/// <summary>
/// 服务器端生成分页。
/// </summary>
public static class MotyPaginationHelper
{
    /// <summary> 
    /// 生成分页HTML。 
    /// </summary> 
    /// <param name="helper"></param> 
    /// <param name="cur">当前页。</param> 
    /// <param name="total">总页数。</param> 
    /// <param name="option">分页选项。</param> 
    /// <returns></returns> 
    public static MvcHtmlString MotyPagination(this HtmlHelper helper, int cur, int total, MotyPaginationOption option)
    {
        if (cur < 0 || total < 0)
        {
            //throw new ArgumentException("Initialization Argument Error('cur' or 'total' must be greater than 0)."); 
            return MvcHtmlString.Empty;
        }
        if (cur > total)
        {
            //throw new ArgumentException("Initialization Argument Error('cur' must be less than 'total')."); 
            return MvcHtmlString.Empty;
        }
        string html = "";
        if (!(total <= 1 && option.HideWhenOnlyOne))
        {
            html = CreateHtml(cur, total, option);
        }
        return MvcHtmlString.Create(html);
    }
    //获取当前需展示的页面按钮。 
    private static List<int> GetShownPages(int cur, int total, int pagesToShow)
    {
        var pages = new List<int>();
        int half = (int)Math.Floor((pagesToShow - 1) / 2.0);
        int pad = cur + half > total ? (cur + half - total) : 0;
        int min = Math.Max(1, cur - half - pad);
        for (var i = min; i <= cur; i++)
        {
            pages.Add(i);
        }
        var max = Math.Min(total, cur + pagesToShow - pages.Count);
        for (var i = cur + 1; i <= max; i++)
        {
            pages.Add(i);
        }
        return pages;
    }
    //生成 
    private static string CreateHtml(int cur, int total, MotyPaginationOption option)
    {
        StringBuilder sb = new StringBuilder(string.Empty);
        sb.Append("<div class='motypc_1604261319'>");
        #region 首页 
        if (option.IsFirstShown)
        {
            if (cur == 1)
            {
                sb.AppendFormat("<span style='color:{0}'>{1}</span>",
                ColorTranslator.ToHtml(option.DisabledForeColor), option.FirstText);
            }
            else
            {
                sb.AppendFormat("<a href='{0}' style='color:{1}' onmouseover=\"this.style.color='{2}';this.style.borderColor='{3}'\" onmouseout=\"this.style.color='{4}';this.style.borderColor='{5}'\">{6}</a>",
                option.Url(1),
                ColorTranslator.ToHtml(option.ForeColor), ColorTranslator.ToHtml(option.HoverForeColor),
                ColorTranslator.ToHtml(option.HoverForeColor), ColorTranslator.ToHtml(option.ForeColor),
                ColorTranslator.ToHtml(Color.Transparent), option.FirstText);
            }
        }
        #endregion 
        #region 上一页 
        if (option.IsPrevShown)
        {
            if (cur == 1)
            {
                sb.AppendFormat("<span style='color:{0}'>{1}</span>",
                ColorTranslator.ToHtml(option.DisabledForeColor), option.PrevText);
            }
            else
            {
                sb.AppendFormat("<a href='{0}' style='color:{1}' onmouseover=\"this.style.color='{2}';this.style.borderColor='{3}'\" onmouseout=\"this.style.color='{4}';this.style.borderColor='{5}'\">{6}</a>",
                option.Url(cur - 1),
                ColorTranslator.ToHtml(option.ForeColor), ColorTranslator.ToHtml(option.HoverForeColor),
                ColorTranslator.ToHtml(option.HoverForeColor), ColorTranslator.ToHtml(option.ForeColor),
                ColorTranslator.ToHtml(Color.Transparent), option.PrevText);
            }
        }
        #endregion 
        #region 中间页面按钮
        sb.Append("<div class='motypc_horizontal_pager_btn'>");
        foreach (var page in GetShownPages(cur, total, option.PagesToShow))
        {
            if (page == cur)
            {
                sb.AppendFormat("<a href='javascript:void(0)' style='color:{0}; background-color:{1};border-color:transparent'>{2}</a>",
                ColorTranslator.ToHtml(option.CurrentForeColor), ColorTranslator.ToHtml(option.CurrentBackColor), page);
            }
            else
            {
