1 files changed, 143 insertions, 0 deletions
diff --git a/library/Graphite/Web/Widget/GraphImage.php b/library/Graphite/Web/Widget/GraphImage.php
new file mode 100644
index 0000000..af64e69
--- /dev/null
+++ b/library/Graphite/Web/Widget/GraphImage.php
@@ -0,0 +1,143 @@
+<?php
+
+namespace Icinga\Module\Graphite\Web\Widget;
+
+use Icinga\Module\Graphite\Graphing\Chart;
+use Icinga\Web\Url;
+use Icinga\Web\UrlParams;
+use Icinga\Web\Widget\AbstractWidget;
+use RuntimeException;
+
+class GraphImage extends AbstractWidget
+{
+    /**
+     * The chart to be rendered
+     *
+     * @var Chart
+     */
+    protected $chart;
+
+    /**
+     * The rendered PNG image
+     *
+     * @var string|null
+     */
+    protected $rendered;
+
+    /**
+     * Constructor
+     *
+     * @param   Chart   $chart  The chart to be rendered
+     */
+    public function __construct(Chart $chart)
+    {
+        $this->chart = $chart;
+    }
+
+    /**
+     * Render the graph lazily
+     *
+     * @return string
+     */
+    public function render()
+    {
+        if ($this->rendered === null) {
+            $now = time();
+
+            $from = (int) $this->chart->getFrom();
+            if ($from < 0) {
+                $from += $now;
+            }
+
+            $until = (string) $this->chart->getUntil();
+
+            if ($until === '') {
+                $until = $now;
+            } else {
+                $until = (int) $until;
+                if ($until < 0) {
+                    $until += $now;
+                }
+            }
+
+            $variables = $this->chart->getMetricVariables();
+            $template = $this->chart->getTemplate();
+            $graphiteWebClient = $this->chart->getGraphiteWebClient();
+            $params = (new UrlParams())->addValues([
+                'from'                  => $from,
+                'until'                 => $until,
+                'bgcolor'               => $this->chart->getBackgroundColor() ?? 'black',
+                'fgcolor'               => $this->chart->getForegroundColor() ?? 'white',
+                'majorGridLineColor'    => $this->chart->getMajorGridLineColor() ?? '0000003F',
+                'minorGridLineColor'    => $this->chart->getMinorGridLineColor() ?? 'black',
+                'width'                 => $this->chart->getWidth(),
+                'height'                => $this->chart->getHeight(),
+                'hideLegend'            => (string) ! $this->chart->getShowLegend(),
+                'tz'                    => date_default_timezone_get(),
+                '_salt'                 => "$now.000",
+                'vTitle'                => 'Percent',
+                'lineMode'              => 'connected',
+                'drawNullAsZero'        => 'false',
+                'graphType'             => 'line',
+                '_ext'                  => 'whatever.svg'
+            ]);
+
+            foreach ($template->getUrlParams() as $key => $value) {
+                $params->set($key, $value->resolve($variables));
+            }
+
+            $metrics = $this->chart->getMetrics();
+            $allVars = [];
+
+            foreach ($template->getCurves() as $curveName => $curve) {
+                if (!isset($metrics[$curveName])) {
+                    continue;
+                }
+
+                $vars = $curve[0]->reverseResolve($metrics[$curveName]);
+
+                if ($vars !== false) {
+                    $allVars = array_merge($allVars, $vars);
+                }
+            }
+
+            foreach ($metrics as $curveName => $metric) {
+                $allVars['metric'] = $metric;
+                $params->add('target', $template->getCurves()[$curveName][1]->resolve($allVars));
+            }
+
+            $url = Url::fromPath('/render')->setParams($params);
+            $headers = [
+                'Accept-language'   => 'en',
+                'Content-type'      => 'application/x-www-form-urlencoded'
+            ];
+
+            for (;;) {
+                try {
+                    $this->rendered = $graphiteWebClient->request($url, 'GET', $headers);
+                } catch (RuntimeException $e) {
+                    if (preg_match('/\b500\b/', $e->getMessage())) {
+                        // A 500 Internal Server Error, probably because of
+                        // a division by zero because of a too low time range to render.
+
+                        $until = (int) $url->getParam('until');
+                        $diff = $until - (int) $url->getParam('from');
+
+                        // Try to render a higher time range, but give up
+                        // once our default (1h) has been reached (non successfully).
+                        if ($diff < 3600) {
+                            $url->setParam('from', $until - $diff * 2);
+                            continue;
+                        }
+                    }
+
+                    throw $e;
+                }
+
+                break;
+            }
+        }
+
+        return $this->rendered;
+    }
+}