/*
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * 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.
 */
package org.uberfire.annotations.processors;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.processing.Messager;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.PackageElement;
import javax.lang.model.element.TypeElement;
import javax.tools.Diagnostic.Kind;

import freemarker.template.Template;
import freemarker.template.TemplateException;
import org.uberfire.annotations.processors.exceptions.GenerationException;
import org.uberfire.annotations.processors.facades.ClientAPIModule;

/**
 * A source code generator for Activities
 */
public class ClientEditorActivityGenerator extends AbstractGenerator {

    @Override
    public StringBuffer generate(final String packageName,
                                 final PackageElement packageElement,
                                 final String className,
                                 final Element element,
                                 final ProcessingEnvironment processingEnvironment) throws GenerationException {

        final Messager messager = processingEnvironment.getMessager();
        messager.printMessage(Kind.NOTE,
                              "Starting code generation for [" + className + "]");

        //Extract required information
        final TypeElement classElement = (TypeElement) element;

        final String annotationName = ClientAPIModule.getWorkbenchClientEditorClass();
        final boolean isDynamic = ClientAPIModule.getWbEditorIsDynamicValueOnClass(classElement);

        String identifier = null;

        for (final AnnotationMirror am : classElement.getAnnotationMirrors()) {
            if (annotationName.equals(am.getAnnotationType().toString())) {
                for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : am.getElementValues().entrySet()) {
                    AnnotationValue aval = entry.getValue();
                    if ("identifier".equals(entry.getKey().getSimpleName().toString())) {
                        identifier = aval.getValue().toString();
                    }
                }
                break;
            }
        }

        final String beanActivatorClass = GeneratorUtils.getBeanActivatorClassName(classElement,
                                                                                   processingEnvironment);

        final ExecutableElement onStartupMethod = GeneratorUtils.getOnStartupMethodForNonEditors(classElement,
                                                                                                 processingEnvironment);

        final String onStartup0ParameterMethodName;
        final String onStartup1ParameterMethodName;
        if (onStartupMethod == null) {
            onStartup0ParameterMethodName = null;
            onStartup1ParameterMethodName = null;
        } else if (onStartupMethod.getParameters().isEmpty()) {
            onStartup0ParameterMethodName = onStartupMethod.getSimpleName().toString();
            onStartup1ParameterMethodName = null;
        } else {
            onStartup0ParameterMethodName = null;
            onStartup1ParameterMethodName = onStartupMethod.getSimpleName().toString();
        }

        final String onMayCloseMethodName = GeneratorUtils.getOnMayCloseMethodName(classElement,
                                                                                   processingEnvironment);
        final String onCloseMethodName = GeneratorUtils.getOnCloseMethodName(classElement,
                                                                             processingEnvironment);
        final String onShutdownMethodName = GeneratorUtils.getOnShutdownMethodName(classElement,
                                                                                   processingEnvironment);
        final String onOpenMethodName = GeneratorUtils.getOnOpenMethodName(classElement,
                                                                           processingEnvironment);
        final String onLostFocusMethodName = GeneratorUtils.getOnLostFocusMethodName(classElement,
                                                                                     processingEnvironment);
        final String onFocusMethodName = GeneratorUtils.getOnFocusMethodName(classElement,
                                                                             processingEnvironment);
        final String getDefaultPositionMethodName = GeneratorUtils.getDefaultPositionMethodName(classElement,
                                                                                                processingEnvironment);
        final String getTitleMethodName = GeneratorUtils.getTitleMethodName(classElement,
                                                                            processingEnvironment);
        final String getContextIdMethodName = GeneratorUtils.getContextIdMethodName(classElement,
                                                                                    processingEnvironment);
        final ExecutableElement getTitleWidgetMethod = GeneratorUtils.getTitleWidgetMethodName(classElement,
                                                                                               processingEnvironment);
        final String getTitleWidgetMethodName = getTitleWidgetMethod == null ? null : getTitleWidgetMethod.getSimpleName().toString();

