/*
 * Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.lwawt.macosx;

import java.awt.*;
import java.beans.*;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
import java.util.concurrent.Callable;

import javax.accessibility.*;
import javax.swing.*;

class CAccessibility implements PropertyChangeListener {
    private static Set<String> ignoredRoles;

    static {
        // Need to load the native library for this code.
        java.security.AccessController.doPrivileged(
            new java.security.PrivilegedAction<Void>() {
                public Void run() {
                    System.loadLibrary("awt");
                    return null;
                }
            });
    }

    static CAccessibility sAccessibility;
    static synchronized CAccessibility getAccessibility(final String[] roles) {
        if (sAccessibility != null) return sAccessibility;
        sAccessibility = new CAccessibility();

        if (roles != null) {
            ignoredRoles = new HashSet<String>(roles.length);
            for (final String role : roles) ignoredRoles.add(role);
        } else {
            ignoredRoles = new HashSet<String>();
        }

        return sAccessibility;
    }

    private CAccessibility() {
        KeyboardFocusManager.getCurrentKeyboardFocusManager().addPropertyChangeListener("focusOwner", this);
    }

    public void propertyChange(final PropertyChangeEvent evt) {
        if (evt.getNewValue() == null) return;
        focusChanged();
    }

    private native void focusChanged();

    static <T> T invokeAndWait(final Callable<T> callable, final Component c) {
        try {
            return LWCToolkit.invokeAndWait(callable, c);
        } catch (final Exception e) { e.printStackTrace(); }
        return null;
    }

    static void invokeLater(final Runnable runnable, final Component c) {
        try {
            LWCToolkit.invokeLater(runnable, c);
        } catch (InvocationTargetException e) { e.printStackTrace(); }
    }

    public static String getAccessibleActionDescription(final AccessibleAction aa, final int index, final Component c) {
        if (aa == null) return null;

        return invokeAndWait(new Callable<String>() {
            public String call() throws Exception {
                return aa.getAccessibleActionDescription(index);
            }
        }, c);
    }

    public static void doAccessibleAction(final AccessibleAction aa, final int index, final Component c) {
        // We make this an invokeLater because we don't need a reply.
        if (aa == null) return;

        invokeLater(new Runnable() {
            public void run() {
                aa.doAccessibleAction(index);
            }
        }, c);
    }

    public static Dimension getSize(final AccessibleComponent ac, final Component c) {
        if (ac == null) return null;

        return invokeAndWait(new Callable<Dimension>() {
            public Dimension call() throws Exception {
                return ac.getSize();
            }
        }, c);
    }

    public static AccessibleSelection getAccessibleSelection(final AccessibleContext ac, final Component c) {
        if (ac == null) return null;

        return invokeAndWait(new Callable<AccessibleSelection>() {
            public AccessibleSelection call() throws Exception {
                return ac.getAccessibleSelection();
            }
        }, c);
    }

    public static Accessible ax_getAccessibleSelection(final AccessibleContext ac, final int index, final Component c) {
        if (ac == null) return null;

        return invokeAndWait(new Callable<Accessible>() {
            public Accessible call() throws Exception {
                final AccessibleSelection as = ac.getAccessibleSelection();
                if (as == null) return null;
                return as.getAccessibleSelection(index);
            }
        }, c);
    }

    // KCH - can we make this a postEvent?
    public static void addAccessibleSelection(final AccessibleContext ac, final int index, final Component c) {
        if (ac == null) return;

        invokeLater(new Runnable() {
            public void run() {
                final AccessibleSelection as = ac.getAccessibleSelection();
                if (as == null) return;
                as.addAccessibleSelection(index);
            }
        }, c);
    }

    public static AccessibleContext getAccessibleContext(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<AccessibleContext>() {
            public AccessibleContext call() throws Exception {
                return a.getAccessibleContext();
            }
        }, c);
    }

    public static boolean isAccessibleChildSelected(final Accessible a, final int index, final Component c) {
        if (a == null) return false;

        return invokeAndWait(new Callable<Boolean>() {
            public Boolean call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return Boolean.FALSE;

                final AccessibleSelection as = ac.getAccessibleSelection();
                if (as == null) return Boolean.FALSE;

                return new Boolean(as.isAccessibleChildSelected(index));
            }
        }, c);
    }

    public static AccessibleStateSet getAccessibleStateSet(final AccessibleContext ac, final Component c) {
        if (ac == null) return null;