                sb.AppendFormat("<a href='{0}' style='color:{1}' onmouseover=\"this.style.color='{2}';this.style.borderColor='{3}'\" onmouseout=\"this.style.color='{4}';this.style.borderColor='{5}'\">{6}</a>",
                option.Url(page),
                ColorTranslator.ToHtml(option.ForeColor), ColorTranslator.ToHtml(option.HoverForeColor),
                ColorTranslator.ToHtml(option.HoverForeColor), ColorTranslator.ToHtml(option.ForeColor),
                ColorTranslator.ToHtml(Color.Transparent), page);
            }
        }
        sb.Append("</div>");
        sb.AppendFormat("<select class='motypc_vertical_pager_btn' onchange=\"window.location=this.options[this.selectedIndex].getAttribute('data-url')\">");
        for (int i = 1; i <= total; i++)
        {
            if (i == cur)
            {
                sb.AppendFormat("<option selected='selected' value='{0}' data-url='{1}'>{2}</option>", i, option.Url(i), i);
            }
            else
            {
                sb.AppendFormat("<option value='{0}' data-url='{1}'>{2}</option>", i, option.Url(i), i);
            }
        }
        sb.Append("</select>");
        #endregion 
        #region 下一页 
        if (option.IsNextShown)
        {
            if (cur == total)
            {
                sb.AppendFormat("<span style='color:{0}'>{1}</span>",
                ColorTranslator.ToHtml(option.DisabledForeColor), option.NextText);
            }
            else
            {
                sb.AppendFormat("<a href='{0}' style='color:{1}' onmouseover=\"this.style.color='{2}';this.style.borderColor='{3}'\" onmouseout=\"this.style.color='{4}';this.style.borderColor='{5}'\">{6}</a>",
                option.Url(cur + 1),
                ColorTranslator.ToHtml(option.ForeColor), ColorTranslator.ToHtml(option.HoverForeColor),
                ColorTranslator.ToHtml(option.HoverForeColor), ColorTranslator.ToHtml(option.ForeColor),
                ColorTranslator.ToHtml(Color.Transparent), option.NextText);
            }
        }
        #endregion 
        #region 尾页 
        if (option.IsFirstShown)
        {
            if (cur == total)
            {
                sb.AppendFormat("<span style='color:{0}'>{1}</span>",
                ColorTranslator.ToHtml(option.DisabledForeColor), option.LastText);
            }
            else
            {
            sb.AppendFormat("<a href='{0}' style='color:{1}' onmouseover=\"this.style.color='{2}';this.style.borderColor='{3}'\" onmouseout=\"this.style.color='{4}';this.style.borderColor='{5}'\">{6}</a>",
            option.Url(total),
            ColorTranslator.ToHtml(option.ForeColor), ColorTranslator.ToHtml(option.HoverForeColor),
            ColorTranslator.ToHtml(option.HoverForeColor), ColorTranslator.ToHtml(option.ForeColor),
            "transparent", option.LastText);
            }
        }
        #endregion
        sb.Append("</div>");
        return sb.ToString();
    }
}
        
/// <summary>
/// 分页选项。
/// </summary>
public class MotyPaginationOption
{
    private Color foreColor = ColorTranslator.FromHtml("#787d82");
    /// <summary> 
    /// 获取或设置正常文本颜色。 
    /// </summary> 
    public Color ForeColor
    {
        get { return foreColor; }
        set
        {
            if (foreColor.Equals(value))
                return;
            foreColor = value;
        }
    }
    private Color disabledForeColor = ColorTranslator.FromHtml("#abaaa9");
    /// <summary> 
    /// 获取或设置失效文本颜色。 
    /// </summary> 
    public Color DisabledForeColor
    {
        get { return disabledForeColor; }
        set
        {
            if (disabledForeColor.Equals(value))
                return;
            disabledForeColor = value;
        }
    }
    private Color hoverForeColor = ColorTranslator.FromHtml("#ec1500");
    /// <summary> 
    /// 获取或设置鼠标悬停文本颜色及该项的下边界颜色。 
    /// </summary> 
    public Color HoverForeColor
    {
        get { return hoverForeColor; }
        set
        {
            if (hoverForeColor.Equals(value))
                return;
            hoverForeColor = value;
        }
    }
    private Color currentForeColor = ColorTranslator.FromHtml("#fff");
    /// <summary> 
    /// 获取或设置当前选中页按钮文字颜色。 
    /// </summary> 
    public Color CurrentForeColor
    {
        get { return currentForeColor; }
