package inventory;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import java.io.File;
import javax.swing.filechooser.FileFilter;

import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;

public class Main {

    //Initialize ArrayLists and File
    protected static File masterDBFile = new File("master.zbdb");
    protected static File masterDBFileBackup = new File("master.backup.zbdb");
    protected static File userLoadedFile = null;
    private static boolean fileExists = false;
    private static boolean forceSaveAs = false;
    private static JFileChooser forceSave = null;
    protected static boolean userAuthorized = false;
    protected static ArrayList<Users> userList = new ArrayList<Users>();
    protected static ArrayList<ArrayList<Products>> productLineList = new ArrayList<ArrayList<Products>>();
    protected static ArrayList<Components> componentList = new ArrayList<Components>();
    //JFrame
    protected static JFrame zbFrame = null;

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }
        catch (Exception ignore) { }

        //Check if master.zbdb or master.backup.zbdb exist. This to avoid dual error
        fileExists = (masterDBFile.exists() || masterDBFileBackup.exists()) ? true : false;
        //If it doesn't exist skip login and loading database
        if(!fileExists) {
            showDialog(1, "No default database exists. A new one will be created.", null);
            showSplashScreen();
            createAndShowGUI();
        }
        //If it does then load everything
        else {
            showSplashScreen();
            loadUserDatabase(null);
            //User Authorization first if user ArrayList is populated. Function loads full database and GUI if credentials are valid
            if(!userList.isEmpty()) {
                showUserLoginFrame();
                if(userAuthorized) {
                    //Load entire database and GUI. Reset userAuthorized to false for future use.
                    userAuthorized = false;
                    loadDatabase(null);
                    createAndShowGUI();
                }
            }
            else {
                loadDatabase(null);
                createAndShowGUI();
            }
        }
    }

    protected static void createAndShowGUI() {
        //Tabs
        InventoryTabs zbTabs = new InventoryTabs();
        //GUI
        zbFrame = new JFrame("ZeroBull Inventory v0.2 BUILD_0200_ALPHA");
        zbFrame.getContentPane().add(zbTabs.topPanel);
        zbFrame.setPreferredSize(new Dimension(800,600));
        zbFrame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
        zbFrame.setResizable(false);
        zbFrame.setJMenuBar(new InventoryMenubar().menuBar);
        zbFrame.add(zbTabs, BorderLayout.EAST);
        zbFrame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                int closeOperation = saveBeforeExit();
                if(closeOperation == 0)
                    System.exit(0);
                else
                    zbFrame.setVisible(true);
            }
        });
        zbFrame.pack();
        zbFrame.setLocationRelativeTo(null);
        zbFrame.setVisible(true);
    }

    private static void showSplashScreen() {
        new SplashScreen();
    }

    protected static void disposeMainFrame() {
        zbFrame.dispose();
    }

    //This should ONLY be called after calling disposeMainFrame()
    protected static void reloadGUI() {
        createAndShowGUI();
    }

    public static void showUserLoginFrame() {
        final JFrame authFrame = new JFrame("Login");
        authFrame.setPreferredSize(new Dimension(200,150));
        authFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        authFrame.setResizable(false);
        JPanel authPanel = new JPanel();
        authPanel.setLayout(new BorderLayout());

            authPanel.setBorder(BorderFactory.createTitledBorder("Enter Credentials"));
            JPanel leftColumn = new JPanel(new GridLayout(0,1,0,25));
            JPanel rightColumn = new JPanel(new GridLayout(0,1,0,25));
            JPanel bottomPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));

                JLabel userLabel = new JLabel("Username: ");
                JLabel passLabel = new JLabel("Password: ");
                final JTextField userField = new JTextField(15);
                userField.setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY));
                final JPasswordField passField = new JPasswordField(15);
                passField.setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY));

