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package org.apidesign.livedb.impl;

import java.io.IOException;

import java.io.Writer;

import java.sql.CallableStatement;

import java.sql.Connection;

import java.sql.Driver;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.util.Enumeration;

import java.util.Properties;

import java.util.ServiceLoader;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.annotation.processing.AbstractProcessor;

import javax.annotation.processing.Processor;

import javax.annotation.processing.RoundEnvironment;

import javax.annotation.processing.SupportedAnnotationTypes;

import javax.annotation.processing.SupportedSourceVersion;

import javax.lang.model.SourceVersion;

import javax.lang.model.element.Element;

import javax.lang.model.element.PackageElement;

import javax.lang.model.element.TypeElement;

import javax.tools.JavaFileObject;

import org.apidesign.livedb.LiveDB;

import org.openide.util.lookup.ServiceProvider;

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

@SupportedAnnotationTypes("org.apidesign.livedb.LiveDB")

@SupportedSourceVersion(SourceVersion.RELEASE_6)

@ServiceProvider(service=Processor.class)

public class LiveDBProcessor extends AbstractProcessor {

    @Override

    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {

        for (Element e : roundEnv.getElementsAnnotatedWith(LiveDB.class)) {

            LiveDB db = e.getAnnotation(LiveDB.class);

            PackageElement pe = (PackageElement)e;

            String clsName = pe.getQualifiedName().toString() + "." + db.classname();

            try {

                JavaFileObject src = processingEnv.getFiler().createSourceFile(clsName, pe);

                Writer w = src.openWriter();

                Connection c = getConnection(db.url(), db.user(), db.password());

                CallableStatement s = c.prepareCall(db.query());

                ResultSet rs = s.executeQuery();

                ResultSetMetaData md = rs.getMetaData();

                w.append("package " + pe.getQualifiedName() + ";\n");

                w.append("import java.util.List;\n");

                w.append("import java.util.ArrayList;\n");

                w.append("import java.sql.*;\n");

                w.append("class " + db.classname() + " {\n");

                for (int i = 1; i <= md.getColumnCount(); i++) {

                    w.append("  public final " + md.getColumnClassName(i) + " " + md.getColumnName(i) + ";\n");

                }

                w.append("  private " + db.classname() + "(\n");

                for (int i = 1; i <= md.getColumnCount(); i++) {

                    w.append("    " + md.getColumnClassName(i) + " " + md.getColumnName(i));

                    if (i < md.getColumnCount()) {

                        w.append(",\n");

                    } else {

                        w.append("\n");

                    }

                }

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

                for (int i = 1; i <= md.getColumnCount(); i++) {

                    w.append("    this." + md.getColumnName(i) + " = " + md.getColumnName(i) + ";\n");

                }

                w.append("  }\n");

                w.append("  public static List<" + db.classname() + "> query() throws SQLException {\n");

                w.append("    Connection c = DriverManager.getConnection(\"" + db.url() + "\", \"" + db.user() + "\", \"" + db.password() +"\");\n");

                w.append("    List<" + db.classname() + "> res = new ArrayList<" + db.classname() + ">();\n");

                w.append("    CallableStatement s = c.prepareCall(\"" + db.query() + "\");\n");

                w.append("    ResultSet rs = s.executeQuery();\n");

                w.append("    ResultSetMetaData md = rs.getMetaData();\n");

                w.append("    while (rs.next()) {\n");

                w.append("      res.add(new " + db.classname() + "(\n");

                for (int i = 1; i <= md.getColumnCount(); i++) {

                    w.append("        (" + md.getColumnClassName(i) + ")rs.getObject(" + i + ")");

                    if (i < md.getColumnCount()) {

                        w.append(",\n");

                    } else {

                        w.append("\n");

                    }

                }

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

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

                w.append("    return res;\n");

                w.append("  }");

                w.append("}");

                w.close();

            } catch (IOException ex) {

                throw new IllegalStateException(ex);

            } catch (SQLException ex) {

                throw new IllegalStateException(ex);

            }

        }

        return true;

    }

    private static Connection getConnection(String url, String user, String password) 

    throws SQLException {

        final ClassLoader cl = LiveDBProcessor.class.getClassLoader();

        for (Driver d : ServiceLoader.load(Driver.class, cl)) {

//            System.out.println("looked up: " + d);

            if (d.acceptsURL(url)) {

                //System.out.println("accepts: " + d);

                Properties p = new Properties();

                p.put("user", user);

                p.put("password", password);

                return d.connect(url, p);

            }

        }

        throw new SQLException("No driver found for " + url);

    }

}