AbstractPlugin

package com.atlassian.plugin.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.atlassian.plugin.ModuleDescriptor;
import com.atlassian.plugin.Plugin;
import com.atlassian.plugin.PluginException;
import com.atlassian.plugin.PluginInformation;
import com.atlassian.plugin.PluginState;
import com.atlassian.plugin.Resourced;
import com.atlassian.plugin.Resources;
import com.atlassian.plugin.elements.ResourceDescriptor;
import com.atlassian.plugin.elements.ResourceLocation;
import com.atlassian.plugin.util.VersionStringComparator;
import com.atlassian.util.concurrent.CopyOnWriteMap;

public abstract class AbstractPlugin implements Plugin, Comparable<Plugin>
{
    private final Map<String, ModuleDescriptor<?>> modules = CopyOnWriteMap.<String, ModuleDescriptor<?>> builder().stableViews().newLinkedMap();
    private String name;
    private String i18nNameKey;
    private String key;
    private boolean enabledByDefault = true;
    private PluginInformation pluginInformation = new PluginInformation();
    private boolean system;
    private Resourced resources = Resources.EMPTY_RESOURCES;
    private int pluginsVersion = 1;
    private final Date dateLoaded = new Date();
    private final AtomicReference<PluginState> pluginState = new AtomicReference<PluginState>(PluginState.UNINSTALLED);

    private final Logger log = LoggerFactory.getLogger(this.getClass());

    public String getName()
    {
        return !StringUtils.isBlank(name) ? name : !StringUtils.isBlank(i18nNameKey) ? "" : getKey();
    }

    public void setName(final String name)
    {
        this.name = name;
    }

    /**
     * @return the logger used internally
     */
    protected Logger getLog()
    {
        return log;
    }

    public String getI18nNameKey()
    {
        return i18nNameKey;
    }

    public void setI18nNameKey(final String i18nNameKey)
    {
        this.i18nNameKey = i18nNameKey;
    }

    public String getKey()
    {
        return key;
    }

    public void setKey(final String aPackage)
    {
        key = aPackage;
    }

    public void addModuleDescriptor(final ModuleDescriptor<?> moduleDescriptor)
    {
        modules.put(moduleDescriptor.getKey(), moduleDescriptor);
    }

    protected void removeModuleDescriptor(final String key)
    {
        modules.remove(key);
    }

    /**
     * Returns the module descriptors for this plugin
     *
     * @return An unmodifiable list of the module descriptors.
     */
    public Collection<ModuleDescriptor<?>> getModuleDescriptors()
    {
        return modules.values();
    }

    public ModuleDescriptor<?> getModuleDescriptor(final String key)
    {
        return modules.get(key);
    }

    public <T> List<ModuleDescriptor<T>> getModuleDescriptorsByModuleClass(final Class<T> aClass)
    {
        final List<ModuleDescriptor<T>> result = new ArrayList<ModuleDescriptor<T>>();
        for (final ModuleDescriptor<?> moduleDescriptor : modules.values())
        {
            final Class<?> moduleClass = moduleDescriptor.getModuleClass();
            if (moduleClass != null && aClass.isAssignableFrom(moduleClass))
            {
                @SuppressWarnings("unchecked")
                final ModuleDescriptor<T> typedModuleDescriptor = (ModuleDescriptor<T>) moduleDescriptor;
                result.add(typedModuleDescriptor);
            }
        }
        return result;
    }

    public PluginState getPluginState()
    {
        return pluginState.get();
    }

    protected void setPluginState(final PluginState state)
    {
        if (log.isDebugEnabled())
        {
            log.debug("Plugin " + getKey() + " going from " + getPluginState() + " to " + state);
        }
        pluginState.set(state);
    }

