org.openhab.persistence.grafana.internal.GrafanaChartProvider.java Source code

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Here is the source code for org.openhab.persistence.grafana.internal.GrafanaChartProvider.java

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/**
 * Copyright (c) 2010-2014, openHAB.org and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.persistence.grafana.internal;

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.Dictionary;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.lang.StringUtils;
import org.openhab.core.items.ItemNotFoundException;
import org.openhab.ui.chart.ChartProvider;
import org.openhab.ui.items.ItemUIRegistry;
import org.osgi.framework.BundleContext;
import org.osgi.service.cm.ConfigurationException;
import org.osgi.service.cm.ManagedService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This chart provider acts as a proxy to the grafana back end
 * 
 * @author magcode
 * @since 1.7.0
 *
 */
public class GrafanaChartProvider implements ChartProvider, ManagedService {

    private static final Logger logger = LoggerFactory.getLogger(GrafanaChartProvider.class);
    private HttpClient proxy;

    private static final String GRAFANA_BASE_URL = "/render/dashboard-solo/db/";

    protected static final Map<String, Long> PERIODS = new HashMap<String, Long>();

    static {
        PERIODS.put("h", -3600000L);
        PERIODS.put("4h", -14400000L);
        PERIODS.put("8h", -28800000L);
        PERIODS.put("12h", -43200000L);
        PERIODS.put("D", -86400000L);
        PERIODS.put("3D", -259200000L);
        PERIODS.put("W", -604800000L);
        PERIODS.put("2W", -1209600000L);
        PERIODS.put("M", -2592000000L);
        PERIODS.put("2M", -5184000000L);
        PERIODS.put("4M", -10368000000L);
        PERIODS.put("Y", -31536000000L);
    }

    protected ItemUIRegistry itemUIRegistry;
    private String grafanaUrl;
    private String theme;
    private String apiKey;

    public void setItemUIRegistry(ItemUIRegistry itemUIRegistry) {
        this.itemUIRegistry = itemUIRegistry;
    }

    public void unsetItemUIRegistry(ItemUIRegistry itemUIRegistry) {
        this.itemUIRegistry = null;
    }

    public void activate(final BundleContext bundleContext, final Map<String, Object> config) {
        logger.debug("Starting up grafana chart provider");
        MultiThreadedHttpConnectionManager connectionManager = new MultiThreadedHttpConnectionManager();
        proxy = new HttpClient(connectionManager);
    }

    @Override
    public String getName() {
        return "grafana";
    }

    @Override
    public BufferedImage createChart(String service, String theme, Date startTime, Date endTime, int height,
            int width, String items, String groups) throws ItemNotFoundException {
        GetMethod get = null;
        try {
            get = new GetMethod(buildUrl(items, width + "", height + "", startTime.getTime() + ""));
            get.setRequestHeader("Authorization", "Bearer " + this.apiKey);
            proxy.executeMethod(get);
            InputStream is = get.getResponseBodyAsStream();
            if (get.getStatusCode() == HttpStatus.SC_OK) {
                BufferedImage bufferedImage = javax.imageio.ImageIO.read(is);
                return bufferedImage;
            }

        } catch (IOException e) {
            logger.error(e.getMessage(), e);
        } finally {
            get.releaseConnection();
        }
        return null;
    }

    /**
     * Constructs the URL for the grafana backend call
     * 
     * @param itemName
     * @param width
     * @param height
     * @param from
     * @return
     */
    private String buildUrl(String itemName, String width, String height, String from) {
        String label = itemUIRegistry.getLabel(itemName);
        StringBuffer buf = new StringBuffer();
        buf.append(this.grafanaUrl);
        buf.append(GRAFANA_BASE_URL);
        buf.append(StringUtils.substringBeforeLast(label, "-"));
        buf.append("?panelId=" + StringUtils.substringAfterLast(label, "-"));
        buf.append("&fullscreen&theme=");
        buf.append(this.theme);
        buf.append("&from=");
        buf.append(from);
        buf.append("&to=now");
        buf.append("&width=");
        buf.append(width);
        buf.append("&height=");
        buf.append(height);
        return buf.toString();
    }

    @Override
    public ImageType getChartType() {
        return ImageType.png;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void updated(Dictionary<String, ?> properties) throws ConfigurationException {

        if (properties == null)
            return;

        if (properties.get("url") != null) {
            grafanaUrl = (String) properties.get("url");
        }
        if (properties.get("theme") != null) {
            theme = (String) properties.get("theme");
        }
        if (properties.get("apiKey") != null) {
            apiKey = (String) properties.get("apikey");
        }
    }
}