package app;

// Java imports
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;

// Project imports
import util.*;
import vue.*;

// CPU window
class CPU extends ChildWindow {

    // Instance fields
    private int     expandWidth;  // Width of expand buttons
    private Font    font;         // Display font
    private int     fontHeight;   // Font line height
    private int     fontWidth;    // Font maximum character width
    private boolean shown;        // Window has been shown
    private int     systemHeight; // Initial height of system register list

    // UI components
    private JPanel dasm;    // Disassembler
    private JPanel system;  // System registers
    private JPanel program; // Program registers
    private ArrayList<Register> registers; // Register controls



    ///////////////////////////////////////////////////////////////////////////
    //                             Constructors                              //
    ///////////////////////////////////////////////////////////////////////////

    // Default constructor
    CPU(MainWindow parent) {
        super(parent, "cpu.title");
        var client = getContentPane();

        // Configure instance fields
        font = new Font(Util.fontFamily(new String[]
            { "Consolas", Font.MONOSPACED } ), Font.PLAIN, 14);
        registers = new ArrayList<Register>();

        dasm = new JPanel(null);
        dasm.setBackground(SystemColor.window);
        dasm.setFocusable(true);

        var inner = initRegisters();
        var outer = Util.splitPane(JSplitPane.HORIZONTAL_SPLIT);
        outer.setLeftComponent(new JScrollPane(dasm,
            JScrollPane.VERTICAL_SCROLLBAR_NEVER,
            JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));
        outer.setRightComponent(inner);
        outer.setResizeWeight(1);

        client.add(outer);
        client.setPreferredSize(new Dimension(480, 300));
        setFont2(font);
        pack();
    }



    ///////////////////////////////////////////////////////////////////////////
    //                         Register Constructors                         //
    ///////////////////////////////////////////////////////////////////////////

    // Initialize program register list
    private void initProgram() {
        Dimension target = null;

        // Program register container
        var lst = program = new JPanel(new GridBagLayout()) {
            public Dimension getPreferredSize() {
                var ret = super.getPreferredSize();
                if (!shown)
                    ret.height = 0;
                return ret;
            }
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                if (shown)
                    return;
                shown = true;
                system.revalidate();
                program.revalidate();
            }
        };
        lst.setBackground(SystemColor.window);
        lst.setFocusable(true);
        lst.addMouseListener(Util.onMouse(e->lst.requestFocus(),null));

        // Produce the list of program registers
        for (int x = 0; x < 32; x++) {
            String name = "r" + x;
            switch (x) {
                case VUE.GP: name = "gp"; break;
                case VUE.HP: name = "hp"; break;
                case VUE.LP: name = "lp"; break;
                case VUE.SP: name = "sp"; break;
                case VUE.TP: name = "tp"; break;
            }
            registers.add(new Register(
                parent, lst, name, x, Register.PROGRAM));
        }
        endList(lst);
    }

    // Initialize register lists
    private JSplitPane initRegisters() {
        initSystem();
        initProgram();

        var ret = Util.splitPane(JSplitPane.VERTICAL_SPLIT);
        ret.setTopComponent(new JScrollPane(system,
            JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
            JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED
        ));
        ret.setBottomComponent(new JScrollPane(program,
            JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
            JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED
        ));
        return ret;
    }

    // Initialize system register list
    private void initSystem() {

        // System register container
        var lst = system = new JPanel(new GridBagLayout()) {
            public Dimension getPreferredSize() {
                var ret = super.getPreferredSize();
                if (!shown)
                    ret.height = systemHeight;
                return ret;
            }
        };
        system.setBackground(SystemColor.window);
        system.setFocusable(true);
        system.addMouseListener(Util.onMouse(e->system.requestFocus(), null));
        system.putClientProperty("shown", true);