        return invokeAndWait(new Callable<AccessibleStateSet>() {
            public AccessibleStateSet call() throws Exception {
                return ac.getAccessibleStateSet();
            }
        }, c);
    }

    public static boolean contains(final AccessibleContext ac, final AccessibleState as, final Component c) {
        if (ac == null || as == null) return false;

        return invokeAndWait(new Callable<Boolean>() {
            public Boolean call() throws Exception {
                final AccessibleStateSet ass = ac.getAccessibleStateSet();
                if (ass == null) return null;
                return ass.contains(as);
            }
        }, c);
    }

    static Field getAccessibleBundleKeyFieldWithReflection() {
        try {
            final Field fieldKey = AccessibleBundle.class.getDeclaredField("key");
            fieldKey.setAccessible(true);
            return fieldKey;
        } catch (final SecurityException e) {
            e.printStackTrace();
        } catch (final NoSuchFieldException e) {
            e.printStackTrace();
        }
        return null;
    }
    private static final Field FIELD_KEY = getAccessibleBundleKeyFieldWithReflection();

    static String getAccessibleRoleFor(final Accessible a) {
        final AccessibleContext ac = a.getAccessibleContext();
        if (ac == null) return null;

        final AccessibleRole role = ac.getAccessibleRole();
        try {
            return (String)FIELD_KEY.get(role);
        } catch (final IllegalArgumentException e) {
            e.printStackTrace();
        } catch (final IllegalAccessException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String getAccessibleRole(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<String>() {
            public String call() throws Exception {
                final Accessible sa = CAccessible.getSwingAccessible(a);
                final String role = getAccessibleRoleFor(a);

                if (!"text".equals(role)) return role;
                if (sa instanceof JTextArea || sa instanceof JEditorPane) {
                    return "textarea";
                }
                return role;
            }
        }, c);
    }

    public static Point getLocationOnScreen(final AccessibleComponent ac, final Component c) {
        if (ac == null) return null;

        return invokeAndWait(new Callable<Point>() {
            public Point call() throws Exception {
                return ac.getLocationOnScreen();
            }
        }, c);
    }

    public static int getCharCount(final AccessibleText at, final Component c) {
        if (at == null) return 0;

        return invokeAndWait(new Callable<Integer>() {
            public Integer call() throws Exception {
                return at.getCharCount();
            }
        }, c);
    }

    // Accessibility Threadsafety for JavaComponentAccessibility.m
    public static Accessible getAccessibleParent(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<Accessible>() {
            public Accessible call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;
                return ac.getAccessibleParent();
            }
        }, c);
    }

    public static int getAccessibleIndexInParent(final Accessible a, final Component c) {
        if (a == null) return 0;

        return invokeAndWait(new Callable<Integer>() {
            public Integer call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;
                return ac.getAccessibleIndexInParent();
            }
        }, c);
    }

    public static AccessibleComponent getAccessibleComponent(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<AccessibleComponent>() {
            public AccessibleComponent call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;
                return ac.getAccessibleComponent();
            }
        }, c);
    }

    public static AccessibleValue getAccessibleValue(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<AccessibleValue>() {
            public AccessibleValue call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                AccessibleValue accessibleValue = ac.getAccessibleValue();
                return accessibleValue;
            }
        }, c);
    }

    public static String getAccessibleName(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<String>() {
            public String call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final String accessibleName = ac.getAccessibleName();
                if (accessibleName == null) {
                    return ac.getAccessibleDescription();
                }
                return accessibleName;
            }
        }, c);
    }

    public static AccessibleText getAccessibleText(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<AccessibleText>() {
            public AccessibleText call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                AccessibleText accessibleText = ac.getAccessibleText();
                return accessibleText;
            }
        }, c);
    }

    public static String getAccessibleDescription(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<String>() {
            public String call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final String accessibleDescription = ac.getAccessibleDescription();
                if (accessibleDescription == null) {
                    if (c instanceof JComponent) {
                        String toolTipText = ((JComponent)c).getToolTipText();
                        if (toolTipText != null) {
                            return toolTipText;
                        }
                    }
                }

                return accessibleDescription;
            }
        }, c);
    }

    public static boolean isFocusTraversable(final Accessible a, final Component c) {
        if (a == null) return false;

        return invokeAndWait(new Callable<Boolean>() {
            public Boolean call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final AccessibleComponent aComp = ac.getAccessibleComponent();
                if (aComp == null) return null;

                return aComp.isFocusTraversable();
            }
        }, c);
    }

    public static Accessible accessibilityHitTest(final Container parent, final float hitPointX, final float hitPointY) {
        return invokeAndWait(new Callable<Accessible>() {
            public Accessible call() throws Exception {
                final Point p = parent.getLocationOnScreen();

