/* Objective: Since Windows 10 File Explorer search seems messed-up on my laptop 
(and computers of at least some others reporting online) since late 2019,
try to make something for finding files/folders on my laptop while waiting for a fix!
First just look at file/folder names (might include option to match text within files later)

v5_i1 (version 5, iteration/intermediate 1) 19Jan2020:
Made the search case-insensitive, as this is generally more useful to me.
(However might add a choice between case sensitive and insensitive in the future.)


Items that might be added/addressed later:
--Possible to allow a search to be aborted (while displaying items found up to that point) without closing the
program window (& have the button text toggle to a message indicating this option)? Maybe investigate use of SwingWorker

 */

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.Insets;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.Stream;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

class FindFileOrFolder_v5_i1
{
    String missingStartMessage = "";
    String missingTargetMessage = "";

    int walkDepth = 1; // --specifies how many subdirectory levels to go down when collecting files to access
                       //   initialized to default 1 (do not look in subdirectories)
        
    // GUI components...
        
    JLabel startFolderJLabel = new JLabel("  Enter the path of the folder from within which you want to (start your) search..."); 
    JTextArea startFolderTextArea = new JTextArea(2, 60); // input to specify foolder within which to (start) searching
    JPanel panelForStartComponents = new JPanel(new BorderLayout()); // to hold the above pair of components
  
    JButton depthButton = new JButton("Search in subfolders of the starting folder also"); 

    JLabel targetNameJLabel = new JLabel("  Enter the name or partial name of a file or folder you want to find..."); 
    JTextArea targetNameTextArea = new JTextArea(2, 60); // input to specify file/folder names for which to search       
    JPanel panelForTargetComponents = new JPanel(new BorderLayout()); // to hold the above pair of components    
    
    JPanel panelForInputs = new JPanel(new BorderLayout()); // to hold panelForStartComponents, depthButton, panelForTargetComponents
    
    
    JButton findButton = new JButton("Find files/folders"); 
    JTextArea displayTextArea = new JTextArea(40, 100); // displays output, i.e. paths for files/folders found    
    JPanel panelForFindButtonAndOutput = new JPanel(new BorderLayout()); // to hold the above pair of components
    
    
    JFrame frame = new JFrame("FindFileOrFolder"); // to hold all above (sub)panels
    
    
    FindFileOrFolder_v5_i1() // constructor, called when main method runs
    {   
        panelForStartComponents.add(startFolderJLabel, BorderLayout.NORTH);      
        startFolderTextArea.setLineWrap(true); 
        startFolderTextArea.setMargin(new Insets(5, 5, 5, 5));            
        panelForStartComponents.add(new JScrollPane(startFolderTextArea), BorderLayout.SOUTH);      
        panelForInputs.add(panelForStartComponents, BorderLayout.NORTH);      

        panelForTargetComponents.add(targetNameJLabel, BorderLayout.NORTH);  
        targetNameTextArea.setLineWrap(true); 
        targetNameTextArea.setMargin(new Insets(5, 5, 5, 5));            
        panelForTargetComponents.add(new JScrollPane(targetNameTextArea), BorderLayout.SOUTH);      
        panelForInputs.add(panelForTargetComponents, BorderLayout.SOUTH);          
        
        findButton.addActionListener(actionEvent ->
            { // (the 'actionPerformed' method body of the implicit ActionListner...)
                String startText = startFolderTextArea.getText().trim();

                Path startPath = null; // path to folder within which to (start) searching
                boolean startPathValid = true;
                try 
                {   
                    startPath = Paths.get(startText); // ...for some start inputs on this call
                } 
                catch (Exception e) // to handle possible InvalidPathException
                {
                    startPathValid = false;
                }
                Path validatedStartPath = startPath; // (need an effectively final variable for use later in a lambda)
                
                if (startPathValid) // even if real path input, want to check that it a folder (cf a file), so reassign to...
                {
                    startPathValid = Files.isDirectory(startPath); // (as empty string arg seems to generate Path regarded 
                    // as valid (root/current folder?), so for now including check re startText.isEmpty() below)
                }
                
                final String target = targetNameTextArea.getText(); // (partial) names of files/folders for which to search          

                if (startText.isEmpty() || !startPathValid)
                {
                    missingStartMessage = "No valid start path supplied" + "\n";
                }                
                
                if (target.isEmpty())
                {                
                    missingTargetMessage = "No search term supplied" + "\n";
                }

                if (!startText.isEmpty() && startPathValid && !target.isEmpty())
                { // only run process below if target text and valid start path have been supplied (avoid wasteful processing)

                    // first, clear any previous message or search results and display a message to say the search is in progress    
                    displayTextArea.setForeground(Color.GREEN); 
                    displayTextArea.setFont(new Font("SERIF", Font.BOLD, 20));                 
                    displayTextArea.setText("Search in progress...");                         
                        
