using System;
using System.Windows.Forms;
using Office = Microsoft.Office.Core;
using Excel = Microsoft.Office.Interop.Excel;
using MSForms = Microsoft.Vbe.Interop.Forms;


public class OfficeCodeBehind
{
    private Excel.Worksheet thisWorksheet = null;
    private MSForms.CommandButton btnReset;
    private MSForms.CommandButton btnCheck;
    private MSForms.CommandButton btnApply;
    private MSForms.CommandButton btnSolve;
    private MSForms.TextBox txtMessage;
    private Excel.Range __theGrid;
    private Sudoku __sudoku;


    protected void ThisWorkbook_Open()
    {
        thisWorksheet = (Excel.Worksheet) ThisWorkbook.Sheets[ 1 ];

        this.btnReset = (MSForms.CommandButton)this.FindControl( "btnReset" );

        this.btnCheck = (MSForms.CommandButton)this.FindControl( "btnCheck" );

        this.btnApply = (MSForms.CommandButton)this.FindControl( "btnApply" );

        this.btnSolve = (MSForms.CommandButton)this.FindControl( "btnSolve" );

        this.txtMessage = (MSForms.TextBox) this.FindControl( "txtMessage" );

        if (this.btnReset != null )
        {
            this.btnReset.Click += 
            new MSForms.CommandButtonEvents_ClickEventHandler(btnReset_Click);
        }

        if (this.btnApply != null )
        {
            this.btnApply.Click += 
            new MSForms.CommandButtonEvents_ClickEventHandler(btnApply_Click);
        }

        if (this.btnSolve != null )
        {
            this.btnSolve.Click += 
            new MSForms.CommandButtonEvents_ClickEventHandler(btnSolve_Click);
        }

        if (this.btnCheck != null )
        {
            this.btnCheck.Click += 
            new MSForms.CommandButtonEvents_ClickEventHandler(btnCheck_Click);
        }

        txtMessage.Text = string.Empty;

        this.__theGrid = thisWorksheet.get_Range( "theGrid", Type.Missing );

        this.__sudoku = new Sudoku9();

        //the Grid may contain values from a previous session
        //so put any such values into the Sudoku array
        MapGridToSudokuArray();

        FormatGrid();
    }

    private void MapGridToSudokuArray()
    {
        for (int i = 1; i < 10; i++)
        {
            for (int j = 1; j < 10; j++)
            {
                Excel.Range currentCell = (Excel.Range) __theGrid.Cells[ i, j ];

                if ( currentCell.Value2 != null )
                {
                    __sudoku[ i-1, j-1 ] = Convert.ToChar( currentCell.Value2 );
                }
            }
        }
    }

    private void MapSudokuArrayToGrid()
    {
        for (int i = 0; i < 9; i++)
        {
            for (int j = 0; j < 9; j++)
            {
                char c = __sudoku[ i, j];

                Excel.Range cell = (Excel.Range) __theGrid.Cells[ i+1, j+1 ];

                if ( c != Sudoku.NULL_CHAR )
                {
                    cell.Value2 = c.ToString();
                }
                else
                {
                    cell.Value2 = string.Empty;
                }
            }
        }
    }

    private void FormatGrid()
    {
        for (int i = 0; i < 9; i++)
        {
            for (int j = 0; j < 9; j++)
            {
                char c = __sudoku[ i, j];

                Excel.Range cell = (Excel.Range) __theGrid.Cells[ i+1, j+1 ];

                if ( c != Sudoku.NULL_CHAR )
                {
                    cell.Font.ColorIndex = ExcelColorIndex.Black;
                }
                else
                {
                    cell.Font.ColorIndex = ExcelColorIndex.Blue;
                }
            }
        }
    }

    //Only checks for no duplicates at the minute.
    //TODO: Add a clone method to the Sudoku class - 
    //then you can clone the grid, solve it and compare
    //clone and original.
    private void btnCheck_Click()
    {
        for (int i = 1; i < 10; i++)
        {
            for (int j = 1; j < 10; j++)
            {
                Excel.Range currentCell = (Excel.Range) __theGrid.Cells[ i, j ];

                if ( currentCell.Value2 != null 
                && __sudoku[i-1,j-1] == Sudoku.NULL_CHAR
                && !(__sudoku.IsValidInCell( 
                Convert.ToChar( currentCell.Value2 ), i-1, j-1 )) )
                {
                    currentCell.Font.ColorIndex = ExcelColorIndex.Red;

                    this.txtMessage.Text += 
                    String.Format( "Cell {0},{1} is inconsistent.\n", i,j );
                }
            }
        }
    }

    private void btnReset_Click()
    {
        this.__sudoku = new Sudoku9();

        this.txtMessage.Text = String.Empty;

        this.__theGrid.Value2 = null;

        this.__theGrid.Font.ColorIndex = ExcelColorIndex.Blue;
    }

    private void btnApply_Click()
    {
        MapGridToSudokuArray();

        FormatGrid();
    }

    private void btnSolve_Click()
    {
        this.__sudoku.Solve();

        MapSudokuArrayToGrid();
    }
}