                // Make it into local coords
                final Point localPoint = new Point((int)(hitPointX - p.getX()), (int)(hitPointY - p.getY()));

                final Component component = parent.findComponentAt(localPoint);
                if (component == null) return null;

                final AccessibleContext axContext = component.getAccessibleContext();
                if (axContext == null) return null;

                final AccessibleComponent axComponent = axContext.getAccessibleComponent();
                if (axComponent == null) return null;

                final int numChildren = axContext.getAccessibleChildrenCount();
                if (numChildren > 0) {
                    // It has children, check to see which one is hit.
                    final Point p2 = axComponent.getLocationOnScreen();
                    final Point localP2 = new Point((int)(hitPointX - p2.getX()), (int)(hitPointY - p2.getY()));
                    return CAccessible.getCAccessible(axComponent.getAccessibleAt(localP2));
                }

                if (!(component instanceof Accessible)) return null;
                return CAccessible.getCAccessible((Accessible)component);
            }
        }, parent);
    }

    public static AccessibleAction getAccessibleAction(final Accessible a, final Component c) {
        return invokeAndWait(new Callable<AccessibleAction>() {
            public AccessibleAction call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;
                return ac.getAccessibleAction();
            }
        }, c);
    }

    public static boolean isEnabled(final Accessible a, final Component c) {
        if (a == null) return false;

        return invokeAndWait(new Callable<Boolean>() {
            public Boolean call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final AccessibleComponent aComp = ac.getAccessibleComponent();
                if (aComp == null) return null;

                return aComp.isEnabled();
            }
        }, c);
    }

    // KCH - can we make this a postEvent instead?
    public static void requestFocus(final Accessible a, final Component c) {
        if (a == null) return;

        invokeLater(new Runnable() {
            public void run() {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return;

                final AccessibleComponent aComp = ac.getAccessibleComponent();
                if (aComp == null) return;

                aComp.requestFocus();
            }
        }, c);
    }

    public static Number getMaximumAccessibleValue(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<Number>() {
            public Number call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final AccessibleValue av = ac.getAccessibleValue();
                if (av == null) return null;

                return av.getMaximumAccessibleValue();
            }
        }, c);
    }

    public static Number getMinimumAccessibleValue(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<Number>() {
            public Number call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final AccessibleValue av = ac.getAccessibleValue();
                if (av == null) return null;

                return av.getMinimumAccessibleValue();
            }
        }, c);
    }

    public static String getAccessibleRoleDisplayString(final Accessible a, final Component c) {
        if (a == null) return null;

        return invokeAndWait(new Callable<String>() {
            public String call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final AccessibleRole ar = ac.getAccessibleRole();
                if (ar == null) return null;

                return ar.toDisplayString();
            }
        }, c);
    }

    public static Number getCurrentAccessibleValue(final AccessibleValue av, final Component c) {
        if (av == null) return null;

        return invokeAndWait(new Callable<Number>() {
            public Number call() throws Exception {
                Number currentAccessibleValue = av.getCurrentAccessibleValue();
                return currentAccessibleValue;
            }
        }, c);
    }

    public static Accessible getFocusOwner(final Component c) {
        return invokeAndWait(new Callable<Accessible>() {
            public Accessible call() throws Exception {
                Component c = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
                if (c == null || !(c instanceof Accessible)) return null;
                return CAccessible.getCAccessible((Accessible)c);
            }
        }, c);
    }

    public static boolean[] getInitialAttributeStates(final Accessible a, final Component c) {
        final boolean[] ret = new boolean[7];
        if (a == null) return ret;

        return invokeAndWait(new Callable<boolean[]>() {
            public boolean[] call() throws Exception {
                final AccessibleContext aContext = a.getAccessibleContext();
                if (aContext == null) return ret;

                final AccessibleComponent aComponent = aContext.getAccessibleComponent();
                ret[0] = (aComponent != null);
                ret[1] = ((aComponent != null) && (aComponent.isFocusTraversable()));
                ret[2] = (aContext.getAccessibleValue() != null);
                ret[3] = (aContext.getAccessibleText() != null);

                final AccessibleStateSet aStateSet = aContext.getAccessibleStateSet();
                ret[4] = (aStateSet.contains(AccessibleState.HORIZONTAL) || aStateSet.contains(AccessibleState.VERTICAL));
                ret[5] = (aContext.getAccessibleName() != null);
                ret[6] = (aContext.getAccessibleChildrenCount() > 0);
                return ret;
            }
        }, c);
    }

