/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *   Granite Data Services is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   Granite Data Services is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 *   General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 *   USA, or see <http://www.gnu.org/licenses/>.
 */

package org.granite.generator.ant;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.tools.ant.AntClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.FileSet;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Reference;
import org.apache.tools.ant.types.ZipFileSet;
import org.granite.generator.Generator;
import org.granite.generator.Output;
import org.granite.generator.TemplateUri;
import org.granite.generator.Transformer;
import org.granite.generator.as3.As3TypeFactory;
import org.granite.generator.as3.DefaultEntityFactory;
import org.granite.generator.as3.DefaultRemoteDestinationFactory;
import org.granite.generator.as3.EntityFactory;
import org.granite.generator.as3.JavaAs3GroovyConfiguration;
import org.granite.generator.as3.JavaAs3Input;
import org.granite.generator.as3.PackageTranslator;
import org.granite.generator.as3.RemoteDestinationFactory;
import org.granite.generator.as3.reflect.JavaType.Kind;
import org.granite.generator.gsp.GroovyTemplateFactory;

/**
 * @author Franck WOLFF
 */
public abstract class AbstractAntJavaGenTask extends Task implements JavaAs3GroovyConfiguration {

    ///////////////////////////////////////////////////////////////////////////
    // Configurable fields (xml attributes).

    private String outputdir = ".";
    private String baseoutputdir = null;

    private String uid = "uid";

    private String entitytemplate = null;
    private String entitybasetemplate = null;

    private String beantemplate = null;
    private String beanbasetemplate = null;

    private String interfacetemplate = null;

    private String enumtemplate = null;

    private String remotetemplate = null;
    private String remotebasetemplate = null;

    private boolean tide = false;

    private String clienttypefactory = null;
    private String entityfactory = null;
    private String remotedestinationfactory = null;
    private String transformer = null;

    private Path classpath = null;
    private List<FileSet> fileSets = new ArrayList<FileSet>();
    private List<ZipFileSet> zipFileSets = new ArrayList<ZipFileSet>();

    private List<PackageTranslator> translators = new ArrayList<PackageTranslator>();

    ///////////////////////////////////////////////////////////////////////////
    // Configuration implementation fields.

    private File outputDirFile = null;
    private File baseOutputDirFile = null;
    
    private As3TypeFactory clientTypeFactoryImpl = null;
    private Transformer<?, ?, ?> transformerImpl = null;
    private EntityFactory entityFactoryImpl = null;
    private RemoteDestinationFactory remoteDestinationFactoryImpl = null;
    
    private GroovyTemplateFactory groovyTemplateFactory = null;
    
    private TemplateUri[] entityTemplateUris = null;
    private TemplateUri[] interfaceTemplateUris = null;
    private TemplateUri[] beanTemplateUris = null;
    private TemplateUri[] enumTemplateUris = null;
    private TemplateUri[] remoteTemplateUris = null;
    
    private Map<Class<?>, File> filesetClasses = null;
    
    ///////////////////////////////////////////////////////////////////////////
    // Task attributes.

    public void setOutputdir(String outputdir) {
        this.outputdir = outputdir;
    }

    public void setBaseoutputdir(String baseoutputdir) {
                this.baseoutputdir = baseoutputdir;
        }

        public void setAs3typefactory(String as3typefactory) {
        this.clienttypefactory = as3typefactory;
    }

        public void setClienttypefactory(String clienttypefactory) {
        this.clienttypefactory = clienttypefactory;
    }

        public void setEntityfactory(String entityfactory) {
        this.entityfactory = entityfactory;
    }

        public void setRemotedestinationfactory(String remotedestinationfactory) {
        this.remotedestinationfactory = remotedestinationfactory;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public void setEntitytemplate(String entitytemplate) {
    
        this.entitytemplate = entitytemplate;
    }
    public void setEntitybasetemplate(String entitybasetemplate) {
        this.entitybasetemplate = entitybasetemplate;
    }

    public void setBeantemplate(String beantemplate) {
        this.beantemplate = beantemplate;
    }
    public void setBeanbasetemplate(String beanbasetemplate) {
        this.beanbasetemplate = beanbasetemplate;
    }

    public void setInterfacetemplate(String interfacetemplate) {
        this.interfacetemplate = interfacetemplate;
    }

    public void setEnumtemplate(String enumtemplate) {
        this.enumtemplate = enumtemplate;
    }

    public void setRemotetemplate(String remotetemplate) {
        this.remotetemplate = remotetemplate;
    }
    public void setRemotebasetemplate(String remotebasetemplate) {
        this.remotebasetemplate = remotebasetemplate;
    }

    public void setTide(boolean tide) {
        this.tide = tide;
    }

        public void setTransformer(String transformer) {
                this.transformer = transformer;
        }
        
        protected abstract As3TypeFactory initDefaultClientTypeFactory();
        
        protected abstract Transformer<?, ?, ?> initDefaultTransformer();

