using System;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Threading;
using System.Globalization;

using SbsSW.SwiPlCs;


namespace ChessBoard
{
    public partial class ChessBoard : System.Web.UI.Page
    {

        // It is nessesary to store thise information in the session state
        // to give a error message if two clients work on the same session
        // happens if a second client browser was created by <crtl> + n
        // or the back botton was used
        const string cs_cb_size = "cb_size";	// amount of queens (ChessBoardSize)
        const string cs_sol_count = "sol_count";		// solution count
        protected int m_solution_count = 0;
        protected string m_cb_size = "";
        
        
        protected void Page_Load(object sender, EventArgs e)
        {
            if (Session[cs_cb_size] != null)
            {
                m_cb_size = (string)Session[cs_cb_size];
            }
            if (Session[cs_sol_count] != null)
            {
                m_solution_count = (int)Session[cs_sol_count];
            }
            if (Page.IsPostBack == false)
            {
                // To show the actual solution after the language was changes ( Response.Redirect )
                ShowSolution();
            }
        }

        #region localize methods

        // tool to translate resource files see
        // ResEx
        //


        /// <summary>
        /// Gets the lamnguage abraviation ( de, en or fr )
        /// </summary>
        private string Language
        {
            get
            {
                // string lang = string.Empty;//default to the invariant culture
                string lang = "de";		//default to the German culture
                if (null != Session["PreferredCulture"] && !string.IsNullOrEmpty((string)Session["PreferredCulture"]))
                    lang = (string)Session["PreferredCulture"];

                // Wenn in cookie speichern
                //string lang = string.Empty;//default to the invariant culture
                //HttpCookie cookie = Request.Cookies["PreferredCulture"];
                //if (cookie != null && cookie.Value != null)
                //    lang = cookie.Value;
                return lang;
            }
        }

        protected override void InitializeCulture()
        {
            // override virtual method InitializeCulture() to check if profile contains a user language setting
            string lang = Language;
            Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo(lang);
            Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(lang);

        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="culture">DE oder EN oder FR</param>
        private void StoreCulture(string culture)
        {
            if (null == Session["PreferredCulture"] || (string)Session["PreferredCulture"] != culture)
            {
                //Save selected user language in profile 
                Session["PreferredCulture"] = culture;
                //Force re-initialization of the page to fire InitializeCulture()
                // redirect to take the new culture effects
                Response.Redirect(Request.Url.LocalPath);
            }
        }

        #endregion


        protected override void OnPreRender(EventArgs e)
        {
            Session[cs_cb_size] = tb_amount.Text;
            Session[cs_sol_count] = m_solution_count;
            tb_solution_count.Text = m_solution_count.ToString();
        }


        #region lib
        public static void buildImagePathWitTheme(string theme, Image img)
        {
            if (!img.ImageUrl.StartsWith("~/"))
                img.ImageUrl = "~/" + buildImagePathWitTheme(theme, img.ImageUrl);
        }

        public static string buildImagePathWitTheme(string theme, string baseUrl)
        {
            string sRet = baseUrl;
            string prefix = "App_Themes/";
            if (!baseUrl.Contains(prefix))
            {
                sRet = prefix + theme;
                if (!baseUrl.StartsWith("/"))
                    sRet += "/";
                sRet += baseUrl;
            }
            return "/" + sRet;
        }
        #endregion