        set
        {
            if (currentForeColor.Equals(value))
                return;
            currentForeColor = value;
        }
    }
    private Color currentBackColor = ColorTranslator.FromHtml("#ec1500");
    /// <summary> 
    /// 获取或设置当前选中页按钮背景颜色。 
    /// </summary> 
    public Color CurrentBackColor
    {
        get { return currentBackColor; }
        set
        {
            if (currentBackColor.Equals(value))
                return;
            currentBackColor = value;
        }
    }
    private int pagesToShow = 5;
    /// <summary> 
    /// 获取或设置显示的页面按钮数目，不包括首页、尾页、上一页和下一页，建议设成奇数。 
    /// </summary> 
    public int PagesToShow
    {
        get { return pagesToShow; }
        set
        {
            if (pagesToShow == value)
                return;
            pagesToShow = value;
        }
    }
    private string firstText = "首页";
    /// <summary> 
    /// 获取或设置首页按钮显示文本。 
    /// </summary> 
    public string FirstText
    {
        get { return firstText; }
        set
        {
            if (firstText.Equals(value))
                 return;
            firstText = value;
        }
    }
    private string lastText = "尾页";
    /// <summary> 
    /// 获取或设置尾页按钮显示文本。 
    /// </summary> 
    public string LastText
    {
        get { return lastText; }
        set
            {
            if (lastText.Equals(value))
                return;
            lastText = value;
        }
    }
    private string prevText = "上一页";
    /// <summary> 
    /// 获取或设置上一页按钮显示文本。 
    /// </summary> 
    public string PrevText
    {
        get { return prevText; }
        set
        {
            if (prevText.Equals(value))
                return;
            prevText = value;
        }
    }
    private string nextText = "下一页";
    /// <summary> 
    /// 获取或设置下一页按钮显示文本。 
    /// </summary> 
    public string NextText
    {
        get { return nextText; }
        set
        {
            if (nextText.Equals(value))
                return;
            nextText = value;
        }
    }
    private bool isFirstShown = true;
    /// <summary> 
    /// 获取或设置是否显示首页按钮。 
    /// </summary> 
    public bool IsFirstShown
    {
        get { return isFirstShown; }
        set
        {
            if (isFirstShown == value)
                 return;
            isFirstShown = value;
        }
    }
    private bool isLastShown = true;
    /// <summary> 
    /// 获取或设置是否显示尾页按钮。 
    /// </summary> 
    public bool IsLastShown
    {
        get { return isLastShown; }
        set
        {
            if (isLastShown == value)
                return;
            isLastShown = value;
        }
    }
    private bool isPrevShown = true;
    /// <summary> 
    /// 获取或设置是否显示上一页按钮。 
    /// </summary> 
    public bool IsPrevShown
    {
    get { return isPrevShown; }
    set
    {
        if (isPrevShown == value)
            return;
            isPrevShown = value;
        }
    }
    private bool isNextShown = true;
    /// <summary> 
    /// 获取或设置显示下一页按钮。 
    /// </summary> 
    public bool IsNextShown
    {
        get { return isNextShown; }
        set
        {
            if (isNextShown == value)
            return;
            isNextShown = value;
        }
    }
    private bool isHorizontal = true;
    /// <summary> 
    /// 获取或设置横向还是竖向，如果是横向，那么将是一字排开，否则将会是一个select。 
    /// </summary> 
    public bool IsHorizontal
    {
        get { return isHorizontal; }
        set
        {
            if (isHorizontal == value)
            return;
            isHorizontal = value;
        }
    }
    private bool hideWhenOnlyOne = true;
    /// <summary> 
    /// 获取或设置当只有一项时是否隐藏。 
    /// </summary> 
    public bool HideWhenOnlyOne
    {
        get { return hideWhenOnlyOne; }
        set
        {
            if (hideWhenOnlyOne == value)
            return;
            hideWhenOnlyOne = value;
        }
    }
    private Func<int, string> url = (index) => { return index.ToString(); };
    /// <summary> 
    /// 获取或设置页面跳转链接。 
    /// </summary> 
    public Func<int, string> Url
    {
        get { return url; }
        set
        {
            if (url.Equals(value))
            {
                return;
            }
            url = value;
        }
    }
}