package org.dataone.jibx.schema.codegen.extend;

import java.util.Iterator;

import org.apache.bcel.generic.Type;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.Assignment;
import org.eclipse.jdt.core.dom.Block;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.Expression;
import org.eclipse.jdt.core.dom.ExpressionStatement;
import org.eclipse.jdt.core.dom.FieldDeclaration;
import org.eclipse.jdt.core.dom.IfStatement;
import org.eclipse.jdt.core.dom.InfixExpression;
import org.eclipse.jdt.core.dom.MethodDeclaration;
import org.eclipse.jdt.core.dom.MethodInvocation;
import org.eclipse.jdt.core.dom.PrimitiveType;
import org.eclipse.jdt.core.dom.SingleVariableDeclaration;
import org.eclipse.jdt.core.dom.TypeDeclaration;
import org.eclipse.jdt.core.dom.VariableDeclarationFragment;
import org.eclipse.jdt.core.dom.VariableDeclarationStatement;
import org.jibx.binding.model.ElementBase;
import org.jibx.schema.codegen.IClassHolder;
import org.jibx.schema.codegen.NameUtils;
import org.jibx.schema.codegen.extend.ClassDecorator;
import org.jibx.schema.codegen.extend.NameMatchDecoratorBase;
import org.jibx.util.NameUtilities;

public class SliceMethodsDecorator extends NameMatchDecoratorBase implements ClassDecorator {

    /** Parser instance used by class. */
    private final ASTParser m_parser = ASTParser.newParser(AST.JLS3);
    
    /** Serial version UID value (<code>null</code> if not set). */
    private Long m_serialVersion;
    
    /** Text for template class. */
    private static final String s_classText = "class Gorph { "
        + "java.util.List $1; "
        
        + "/** Get the 'count' attribute value. The number of entries in the slice.\n"
        + " * @return size of wrapped list\n */\n"
        + "@Override\n"
        + "public int getCount() { "
            + "if ($1 == null) { $1 = new ArrayList<$3>(); } "
            + "return $1.size(); "
        + "}"
    
        + "/** Get the number of $0 items.\n * @return count\n */\n "
        + "public int size$5() { "
            + "if ($1 == null) { $1 = new ArrayList<$3>(); } "
        + "return $1.size(); } "
        
        + "/** Add a $0 item.\n * @param item\n */\n "
        + "public void add$2($3 item) { "
            + "if ($1 == null) { $1 = new ArrayList<$3>(); }\n "
            + "$1.add(item); "
        + "}"
        
        + "/** Get $0 item by position.\n * @return item\n * @param index\n */\n"
        + "public $3 get$2(int index) { "
            + "if ($1 == null) { $1 = new ArrayList<$3>(); } "
            + "return $4$1.get(index); "
        + "}"
        
        + "/** Remove all $0 items.\n */\n "
        + "public void clear$5() { "
            + "if ($1 == null) { $1 = new ArrayList<$3>(); } "
            + "$1.clear(); "
        + "} "
        + "}";
    // $0 is the description text
    // $1 is the field name
    // $2 is the value name with initial uppercase character
    // $3 is the type
    // $4 is a cast if an untyped list is used, or empty if a typed list is used
    // $5 is the uppercase field name
    
    
    /**
     * Method called before starting code generation for the target class.
     */
    @Override
    public void start(IClassHolder holder) {
        // empty
    }

    /**
     * Method called after completing code generation for the target class.
     */
    @Override
    public void finish(ElementBase binding, IClassHolder holder) {
        // empty
    }

    /**
     * Method called after adding each data value to class. 
     * 
     * @param basename base name used for data value
     * @param collect repeated value flag
     * @param type value type (item value type, in the case of a repeated value)
     * @param field actual field
     * @param getmeth read access method (<code>null</code> if a flag value)
     * @param setmeth write access method (<code>null</code> if a flag value)
     * @param descript value description text
     * @param holder
     */
    @Override
    public void valueAdded(String basename, boolean collect, String type, FieldDeclaration field,
            MethodDeclaration getmeth, MethodDeclaration setmeth, String descript, IClassHolder holder) {
            String fieldtype = field.getType().toString();
            
            if (matchName(holder.getName()))
                if (collect && (fieldtype.startsWith("List") || fieldtype.startsWith("java.util.List"))) {
                    
                    // make substitutions in template text
                    StringBuffer buff = new StringBuffer(s_classText);
                    VariableDeclarationFragment vardecl = (VariableDeclarationFragment)field.fragments().get(0);
                    replace("$0", descript, buff);
                    replace("$1", vardecl.getName().getIdentifier(), buff);
                    replace("$2", NameUtilities.depluralize(NameUtils.toNameWord(basename)), buff);
                    replace("$3", holder.getTypeName(type), buff);
                    String cast = field.getType().isParameterizedType() ? "" : ("(" + type + ")");
                    replace("$4", cast, buff);
                    replace("$5", getmeth.getName().getIdentifier().substring(3), buff);
                    
                    // parse the resulting text
                    m_parser.setSource(buff.toString().toCharArray());
                    CompilationUnit unit = (CompilationUnit)m_parser.createAST(null);
                    
                    // add all methods from output tree to class under construction
                    TypeDeclaration typedecl = (TypeDeclaration)unit.types().get(0);
                    for (Iterator iter = typedecl.bodyDeclarations().iterator(); iter.hasNext();) {
                        ASTNode node = (ASTNode)iter.next();
                        if (node instanceof MethodDeclaration) {
                            holder.addMethod((MethodDeclaration)node);
                        }
                    }
                }
        }
    
    /**
     * Replace all occurrences of one string with another in a buffer.
     */
    private static void replace(String match, String replace, StringBuffer buff) {
        int base = 0;
        while ((base = buff.indexOf(match, base)) >= 0) {
            buff.replace(base, base+match.length(), replace);
        }
    }
}