    /**
     * Only sets the plugin state if it is in the expected state.
     *
     * @param requiredExistingState The expected state
     * @param desiredState The desired state
     * @return True if the set was successful, false if not in the expected
     *         state
     * @since 2.4
     */
    protected boolean compareAndSetPluginState(final PluginState requiredExistingState, final PluginState desiredState)
    {
        if (log.isDebugEnabled())
        {
            log.debug("Plugin " + getKey() + " trying to go from " + getPluginState() + " to " + desiredState + " but only if in " + requiredExistingState);
        }
        return pluginState.compareAndSet(requiredExistingState, desiredState);
    }

    public boolean isEnabledByDefault()
    {
        return enabledByDefault && ((pluginInformation == null) || pluginInformation.satisfiesMinJavaVersion());
    }

    public void setEnabledByDefault(final boolean enabledByDefault)
    {
        this.enabledByDefault = enabledByDefault;
    }

    public int getPluginsVersion()
    {
        return pluginsVersion;
    }

    public void setPluginsVersion(final int pluginsVersion)
    {
        this.pluginsVersion = pluginsVersion;
    }

    public PluginInformation getPluginInformation()
    {
        return pluginInformation;
    }

    public void setPluginInformation(final PluginInformation pluginInformation)
    {
        this.pluginInformation = pluginInformation;
    }

    public void setResources(final Resourced resources)
    {
        this.resources = resources != null ? resources : Resources.EMPTY_RESOURCES;
    }

    public List<ResourceDescriptor> getResourceDescriptors()
    {
        return resources.getResourceDescriptors();
    }

    public List<ResourceDescriptor> getResourceDescriptors(final String type)
    {
        return resources.getResourceDescriptors(type);
    }

    public ResourceLocation getResourceLocation(final String type, final String name)
    {
        return resources.getResourceLocation(type, name);
    }

    /**
     * @deprecated
     */
    @Deprecated
    public ResourceDescriptor getResourceDescriptor(final String type, final String name)
    {
        return resources.getResourceDescriptor(type, name);
    }

    /**
     * @return true if the plugin has been enabled
     */
    @Deprecated
    public boolean isEnabled()
    {
        return getPluginState() == PluginState.ENABLED;
    }

    public final void enable()
    {
        final PluginState state = pluginState.get();
        if ((state == PluginState.ENABLED) || (state == PluginState.ENABLING))
        {
            return;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Enabling plugin '" + getKey() + "'");
        }
        try
        {
            // not ideal as comparison and set doesn't happen atomically
            final PluginState desiredState = enableInternal();
            if ((desiredState != PluginState.ENABLED) && (desiredState != PluginState.ENABLING))
            {
                log.warn("Illegal state transition to " + desiredState + " for plugin '" + getKey() + "' on enable()");
            }
            setPluginState(desiredState);
        }
        catch (final PluginException ex)
        {
            log.warn("Unable to enable plugin '" + getKey() + "'", ex);
            throw ex;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Enabled plugin '" + getKey() + "'");
        }
    }

    /**
     * Perform any internal enabling logic. Subclasses should only throw
     * {@link PluginException}.
     *
     * @throws PluginException If the plugin could not be enabled
     * @since 2.2.0
     * @return Either {@link PluginState#ENABLED} or
     *         {@link PluginState#ENABLING}
     */
    protected PluginState enableInternal() throws PluginException
    {
        return PluginState.ENABLED;
    }

    public final void disable()
    {
        if (pluginState.get() == PluginState.DISABLED)
        {
            return;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Disabling plugin '" + getKey() + "'");
        }
        try
        {
            setPluginState(PluginState.DISABLING);
            disableInternal();
            setPluginState(PluginState.DISABLED);
        }
        catch (final PluginException ex)
        {
            setPluginState(PluginState.ENABLED);
            log.warn("Unable to disable plugin '" + getKey() + "'", ex);
            throw ex;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Disabled plugin '" + getKey() + "'");
        }
    }

    /**
     * Perform any internal disabling logic. Subclasses should only throw
     * {@link PluginException}.
     *
     * @throws PluginException If the plugin could not be disabled
     * @since 2.2.0
     */
    protected void disableInternal() throws PluginException
    {}

    public Set<String> getRequiredPlugins()
    {
        return Collections.emptySet();
    }

    public void close()
    {
        uninstall();
    }

    public final void install()
    {
        if (pluginState.get() == PluginState.INSTALLED)
        {
            return;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Installing plugin '" + getKey() + "'");
        }
        try
        {
            installInternal();
            setPluginState(PluginState.INSTALLED);
        }
        catch (final PluginException ex)
        {
            log.warn("Unable to install plugin '" + getKey() + "'", ex);
            throw ex;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Installed plugin '" + getKey() + "'");
        }
    }