    ///////////////////////////////////////////////////////////////////////////
    // Task inner elements.

        public void addFileset(FileSet fileSet) {
        fileSets.add(fileSet);
    }

        public void addZipfileset(ZipFileSet zipFileSet) {
                zipFileSets.add(zipFileSet);
    }

    public void setClasspath(Path path) {
        if (classpath == null)
            classpath = path;
        else
            classpath.append(path);
    }

    public Path createClasspath() {
        if (classpath == null)
            classpath = new Path(getProject());
        return classpath.createPath();
    }

    public void setClasspathRef(Reference r) {
        createClasspath().setRefid(r);
    }

    public void addTranslator(PackageTranslator translator) {
        translators.add(translator);
    }

    ///////////////////////////////////////////////////////////////////////////
    // Task execution.

    @Override
    public void execute() throws BuildException {

        log("Using output dir: " + outputdir, Project.MSG_INFO);
        log("Using classpath: " + classpath, Project.MSG_INFO);

        AntClassLoader loader = new AntClassLoader(AntJavaAs3Task.class.getClassLoader(), getProject(), classpath, true);
        try {
            loader.setThreadContextLoader();

            filesetClasses = new HashMap<Class<?>, File>();

            // Build a Set of all ".class" files in filesets (ignoring nested classes).
            log("Loading all Java classes referenced by inner fileset(s) {", Project.MSG_INFO);
            for (FileSet fileSet : fileSets) {
                DirectoryScanner scanner = fileSet.getDirectoryScanner(getProject());
                scanner.setCaseSensitive(true);
                scanner.scan();

                StringBuilder sb = new StringBuilder("    ");
                String[] names = scanner.getIncludedFiles();
                for (String name : names) {
                    if (name.endsWith(".class")) {
                        log(name, Project.MSG_VERBOSE);
                        try {
                            File jFile = new File(scanner.getBasedir(), name);
                            if (!jFile.exists())
                                throw new FileNotFoundException(jFile.toString());

                            String jClassName = normalizeClassName(name.substring(0, name.length() - 6));
                            Class<?> jClass = loader.loadClass(jClassName);
                            
                            if (!jClass.isMemberClass() || jClass.isEnum()) {
                                    sb.setLength(4);
                                    sb.append(jClass.toString());
                                    log(sb.toString(), Project.MSG_INFO);
        
                                    filesetClasses.put(jClass, jFile);
                            }
                        } catch (Exception e) {
                            log(getStackTrace(e));
                            throw new BuildException("Could not load Java class file: " + name, e);
                        }
                    }
                    else
                        log("Skipping non class file: " + name, Project.MSG_WARN);
                }
            }
            log("}", Project.MSG_INFO);
                        
            // Add all ".class" files from zipfilesets (ignoring nested classes).
            log("Loading all Java classes referenced by inner zipfileset(s) {", Project.MSG_INFO);
            
            for (ZipFileSet zipFileSet : zipFileSets) {
                File zip = zipFileSet.getSrc(getProject());
                if (zip == null)
                        throw new BuildException("zipfileset must use the src attribute");
                if (!zip.getName().endsWith(".jar"))
                        throw new BuildException("Zipfileset src isn't a '.jar' file: " + zip);
                
                log("  -- scanning: " + zip + " --", Project.MSG_INFO);

                DirectoryScanner scanner = zipFileSet.getDirectoryScanner(getProject());
                scanner.setCaseSensitive(true);
                scanner.scan();
                
                StringBuilder sb = new StringBuilder("    ");
                String[] names = scanner.getIncludedFiles();
                for (String name : names) {
                    if (name.endsWith(".class")) {
                        log(name, Project.MSG_VERBOSE);
                        try {
                                String jClassName = normalizeClassName(name.substring(0, name.length() - 6));
                            Class<?> jClass = loader.loadClass(jClassName);
                            
                            if (!jClass.isMemberClass() || jClass.isEnum()) {
                                    sb.setLength(4);
                                    sb.append(jClass.toString());
                                    log(sb.toString(), Project.MSG_INFO);
        
