/*
 * This file is part of lanterna (https://github.com/mabe02/lanterna).
 *
 * lanterna 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 3 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright (C) 2010-2020 Martin Berglund
 */
package com.googlecode.lanterna.gui2;

import com.googlecode.lanterna.graphics.BasicTextImage;
import com.googlecode.lanterna.graphics.TextImage;
import com.googlecode.lanterna.input.*;
import com.googlecode.lanterna.screen.Screen;
import com.googlecode.lanterna.*;
import com.googlecode.lanterna.screen.VirtualScreen;
import com.googlecode.lanterna.gui2.Window.Hint;

import java.io.EOFException;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean
;

Author:
ginkoblongata/**
 * 
 * @author ginkoblongata
 */
public class WindowList {
    
    private final List<Window> windows = new LinkedList<>();
    private final List<Window> stableOrderingOfWindows = new ArrayList<>();
    
    private Window activeWindow = null;
    private boolean hadWindowAtSomePoint = false;

    public List<Window> getWindowsInZOrder() {
        return Collections.unmodifiableList(windows);
    }
    
    public List<Window> getWindowsInStableOrder() {
        return Collections.unmodifiableList(stableOrderingOfWindows);
    }
    
    public void setActiveWindow(Window activeWindow) {
        this.activeWindow = activeWindow;
        if (activeWindow != null) {
            moveToTop(activeWindow);
        }
    }

    public Window getActiveWindow() {
        return activeWindow;
    }
    
    public void addWindow(Window window) {
        if (!stableOrderingOfWindows.contains(window)) {
            stableOrderingOfWindows.add(window);
        }
        if(!windows.contains(window)) {
            windows.add(window);
        }
        if(!window.getHints().contains(Window.Hint.NO_FOCUS)) {
            setActiveWindow(window);
        }
        hadWindowAtSomePoint = true;
    }
    
    
Removes the window from this WindowList.
Returns:
true if this WindowList contained the specified Window/**
     * Removes the window from this WindowList.
     * @return true if this WindowList contained the specified Window
     */
    public boolean removeWindow(Window window) {
        boolean contained = windows.remove(window);
        stableOrderingOfWindows.remove(window);
        
        if(activeWindow == window) {
            // in case no suitable window is found, so pass control back to the background pane
            setActiveWindow(null);
            
            //Go backward in reverse and find the first suitable window
            for(int index = windows.size() - 1; index >= 0; index--) {
                Window candidate = windows.get(index);
                if(!candidate.getHints().contains(Window.Hint.NO_FOCUS)) {
                    setActiveWindow(candidate);
                    break;
                }
            }
        }
        
        return contained;
    }
    
    public boolean isHadWindowAtSomePoint() {
        return hadWindowAtSomePoint;
    }

    public void moveToTop(Window window) {
        if(!windows.contains(window)) {
            throw new IllegalArgumentException("Window " + window + " isn't in MultiWindowTextGUI " + this);
        }
        windows.remove(window);
        windows.add(window);
    }
    
    public void moveToBottom(Window window) {
        if(!windows.contains(window)) {
            throw new IllegalArgumentException("Window " + window + " isn't in MultiWindowTextGUI " + this);
        }
        windows.remove(window);
        windows.add(0, window);
    }
    
Switches the active window by cyclically shuffling the window list. If reverse parameter is false then the current top window is placed at the bottom of the stack and the window immediately behind it is the new top. If reverse is set to true then the window at the bottom of the stack is moved up to the front and the previous top window will be immediately below it 
Params:
reverse – Direction to cycle through the windows/**
     * Switches the active window by cyclically shuffling the window list. If {@code reverse} parameter is {@code false}
     * then the current top window is placed at the bottom of the stack and the window immediately behind it is the new
     * top. If {@code reverse} is set to {@code true} then the window at the bottom of the stack is moved up to the
     * front and the previous top window will be immediately below it
     * @param reverse Direction to cycle through the windows
     */
    public void cycleActiveWindow(boolean reverse) {
        if(windows.isEmpty() || windows.size() == 1 || (activeWindow != null && activeWindow.getHints().contains(Window.Hint.MODAL))) {
            return;
        }
        Window originalActiveWindow = activeWindow;
        Window nextWindow;
        if(activeWindow == null) {
            // Cycling out of active background pane
            nextWindow = reverse ? windows.get(windows.size() - 1) : windows.get(0);
        } else {
            // Switch to the next window
            nextWindow = getNextWindow(reverse, activeWindow);
        }

        int noFocusWindows = 0;
        while(nextWindow.getHints().contains(Window.Hint.NO_FOCUS)) {
            ++noFocusWindows;
            if(noFocusWindows == windows.size()) {
                // All windows are NO_FOCUS, so give up
                return;
            }
            nextWindow = getNextWindow(reverse, nextWindow);
            if(nextWindow == originalActiveWindow) {
                return;
            }
        }

        if(reverse) {
            moveToTop(nextWindow);
        } else if (originalActiveWindow != null) {
            moveToBottom(originalActiveWindow);
        }
        setActiveWindow(nextWindow);
    }

    private Window getNextWindow(boolean reverse, Window window) {
        int index = windows.indexOf(window);
        if(reverse) {
            if(++index >= windows.size()) {
                index = 0;
            }
        } else {
            if(--index < 0) {
                index = windows.size() - 1;
            }
        }
        return windows.get(index);
    }
}