    /**
     * Perform any internal installation logic. Subclasses should only throw
     * {@link PluginException}.
     *
     * @throws PluginException If the plugin could not be installed
     * @since 2.2.0
     */
    protected void installInternal() throws PluginException
    {}

    public final void uninstall()
    {
        if (pluginState.get() == PluginState.UNINSTALLED)
        {
            return;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Uninstalling plugin '" + getKey() + "'");
        }
        try
        {
            uninstallInternal();
            setPluginState(PluginState.UNINSTALLED);
        }
        catch (final PluginException ex)
        {
            log.warn("Unable to uninstall plugin '" + getKey() + "'", ex);
            throw ex;
        }
        if (getLog().isDebugEnabled())
        {
            getLog().debug("Uninstalled plugin '" + getKey() + "'");
        }
    }

    /**
     * Perform any internal uninstallation logic. Subclasses should only throw
     * {@link PluginException}.
     *
     * @throws PluginException If the plugin could not be uninstalled
     * @since 2.2.0
     */
    protected void uninstallInternal() throws PluginException
    {}

    /**
     * Setter for the enabled state of a plugin. If this is set to false then
     * the plugin will not execute.
     */
    @Deprecated
    public void setEnabled(final boolean enabled)
    {
        if (enabled)
        {
            enable();
        }
        else
        {
            disable();
        }
    }

    public boolean isSystemPlugin()
    {
        return system;
    }

    public boolean containsSystemModule()
    {
        for (final ModuleDescriptor<?> moduleDescriptor : modules.values())
        {
            if (moduleDescriptor.isSystemModule())
            {
                return true;
            }
        }
        return false;
    }

    public void setSystemPlugin(final boolean system)
    {
        this.system = system;
    }

    public Date getDateLoaded()
    {
        return dateLoaded;
    }

    public boolean isBundledPlugin()
    {
        return false;
    }

    /**
     * Compares this Plugin to another Plugin for order. The primary sort field
     * is the key, and the secondary field is the version number.
     *
     * @param otherPlugin The plugin to be compared.
     * @return a negative integer, zero, or a positive integer as this Plugin is
     *         less than, equal to, or greater than the specified Plugin.
     * @see VersionStringComparator
     * @see Comparable#compareTo
     */
    public int compareTo(final Plugin otherPlugin)
    {
        if (otherPlugin.getKey() == null)
        {
            if (getKey() == null)
            {
                // both null keys - not going to bother checking the version,
                // who cares?
                return 0;
            }
            return 1;
        }
        if (getKey() == null)
        {
            return -1;
        }

        // If the compared plugin doesn't have the same key, the current object
        // is greater
        if (!otherPlugin.getKey().equals(getKey()))
        {
            return getKey().compareTo(otherPlugin.getKey());
        }

        final String thisVersion = cleanVersionString((getPluginInformation() != null ? getPluginInformation().getVersion() : null));
        final String otherVersion = cleanVersionString((otherPlugin.getPluginInformation() != null ? otherPlugin.getPluginInformation().getVersion() : null));

        // Valid versions should come after invalid versions because when we
        // find multiple instances of a plugin, we choose the "latest".
        if (!VersionStringComparator.isValidVersionString(thisVersion))
        {
            if (!VersionStringComparator.isValidVersionString(otherVersion))
            {
                // both invalid
                return 0;
            }
            return -1;
        }
        if (!VersionStringComparator.isValidVersionString(otherVersion))
        {
            return 1;
        }

        return new VersionStringComparator().compare(thisVersion, otherVersion);
    }

    private String cleanVersionString(final String version)
    {
        if ((version == null) || version.trim().equals(""))
        {
            return "0";
        }
        return version.replaceAll(" ", "");
    }

    @Override
    public String toString()
    {
        final PluginInformation info = getPluginInformation();
        return getKey() + ":" + (info == null ? "?" : info.getVersion());
    }
}