                JButton loginButton = new JButton("Login");
                loginButton.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent ev) {
                        String userName = userField.getText();
                        char[] userPass = passField.getPassword();
                        boolean valid = authorizeUser(userName, userPass);
                        if(valid) {
                            showDialog(2, "Success! Welcome, " +userName, authFrame);
                            authFrame.dispose();
                            userAuthorized = true;
                            createAndShowGUI();
                        }
                        else
                            showDialog(0, "Invalid Credentialds.", authFrame);
                    }
                });
                JButton exitButton = new JButton("Exit");
                exitButton.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent ev) {
                        authFrame.dispose();
                        System.exit(0);
                    }
                });

            leftColumn.add(userLabel);
            leftColumn.add(passLabel);
            rightColumn.add(userField);
            rightColumn.add(passField);
            bottomPanel.add(loginButton);
            bottomPanel.add(exitButton);

        authPanel.add(leftColumn, BorderLayout.WEST);
        authPanel.add(rightColumn, BorderLayout.EAST);
        authPanel.add(bottomPanel, BorderLayout.SOUTH);
        authFrame.add(authPanel);
        authFrame.pack();
        authFrame.setLocationRelativeTo(null);
        authFrame.setVisible(true);
    }

    public static void createNewProductLine(String productLineName, int productLineQty, int productLineComp, int productLineIncomp) {
        ArrayList<Products> productList = new ArrayList<Products>();
        productList.ensureCapacity(productLineQty);
        for(int i=0; i<productLineComp; i++)
            productList.add(new Products(productLineName, "COMPLETE"));
        for(int i=0; i<productLineIncomp; i++)
            productList.add(new Products(productLineName, "INCOMPLETE"));
        productLineList.add(productList);
    }

    public static boolean checkExistingProductLine(String productLineName) {
        for(int i=0; i<productLineList.size(); i++) {
            if (productLineName.equalsIgnoreCase(productLineList.get(i).get(0).getProductLineName()))
                return false;
        }
        return true;
    }

    public static void addToProductLine(int index, int qtyToAdd, int qtyComplete, int qtyIncomplete) {
        ArrayList<Products> temp = new ArrayList<Products>();
        for(int i=0; i<qtyComplete; i++)
            temp.add(new Products(productLineList.get(index).get(0).getProductLineName(), "COMPLETE"));
        for(int i=0; i<qtyIncomplete; i++)
            temp.add(new Products(productLineList.get(index).get(0).getProductLineName(), "INCOMPLETE"));
        productLineList.get(index).addAll(temp);
    }

    public static void renameProductLine(int index, String newname) {

    }
    public static void deleteProductLine(int index) {
         for(int i=0; i<componentList.size(); i++) {
             if(componentList.get(i).getComponentHashMap().containsKey(index))
                 componentList.get(i).getComponentHashMap().remove(index);
         }
         productLineList.remove(index);
    }

    protected static void editSelProdRows(String status, String serial, String date, String loc, int[] selRows, int productLineIndex) {
        for(int i=0; i<selRows.length; i++) {
            if(!status.equalsIgnoreCase("(Status)"))
                productLineList.get(productLineIndex).get(selRows[i]).setProductLineStatus(status);
            if(!serial.equalsIgnoreCase(""))
                productLineList.get(productLineIndex).get(selRows[i]).setProductSerial(serial);
            if(!date.equalsIgnoreCase(""))
                productLineList.get(productLineIndex).get(selRows[i]).setProductMFGDate(date);
            if(!loc.equalsIgnoreCase(""))
                productLineList.get(productLineIndex).get(selRows[i]).setProductMFGLoc(loc);
        }
    }

    public static void createNewComponent(String componentName, int componentQty, int[] plKeys, int[] plValues, String compDesc) {
        componentList.add(new Components(componentName, componentQty, plKeys, plValues, compDesc));
    }

    public static void createNewComponent(String componentName, int componentQty, int[] plKeys, int[] plValues, int shipQty, String compDesc) {
        componentList.add(new Components(componentName, componentQty, plKeys, plValues, shipQty, compDesc));
    }

    public static boolean checkExistingComponent(String compName) {
        for (int i=0; i<componentList.size(); i++)
            if(componentList.get(i).getComponentName().equalsIgnoreCase(compName))
                return false;
        return true;
    }

    public static ArrayList<Components> checkComponentsUsed(int index) {
        ArrayList<Components> temp = new ArrayList<Components>();
        for(int i=0; i<componentList.size(); i++) {
            Iterator<Integer> iter = componentList.get(i).getComponentHashMap().keySet().iterator();
            while(iter.hasNext()) {
                int currentElem = (Integer)iter.next();
                if(currentElem == (Integer)index)
                    temp.add(componentList.get(i));
            }
        }
        return temp;
    }

