/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.yangtools.maven.sal.api.gen.plugin;

import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.maven.plugin.logging.Log;
import org.apache.maven.project.MavenProject;
import org.opendaylight.yangtools.binding.generator.util.BindingGeneratorUtil;
import org.opendaylight.yangtools.sal.binding.generator.api.BindingGenerator;
import org.opendaylight.yangtools.sal.binding.generator.impl.BindingGeneratorImpl;
import org.opendaylight.yangtools.sal.binding.model.api.Type;
import org.opendaylight.yangtools.sal.java.api.generator.GeneratorJavaFile;
import org.opendaylight.yangtools.sal.java.api.generator.YangModuleInfoTemplate;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang2sources.spi.BuildContextAware;
import org.opendaylight.yangtools.yang2sources.spi.CodeGenerator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.sonatype.plexus.build.incremental.BuildContext;

import com.google.common.base.Preconditions;

public final class CodeGeneratorImpl implements CodeGenerator, BuildContextAware {
    private static final String FS = File.separator;
    private BuildContext buildContext;
    private File projectBaseDir;
    private Map<String, String> additionalConfig;

    private static final Logger logger = LoggerFactory.getLogger(CodeGeneratorImpl.class);
    private MavenProject mavenProject;

    @Override
    public Collection<File> generateSources(final SchemaContext context, final File outputDir,
            final Set<Module> yangModules) throws IOException {
        final File outputBaseDir;

        outputBaseDir = outputDir == null ? getDefaultOutputBaseDir() : outputDir;

        final BindingGenerator bindingGenerator = new BindingGeneratorImpl();
        final List<Type> types = bindingGenerator.generateTypes(context, yangModules);
        final GeneratorJavaFile generator = new GeneratorJavaFile(buildContext, new HashSet<>(types));

        File persistentSourcesDir = null;
        if (additionalConfig != null) {
            String persistenSourcesPath = additionalConfig.get("persistentSourcesDir");
            if (persistenSourcesPath != null) {
                persistentSourcesDir = new File(persistenSourcesPath);
            }
        }
        if (persistentSourcesDir == null) {
            persistentSourcesDir = new File(projectBaseDir, "src" + FS + "main" + FS + "java");
        }

        List<File> result = generator.generateToFile(outputBaseDir, persistentSourcesDir);
        for (Module module : yangModules) {
            // TODO: add YangModuleInfo class
            result.add(generateYangModuleInfo(outputBaseDir, module, context));
        }
        return result;
    }

    public static final String DEFAULT_OUTPUT_BASE_DIR_PATH = "target" + File.separator + "generated-sources"
            + File.separator + "maven-sal-api-gen";

    private File getDefaultOutputBaseDir() {
        File outputBaseDir;
        outputBaseDir = new File(DEFAULT_OUTPUT_BASE_DIR_PATH);
        setOutputBaseDirAsSourceFolder(outputBaseDir, mavenProject);
        logger.debug("Adding " + outputBaseDir.getPath() + " as compile source root");
        return outputBaseDir;
    }

    private static void setOutputBaseDirAsSourceFolder(File outputBaseDir, MavenProject mavenProject) {
        Preconditions.checkNotNull(mavenProject, "Maven project needs to be set in this phase");
        mavenProject.addCompileSourceRoot(outputBaseDir.getPath());
    }

    @Override
    public void setLog(Log log) {}

    @Override
    public void setAdditionalConfig(Map<String, String> additionalConfiguration) {
        this.additionalConfig = additionalConfiguration;
    }

    @Override
    public void setResourceBaseDir(File resourceBaseDir) {
        // no resource processing necessary
    }

    @Override
    public void setMavenProject(MavenProject project) {
        this.mavenProject = project;
        this.projectBaseDir = project.getBasedir();
    }

    @Override
    public void setBuildContext(BuildContext buildContext) {
        this.buildContext = Preconditions.checkNotNull(buildContext);
    }

    private File generateYangModuleInfo(File outputBaseDir, Module module, SchemaContext ctx) {
        final YangModuleInfoTemplate template = new YangModuleInfoTemplate(module, ctx);
        String generatedCode = template.generate();
        if (generatedCode.isEmpty()) {
            throw new IllegalStateException("Generated code should not be empty!");
        }

        final File packageDir = GeneratorJavaFile.packageToDirectory(outputBaseDir, BindingGeneratorUtil.moduleNamespaceToPackageName(module));

        final File file = new File(packageDir, "$YangModuleInfoImpl.java");
        try (final OutputStream stream = buildContext.newFileOutputStream(file)) {
            try (final Writer fw = new OutputStreamWriter(stream)) {
                try (final BufferedWriter bw = new BufferedWriter(fw)) {
                    bw.write(generatedCode);
                }
            } catch (Exception e) {
                // TODO handle exception
            }
        } catch (Exception e) {
            // TODO handle exception
        }
        return file;

    }

}