/**

 * Copyright (c) 2010 Symbian Foundation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Symbian Foundation - initial contribution.

 * Contributors:

 * Description:

 * Overview:

 * Details:

 * Platforms/Drives/Compatibility:

 * Assumptions/Requirement/Pre-requisites:

 * Failures and causes:

 */

package org.symbian.tools.tmw.previewer.http.handlers;

import java.io.IOException;

import java.io.InputStream;

import java.util.Map;

import java.util.TreeMap;

import org.eclipse.core.resources.IProject;

import org.eclipse.core.resources.ResourcesPlugin;

import org.eclipse.core.runtime.CoreException;

import org.eclipse.core.runtime.IPath;

import org.eclipse.core.runtime.Path;

import org.json.simple.JSONObject;

import org.symbian.tools.tmw.previewer.PreviewerException;

/**

 * Path is usually in the form /preview/{project name}/{path}

 *

 * There are following spacial cases:

 * - Static previewer resource from plugin is returned when {path} begins with

 *   "preview" or is "preview-frame.html"

 * - Preferences resource is "preview/preferences.js"

 * - Index page (main HTML page of the WRT application) is always wrt_preview_main.html

 * - Debugger commands are submitted to URL __sym_command

 *

 * All other URLs return workspace resources.

 */

public class Providers {

    private final Map<String, IResourceProvider> handlers = new TreeMap<String, IResourceProvider>();

    private final IResourceProvider defaultHandler = new WorkspaceResourceProvider();

    public Providers() {

        addPaths(new MasterScriptProvider());

        addPaths(new PreviewerStaticResourceProvider());

        addPaths(new PreferencesResourceProvider());

        addPaths(new CommandResourceProvider());

        addPaths(new DebuggerResourceProvider());

    }

    private void addPaths(IResourceProvider handler) {

        for (String path : handler.getPaths()) {

            handlers.put(path, handler);

        }

    }

    public InputStream get(String url, Map<String, String[]> parameters, String sessionId) throws PreviewerException {

        final IProject project = getProject(url);

        final IPath resource = new Path(url).removeFirstSegments(1);

        final IResourceProvider provider = getHandlerForPath(resource);

        try {

            return provider.getResourceStream(project, resource, parameters, sessionId);

        } catch (IOException e) {

            throw new PreviewerException(e);

        } catch (CoreException e) {

            throw new PreviewerException(e);

        }

    }

    private IResourceProvider getHandlerForPath(IPath resource) {

        IResourceProvider provider = null;

        IPath mapping = resource;

        while (mapping.segmentCount() > 0) {

            provider = handlers.get(mapping.toString());

            if (provider != null) {

                break;

            }

            mapping = mapping.removeLastSegments(1);

        }

        if (provider == null) {

            provider = defaultHandler;

        }

        return provider;

    }

    private IProject getProject(String url) throws PreviewerException {

        final IPath path = new Path(url);

        if (path.segmentCount() < 2) {

            throw new PreviewerException(String.format("Invalid path: %s", url));

        }

        IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject(path.segment(0));

        if (!project.isAccessible()) {

            throw new PreviewerException(String.format("Project %s does not exist or is not open", project.getName()));

        }

        return project;

    }

    public IResourceProvider getHandlerForPostPath(String url) {

        return null;

    }

    public void post(String url, Map<String, String[]> parameterMap, JSONObject object, String sessionId)

            throws PreviewerException {

        final IProject project = getProject(url);

        final IPath resource = new Path(url).removeFirstSegments(1);

        final IResourceProvider provider = getHandlerForPath(resource);

        try {

            provider.post(project, resource, parameterMap, object, sessionId);

        } catch (IOException e) {

            throw new PreviewerException(e);

        } catch (CoreException e) {

            throw new PreviewerException(e);

        }

    }

}