    public static void createNewUser(String name, char[] pass) {
        userList.add(new Users(name, pass));
    }

    public static boolean authorizeUser(String name, char[] pass) {
        int userIndex = 0;
        boolean userExists = false;
        //First check if user exists. If it doesnt then don't bother checking the pass just return false
        for(int i=0; i<userList.size(); i++) {
            if(userList.get(i).getUserName().equalsIgnoreCase(name)) {
                userIndex = i;
                userExists = true;
                break;
            }
        }
        if(!userExists)
            return false;

        //Name has been validated. Now check password.
        byte[] bytePass = new byte[pass.length];
        byte[] salt = userList.get(userIndex).getUserSalt();
        byte[] digested = null;
        String hashCheck = "";
        for(int i=0; i<bytePass.length; i++)
            bytePass[i] = (byte) pass[i];
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("SHA");
        } catch(NoSuchAlgorithmException nsae) {    }

        md.update(salt);
        md.update(bytePass);

        digested = md.digest();
        for(int i=0; i<999; i++) {
            md.reset();
            digested = md.digest(digested);
        }
        for(int i=0; i<digested.length; i++)
            hashCheck += (Integer.toHexString((0x000000ff & digested[i]) | 0xffffff00).substring(6));
        if(userList.get(userIndex).getUserSHAHash().equals(hashCheck))
            return true;
        else
            return false;
    }

    public static boolean checkUserExists(String name) {
        for(int i=0; i<userList.size(); i++) {
            if(userList.get(i).getUserName().equalsIgnoreCase(name))
                return true;
        }
        return false;
    }

    public static void saveDatabase(File file) {
        ArrayList<Users> userListSave = userList;
        ArrayList<ArrayList<Products>> productLineListSave = productLineList;
        ArrayList<Components> componentListSave = componentList;
        ObjectOutputStream fileOut = null;
        try {
            file.createNewFile();
        } catch (IOException ioe) { }
        if(file.canWrite() == false) {
            showDialog(0, "Program does not have permission to write in current directory. Exit", zbFrame);
            return;
        }
        try {
            fileOut = new ObjectOutputStream(new FileOutputStream(file));
        } catch(IOException ioe) {  }

        try {
            fileOut.writeUTF("ZeroBull(tm) Inventory Master Database\t\t ZB_INVENTORY_BUILD_0700_ALPHA\t\t");
            fileOut.writeUTF(getCurrentDate()+"\t\t");
            fileOut.writeUTF("Begin Database\t\t");
            fileOut.writeObject(userListSave);
            fileOut.writeObject(productLineListSave);
            fileOut.writeObject(componentListSave);
            fileOut.writeUTF("\t\tEnd Database\t\t");
            fileOut.close();
        } catch(IOException ioe) {  }
    }

    @SuppressWarnings("unchecked")
    public static void loadUserDatabase(File customFile) {
        ObjectInputStream fileIn = null;
        //Try and load from main. If that fails use backup
        if(customFile != null) {
            try {
                fileIn = new ObjectInputStream(new FileInputStream(customFile));
            } catch(IOException ioe) {  }
        }

        else {
            if(masterDBFile.exists() == true) {
                try {
                    fileIn = new ObjectInputStream(new FileInputStream(masterDBFile));
                } catch(IOException ioe) {  }
            }

            else if(masterDBFileBackup.exists() == true) {
                try {
                    fileIn = new ObjectInputStream(new FileInputStream(masterDBFileBackup));
                } catch(IOException ioe) {  }
            }
        }

        try {
            fileIn.readUTF();
            fileIn.readUTF();
            fileIn.readUTF();
            userList = (ArrayList<Users>) fileIn.readObject();
            fileIn.close();
        } catch(Exception invalidDB) {
            showDialog(0, "Invalid database file!", zbFrame);
            }
    }

