/*
 * #%L
 * JSQLParser library
 * %%
 * Copyright (C) 2004 - 2013 JSQLParser
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as 
 * published by the Free Software Foundation, either version 2.1 of the 
 * License, or (at your option) any later version.
 * 
 * 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 Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
 * #L%
 */
package net.sf.jsqlparser.expression;

import net.sf.jsqlparser.statement.select.OrderByElement;

import java.util.List;
import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
import net.sf.jsqlparser.statement.select.PlainSelect;

/**
 * Analytic function. The name of the function is variable but the parameters
 * following the special analytic function path. e.g. row_number() over (order
 * by test). Additional there can be an expression for an analytical aggregate
 * like sum(col) or the "all collumns" wildcard like count(*).
 *
 * @author tw
 */
public class AnalyticExpression implements Expression {

    private ExpressionList partitionExpressionList;
    private List<OrderByElement> orderByElements;
    private String name;
    private Expression expression;
    private Expression offset;
    private Expression defaultValue;
    private boolean allColumns = false;
    private WindowElement windowElement;
    private KeepExpression keep = null;

    @Override
    public void accept(ExpressionVisitor expressionVisitor) {
        expressionVisitor.visit(this);
    }

    public List<OrderByElement> getOrderByElements() {
        return orderByElements;
    }

    public void setOrderByElements(List<OrderByElement> orderByElements) {
        this.orderByElements = orderByElements;
    }

    public KeepExpression getKeep() {
        return keep;
    }

    public void setKeep(KeepExpression keep) {
        this.keep = keep;
    }

    public ExpressionList getPartitionExpressionList() {
        return partitionExpressionList;
    }

    public void setPartitionExpressionList(ExpressionList partitionExpressionList) {
        this.partitionExpressionList = partitionExpressionList;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Expression getExpression() {
        return expression;
    }

    public void setExpression(Expression expression) {
        this.expression = expression;
    }

    public Expression getOffset() {
        return offset;
    }

    public void setOffset(Expression offset) {
        this.offset = offset;
    }

    public Expression getDefaultValue() {
        return defaultValue;
    }

    public void setDefaultValue(Expression defaultValue) {
        this.defaultValue = defaultValue;
    }

    public WindowElement getWindowElement() {
        return windowElement;
    }

    public void setWindowElement(WindowElement windowElement) {
        this.windowElement = windowElement;
    }

    @Override
    public String toString() {
        StringBuilder b = new StringBuilder();

        b.append(name).append("(");
        if (expression != null) {
            b.append(expression.toString());
            if (offset != null) {
                b.append(", ").append(offset.toString());
                if (defaultValue != null) {
                    b.append(", ").append(defaultValue.toString());
                }
            }
        } else if (isAllColumns()) {
            b.append("*");
        }
        b.append(") ");
        if (keep != null) {
            b.append(keep.toString()).append(" ");
        }
        b.append("OVER (");

        toStringPartitionBy(b);
        toStringOrderByElements(b);

        b.append(")");

        return b.toString();
    }

    public boolean isAllColumns() {
        return allColumns;
    }

    public void setAllColumns(boolean allColumns) {
        this.allColumns = allColumns;
    }

    private void toStringPartitionBy(StringBuilder b) {
        if (partitionExpressionList != null && !partitionExpressionList.getExpressions().isEmpty()) {
            b.append("PARTITION BY ");
            b.append(PlainSelect.getStringList(partitionExpressionList.getExpressions(), true, false));
            b.append(" ");
        }
    }

    private void toStringOrderByElements(StringBuilder b) {
        if (orderByElements != null && !orderByElements.isEmpty()) {
            b.append("ORDER BY ");
            for (int i = 0; i < orderByElements.size(); i++) {
                if (i > 0) {
                    b.append(", ");
                }
                b.append(orderByElements.get(i).toString());
            }

            if (windowElement != null) {
                b.append(' ');
                b.append(windowElement);
            }
        }
    }
}
