/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 2 of the License.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.bck2brwsr.htmlpage;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.io.Writer;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.Map;

import java.util.Map.Entry;

import java.util.ServiceLoader;

import javax.annotation.processing.ProcessingEnvironment;

import javax.lang.model.element.Element;

import javax.tools.Diagnostic;

import javax.tools.FileObject;

import org.netbeans.modules.html.editor.lib.api.HtmlVersion;

import org.netbeans.modules.html.editor.lib.api.model.HtmlModel;

import org.netbeans.modules.html.editor.lib.api.model.HtmlModelProvider;

import org.netbeans.modules.html.editor.lib.api.model.HtmlTag;

import org.netbeans.modules.html.editor.lib.api.model.HtmlTagAttribute;

/**

 *

 * @author Jan Horvath <jhorvath@netbeans.org>

 */

public class ElementGenerator {

    static final Map<String, String> NAMING_EXCEPTIONS = new HashMap<String, String>() {

        {

            put("img", "Image");

            put("class", "Clazz");

        }

    };

    static final String javaKeywords[] = {

        "abstract", "assert", "boolean", "break", "byte", "case",

        "catch", "char", "class", "const", "continue", "default", 

        "do", "double", "else", "extends", "false", "final", "finally", 

        "float", "for", "goto", "if", "implements", "import", 

        "instanceof", "int", "interface", "long", "native", "new",

        "null", "package", "private", "protected", "public",

        "return", "short", "static", "strictfp", "super",

        "switch", "synchronized", "this", "throw", "throws",

        "transient", "true", "try", "void", "volatile", "while"

    };

    private static Map<String, String> elements = new HashMap<String, String>();

    private final ProcessingEnvironment processingEnv;

    private HtmlModel model = null;

    ElementGenerator(ProcessingEnvironment processingEnv) {

        this.processingEnv = processingEnv;

    }

    String getType(String pkg, String tag, Element e) {

        String className = elements.get(tag);

        if (className == null) {

            className = createClass(pkg, tag, e);

            elements.put(tag, className);

        }

        return className;

    }

    private String createClass(String pkg, String tag, Element e) {

        String className = className(tag);

        Writer w;

        try {

            FileObject java = processingEnv.getFiler().createSourceFile(pkg + '.' + className, e);

            w = new OutputStreamWriter(java.openOutputStream());

            try {

                w.append("package " + pkg + ";\n\n");

                w.append("import org.apidesign.bck2brwsr.htmlpage.api.*;\n");

                PredefinedFields.appendImports(w, tag);

                w.append("\n");

                w.append("class ").append(className).append(" extends Element {\n\n");

                w.append("    public ").append(className).append("(String id) {\n");

                w.append("        super(id);\n");

                w.append("    }\n\n");

                for (Entry<String, String> entry : getAttributes(tag).entrySet()) {

                    String attrName = entry.getKey();

                    String attrType = entry.getValue();

                    // getter

                    w.append("    public ").append(attrType).append(" ")

                            .append("get").append(className(attrName)).append("() {\n");

                    w.append("        return (").append(attrType).append(")getAttribute(\"")

                            .append(attrName).append("\");\n");

                    w.append("    }\n\n");

                    // setter

                    w.append("    public void ")

                            .append("set").append(className(attrName)).append("(")

                            .append(attrType).append(" ").append(attributeName(attrName)).append(") {\n");

                    w.append("        setAttribute(\"").append(attrName).append("\", ").append(attributeName(attrName)).append(");\n");

                    w.append("    }\n\n");

                }

                PredefinedFields.appendFields(w, tag);

                w.append("}\n");

            } finally {

                w.close();

            }

        } catch (IOException ex) {

            processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, "Can't create " + className + ".java", e);

            return null;

        }

        return className;

    }

    Map<String, String> getAttributes(String tagName) {

        Map<String, String> result = new HashMap<String, String>();

        if (model == null) {

            // HtmlModelProvider modelProvider = Lookup.getDefault().lookup(HtmlModelProvider.class);

            ServiceLoader<HtmlModelProvider> hmpLoader = 

                    ServiceLoader.load(HtmlModelProvider.class, this.getClass().getClassLoader());

            for (HtmlModelProvider htmlModelProvider : hmpLoader) {

                model = htmlModelProvider.getModel(HtmlVersion.HTML5);

                if (model != null) {

                    break;

                }

            }

        }

        if (model == null) {

            processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, 

                    "HTML 5 model provider was not found on classpath");

            return Collections.emptyMap();

        }

        HtmlTag tag = model.getTag(tagName);

        for (HtmlTagAttribute attr : tag.getAttributes()) {

            String name = attr.getName();

            String type = Attributes.TYPES.get(name);

            if (type != null) {

                result.put(name, type);

            }

        }

        return result;

    }

    private String className(String s) {

        if (s.length() == 0) {

            return s;

        }

        String name = NAMING_EXCEPTIONS.get(s.toLowerCase());

        if (name == null) {

            name = s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();

        }

        return name;

    }

    private String attributeName(String s) {

        if (Arrays.binarySearch(javaKeywords, s) >= 0) {

            return String.format("%sAttr", s);

        }

        return s;

    }

}