using System.Globalization;
using System.Text;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;
using Nop.Services.Localization;
using Nop.Web.Framework.Extensions;

namespace Nop.Web.Framework.TagHelpers.Shared;

/// <summary>
/// "nop-date-picker" tag helper
/// </summary>
[HtmlTargetElement("nop-date-picker", Attributes = DAY_NAME_ATTRIBUTE_NAME + "," + MONTH_NAME_ATTRIBUTE_NAME + "," + YEAR_NAME_ATTRIBUTE_NAME, TagStructure = TagStructure.WithoutEndTag)]
public partial class NopDatePickerTagHelper : TagHelper
{
    #region Constants

    protected const string DAY_NAME_ATTRIBUTE_NAME = "asp-day-name";
    protected const string MONTH_NAME_ATTRIBUTE_NAME = "asp-month-name";
    protected const string YEAR_NAME_ATTRIBUTE_NAME = "asp-year-name";
    protected const string BEGIN_YEAR_ATTRIBUTE_NAME = "asp-begin-year";
    protected const string END_YEAR_ATTRIBUTE_NAME = "asp-end-year";
    protected const string SELECTED_DATE_ATTRIBUTE_NAME = "asp-selected-date";
    protected const string WRAP_TAGS_ATTRIBUTE_NAME = "asp-wrap-tags";

    #endregion

    #region Fields

    protected readonly IHtmlHelper _htmlHelper;
    protected readonly ILocalizationService _localizationService;

    #endregion

    #region Ctor

    public NopDatePickerTagHelper(IHtmlGenerator generator, IHtmlHelper htmlHelper, ILocalizationService localizationService)
    {
        Generator = generator;
        _htmlHelper = htmlHelper;
        _localizationService = localizationService;
    }

    #endregion

    #region Methods

    /// <summary>
    /// Asynchronously executes the tag helper with the given context and output
    /// </summary>
    /// <param name="context">Contains information associated with the current HTML tag</param>
    /// <param name="output">A stateful HTML element used to generate an HTML tag</param>
    /// <returns>A task that represents the asynchronous operation</returns>
    public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
    {
        ArgumentNullException.ThrowIfNull(context);

        ArgumentNullException.ThrowIfNull(output);

        //contextualize IHtmlHelper
        var viewContextAware = _htmlHelper as IViewContextAware;
        viewContextAware?.Contextualize(ViewContext);

        //tag details
        output.TagName = "div";
        output.TagMode = TagMode.StartTagAndEndTag;
        output.Attributes.SetAttribute("class", "date-picker-wrapper");

        //build date selects
        var daysList = new TagBuilder("select");
        var monthsList = new TagBuilder("select");
        var yearsList = new TagBuilder("select");

        daysList.Attributes.Add("name", DayName);
        monthsList.Attributes.Add("name", MonthName);
        yearsList.Attributes.Add("name", YearName);

        var tagHelperAttributes = new List<string>
        {
            DAY_NAME_ATTRIBUTE_NAME,
            MONTH_NAME_ATTRIBUTE_NAME,
            YEAR_NAME_ATTRIBUTE_NAME,
            BEGIN_YEAR_ATTRIBUTE_NAME,
            END_YEAR_ATTRIBUTE_NAME,
            SELECTED_DATE_ATTRIBUTE_NAME,
            WRAP_TAGS_ATTRIBUTE_NAME
        };
        var customerAttributes = new Dictionary<string, object>();
        foreach (var attribute in context.AllAttributes)
        {
            if (!tagHelperAttributes.Contains(attribute.Name))
                customerAttributes.Add(attribute.Name, attribute.Value);
        }
        var htmlAttributesDictionary = HtmlHelper.AnonymousObjectToHtmlAttributes(customerAttributes);
        daysList.MergeAttributes(htmlAttributesDictionary, true);
        monthsList.MergeAttributes(htmlAttributesDictionary, true);
        yearsList.MergeAttributes(htmlAttributesDictionary, true);

