/*
 * This file is part of McIDAS-V
 *
 * Copyright 2007-2024
 * Space Science and Engineering Center (SSEC)
 * University of Wisconsin - Madison
 * 1225 W. Dayton Street, Madison, WI 53706, USA
 * https://www.ssec.wisc.edu/mcidas/
 * 
 * All Rights Reserved
 * 
 * McIDAS-V is built on Unidata's IDV and SSEC's VisAD libraries, and
 * some McIDAS-V source code is based on IDV and VisAD source code.  
 * 
 * McIDAS-V is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 * 
 * McIDAS-V 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 Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser Public License
 * along with this program.  If not, see https://www.gnu.org/licenses/.
 */

package edu.wisc.ssec.mcidasv.util;

import java.awt.BorderLayout;

import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

import javax.swing.InputVerifier;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JTextField;

import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import javax.swing.text.PlainDocument;

/**
 * Extend JTextField to add niceties such as uppercase,
 * length limits, and allow/deny character sets
 */
public class McVTextField extends JTextField {
    
    public static char[] mcidasDeny = 
        new char[] { '/', '.', ' ', '[', ']', '%' };
    
    public static Pattern ipAddress = 
        Pattern.compile("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}");
    
    private McVTextFieldDocument document = new McVTextFieldDocument();
    
    private Pattern validPattern;
    
    private String[] validStrings;
    
    public McVTextField() {
        this("", 0, false);
    }
    
    public McVTextField(String defaultString) {
        this(defaultString, 0, false);
    }
    
    public McVTextField(String defaultString, int limit) {
        this(defaultString, limit, false);
    }
    
    public McVTextField(String defaultString, boolean upper) {
        this(defaultString, 0, upper);
    }
    
    // All other constructors call this one
    public McVTextField(String defaultString, int limit, boolean upper) {
        super(limit);
        this.document = new McVTextFieldDocument(limit, upper);
        super.setDocument(document);
        this.setText(defaultString);
    }
    
    public McVTextField(String defaultString, int limit, boolean upper, 
                        String allow, String deny) 
    {
        this(defaultString, limit, upper);
        setAllow(makePattern(allow));
        setDeny(makePattern(deny));
    }
    
    public McVTextField(String defaultString, int limit, boolean upper, 
                        char[] allow, char[] deny) 
    {
        this(defaultString, limit, upper);
        setAllow(makePattern(allow));
        setDeny(makePattern(deny));
    }
    
    public McVTextField(String defaultString, int limit, boolean upper, 
                        Pattern allow, Pattern deny) 
    {
        this(defaultString, limit, upper);
        setAllow(allow);
        setDeny(deny);
    }
    
    public int getLimit() {
        return this.document.getLimit();
    }
    
    public void setLimit(int limit) {
        this.document.setLimit(limit);
        super.setDocument(document);
    }
    
    public boolean getUppercase() {
        return this.document.getUppercase();
    }
    
    public void setUppercase(boolean uppercase) {
        this.document.setUppercase(uppercase);
        super.setDocument(document);
    }
    
    /** @see #setAllow(Pattern, boolean) */
    public void setAllow(char... characters) {
        setAllow(makePattern(characters), false);
    }
    
    /** @see #setAllow(Pattern, boolean) */
    public void setAllow(String string) {
        setAllow(makePattern(string), false);
    }
    
    /** @see #setAllow(Pattern, boolean) */
    public void setAllow(Pattern newPattern) {
        setAllow(newPattern, false);
    }
    
    /** @see #setAllow(Pattern, boolean) */
    public void setAllow(String string, boolean useComplete) {
        setAllow(makePattern(string), useComplete);
    }
    
    /** @see #setAllow(Pattern, boolean) */
    public void setAllow(char[] characters, boolean useComplete) {
        setAllow(makePattern(characters), useComplete);
    }
    
    /** @see #setDeny(Pattern, boolean) */
    public void setDeny(char... characters) {
        setDeny(characters, false);
    }
    
    /** @see #setDeny(Pattern, boolean) */
    public void setDeny(String string) {
        setDeny(makePattern(string), false);
    }
    
    /** @see #setDeny(Pattern, boolean) */
    public void setDeny(Pattern newPattern) {
        setDeny(newPattern, false);
    }
    
    /** @see #setDeny(Pattern, boolean) */
    public void setDeny(String string, boolean useComplete) {
        setDeny(makePattern(string), useComplete);
    }
    
    /** @see #setDeny(Pattern, boolean) */
    public void setDeny(char[] characters, boolean useComplete) {
        setDeny(makePattern(characters), useComplete);
    }
    
    /**
     * Change the regular expression used to match allowed strings.
     * 
     * <p>Note: if set to {@code true}, {@code useComplete} parameter will allow
     * you to match {@code newPattern} against the complete text of this text 
     * field, including the tentative updates. If set to {@code false}, 
     * {@code newPattern} will be used against the <i>only</i> the updated 
     * characters.</p>
     * 
     * @param newPattern New regular expression. Cannot be {@code null}.
     * @param useComplete Whether or not the complete contents of the text field
     *                    should be used.
     */
    public void setAllow(Pattern newPattern, boolean useComplete) {
        this.document.setAllow(newPattern);
        this.document.setUseComplete(useComplete);
        super.setDocument(document);
    }
    