                                    filesetClasses.put(jClass, zip);
                            }
                            } catch (Exception e) {
                                log(getStackTrace(e));
                                throw new BuildException("Could not load Java class file: " + name, e);
                            }
                    }
                    else
                        log("Skipping non class file: " + name, Project.MSG_WARN);
                }
            }
            
            log("}", Project.MSG_INFO);

            log("Setting up the generator...", Project.MSG_INFO);

            // ClientTypeFactory.
            if (clienttypefactory == null) {
                clientTypeFactoryImpl = initDefaultClientTypeFactory();
            }
            else {
                log("Instantiating custom ClientTypeFactory class: " + clienttypefactory, Project.MSG_INFO);
                clientTypeFactoryImpl = newInstance(loader, clienttypefactory);
            }
            
            // EntityFactory
            if (entityfactory == null)
                entityFactoryImpl = new DefaultEntityFactory();
            else {
                log("Instantiating custom EntityFactory class: " + entityfactory, Project.MSG_INFO);
                entityFactoryImpl = newInstance(loader, entityfactory);
            }
            
            // RemoteDestinationFactory
            if (remotedestinationfactory == null)
                remoteDestinationFactoryImpl = new DefaultRemoteDestinationFactory();
            else {
                log("Instantiating custom RemoteDestinationFactory class: " + remotedestinationfactory, Project.MSG_INFO);
                remoteDestinationFactoryImpl = newInstance(loader, remotedestinationfactory);
            }

            // Listener.
            AntListener listener = new AntListener(this);

            // Transformer.
            if (transformer == null)
                transformerImpl = initDefaultTransformer();
            else {
                log("Instantiating custom Transformer class: " + transformer, Project.MSG_INFO);
                transformerImpl = newInstance(loader, transformer);
            }
            transformerImpl.setListener(listener);
            
            // Enum templates.
            String baseTemplateUri = null;
            String templateUri = defaultTemplateUri("ENUM");
            if (enumtemplate != null) {
                log("Using custom enum template: " + enumtemplate, Project.MSG_INFO);
                templateUri = enumtemplate;
            }
            enumTemplateUris = createTemplateUris(baseTemplateUri, templateUri);
            
            // Interface templates.
            templateUri = defaultTemplateUri("INTERFACE");
            if (interfacetemplate != null) {
                log("Using custom interface template: " + interfacetemplate, Project.MSG_INFO);
                templateUri = interfacetemplate;
            }
            interfaceTemplateUris = createTemplateUris(baseTemplateUri, templateUri);
            
            // Entity templates.
            baseTemplateUri = defaultTemplateUri("ENTITY_BASE");
            templateUri = defaultTemplateUri("ENTITY");
            if (entitytemplate != null) {
                log("Using custom entity template: " + entitytemplate, Project.MSG_INFO);
                templateUri = entitytemplate;
            }
            if (entitybasetemplate != null) {
                log("Using custom entity base template: " + entitybasetemplate, Project.MSG_INFO);
                baseTemplateUri = entitybasetemplate;
            }
            else if (tide) {
                log("Using tide entity base template.", Project.MSG_INFO);
                baseTemplateUri = defaultTemplateUri("TIDE_ENTITY_BASE");
            }
            entityTemplateUris = createTemplateUris(baseTemplateUri, templateUri);
            
            // Other bean templates.
            baseTemplateUri = defaultTemplateUri("BEAN_BASE");
            templateUri = defaultTemplateUri("BEAN");
            if (beantemplate != null) {
                log("Using custom bean template: " + beantemplate, Project.MSG_INFO);
                templateUri = beantemplate;
            }
            if (beanbasetemplate != null) {
                log("Using custom bean base template: " + beanbasetemplate, Project.MSG_INFO);
                baseTemplateUri = beanbasetemplate;
            }
            else if (tide) {
                log("Using tide bean base template.", Project.MSG_INFO);
                baseTemplateUri = defaultTemplateUri("TIDE_BEAN_BASE");
            }
                beanTemplateUris = createTemplateUris(baseTemplateUri, templateUri);
            
                // Remote service templates.
            baseTemplateUri = defaultTemplateUri("REMOTE_BASE");
            templateUri = defaultTemplateUri("REMOTE");
            if (remotetemplate != null) {
                log("Using custom remote template: " + remotetemplate, Project.MSG_INFO);
                templateUri = remotetemplate;
            }
            else if (tide) {
                log("Using Tide remote destination template.", Project.MSG_INFO);
                templateUri = defaultTemplateUri("TIDE_REMOTE");
            }
            if (remotebasetemplate != null) {
                log("Using custom remote base template: " + remotebasetemplate, Project.MSG_INFO);
                baseTemplateUri = remotebasetemplate;
            }
            else if (tide) {
                log("Using Tide remote destination base template.", Project.MSG_INFO);
                baseTemplateUri = defaultTemplateUri("TIDE_REMOTE_BASE");
            }
                remoteTemplateUris = createTemplateUris(baseTemplateUri, templateUri);
                
