package org.jdesktop.swingx.plaf;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.border.Border;
import javax.swing.plaf.UIResource;
import javax.swing.plaf.basic.BasicBorders.MarginBorder;

import org.jdesktop.swingx.prompt.BuddySupport;
import org.jdesktop.swingx.prompt.BuddySupport.Position;

public class BuddyLayoutAndBorder implements LayoutManager, Border, PropertyChangeListener, UIResource {
        private JTextField textField;

        private Border borderDelegate;

        /**
         * Installs a {@link BuddyLayoutAndBorder} as a layout and border of the
         * given text field. Registers a {@link PropertyChangeListener} to wrap any
         * subsequently set border on the text field.
         */
        protected void install(JTextField textField) {
                uninstall();
                this.textField = textField;

                textField.setLayout(this);

                replaceBorderIfNecessary();
                textField.addPropertyChangeListener("border", this);
        }

        public Border getBorderDelegate() {
                return borderDelegate;
        }

        /**
         * Wraps and replaces the text fields default border with this object, to
         * honor the button margins and sizes of the search, clear and popup buttons
         * and the layout style.
         */
        protected void replaceBorderIfNecessary() {
                Border original = textField.getBorder();

                if (!(original instanceof BuddyLayoutAndBorder)) {
                        borderDelegate = original;
                        textField.setBorder(this);
                }
        }

        /**
         * Does nothing.
         * 
         * @see BuddySupport#add(javax.swing.JComponent, Position, JTextField)
         */
        @Override
    public void addLayoutComponent(String name, Component comp) {
        }

        @Override
    public Dimension minimumLayoutSize(Container parent) {
                return preferredLayoutSize(parent);
        }

        @Override
    public Dimension preferredLayoutSize(Container parent) {
                Dimension d = new Dimension();

                // height of highest buddy.
                for (Component c : BuddySupport.getLeft(textField)) {
                        d.height = Math.max(d.height, c.getPreferredSize().height);
                }
                for (Component c : BuddySupport.getRight(textField)) {
                        d.height = Math.max(d.height, c.getPreferredSize().height);
                }

                Insets insets = getRealBorderInsets();
                d.height += insets.top + insets.bottom;
                d.width += insets.left + insets.right;

                Insets outerMargin = BuddySupport.getOuterMargin(textField);
                if (outerMargin != null) {
                        d.width += outerMargin.left + outerMargin.right;
                        d.height += outerMargin.bottom + outerMargin.top;
                }

                return d;
        }

        /**
         * Does nothing.
         * 
         * @see BuddySupport#remove(javax.swing.JComponent, JTextField)
         */
        @Override
    public void removeLayoutComponent(Component comp) {
        }

        @Override
    public void layoutContainer(Container parent) {
                Rectangle visibleRect = getVisibleRect();
                Dimension size;

                for (Component comp : BuddySupport.getLeft(textField)) {
                        if (!comp.isVisible()) {
                                continue;
                        }
                        size = comp.getPreferredSize();
                        comp.setBounds(visibleRect.x, centerY(visibleRect, size), size.width, size.height);

                        visibleRect.x += size.width;
                        visibleRect.width -= size.width;
                }

                for (Component comp : BuddySupport.getRight(textField)) {
                        if (!comp.isVisible()) {
                                continue;
                        }

                        size = comp.getPreferredSize();
                        comp.setBounds(visibleRect.x + visibleRect.width - size.width, centerY(visibleRect, size), size.width,
                                        size.height);
                        visibleRect.width -= size.width;
                }
        }

        protected int centerY(Rectangle rect, Dimension size) {
                return (int) (rect.getCenterY() - (size.height / 2));
        }

        /**
         * @return the rectangle allocated by the text field, including the space
         *         allocated by the child components left and right, the text fields
         *         original border insets and the outer margin.
         * 
         */
        protected Rectangle getVisibleRect() {
                Rectangle alloc = SwingUtilities.getLocalBounds(textField);

                substractInsets(alloc, getRealBorderInsets());
                substractInsets(alloc, BuddySupport.getOuterMargin(textField));

                return alloc;
        }

        private void substractInsets(Rectangle alloc, Insets insets) {
                if (insets != null) {
                        alloc.x += insets.left;
                        alloc.y += insets.top;
                        alloc.width -= insets.left + insets.right;
                        alloc.height -= insets.top + insets.bottom;
                }
        }

        /**
         * Returns the {@link Insets} of the original {@link Border} plus the space
         * required by the child components.
         * 
         * @see javax.swing.border.Border#getBorderInsets(java.awt.Component)
         */
        @Override
    public Insets getBorderInsets(Component c) {
                Insets insets = null;
                if (borderDelegate != null) {
                        // Original insets are cloned to make it work in Mac OS X Aqua LnF.
                        // Seems that this LnF uses a shared insets instance which should
                        // not be modified.
                        // Include margin here
                        insets = (Insets) borderDelegate.getBorderInsets(textField).clone();
                } else {
                        insets = new Insets(0, 0, 0, 0);
                }
                //somehow this happens sometimes
                if (textField == null) {
                        return insets;
                }
                
                for (Component comp : BuddySupport.getLeft(textField)) {
                        insets.left += comp.isVisible() ? comp.getPreferredSize().width : 0;
                }
                for (Component comp : BuddySupport.getRight(textField)) {
                        insets.right += comp.isVisible() ? comp.getPreferredSize().width : 0;
                }

                Insets outerMargin = BuddySupport.getOuterMargin(textField);
                if (outerMargin != null) {
                        insets.left += outerMargin.left;
                        insets.right += outerMargin.right;
                        insets.top += outerMargin.top;
                        insets.bottom += outerMargin.bottom;
                }

                return insets;
        }

        /**
         * Returns the insets of the original border (without the margin! Beware of
         * {@link MarginBorder}!).
         * 
         * @return the insets of the border delegate
         */
        public Insets getRealBorderInsets() {
                if (borderDelegate == null) {
                    //SwingX 1287: null borders are possible and give no insets
                        return new Insets(0, 0, 0, 0);
                }

                Insets insets = borderDelegate.getBorderInsets(textField);

                // for some reason, all LnFs add the margin to the insets.
                // we want the insets without the margin, so substract the margin here!!
                // TODO: consider checking, if the current border really includes the
                // margin. Consider:
                // 1. Not only MarginBorder adds margin
                // 2. Calling getBorderInsets(null) is not appropriate, since some
                // Borders can't handle null values.
                Insets margin = textField.getMargin();
                if (margin != null) {
                        insets.left -= margin.left;
                        insets.right -= margin.right;
                        insets.top -= margin.top;
                        insets.bottom -= margin.bottom;
                }

                return insets;
        }

        @Override
    public boolean isBorderOpaque() {
                if (borderDelegate == null) {
                        return false;
                }
                return borderDelegate.isBorderOpaque();
        }

        @Override
    public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
                if (borderDelegate != null) {
                        borderDelegate.paintBorder(c, g, x, y, width, height);
                }
        }

        @Override
    public void propertyChange(PropertyChangeEvent evt) {
                replaceBorderIfNecessary();
        }

        public void uninstall() {
                if (textField != null) {
                        textField.removePropertyChangeListener("border", this);
                        if (textField.getBorder() == this) {
                                textField.setBorder(borderDelegate);
                        }
                        textField.setLayout(null);
                        textField = null;
                }
        }

        @Override
        public String toString() {
                return String.format("%s (%s): %s", getClass().getName(), getBorderInsets(null), borderDelegate);
        }
}