/plugin/src/main/java/com/atlassian/developer/calliope/plugin/macro/TemplateRendererMacro.java

package com.atlassian.developer.calliope.plugin.macro;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Map;

import com.atlassian.renderer.RenderContext;
import com.atlassian.renderer.v2.RenderMode;
import com.atlassian.renderer.v2.macro.BaseMacro;
import com.atlassian.renderer.v2.macro.MacroException;
import com.atlassian.templaterenderer.TemplateRenderer;

import com.google.common.collect.ImmutableMap;

import static com.atlassian.renderer.v2.RenderMode.F_LINEBREAKS;
import static com.atlassian.renderer.v2.RenderMode.F_PARAGRAPHS;
import static com.atlassian.renderer.v2.RenderMode.suppress;
import static com.google.common.base.Preconditions.checkNotNull;

public abstract class TemplateRendererMacro extends BaseMacro
{
    private final TemplateRenderer renderer;
    private final String path;

    protected TemplateRendererMacro(TemplateRenderer renderer, String path)
    {
        this.renderer = renderer;
        this.path = path;
    }

    public boolean hasBody()
    {
        return true;
    }

    public RenderMode getBodyRenderMode()
    {
        return suppress(F_LINEBREAKS | F_PARAGRAPHS);
    }

    @SuppressWarnings("unchecked")
    public final String execute(final Map parameters, String body, RenderContext renderContext) throws MacroException
    {
        Writer writer = new StringWriter();
        try
        {
            renderer.render(path, getTemplateRendererContext(parameters, body), writer);
        }
        catch (IOException e)
        {
            PrintWriter printWriter = new PrintWriter(writer);
            e.printStackTrace(printWriter);
            printWriter.close();
        }
        return writer.toString();
    }

    // TODO: terrible api design for subclasses; fix.
    protected Map<String, Object> getTemplateRendererContext(Map<String, String> parameters, String body)
    {
        return ImmutableMap.<String, Object> of("body", checkNotNull(body, "body"));
    }
}