/*
 * Jexer - Java Text User Interface
 *
 * The MIT License (MIT)
 *
 * Copyright (C) 2017 Kevin Lamonte
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * @author Kevin Lamonte [kevin.lamonte@gmail.com]
 * @version 1
 */
package jexer.menu;

import java.util.ResourceBundle;

import jexer.TApplication;
import jexer.TKeypress;
import jexer.TWidget;
import jexer.TWindow;
import jexer.bits.CellAttributes;
import jexer.bits.GraphicsChars;
import jexer.bits.MnemonicString;
import jexer.event.TKeypressEvent;
import jexer.event.TMouseEvent;
import static jexer.TKeypress.*;

/**
 * TMenu is a top-level collection of TMenuItems.
 */
public final class TMenu extends TWindow {

    /**
     * Translated strings.
     */
    private static final ResourceBundle i18n = ResourceBundle.getBundle(TMenu.class.getName());

    /**
     * If true, this is a sub-menu.  Note package private access.
     */
    boolean isSubMenu = false;

    /**
     * The shortcut and title.
     */
    private MnemonicString mnemonic;

    /**
     * Get the mnemonic string.
     *
     * @return the full mnemonic string
     */
    public MnemonicString getMnemonic() {
        return mnemonic;
    }

    // Reserved menu item IDs
    public static final int MID_UNUSED          = -1;

    // File menu
    public static final int MID_EXIT            = 1;
    public static final int MID_QUIT            = MID_EXIT;
    public static final int MID_OPEN_FILE       = 2;
    public static final int MID_SHELL           = 3;

    // Edit menu
    public static final int MID_CUT             = 10;
    public static final int MID_COPY            = 11;
    public static final int MID_PASTE           = 12;
    public static final int MID_CLEAR           = 13;

    // Window menu
    public static final int MID_TILE            = 20;
    public static final int MID_CASCADE         = 21;
    public static final int MID_CLOSE_ALL       = 22;
    public static final int MID_WINDOW_MOVE     = 23;
    public static final int MID_WINDOW_ZOOM     = 24;
    public static final int MID_WINDOW_NEXT     = 25;
    public static final int MID_WINDOW_PREVIOUS = 26;
    public static final int MID_WINDOW_CLOSE    = 27;

    // Help menu
    public static final int MID_HELP_CONTENTS           = 40;
    public static final int MID_HELP_INDEX              = 41;
    public static final int MID_HELP_SEARCH             = 42;
    public static final int MID_HELP_PREVIOUS           = 43;
    public static final int MID_HELP_HELP               = 44;
    public static final int MID_HELP_ACTIVE_FILE        = 45;
    public static final int MID_ABOUT                   = 46;

    // Other
    public static final int MID_REPAINT         = 50;

    /**
     * Public constructor.
     *
     * @param parent parent application
     * @param x column relative to parent
     * @param y row relative to parent
     * @param label mnemonic menu title.  Label must contain a keyboard
     * shortcut (mnemonic), denoted by prefixing a letter with "&",
     * e.g. "&File"
     */
    public TMenu(final TApplication parent, final int x, final int y,
        final String label) {

        super(parent, label, x, y, parent.getScreen().getWidth(),
            parent.getScreen().getHeight());

        // Setup the menu shortcut
        mnemonic = new MnemonicString(label);
        setTitle(mnemonic.getRawLabel());
        assert (mnemonic.getShortcutIdx() >= 0);

        // Recompute width and height to reflect an empty menu
        setWidth(getTitle().length() + 4);
        setHeight(2);

        setActive(false);
    }

    /**
     * Draw a top-level menu with title and menu items.
     */
    @Override
    public void draw() {
        CellAttributes background = getTheme().getColor("tmenu");

        assert (isAbsoluteActive());

        // Fill in the interior background
        for (int i = 0; i < getHeight(); i++) {
            hLineXY(0, i, getWidth(), ' ', background);
        }

        // Draw the box
        char cTopLeft;
        char cTopRight;
        char cBottomLeft;
        char cBottomRight;
        char cHSide;

        cTopLeft = GraphicsChars.ULCORNER;
        cTopRight = GraphicsChars.URCORNER;
        cBottomLeft = GraphicsChars.LLCORNER;
        cBottomRight = GraphicsChars.LRCORNER;
        cHSide = GraphicsChars.SINGLE_BAR;

        // Place the corner characters
        putCharXY(1, 0, cTopLeft, background);
        putCharXY(getWidth() - 2, 0, cTopRight, background);
        putCharXY(1, getHeight() - 1, cBottomLeft, background);
        putCharXY(getWidth() - 2, getHeight() - 1, cBottomRight, background);

        // Draw the box lines
        hLineXY(1 + 1, 0, getWidth() - 4, cHSide, background);
        hLineXY(1 + 1, getHeight() - 1, getWidth() - 4, cHSide, background);

        // Draw a shadow
        getScreen().drawBoxShadow(0, 0, getWidth(), getHeight());
    }