    @SuppressWarnings("unchecked")
    public static void loadDatabase(File customFile) {
        //Must clear user ArrayList first since it was [supposedly] already loaded.
        userList.clear();
        ObjectInputStream fileIn = null;
        //Try main database first. If file does not exist load backup. If that fails then throw error message and let user select a database.
        if(customFile != null) {
            try {
                fileIn = new ObjectInputStream(new FileInputStream(customFile));
            } catch(IOException ioe) {  }
        }
        else {
            if(masterDBFile.exists() == true) {
                try {
                    fileIn = new ObjectInputStream(new FileInputStream(masterDBFile));
                } catch(IOException ioe) {  }
            }
            else if(masterDBFileBackup.exists() == true) {
                try {
                    fileIn = new ObjectInputStream(new FileInputStream(masterDBFileBackup));
                } catch(IOException ioe) {  }
            }
        }
        try {
            fileIn.readUTF();
            fileIn.readUTF();
            fileIn.readUTF();
            userList = (ArrayList<Users>) fileIn.readObject();
            productLineList = (ArrayList<ArrayList<Products>>) fileIn.readObject();
            componentList = (ArrayList<Components>) fileIn.readObject();
            fileIn.readUTF();
            fileIn.close();
        } catch(Exception ignore) { }
    }

    protected static void flushDatabases() {
        userList.clear();
        productLineList.clear();
        componentList.clear();
    }

    public static void setForceSaveAs() {
        forceSaveAs = true;
    }

    public static int saveBeforeExit() {
        int option = JOptionPane.showConfirmDialog(null, "Save before exiting?", "Save", JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE);
        if(option == JOptionPane.YES_OPTION) {
            if(!forceSaveAs) {
                if (userLoadedFile != null)
                    saveDatabase(userLoadedFile);
                else {
                    saveDatabase(masterDBFile);
                    saveDatabase(masterDBFileBackup);
                }
                return 0;
            }
            else {
                forceSave = new JFileChooser("Save As...");
                forceSave.setFileFilter(new FileFilter() {
                    public boolean accept(File saveFile) {
                        return saveFile.getName().toLowerCase().endsWith(".zbdb") || saveFile.isDirectory();
                    }

                    public String getDescription() {
                        return "ZeroBull Database";
                    }
                });
                int saveReturn = forceSave.showSaveDialog(null);
                if(saveReturn == JFileChooser.APPROVE_OPTION) {
                    if (Main.productLineList.isEmpty() && Main.componentList.isEmpty() && Main.userList.isEmpty())
                        JOptionPane.showMessageDialog(null, "Can not save an empty database!", "Error!", JOptionPane.ERROR_MESSAGE);
                    else {
                        String savePath = forceSave.getSelectedFile().getPath() +".zbdb";
                        saveDatabase(new File(savePath));
                    }
                }
            }
        }
        else if(option == JOptionPane.NO_OPTION)
            return 0;
        else if(option == JOptionPane.CANCEL_OPTION)
            return 1;
        return 0;
    }

    public static String getCurrentDate() {
        DateFormat date = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
        Date currentDate = new Date();
        return date.format(currentDate);
    }

    private static void showDialog(int level, String message, JFrame owner) {
        switch(level) {
        case 0:
            JOptionPane.showMessageDialog(owner, message, "Error", JOptionPane.ERROR_MESSAGE); break;
        case 1:
            JOptionPane.showMessageDialog(owner, message, "Warning", JOptionPane.WARNING_MESSAGE); break;
        case 2:
            JOptionPane.showMessageDialog(owner, message, "Message", JOptionPane.INFORMATION_MESSAGE); break;
        }
    }
}

class outWriter {
    //This awesome class here allows me to write to the log file from ANYWHERE.
    private static final File logFile = new File("log.txt");
    private static BufferedWriter logOut = null;

    public static boolean initialize() {
        try {
            if(logOut == null) {
                logOut = new BufferedWriter(new FileWriter(logFile, true));
                return true;
            }
        } catch(IOException ioe) { }
        return false;
    }

    public static boolean write (String out, boolean close) {
        try {
            if(out != null && logOut != null) {
                logOut.write(out +"\r\n");
                return true;
            }
        } catch(IOException ioe) { }
        return false;
    }

    public static boolean close() {
        try {
            if(logOut != null) {
                logOut.close();
                return true;
            }
        } catch(IOException ioe) { }
        return false;
    }
}