/*
 * (C) Copyright 2006-2017O Nuxeo (http://nuxeo.com/) and others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Contributors:
 *     bstefanescu
 */
package org.nuxeo.runtime.test.runner;

import org.nuxeo.runtime.api.Framework;

/**
 * A dynamic component deployer which enable tests to deploy new contributions after the test was started (i.e. from
 * inside the test method) The deployer is reloading all the components and reinject the test members.
 *
 * @author bogdan
 */
public class HotDeployer {

    public static final String DEPLOY_ACTION = "deploy";

    public static final String RESTART_ACTION = "restart";

    public static final String RESET_ACTION = "reset";

    protected FeaturesRunner runner;

    protected RuntimeHarness harness;

    protected ActionHandler head;

    public HotDeployer(FeaturesRunner runner, RuntimeHarness harness) {
        this.runner = runner;
        this.harness = harness;
        this.head = new DefaultDeployHandler();
    }

    /**
     * Add a custom deploy action that wraps the default action. You should call next.exec(...) in your action code to
     * call the next action
     */
    public HotDeployer addHandler(ActionHandler action) {
        action.next = this.head;
        this.head = action;
        return this;
    }

    /**
     * Remove the given handler if already registered
     */
    public boolean removeHandler(ActionHandler handler) {
        ActionHandler p = null;
        ActionHandler h = this.head;
        while (h != null && h != handler) {
            p = h;
            h = h.next;
        }
        if (h != null) {
            if (p == null) {
                this.head = h.next;
            } else {
                p.next = h.next;
            }
            h.next = null;
            return true;
        }
        return false;
    }

    /**
     * Deploy the given list of contributions. The format is [@]bundleId[:componentPath]. If no component path is
     * specified then the bundle identified by the bundleId part will be deployed. If a componentPath is given
     * {@link RuntimeHarness#deployContrib(String,String)} will be used to deploy the contribution. If
     * bundleId:componentPath expression is prefixed by a '@' character then
     * {@link RuntimeHarness#deployTestContrib(String,String)} will be used to deploy the contribution.
     */
    public void deploy(String... contribs) throws Exception {
        this.head.exec(DEPLOY_ACTION, contribs);
        reinject();
    }

    /**
     * Restart the components and preserve the current registry state.
     */
    public void restart() throws Exception {
        this.head.exec(RESTART_ACTION);
        reinject();
    }

    /**
     * Restart the components and revert to the initial registry snapshot if any.
     */
    public void reset() throws Exception {
        this.head.exec(RESET_ACTION);
        reinject();
    }

    public void reinject() {
        runner.getInjector().injectMembers(runner.getTargetTestInstance());
    }

    /**
     * Deploy actions are usually used by features to customize the deployment of the runtime feature (which is using
     * the DeaultDeployAction)
     *
     * @author bogdan
     */
    public static abstract class ActionHandler {

        protected ActionHandler next;

        /**
         * Can wrap another deploy action with custom code. Should call the next action using
         * <code>next.exec(action, args...)</code>
         */
        public abstract void exec(String action, String... args) throws Exception;

    }

    /**
     * This action has no next action and will deploy the contributions and then reload the component manager
     *
     * @author bogdan
     */
    protected class DefaultDeployHandler extends ActionHandler {

        @Override
        public void exec(String action, String... args) throws Exception {
            if (DEPLOY_ACTION.equals(action)) {
                deploy(args);
            } else if (RESTART_ACTION.equals(action)) {
                restart();
            } else if (RESET_ACTION.equals(action)) {
                reset();
            }
        }

        public void deploy(String... contribs) throws Exception {
            if (contribs != null && contribs.length > 0) {
                for (String contrib : contribs) {
                    int i = contrib.indexOf(':');
                    if (i > -1) {
                        String bundleId = contrib.substring(0, i);
                        if (bundleId.startsWith("@")) {
                            bundleId = bundleId.substring(1);
                            harness.deployTestContrib(bundleId, contrib.substring(i + 1));
                        } else {
                            harness.deployContrib(bundleId, contrib.substring(i + 1));
                        }
                    } else {
                        harness.deployBundle(contrib);
                    }
                }
            }
            // use false to prevent removing the local test method deployments
            Framework.getRuntime().getComponentManager().refresh(false);
        }

        public void restart() throws Exception {
            Framework.getRuntime().getComponentManager().restart(false);
        }

        public void reset() throws Exception {
            Framework.getRuntime().getComponentManager().restart(true);
        }

    }

}