    // Duplicated from JavaComponentAccessibility
    // Note that values >=0 are indexes into the child array
    final static int JAVA_AX_ALL_CHILDREN = -1;
    final static int JAVA_AX_SELECTED_CHILDREN = -2;
    final static int JAVA_AX_VISIBLE_CHILDREN = -3;

    // Each child takes up two entries in the array: one for itself and one for its role
    public static Object[] getChildrenAndRoles(final Accessible a, final Component c, final int whichChildren, final boolean allowIgnored) {
        if (a == null) return null;
        return invokeAndWait(new Callable<Object[]>() {
            public Object[] call() throws Exception {
                final ArrayList<Object> childrenAndRoles = new ArrayList<Object>();
                _addChildren(a, whichChildren, allowIgnored, childrenAndRoles);

                if ((whichChildren < 0) || (whichChildren * 2 >= childrenAndRoles.size())) {
                    return childrenAndRoles.toArray();
                }

                return new Object[] { childrenAndRoles.get(whichChildren * 2), childrenAndRoles.get((whichChildren * 2) + 1) };
            }
        }, c);
    }

    private static AccessibleRole getAccessibleRoleForLabel(JLabel l, AccessibleRole fallback) {
        String text = l.getText();
        if (text != null && text.length() > 0) {
            return fallback;
        }
        Icon icon = l.getIcon();
        if (icon != null) {
            return AccessibleRole.ICON;
        }
        return fallback;
    }

    private static AccessibleRole getAccessibleRole(Accessible a) {
        AccessibleContext ac = a.getAccessibleContext();
        AccessibleRole role = ac.getAccessibleRole();
        Object component = CAccessible.getSwingAccessible(a);
        if (role == null) return null;
        String roleString = role.toString();
        if ("label".equals(roleString) && component instanceof JLabel) {
            return getAccessibleRoleForLabel((JLabel) component, role);
        }
        return role;
    }


    // Either gets the immediate children of a, or recursively gets all unignored children of a
    private static void _addChildren(final Accessible a, final int whichChildren, final boolean allowIgnored, final ArrayList<Object> childrenAndRoles) {
        if (a == null) return;

        final AccessibleContext ac = a.getAccessibleContext();
        if (ac == null) return;

        final int numChildren = ac.getAccessibleChildrenCount();

        // each child takes up two entries in the array: itself, and its role
        // so the array holds alternating Accessible and AccessibleRole objects
        for (int i = 0; i < numChildren; i++) {
            final Accessible child = ac.getAccessibleChild(i);
            if (child == null) continue;

            final AccessibleContext context = child.getAccessibleContext();
            if (context == null) continue;

            if (whichChildren == JAVA_AX_VISIBLE_CHILDREN) {
                if (!context.getAccessibleComponent().isVisible()) continue;
            } else if (whichChildren == JAVA_AX_SELECTED_CHILDREN) {
                if (!ac.getAccessibleSelection().isAccessibleChildSelected(i)) continue;
            }

            if (!allowIgnored) {
                final AccessibleRole role = context.getAccessibleRole();
                if (role != null && ignoredRoles != null && ignoredRoles.contains(roleKey(role))) {
                    // Get the child's unignored children.
                    _addChildren(child, whichChildren, false, childrenAndRoles);
                } else {
                    childrenAndRoles.add(child);
                    childrenAndRoles.add(getAccessibleRole(child));
                }
            } else {
                childrenAndRoles.add(child);
                childrenAndRoles.add(getAccessibleRole(child));
            }

            // If there is an index, and we are beyond it, time to finish up
            if ((whichChildren >= 0) && (childrenAndRoles.size() / 2) >= (whichChildren + 1)) {
                return;
            }
        }
    }

    private static native String roleKey(AccessibleRole aRole);

    public static Object[] getChildren(final Accessible a, final Component c) {
        if (a == null) return null;
        return invokeAndWait(new Callable<Object[]>() {
            public Object[] call() throws Exception {
                final AccessibleContext ac = a.getAccessibleContext();
                if (ac == null) return null;

                final int numChildren = ac.getAccessibleChildrenCount();
                final Object[] children = new Object[numChildren];
                for (int i = 0; i < numChildren; i++) {
                    children[i] = ac.getAccessibleChild(i);
                }
                return children;
            }
        }, c);
    }
}