package gui;

import sudoku.SudokuSolver;
import java.awt.event.*;

/**
 * SolverController is a controller for the SudokuSolver interface
 */
public class SudokuController {
    SudokuSolver model;
    SudokuView view;

    /**
     * Constructor
     * 
     * @param model SudokuSolver model
     * @param view  SudokuView view
     */
    public SudokuController(SudokuSolver model, SudokuView view) {
        this.model = model;
        this.view = view;

        // Add action listeners to the buttons
        view.addSolveButtonListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // Solve the board
                boolean solved = model.solve();
                if (!solved) {
                    view.showErrorMessage("Could not solve the board.");
                    System.out.println("Could not solve the board.");
                    System.out.println(model.toString());
                } else {
                    // Update the view
                    view.updateView(model.getBoard());
                }

            }
        });

        view.addResetButtonListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // Clear the board
                model.clear();

                // Update the view
                view.updateView(model.getBoard());
            }
        });

        view.addRandomButtonListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // Randomize the board
                model.randomizeBoard();

                // Update the view
                view.updateView(model.getBoard());
            }
        });

        view.addFileButtonListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // Open a file, view handles the parsing internally via SudokuParser
                int[][] newBoard = view.openFile();

                // If the file was parsed successfully
                if (newBoard != null) {
                    // Set the model
                    model.setBoard(newBoard);
                    // Update the view
                    view.updateView(model.getBoard());
                }
            }
        });

        view.addCellActionListener(new CellActionListener());
    }

    /** Start the GUI */
    public void start() {
        view.setVisible(true);
    }

    /**
     * CellActionListener is an ActionListener for the Sudoku grid cells
     */
    private class CellActionListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            // Get the row and column from the clicked cell
            int row = view.getSelectedRow();
            int col = view.getSelectedColumn();

            // The value to be inserted into the cell
            // Zero inicates an empty cell
            // Negative values are invalid
            int value = 0;

            String cellValue = view.getCellValue(row, col);

            // We need to check for null and empty string
            if (cellValue == null || cellValue.equals("")) {
                value = 0;
            } else {
                try {
                    value = Integer.parseInt(cellValue);
                } catch (NumberFormatException ex) {
                    value = -1;
                }
            }

            // If the input is invalid, value < 0 indicates parse error
            if (!model.isLegal(row, col, value) || value < 0) {
                value = 0;
                view.showErrorMessage("Invalid input. Try again.");
            }

            // Update the model and view
            model.set(row, col, value);
            view.updateView(model.getBoard());
        }
    }
}