        final ExecutableElement getWidgetMethod = GeneratorUtils.getWidgetMethodName(classElement,
                                                                                     processingEnvironment);
        final String getWidgetMethodName = getWidgetMethod == null ? null : getWidgetMethod.getSimpleName().toString();

        final boolean isWidgetMethodReturnTypeElement = getWidgetMethod != null && GeneratorUtils.getIsElement(getWidgetMethod.getReturnType(),
                                                                                                               processingEnvironment);

        final boolean hasUberView = GeneratorUtils.hasPresenterInitMethod(classElement, processingEnvironment, getWidgetMethod);

        final boolean isWidget = GeneratorUtils.getIsWidget(classElement,
                                                            processingEnvironment);

        final String isDirtyMethodName = GeneratorUtils.getIsDirtyMethodName(classElement,
                                                                             processingEnvironment);

        final ExecutableElement setContentMethod = GeneratorUtils.getSetContentMethodName(classElement,
                                                                                          processingEnvironment);

        final String setContentMethodName = setContentMethod == null ? null : setContentMethod.getSimpleName().toString();

        final ExecutableElement getContentMethod = GeneratorUtils.getGetContentMethodName(classElement,
                                                                                          processingEnvironment);

        final String getContentMethodName = getContentMethod == null ? null : getContentMethod.getSimpleName().toString();

        final ExecutableElement getPreviewMethod = GeneratorUtils.getGetPreviewMethodName(classElement,
                                                                                          processingEnvironment);
        final String getPreviewMethodName = getPreviewMethod == null ? null : getPreviewMethod.getSimpleName().toString();

        final List<String> qualifiers = GeneratorUtils.getAllQualifiersDeclarationFromType(classElement);

        if (GeneratorUtils.debugLoggingEnabled()) {
            messager.printMessage(Kind.NOTE,
                                  "Package name: " + packageName);
            messager.printMessage(Kind.NOTE,
                                  "Class name: " + className);
            messager.printMessage(Kind.NOTE,
                                  "Identifier: " + identifier);
            messager.printMessage(Kind.NOTE,
                                  "getContextIdMethodName: " + getContextIdMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onStartup0ParameterMethodName: " + onStartup0ParameterMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onStartup1ParameterMethodName: " + onStartup1ParameterMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onMayCloseMethodName: " + onMayCloseMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onCloseMethodName: " + onCloseMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onShutdownMethodName: " + onShutdownMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onOpenMethodName: " + onOpenMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onLostFocusMethodName: " + onLostFocusMethodName);
            messager.printMessage(Kind.NOTE,
                                  "onFocusMethodName: " + onFocusMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getDefaultPositionMethodName: " + getDefaultPositionMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getTitleMethodName: " + getTitleMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getTitleWidgetMethodName: " + getTitleWidgetMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getWidgetMethodName: " + getWidgetMethodName);
            messager.printMessage(Kind.NOTE,
                                  "isWidgetMethodReturnTypeElement: " + isWidgetMethodReturnTypeElement);
            messager.printMessage(Kind.NOTE,
                                  "isWidget: " + Boolean.toString(isWidget));
            messager.printMessage(Kind.NOTE,
                                  "hasUberView: " + Boolean.toString(hasUberView));
            messager.printMessage(Kind.NOTE,
                                  "setContentMethodName: " + setContentMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getContentMethodName: " + getContentMethodName);
            messager.printMessage(Kind.NOTE,
                                  "getPreviewMethodName: " + getPreviewMethodName);
            messager.printMessage(Kind.NOTE,
                                  "isDirtyMethodName: " + isDirtyMethodName);
            messager.printMessage(Kind.NOTE,
                                  "Qualifiers: " + String.join(", ",
                                                               qualifiers));
        }