    /**
     * Handle mouse button presses.
     *
     * @param mouse mouse button event
     */
    @Override
    public void onMouseDown(final TMouseEvent mouse) {
        this.mouse = mouse;

        // Pass to children
        for (TWidget widget: getChildren()) {
            if (widget.mouseWouldHit(mouse)) {
                // Dispatch to this child, also activate it
                activate(widget);

                // Set x and y relative to the child's coordinates
                mouse.setX(mouse.getAbsoluteX() - widget.getAbsoluteX());
                mouse.setY(mouse.getAbsoluteY() - widget.getAbsoluteY());
                widget.handleEvent(mouse);
                return;
            }
        }
    }

    /**
     * Handle mouse button releases.
     *
     * @param mouse mouse button release event
     */
    @Override
    public void onMouseUp(final TMouseEvent mouse) {
        this.mouse = mouse;

        // Pass to children
        for (TWidget widget: getChildren()) {
            if (widget.mouseWouldHit(mouse)) {
                // Dispatch to this child, also activate it
                activate(widget);

                // Set x and y relative to the child's coordinates
                mouse.setX(mouse.getAbsoluteX() - widget.getAbsoluteX());
                mouse.setY(mouse.getAbsoluteY() - widget.getAbsoluteY());
                widget.handleEvent(mouse);
                return;
            }
        }
    }

    /**
     * Handle mouse movements.
     *
     * @param mouse mouse motion event
     */
    @Override
    public void onMouseMotion(final TMouseEvent mouse) {
        this.mouse = mouse;

        // See if we should activate a different menu item
        for (TWidget widget: getChildren()) {
            if ((mouse.isMouse1())
                && (widget.mouseWouldHit(mouse))
            ) {
                // Activate this menu item
                activate(widget);
                if (widget instanceof TSubMenu) {
                    ((TSubMenu) widget).dispatch();
                }
                return;
            }
        }
    }

    /**
     * Handle keystrokes.
     *
     * @param keypress keystroke event
     */
    @Override
    public void onKeypress(final TKeypressEvent keypress) {

        /*
        System.err.printf("keypress: %s active child: %s\n", keypress,
            getActiveChild());
         */

        if (getActiveChild() != this) {
            if ((getActiveChild() instanceof TSubMenu)
                || (getActiveChild() instanceof TMenu)
            ) {
                getActiveChild().onKeypress(keypress);
                return;
            }
        }

        if (keypress.equals(kbEsc)) {
            getApplication().closeMenu();
            return;
        }
        if (keypress.equals(kbDown)) {
            switchWidget(true);
            return;
        }
        if (keypress.equals(kbUp)) {
            switchWidget(false);
            return;
        }
        if (keypress.equals(kbRight)) {
            getApplication().switchMenu(true);
            return;
        }
        if (keypress.equals(kbLeft)) {
            if (isSubMenu) {
                getApplication().closeSubMenu();
            } else {
                getApplication().switchMenu(false);
            }
            return;
        }

        // Switch to a menuItem if it has an mnemonic
        if (!keypress.getKey().isFnKey()
            && !keypress.getKey().isAlt()
            && !keypress.getKey().isCtrl()) {
            for (TWidget widget: getChildren()) {
                TMenuItem item = (TMenuItem) widget;
                if ((item.getMnemonic() != null)
                    && (Character.toLowerCase(item.getMnemonic().getShortcut())
                        == Character.toLowerCase(keypress.getKey().getChar()))
                ) {
                    // Send an enter keystroke to it
                    activate(item);
                    item.handleEvent(new TKeypressEvent(kbEnter));
                    return;
                }
            }
        }

        // Dispatch the keypress to an active widget
        for (TWidget widget: getChildren()) {
            if (widget.isActive()) {
                widget.handleEvent(keypress);
                return;
            }
        }
    }

    /**
     * Convenience function to add a menu item.
     *
     * @param id menu item ID.  Must be greater than 1024.
     * @param label menu item label
     * @return the new menu item
     */
    public TMenuItem addItem(final int id, final String label) {
        assert (id >= 1024);
        return addItemInternal(id, label, null);
    }

    /**
     * Convenience function to add a custom menu item.
     *
     * @param id menu item ID.  Must be greater than 1024.
     * @param label menu item label
     * @param key global keyboard accelerator
     * @return the new menu item
     */
    public TMenuItem addItem(final int id, final String label,
        final TKeypress key) {

        assert (id >= 1024);
        return addItemInternal(id, label, key);
    }

    /**
     * Convenience function to add a custom menu item.
     *
     * @param id menu item ID.  Must be greater than 1024.
     * @param label menu item label
     * @param key global keyboard accelerator
     * @param enabled default state for enabled
     * @return the new menu item
     */
    public TMenuItem addItem(final int id, final String label,
        final TKeypress key, final boolean enabled) {

        TMenuItem item = addItem(id, label, key);
        item.setEnabled(enabled);
        return item;
    }

