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 * CruiseControl, a Continuous Integration Toolkit
 * Copyright (c) 2007, ThoughtWorks, Inc.
 * 200 E. Randolph, 25th Floor
 * Chicago, IL 60601 USA
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package net.sourceforge.cruisecontrol.dashboard.service;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.web.context.ServletContextAware;
import org.springframework.web.context.support.ServletContextResource;

import javax.servlet.ServletContext;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class TemplateRenderService implements ServletContextAware, InitializingBean {

    private String resourceLoaderPath = "WEB-INF/templates";
    private ServletContext servletContext;
    private Map templates = new HashMap();

    public void setServletContext(ServletContext servletContext) {
        this.servletContext = servletContext;
    }

    public void afterPropertiesSet() {
        try {
            loadTemplates();
        } catch (Exception e) {
            throw new RuntimeException("Failed to load template files", e);
        }
    }

    public void loadTemplates() throws IOException {
        loadTemplate("project_xml.template");
        loadTemplate("directory.template");
        loadTemplate("file.template");
    }

    private void loadTemplate(String name) throws IOException {
        Resource resource;
        if (servletContext != null) {
            resource = new ServletContextResource(servletContext, resourceLoaderPath + "/" + name);
        } else {
            resource = new FileSystemResource("webapp/" + resourceLoaderPath + "/" + name);
        }
        if (!resource.exists()) {
            throw new RuntimeException("Failed to load template from [" + resource.getFile().getAbsolutePath() + "].");
        }
        templates.put(name, IOUtils.toString(resource.getInputStream()));
    }

    public String renderTemplate(String templateName, Map values) {
        String template = (String) templates.get(templateName);

        for (Iterator iterator = values.keySet().iterator(); iterator.hasNext();) {
            Object key = iterator.next();
            Object value = values.get(key);
            template = StringUtils.replace(template, key.toString(), value.toString());
        }
        return StringUtils.defaultString(template);
    }

}