        #region private helpers
        private void drawBoard()
        {
            int rowCnt;	// Current row count
            int rowCtr;	// Total number of cells per row (columns)
            int cellCtr;// Current cell counter
            int cellCnt;
            rowCnt = int.Parse(tb_amount.Text);
            cellCnt = int.Parse(tb_amount.Text);
            for (rowCtr = 1; rowCtr <= rowCnt; rowCtr++)
            {	// Create new row and add it to the table.
                TableRow tRow = new TableRow();
                tbl_board.Rows.Add(tRow);
                for (cellCtr = 1; cellCtr <= cellCnt; cellCtr++)
                {	// Create a new cell and add it to the row.
                    TableCell tCell = new TableCell();
                    tCell.Text = "Row " + rowCtr + ", Cell " + cellCtr;
                    System.Web.UI.WebControls.Image img = new System.Web.UI.WebControls.Image();
                    double test_x = Math.IEEERemainder((rowCtr - 1) * rowCnt + cellCtr, 2);
                    int gerade = (int)Math.IEEERemainder(rowCnt + 1, 2); // 1 | 0
                    if ((int)Math.IEEERemainder((rowCtr + 1) * (rowCnt + gerade) + cellCtr, 2) != 0)
                    {
                        img.ImageUrl = "Images/White_Square.gif";
                    }
                    else
                    {
                        img.ImageUrl = "Images/Black_Square.gif";
                    }
                    buildImagePathWitTheme(Page.Theme, img);
                    tCell.Controls.Add(img);
                    tRow.Cells.Add(tCell);
                }
            }
        }

        private void SetQueen(int row, int col)
        {
            TableRow TR = tbl_board.Rows[row - 1];
            TableCell TC = TR.Cells[col - 1];
            System.Web.UI.WebControls.Image img = (System.Web.UI.WebControls.Image)TC.Controls[0];
            if (img.ImageUrl.EndsWith("Images/White_Square.gif"))
                img.ImageUrl = "Images/White_Queen_White.gif";
            else
                img.ImageUrl = "Images/White_Queen_Black.gif";
            buildImagePathWitTheme(Page.Theme, img);
        }

        private void GetFirstQueenSolution(int AmountOfQueens)
        {
            if (Session["SolutionQuery"] != null)
            {
                ((PlQuery)Session["SolutionQuery"]).Free(true);
            }
            PlTermV av = new PlTermV(2);
            av[0] = new PlTerm(AmountOfQueens);
            PlQuery q = new PlQuery("queens", av);
            // Global.log("    FirstQueenSolution with qid = " + q.dump_qid);
            bool x = q.NextSolution();
            Session["solution"] = q.Args[1].ToString();
            Session["SolutionQuery"] = q;
        }

        private void GetNextQueenSolution()
        {
            if (Session["SolutionQuery"] == null)
            {
                err_msg.Text = Resources.Text.err_text_1;
                return;
            }
            PlQuery q = (PlQuery)Session["SolutionQuery"];
//            Global.log("    NextQueenSolution with qid = " + q.dump_qid);
            if (q.NextSolution())
            {
                Session["solution"] = q.Args[1].ToString();
            }
            else
            {
                err_msg.Text = Resources.Text.err_text_2;
            }
        }




        private void ShowSolution()
        {
            if (Session["solution"] != null)
            {
                drawBoard();

                string strsol = (string)Session["solution"];
                strsol = strsol.TrimStart('[');
                strsol = strsol.TrimEnd(']');
                string[] positions = strsol.Split(',');
                foreach (string SinglePos in positions)
                {
                    string[] pos = SinglePos.ToString().Split('-');
                    SetQueen(Int32.Parse(pos[0]), Int32.Parse(pos[1]));
                }
            }
        }

        #endregion

        /////////////
        // events
        protected void OnClickNextSolution(object sender, System.EventArgs e)
        {
            if (m_solution_count != Int32.Parse(tb_solution_count.Text))
            {
                err_msg.Text = Resources.Text.err_text_same_session + "<br>";
                if (m_cb_size != tb_amount.Text)
                {
                    err_msg.Text += Resources.Text.err_text_crtl_n;
                }
                else
                {
                    err_msg.Text += Resources.Text.err_text_back_btn;
                }
            }
            else
            {
                GetNextQueenSolution();
                ShowSolution();
                m_solution_count++;
            }
        }

        protected void OnClickStart(object sender, System.EventArgs e)
        {
            if (Page.IsValid)
            {
                GetFirstQueenSolution(Int32.Parse(tb_amount.Text));
                ShowSolution();
                m_solution_count = 1;
            }
        }

        protected void OnSelectedLanguageChanged(object sender, EventArgs e)
        {
            if (MyUICulture.SelectedIndex > 0)
            {	// If another culture was selected, use that instead.
                StoreCulture(MyUICulture.SelectedItem.Value);
            }
        }


    }
}