                    SwingUtilities.invokeLater(() -> // (want the above progress' message to appear first if search takes a while)
                    {                        
                            displayTextArea.setForeground(Color.BLACK);
                            displayTextArea.setFont(null);// this seems to work to restore the font to default (as desired)      
                            displayTextArea.setText(null); // clear any previous text before displaying the results

                            try 
                            {  
                                Stream<Path> targetStream = Files.find(validatedStartPath, walkDepth,
                                        (p,a) -> 
                                                !isHiddenHandler(p) && // to exclude hidden (temporary etc) files
                                                        
                                                        
                                                        
                                                // v5_i1 alteration
//                                                toStringHandled(p.getFileName().contains(target));
                                                toStringHandled(p.getFileName()).toLowerCase().contains(target.toLowerCase()));
                                                // (toLowerCase() call makes it case-insensitive; could remove again, or make optional
                                
                                
                                

                                targetStream.forEach(p -> displayTextArea.append(toStringHandled(p) + "\n")); // print paths found in output/display area   
                                
                                if (displayTextArea.getText().equals(""))
                                {
                                    displayTextArea.setForeground(Color.BLUE);
                                    displayTextArea.setText("No results found");
                                } // (seems inelegant, but have not thought of a way to do directly from the stream code yet)
                            }
                            catch (IOException ex)
                            {
                                if (ex.getClass().getName().equals("java.nio.file.NoSuchFileException"))          
                                {
                                    missingInputsMessage();
                                } // (probably not needed now, though, as should not get to try clause without valid start path)      
                            } 
                        }
                    );
                }
                else
                {
                    missingInputsMessage();
                } 
            } 
        );         
        findButton.setMargin(new Insets(10, 10, 10, 10));
        findButton.setFont(new Font("SansSerif", Font.BOLD, 20));         
        panelForFindButtonAndOutput.add(findButton, BorderLayout.NORTH);         
        
        depthButton.addActionListener(actionEvent ->
            {                      
                if (walkDepth == 1)
                {
                    walkDepth = Integer.MAX_VALUE;
                    depthButton.setText("Search in the starting folder only");
                }                           
                else // (walkDepth is Integer.MAX_VALUE)
                {
                    walkDepth = 1;
                    depthButton.setText("Search in subfolders of the starting folder also");
                }
            } 
        ); // toggles walk dept between no-subfolders and all-subfolders
        panelForInputs.add(depthButton, BorderLayout.CENTER);   

        displayTextArea.setEditable(false);
        displayTextArea.setLineWrap(true);
        displayTextArea.setWrapStyleWord(true);
        displayTextArea.setMargin(new Insets(5, 5, 5, 5)); 
        panelForFindButtonAndOutput.add(new JScrollPane(displayTextArea), BorderLayout.SOUTH); 
        
        frame.add(panelForInputs, BorderLayout.NORTH); 
        frame.add(panelForFindButtonAndOutput, BorderLayout.SOUTH); 
        frame.setResizable(false); // (buttons disappear if user drags frame bottom up, 
        // while if it's dragged down, the extra space just appears as a gap between the panels,
        // so just hard-coding big displayTextArea for the moment;
        // looking briefly online, see descriptions/code for how to make rezizable by dragging, but not trivial
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    
        frame.pack(); // (may need to keep this positioned last)
    }
    
    void missingInputsMessage() // puts message in display area if one or both user inputs missing/incorrect
    {
        displayTextArea.setForeground(Color.red);
        displayTextArea.setText(missingStartMessage + missingTargetMessage);    
        missingStartMessage = ""; // reset for future clicks 
        missingTargetMessage = ""; // (ditto)
    }
    
    boolean isHiddenHandler (Path p) // as Files.isHidden(...) throws checked exception...
    { // ...easier to handle it externally than in stream coded in findButton's addActionListener above
        boolean result = false;
        try
        {
            result = Files.isHidden(p);
        } 
        catch (IOException ex)
        {
            System.out.println(ex);
        }
        return result;
    }

    String toStringHandled (Path p) // as Path's toString() can throw NullPointerException...
    { // ...easier to handle it externally than in stream coded in findButton's addActionListener above
        String result = "";
        try
        {
            result = p.toString(); // p is filename for start path, and is null if that is root, e.g. C:\
        } 
        catch (NullPointerException npEx) // ...in which case NullPointerException is thrown
        {
            displayTextArea.setText("Note: as you are starting from the root, "
                    + "the search may terminate early if subfolders without access permission are encountered. "
                    + "(This is a known issue, and may also affect searches starting further down the hierarchy, "
                    + "in which case you will not see feedback, unfortunately)."
                    + " May be addressed in a subsequent version of the program." + "\n\n");   
        }
        return result;
    }  

    public static void main(String[] args)
    {   
        new FindFileOrFolder_v5_i1();  
    }
}