        //Validate getWidgetMethodName and isWidget
        if (!isWidget && getWidgetMethodName == null) {
            throw new GenerationException("The WorkbenchClientEditor must either extend IsWidget or provide a @WorkbenchPartView annotated method to return a com.google.gwt.user.client.ui.IsWidget.",
                                          packageName + "." + className);
        }
        if (isWidget && getWidgetMethodName != null) {
            final String msg = "The WorkbenchClientEditor both extends com.google.gwt.user.client.ui.IsWidget and provides a @WorkbenchPartView annotated method. The annotated method will take precedence.";
            messager.printMessage(Kind.WARNING,
                                  msg,
                                  classElement);
        }

        //Validate getTitleMethodName
        if (getTitleMethodName == null) {
            throw new GenerationException("The WorkbenchClientEditor must provide a @WorkbenchPartTitle annotated method to return a java.lang.String.",
                                          packageName + "." + className);
        }
        //Validate setContentMethodName
        if (setContentMethodName == null) {
            throw new GenerationException("org.uberfire.annotations.processors.WorkbenchClientEditorTest4Activity: The WorkbenchClientEditor must provide a @SetContent annotated method that has two java.lang.String (path and content) as parameters.",
                                          packageName + "." + className);
        }
        //Validate getContentMethodName
        if (getContentMethodName == null) {
            throw new GenerationException("The WorkbenchClientEditor must provide a @GetContent annotated method to return a elemental2.promise.Promise.",
                                          packageName + "." + className);
        }

        //Setup data for template sub-system
        Map<String, Object> root = new HashMap<String, Object>();
        root.put("packageName",
                 packageName);
        root.put("className",
                 className);
        root.put("identifier",
                 identifier);
        root.put("getContextIdMethodName",
                 getContextIdMethodName);
        root.put("realClassName",
                 classElement.getSimpleName().toString());
        root.put("beanActivatorClass",
                 beanActivatorClass);
        root.put("onStartup0ParameterMethodName",
                 onStartup0ParameterMethodName);
        root.put("onStartup1ParameterMethodName",
                 onStartup1ParameterMethodName);
        root.put("onMayCloseMethodName",
                 onMayCloseMethodName);
        root.put("onCloseMethodName",
                 onCloseMethodName);
        root.put("onShutdownMethodName",
                 onShutdownMethodName);
        root.put("onOpenMethodName",
                 onOpenMethodName);
        root.put("onLostFocusMethodName",
                 onLostFocusMethodName);
        root.put("onFocusMethodName",
                 onFocusMethodName);
        root.put("getDefaultPositionMethodName",
                 getDefaultPositionMethodName);
        root.put("getTitleMethodName",
                 getTitleMethodName);
        root.put("getTitleWidgetMethodName",
                 getTitleWidgetMethodName);
        root.put("getWidgetMethodName",
                 getWidgetMethodName);
        root.put("isWidgetMethodReturnTypeElement",
                 isWidgetMethodReturnTypeElement);
        root.put("isWidget",
                 isWidget);
        root.put("hasUberView",
                 hasUberView);
        root.put("isDirtyMethodName",
                 isDirtyMethodName);

        root.put("setContentMethodName",
                 setContentMethodName);
        root.put("getContentMethodName",
                 getContentMethodName);
        root.put("getPreviewMethodName",
                 getPreviewMethodName);
        root.put("isDynamic",
                 isDynamic);
        root.put("qualifiers",
                 qualifiers);

        //Generate code
        final StringWriter sw = new StringWriter();
        final BufferedWriter bw = new BufferedWriter(sw);
        try {
            final Template template = config.getTemplate("activityClientEditor.ftl");
            template.process(root,
                             bw);
        } catch (IOException ioe) {
            throw new GenerationException(ioe);
        } catch (TemplateException te) {
            throw new GenerationException(te);
        } finally {
            try {
                bw.close();
                sw.close();
            } catch (IOException ioe) {
                throw new GenerationException(ioe);
            }
        }
        messager.printMessage(Kind.NOTE,
                              "Successfully generated code for [" + className + "]");

        return sw.getBuffer();
    }
}
