/*
 * Copyright (c) 2010 Mysema Ltd.
 * All rights reserved.
 *
 */
package com.mysema.query.sql;

import java.util.List;

import com.mysema.query.DefaultQueryMetadata;
import com.mysema.query.JoinExpression;
import com.mysema.query.JoinFlag;
import com.mysema.query.QueryFlag;
import com.mysema.query.QueryMetadata;
import com.mysema.query.QueryFlag.Position;
import com.mysema.query.support.DetachableQuery;
import com.mysema.query.support.QueryMixin;
import com.mysema.query.types.Expression;
import com.mysema.query.types.ExpressionUtils;
import com.mysema.query.types.Path;
import com.mysema.query.types.Predicate;
import com.mysema.query.types.SubQueryExpression;
import com.mysema.query.types.TemplateExpressionImpl;

/**
 * Abstract superclass for SubQuery implementations
 *
 * @author tiwe
 *
 */
public class AbstractSQLSubQuery<Q extends AbstractSQLSubQuery<Q>> extends DetachableQuery<Q> {

    public AbstractSQLSubQuery() {
        this(new DefaultQueryMetadata(false));
    }

    @SuppressWarnings("unchecked")
    public AbstractSQLSubQuery(QueryMetadata metadata) {
        super(new QueryMixin<Q>(metadata));
        this.queryMixin.setSelf((Q)this);
    }

    /**
     * Add the given prefix and expression as a general query flag
     * 
     * @param position position of the flag
     * @param prefix prefix for the flag
     * @param expr expression of the flag
     * @return
     */
    public Q addFlag(Position position, String prefix, Expression<?> expr){
        Expression<?> flag = TemplateExpressionImpl.create(expr.getType(), prefix + "{0}", expr);
        return queryMixin.addFlag(new QueryFlag(position, flag));
    }
    
    /**
     * Add the given String literal as a query flag
     * 
     * @param position
     * @param flag
     * @return
     */
    public Q addFlag(Position position, String flag){
        return queryMixin.addFlag(new QueryFlag(position, flag));
    }
    
    /**
     * Add the given Expression as a query flag
     * 
     * @param position
     * @param flag
     * @return
     */
    public Q addFlag(Position position, Expression<?> flag){
        return queryMixin.addFlag(new QueryFlag(position, flag));
    }
    
    /**
     * Add the given String literal as a join flag to the last added join with the position BEFORE_TARGET
     *
     * @param flag
     * @return
     */
    public Q addJoinFlag(String flag){
        return addJoinFlag(flag, JoinFlag.Position.BEFORE_TARGET);
    }

    /**
     * Add the given String literal as a join flag to the last added join
     *
     * @param flag
     * @param position
     * @return
     */
    @SuppressWarnings("unchecked")
    public Q addJoinFlag(String flag, JoinFlag.Position position){
        List<JoinExpression> joins = queryMixin.getMetadata().getJoins();
        joins.get(joins.size()-1).addFlag(new JoinFlag(flag, position));
        return (Q)this;
    }
    
    public Q from(Expression<?>... args){
        return queryMixin.from(args);
    }

    @SuppressWarnings("unchecked")
    public Q from(SubQueryExpression<?> subQuery, Path<?> alias){
        return queryMixin.from(ExpressionUtils.as((Expression)subQuery, alias));
    }
    
    public <E> Q fullJoin(ForeignKey<E> key, RelationalPath<E> entity) {
        return queryMixin.fullJoin(entity).on(key.on(entity));
    }

    public Q fullJoin(RelationalPath<?> target) {
        return queryMixin.fullJoin(target);
    }

    public Q fullJoin(SubQueryExpression<?> target, Path<?> alias) {
        return queryMixin.fullJoin(target, alias);
    }

    public <E> Q innerJoin(ForeignKey<E> key, RelationalPath<E> entity) {
        return queryMixin.innerJoin(entity).on(key.on(entity));
    }

    public Q innerJoin(RelationalPath<?> target) {
        return queryMixin.innerJoin(target);
    }

    public Q innerJoin(SubQueryExpression<?> target, Path<?> alias) {
        return queryMixin.innerJoin(target, alias);
    }

    public <E> Q join(ForeignKey<E> key, RelationalPath<E>  entity) {
        return queryMixin.join(entity).on(key.on(entity));
    }

    public Q join(RelationalPath<?> target) {
        return queryMixin.join(target);
    }

    public Q join(SubQueryExpression<?> target, Path<?> alias) {
        return queryMixin.join(target, alias);
    }

    public <E> Q leftJoin(ForeignKey<E> key, RelationalPath<E>  entity) {
        return queryMixin.leftJoin(entity).on(key.on(entity));
    }

    public Q leftJoin(RelationalPath<?> target) {
        return queryMixin.leftJoin(target);
    }   

    public Q leftJoin(SubQueryExpression<?> target, Path<?> alias) {
        return queryMixin.leftJoin(target, alias);
    }

    public Q on(Predicate... conditions){
        return queryMixin.on(conditions);
    }

    public <E> Q rightJoin(ForeignKey<E> key, RelationalPath<E>  entity) {
        return queryMixin.rightJoin(entity).on(key.on(entity));
    }

    public Q rightJoin(RelationalPath<?> target) {
        return queryMixin.leftJoin(target);
    }

    public Q rightJoin(SubQueryExpression<?> target, Path<?> alias) {
        return queryMixin.leftJoin(target, alias);
    }

    @Override
    public String toString(){
        if (!queryMixin.getMetadata().getJoins().isEmpty()){
            SQLSerializer serializer = new SQLSerializer(SQLTemplates.DEFAULT);
            serializer.serialize(queryMixin.getMetadata(), false);
            return serializer.toString().trim();
        }else{
            return super.toString();
        }
    }

}