                // Create the generator.
            Generator generator = new Generator(this);
            generator.add(transformerImpl);
            
            // Call the generator for each ".class".
            log("Calling the generator for each Java class {", Project.MSG_INFO);
            int count = 0;
            for (Map.Entry<Class<?>, File> classFile : filesetClasses.entrySet()) {
                if (classFile.getKey().isAnonymousClass())
                        continue;
                try {
                        JavaAs3Input input = new JavaAs3Input(classFile.getKey(), classFile.getValue());
                    for (Output<?> output : generator.generate(input)) {
                        if (output.isOutdated())
                                count++;
                    }
                } catch (Exception e) {
                    log(getStackTrace(e));
                    throw new BuildException("Could not generate AS3 beans for: " + classFile.getKey(), e);
                }
            }

            log("}", Project.MSG_INFO);
            log("Files affected: " + count +  (count == 0 ? " (nothing to do)." : "."));
        } finally {
                loader.resetThreadContextLoader();
        }
    }
    
    private String normalizeClassName(String name) {
        return name.replace('/', '.').replace('\\', '.');
    }

    ///////////////////////////////////////////////////////////////////////////
    // Configuration implementation methods.
    
    @Override
        public As3TypeFactory getAs3TypeFactory() {
                return clientTypeFactoryImpl;
        }
    
    public As3TypeFactory getClientTypeFactory() {
                return clientTypeFactoryImpl;
        }
    
    @Override
        public EntityFactory getEntityFactory() {
        return entityFactoryImpl;
    }
    
    @Override
        public RemoteDestinationFactory getRemoteDestinationFactory() {
        return remoteDestinationFactoryImpl;
    }

        @Override
        public File getBaseOutputDir(JavaAs3Input input) {
                if (baseOutputDirFile == null)
                        baseOutputDirFile = new File(baseoutputdir != null ? baseoutputdir : outputdir);
                return baseOutputDirFile;
        }

        @Override
        public File getOutputDir(JavaAs3Input input) {
                if (outputDirFile == null)
                        outputDirFile = new File(outputdir);
                return outputDirFile;
        }

        @Override
        public TemplateUri[] getTemplateUris(Kind kind, Class<?> clazz) {
                switch (kind) {
                case ENTITY:
                return entityTemplateUris;
                case INTERFACE:
                        return interfaceTemplateUris;
                case ENUM:
                        return enumTemplateUris;
                case BEAN:
                        return beanTemplateUris;
                case REMOTE_DESTINATION:
                        return remoteTemplateUris;
                default:
                        throw new IllegalArgumentException("Unknown template kind: " + kind + " / " + clazz);
                }
        }
        
        protected abstract String defaultTemplateUri(String type);

        @Override
        public List<PackageTranslator> getTranslators() {
                return translators;
        }
        
        @Override
        public String getUid() {
                return uid;
        }

        @Override
        public boolean isGenerated(Class<?> clazz) {
                return filesetClasses.containsKey(clazz);
        }

        @Override
        public ClassLoader getClassLoader() {
                return Thread.currentThread().getContextClassLoader();
        }

        @Override
        public GroovyTemplateFactory getGroovyTemplateFactory() {
                if (groovyTemplateFactory == null)
                        groovyTemplateFactory = new GroovyTemplateFactory();
                return groovyTemplateFactory;
        }

        @Override
        public File getWorkingDirectory() {
                return getProject().getBaseDir();
        }

    ///////////////////////////////////////////////////////////////////////////
    // Utilities.

        @SuppressWarnings("unchecked")
        private <T> T newInstance(ClassLoader loader, String className) {
                try {
            return (T)loader.loadClass(className).newInstance();
        } catch (Exception e) {
            log(getStackTrace(e));
            throw new BuildException("Could not instantiate custom class: " + className, e);
        }
    }

    private static String getStackTrace(Exception e) {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        e.printStackTrace(pw);
        return sw.toString();
    }
        
        private TemplateUri[] createTemplateUris(String baseUri, String uri) {
                TemplateUri[] templateUris = new TemplateUri[baseUri == null ? 1 : 2];
                int i = 0;
                if (baseUri != null)
                        templateUris[i++] = new TemplateUri(baseUri, true);
                templateUris[i] = new TemplateUri(uri, false);
                return templateUris;
        }
}