    /**
     * Change the regular expression used to match denied strings.
     *
     * <p>Note: if set to {@code true}, {@code useComplete} parameter will allow
     * you to match {@code newPattern} against the complete text of this text 
     * field, including the tentative updates. If set to {@code false}, 
     * {@code newPattern} will be used against the <i>only</i> the updated 
     * characters.</p>
     *
     * @param newPattern New regular expression. Cannot be {@code null}.
     * @param useComplete Whether or not the complete contents of the text field
     *                    should be used.
     */
    public void setDeny(Pattern newPattern, boolean useComplete) {
        this.document.setDeny(newPattern);
        this.document.setUseComplete(useComplete);
        super.setDocument(document);
    }
    
    // Take a string and turn it into a pattern
    private Pattern makePattern(String string) {
        if (string == null) {
            return null;
        }
        try {
            return Pattern.compile(string);
        } catch (PatternSyntaxException e) {
            return null;
        }
    }
    
    // Take a character array and turn it into a [abc] class pattern
    private Pattern makePattern(char... characters) {
        if (characters == null) {
            return null;
        }
        StringBuilder string = new StringBuilder(".*");
        if (characters.length > 0) {
            string = new StringBuilder("[");
            for (char c : characters) {
                if (c == '[') {
                    string.append("\\[");
                } else if (c == ']') {
                    string.append("\\]");
                } else if (c == '\\') {
                    string.append("\\\\");
                } else {
                    string.append(c);
                }
            }
            string.append("]");
        }
        try {
            return Pattern.compile(string.toString());
        } catch (PatternSyntaxException e) {
            return null;
        }
    }
    
    // Add an InputVerifier if we want to validate a particular pattern
    public void setValidPattern(String string) {
        if (string == null) {
            return;
        }
        try {
            Pattern newPattern = Pattern.compile(string);
            setValidPattern(newPattern);
        } catch (PatternSyntaxException e) {
        }
    }
    
    // Add an InputVerifier if we want to validate a particular pattern
    public void setValidPattern(Pattern pattern) {
        if (pattern == null) {
            this.validPattern = null;
            if (this.validStrings == null) {
                removeInputVerifier();
            }
        } else {
            this.validPattern = pattern;
            addInputVerifier();
        }
    }
    
    // Add an InputVerifier if we want to validate a particular set of strings
    public void setValidStrings(String... strings) {
        if (strings == null) {
            this.validStrings = null;
            if (this.validPattern == null) {
                removeInputVerifier();
            }
        } else {
            this.validStrings = strings;
            addInputVerifier();
        }
    }
    
    private void addInputVerifier() {
        this.setInputVerifier(new InputVerifier() {
            @Override public boolean verify(JComponent comp) {
                return verifyInput();
            }
            
            @Override public boolean shouldYieldFocus(JComponent comp) {
                boolean valid = verify(comp);
                if (!valid) {
                    getToolkit().beep();
                }
                return valid;
            }
        });
        verifyInput();
    }
    
    private void removeInputVerifier() {
        this.setInputVerifier(null);
    }
    
    private boolean verifyInput() {
        boolean isValid = false;
        String checkValue = this.getText();
        if (checkValue.isEmpty()) return true;
        
        if (this.validStrings != null) {
            for (String string : validStrings) {
                if (checkValue.equals(string)) {
                    isValid = true;
                }
            }
        }
        
        if (this.validPattern != null) {
            Matcher validMatch = this.validPattern.matcher(checkValue);
            isValid = isValid || validMatch.matches();
        }
        
        if (!isValid) {
            this.selectAll();
        }
        
        return isValid;
    }
    
    /**
     * Extend PlainDocument to get the character validation features we require
     */
    private class McVTextFieldDocument extends PlainDocument {
        private int limit;
        private boolean toUppercase = false;
        private boolean hasPatterns = false;
        private boolean useComplete = false;
        private Pattern allow = Pattern.compile(".*");
        private Pattern deny = null;
        
        public McVTextFieldDocument() {
            super();
        }
        
        public McVTextFieldDocument(int limit, boolean upper) {
            super();
            setLimit(limit);
            setUppercase(upper);
        }
    
        /**
         * Apply the given {@code update} to the {@code offset} within the 
         * {@code original} string.
         * 
         * @param original Text field contents before update.
         * @param offset Offset within {@code original}.
         * @param update Update to apply.
         * 
         * @return String that represents text field contents after a 
         * {@link JTextField} change.
         */
        private String makeComplete(String original, int offset, String update) 
        {
            StringBuilder sb = 
                new StringBuilder(original.length() + update.length());
            // TODO(jon): probably a smarter way to do this...
            if (offset >= original.length()) {
                sb.append(original).append(update);
            } else {
                for (int i = 0; i < original.length(); i++) {
                    if (i == offset) {
                        sb.append(update);
                    }
                    sb.append(original.charAt(i));
                }
            }
            return sb.toString();
        }
        
        public void insertString(int offset, String str, AttributeSet attr) 
            throws BadLocationException 
        {
            if (str == null) {
                return;
            }
            if (toUppercase) {
                str = str.toUpperCase();
            }
    