        // Add the first two system registers and expand PSW
        int plain = Register.PLAIN;
        registers.add(new Register(parent, lst, "PC"   , VUE.PC   , plain   ));
        Register psw =new Register(parent, lst, "PSW"  , VUE.PSW  , VUE.PSW );
        psw.setExpanded(true);
        registers.add(psw);
        shown = true;
        systemHeight = system.getPreferredSize().height + 6;
        shown = false;

        // Add the remaining system registers
        registers.add(new Register(parent, lst, "EIPC" , VUE.EIPC , plain   ));
        registers.add(new Register(parent, lst, "EIPSW", VUE.EIPSW, VUE.PSW ));
        registers.add(new Register(parent, lst, "FEPC" , VUE.FEPC , plain   ));
        registers.add(new Register(parent, lst, "FEPSW", VUE.FEPSW, VUE.PSW ));
        registers.add(new Register(parent, lst, "ECR"  , VUE.ECR  , VUE.ECR ));
        registers.add(new Register(parent, lst, "ADTRE", VUE.ADTRE, plain   ));
        registers.add(new Register(parent, lst, "CHCW" , VUE.CHCW , VUE.CHCW));
        registers.add(new Register(parent, lst, "PIR"  , VUE.PIR  , VUE.PIR ));
        registers.add(new Register(parent, lst, "TKCW" , VUE.TKCW , VUE.TKCW));
        registers.add(new Register(parent, lst, "29"   ,        29, plain   ));
        registers.add(new Register(parent, lst, "30"   ,        30, plain   ));
        registers.add(new Register(parent, lst, "31"   ,        31, plain   ));
        endList(lst);
    }



    ///////////////////////////////////////////////////////////////////////////
    //                            Event Handlers                             //
    ///////////////////////////////////////////////////////////////////////////

    // Client resize
    private void onResize() {
        //refreshDasm();
    }



    ///////////////////////////////////////////////////////////////////////////
    //                            Package Methods                            //
    ///////////////////////////////////////////////////////////////////////////

    // Update the display
    void refresh() {

        // The element is not ready
        if (registers == null)
            return;

        // Refresh registers
        for (var reg : registers)
            reg.refresh();
    }

    // Specify a new font
    void setFont2(Font font) {
        this.font = font;

        // Configure the maximum font dimensions
        var fontMax = new JLabel("!");
        fontMax.setFont(font);
        fontHeight = Math.max(1, fontMax.getPreferredSize().height);
        fontWidth  = -1;
        for (int x = 0; x < 16; x++) {
            fontMax.setText(Integer.toString(x, 16).toUpperCase());
            fontWidth = Math.max(fontWidth, fontMax.getPreferredSize().width);
        }

        // Configure register list scrolling
        for (int x = 0; x < 2; x++) {
            Component ctrl = x == 0 ? system : program;
            while (!(ctrl instanceof JScrollPane))
                ctrl = ctrl.getParent();
            ((JScrollPane) ctrl).getVerticalScrollBar()
                .setUnitIncrement(fontHeight);
        }

        // Determine the width of the register expand buttons
        var expand = new JLabel("+");
        int width = expand.getPreferredSize().width;
        expand.setText("-");
        width = Math.max(width, expand.getPreferredSize().width) + 4;

        // Configure registers
        for (var reg : registers) {
            reg.setExpandWidth(width);
            reg.setFont(font, fontWidth, fontHeight);
        }

        onResize();
    }



    ///////////////////////////////////////////////////////////////////////////
    //                            Private Methods                            //
    ///////////////////////////////////////////////////////////////////////////

    // Terminate a register list
    private JPanel endList(JPanel list) {
        var spacer = new JPanel(null);
        spacer.setOpaque(false);
        spacer.setPreferredSize(new Dimension(1, 1));
        var gbc = new GridBagConstraints();
        gbc.gridheight = GridBagConstraints.REMAINDER;
        gbc.gridwidth  = GridBagConstraints.REMAINDER;
        gbc.weighty    = 1;
        list.add(spacer, gbc);
        return spacer;
    }

}