme]),
+      getThemeVariable('fallingColor', $themes[$theme])
+    ], $result);
+    echo $result;
   } else {
     return false;
   }
diff --git a/views/index.php b/views/index.php
index 9f90f01..137f43b 100644
--- a/views/index.php
+++ b/views/index.php
@@ -72,8 +72,8 @@
     <section>
       <h2>Transparent SVG and PNG charts with your favorite cryptocurrencies</h2>
       <figure>
-        <img src="/charts/dark/dash-btc/30d/svg?lineColor=1C74BC" alt="Poloniex Dash/BTC price">
-        <figcaption>30 Day Dash price in BTC <code><a href="/charts/dark/dash-btc/30d/svg?lineColor=1C74BC">http://cryptohistory.org/charts/dark/dash-btc/30d/svg?lineColor=1C74BC</a></code></figcaption>
+        <img src="/charts/candlestick/dash-btc/7d/svg" alt="Poloniex Dash/BTC price">
+        <figcaption>30 day Dash price candlesticks in BTC <code><a href="/charts/candlestick/dash-btc/30d/svg">http://cryptohistory.org/charts/candlestick/dash-btc/30d/svg</a></code></figcaption>
       </figure>
       <p>Sparklines too! ETH 7 days: <img src="/charts/sparkline/eth-btc/7d/svg" alt="ETH 7d chart" style="vertical-align: bottom;">
         <code>&lt;img src=&quot;http://cryptohistory.org/charts/sparkline/eth-btc/7d/svg&quot; alt=&quot;ETH 7d chart&quot; style=&quot;vertical-align: bottom;&quot;&gt;</code>