            String update = str;
            if (useComplete) {
                str = makeComplete(getText(0, getLength()), offset, str);
            }
            
            // Only allow certain patterns, and only check if we think we 
            // have patterns
            if (hasPatterns) {
                char[] characters = str.toCharArray();
                StringBuilder okString = new StringBuilder(characters.length);
                for (char c : characters) {
                    String s = String.valueOf(c);
                    if (deny != null) {
                        Matcher denyMatch = deny.matcher(s);
                        if (denyMatch.matches()) {
                            continue;
                        }
                    }
                    if (allow != null) {
                        Matcher allowMatch = allow.matcher(s);
                        if (allowMatch.matches()) {
                            okString.append(s);
                        }
                    }
                }
                str = okString.toString();
            }
            
            if (useComplete) {
                str = update;
            }
            
            if (str.isEmpty()) {
                return;
            }
            
            if ((getLength() + str.length()) <= limit || limit <= 0) {
                super.insertString(offset, str, attr);
            }
        }
        
        public int getLimit() {
            return this.limit;
        }
        
        public void setLimit(int limit) {
            this.limit = limit;
        }
        
        public boolean getUppercase() {
            return this.toUppercase;
        }
        
        public void setUppercase(boolean uppercase) {
            this.toUppercase = uppercase;
        }
        
        public void setAllow(Pattern newPattern) {
            if (newPattern == null) {
                return;
            }
            this.allow = newPattern;
            hasPatterns = true;
        }
        
        public void setDeny(Pattern newPattern) {
            if (newPattern == null) {
                return;
            }
            this.deny = newPattern;
            hasPatterns = true;
        }
        
        public void setUseComplete(boolean useComplete) {
            this.useComplete = useComplete;
        }
    }
    
    public static class Prompt extends JLabel implements FocusListener, 
                                                         DocumentListener 
    {
        
        public enum FocusBehavior { ALWAYS, FOCUS_GAINED, FOCUS_LOST }
        
        private final JTextComponent component;
        
        private final Document document;
        
        private FocusBehavior focus;
        
        private boolean showPromptOnce;
        
        private int focusLost;
        
        public Prompt(final JTextComponent component, final String text) {
            this(component, FocusBehavior.FOCUS_LOST, text);
        }
        
        public Prompt(final JTextComponent component, 
                      final FocusBehavior focusBehavior, final String text) 
        {
            this.component = component;
            setFocusBehavior(focusBehavior);
            
            document = component.getDocument();
            
            setText(text);
            setFont(component.getFont());
            setForeground(component.getForeground());
            setHorizontalAlignment(JLabel.LEADING);
            setEnabled(false);
            
            component.addFocusListener(this);
            document.addDocumentListener(this);
            
            component.setLayout(new BorderLayout());
            component.add(this);
            checkForPrompt();
        }
        
        public FocusBehavior getFocusBehavior() {
            return focus;
        }
        
        public void setFocusBehavior(final FocusBehavior focus) {
            this.focus = focus;
        }
        
        public boolean getShowPromptOnce() {
            return showPromptOnce;
        }
        
        public void setShowPromptOnce(final boolean showPromptOnce) {
            this.showPromptOnce = showPromptOnce;
        }
        
        /**
         * Check whether the prompt should be visible or not. The visibility
         * will change on updates to the Document and on focus changes.
         */
        private void checkForPrompt() {
            // text has been entered, remove the prompt
            if (document.getLength() > 0) {
                setVisible(false);
                return;
            }
            
            // prompt has already been shown once, remove it
            if (showPromptOnce && focusLost > 0) {
                setVisible(false);
                return;
            }
            
            // check the behavior property and component focus to determine if the
            // prompt should be displayed.
            if (component.hasFocus()) {
                if ((focus == FocusBehavior.ALWAYS) || 
                    (focus == FocusBehavior.FOCUS_GAINED)) 
                {
                    setVisible(true);
                } else {
                    setVisible(false);
                }
            } else {
                if ((focus == FocusBehavior.ALWAYS) || 
                    (focus == FocusBehavior.FOCUS_LOST)) 
                {
                    setVisible(true);
                } else {
                    setVisible(false);
                }
            }
        }
        
        // from FocusListener
        @Override public void focusGained(FocusEvent e) {
            checkForPrompt();
        }
    
        @Override public void focusLost(FocusEvent e) {
            focusLost++;
            checkForPrompt();
        }
        
        // from DocumentListener
        @Override public void insertUpdate(DocumentEvent e) {
            checkForPrompt();
        }
    
        @Override public void removeUpdate(DocumentEvent e) {
            checkForPrompt();
        }
    
        @Override public void changedUpdate(DocumentEvent e) {}
    }
}