    /**
     * Convenience function to add a custom menu item.
     *
     * @param id menu item ID.  Must be greater than 1024.
     * @param label menu item label
     * @param key global keyboard accelerator
     * @return the new menu item
     */
    private TMenuItem addItemInternal(final int id, final String label,
        final TKeypress key) {

        int newY = getChildren().size() + 1;
        assert (newY < getHeight());

        TMenuItem menuItem = new TMenuItem(this, id, 1, newY, label);
        menuItem.setKey(key);
        setHeight(getHeight() + 1);
        if (menuItem.getWidth() + 2 > getWidth()) {
            setWidth(menuItem.getWidth() + 2);
        }
        for (TWidget widget: getChildren()) {
            widget.setWidth(getWidth() - 2);
        }
        getApplication().addMenuItem(menuItem);
        getApplication().recomputeMenuX();
        activate(0);
        return menuItem;
    }

    /**
     * Convenience function to add one of the default menu items.
     *
     * @param id menu item ID.  Must be between 0 (inclusive) and 1023
     * (inclusive).
     * @return the new menu item
     */
    public TMenuItem addDefaultItem(final int id) {
        assert (id >= 0);
        assert (id < 1024);

        String label;
        TKeypress key = null;

        switch (id) {

        case MID_EXIT:
            label = i18n.getString("menuExit");
            key = kbAltX;
            break;

        case MID_SHELL:
            label = i18n.getString("menuShell");
            break;

        case MID_OPEN_FILE:
            label = i18n.getString("menuOpen");
            key = kbAltO;
            break;

        case MID_CUT:
            label = i18n.getString("menuCut");
            key = kbCtrlX;
            break;
        case MID_COPY:
            label = i18n.getString("menuCopy");
            key = kbCtrlC;
            break;
        case MID_PASTE:
            label = i18n.getString("menuPaste");
            key = kbCtrlV;
            break;
        case MID_CLEAR:
            label = i18n.getString("menuClear");
            // key = kbDel;
            break;

        case MID_TILE:
            label = i18n.getString("menuWindowTile");
            break;
        case MID_CASCADE:
            label = i18n.getString("menuWindowCascade");
            break;
        case MID_CLOSE_ALL:
            label = i18n.getString("menuWindowCloseAll");
            break;
        case MID_WINDOW_MOVE:
            label = i18n.getString("menuWindowMove");
            key = kbCtrlF5;
            break;
        case MID_WINDOW_ZOOM:
            label = i18n.getString("menuWindowZoom");
            key = kbF5;
            break;
        case MID_WINDOW_NEXT:
            label = i18n.getString("menuWindowNext");
            key = kbF6;
            break;
        case MID_WINDOW_PREVIOUS:
            label = i18n.getString("menuWindowPrevious");
            key = kbShiftF6;
            break;
        case MID_WINDOW_CLOSE:
            label = i18n.getString("menuWindowClose");
            key = kbCtrlW;
            break;

        case MID_HELP_CONTENTS:
            label = i18n.getString("menuHelpContents");
            break;
        case MID_HELP_INDEX:
            label = i18n.getString("menuHelpIndex");
            key = kbShiftF1;
            break;
        case MID_HELP_SEARCH:
            label = i18n.getString("menuHelpSearch");
            key = kbCtrlF1;
            break;
        case MID_HELP_PREVIOUS:
            label = i18n.getString("menuHelpPrevious");
            key = kbAltF1;
            break;
        case MID_HELP_HELP:
            label = i18n.getString("menuHelpHelp");
            break;
        case MID_HELP_ACTIVE_FILE:
            label = i18n.getString("menuHelpActive");
            break;
        case MID_ABOUT:
            label = i18n.getString("menuHelpAbout");
            break;

        case MID_REPAINT:
            label = i18n.getString("menuRepaintDesktop");
            break;

        default:
            throw new IllegalArgumentException("Invalid menu ID: " + id);
        }

        return addItemInternal(id, label, key);
    }

    /**
     * Convenience function to add a menu separator.
     */
    public void addSeparator() {
        int newY = getChildren().size() + 1;
        assert (newY < getHeight());

        // We just have to construct it, don't need to hang onto what it
        // makes.
        new TMenuSeparator(this, 1, newY);
        setHeight(getHeight() + 1);
    }

    /**
     * Convenience function to add a sub-menu.
     *
     * @param title menu title.  Title must contain a keyboard shortcut,
     * denoted by prefixing a letter with "&", e.g. "&File"
     * @return the new sub-menu
     */
    public TSubMenu addSubMenu(final String title) {
        int newY = getChildren().size() + 1;
        assert (newY < getHeight());

        TSubMenu subMenu = new TSubMenu(this, title, 1, newY);
        setHeight(getHeight() + 1);
        if (subMenu.getWidth() + 2 > getWidth()) {
            setWidth(subMenu.getWidth() + 2);
        }
        for (TWidget widget: getChildren()) {
            widget.setWidth(getWidth() - 2);
        }
        getApplication().recomputeMenuX();
        activate(0);
        subMenu.menu.setX(getX() + getWidth() - 2);

        return subMenu;
    }

}