        var currentCalendar = CultureInfo.CurrentCulture.Calendar;

        var days = new StringBuilder();
        var months = new StringBuilder();
        var years = new StringBuilder();

        days.AppendFormat("<option value='{0}'>{1}</option>", "0", await _localizationService.GetResourceAsync("Common.Day"));

        for (var i = 1; i <= 31; i++)
            days.AppendFormat("<option value='{0}'{1}>{0}</option>", i,
                (SelectedDate.HasValue && currentCalendar.GetDayOfMonth(SelectedDate.Value) == i) ? " selected=\"selected\"" : null);

        months.AppendFormat("<option value='{0}'>{1}</option>", "0", await _localizationService.GetResourceAsync("Common.Month"));

        for (var i = 1; i <= 12; i++)
        {
            months.AppendFormat("<option value='{0}'{1}>{2}</option>",
                i,
                (SelectedDate.HasValue && currentCalendar.GetMonth(SelectedDate.Value) == i) ? " selected=\"selected\"" : null,
                CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(i));
        }

        years.AppendFormat("<option value='{0}'>{1}</option>", "0", await _localizationService.GetResourceAsync("Common.Year"));

        BeginYear ??= DateTime.UtcNow.AddYears(-100);
        EndYear ??= DateTime.UtcNow;

        if (EndYear > BeginYear)
        {
            for (var i = currentCalendar.GetYear(BeginYear.Value); i <= currentCalendar.GetYear(EndYear.Value); i++)
                years.AppendFormat("<option value='{0}'{1}>{0}</option>", i,
                    (SelectedDate.HasValue && currentCalendar.GetYear(SelectedDate.Value) == i) ? " selected=\"selected\"" : null);
        }
        else
        {
            for (var i = currentCalendar.GetYear(BeginYear.Value); i >= currentCalendar.GetYear(EndYear.Value); i--)
                years.AppendFormat("<option value='{0}'{1}>{0}</option>", i,
                    (SelectedDate.HasValue && currentCalendar.GetYear(SelectedDate.Value) == i) ? " selected=\"selected\"" : null);
        }

        daysList.InnerHtml.AppendHtml(days.ToString());
        monthsList.InnerHtml.AppendHtml(months.ToString());
        yearsList.InnerHtml.AppendHtml(years.ToString());

        if (bool.TryParse(WrapTags, out var wrapTags) && wrapTags)
        {
            var wrapDaysList = "<span class=\"days-list select-wrapper\">" + await daysList.RenderHtmlContentAsync() + "</span>";
            var wrapMonthsList = "<span class=\"months-list select-wrapper\">" + await monthsList.RenderHtmlContentAsync() + "</span>";
            var wrapYearsList = "<span class=\"years-list select-wrapper\">" + await yearsList.RenderHtmlContentAsync() + "</span>";

            output.Content.AppendHtml(wrapDaysList);
            output.Content.AppendHtml(wrapMonthsList);
            output.Content.AppendHtml(wrapYearsList);
        }
        else
        {
            output.Content.AppendHtml(daysList);
            output.Content.AppendHtml(monthsList);
            output.Content.AppendHtml(yearsList);
        }
    }

    #endregion

    #region Properties

    protected IHtmlGenerator Generator { get; set; }

    /// <summary>
    /// Day name
    /// </summary>
    [HtmlAttributeName(DAY_NAME_ATTRIBUTE_NAME)]
    public string DayName { get; set; }

    /// <summary>
    /// Month name
    /// </summary>
    [HtmlAttributeName(MONTH_NAME_ATTRIBUTE_NAME)]
    public string MonthName { get; set; }

    /// <summary>
    /// Year name
    /// </summary>
    [HtmlAttributeName(YEAR_NAME_ATTRIBUTE_NAME)]
    public string YearName { get; set; }

    /// <summary>
    /// Begin year
    /// </summary>
    [HtmlAttributeName(BEGIN_YEAR_ATTRIBUTE_NAME)]
    public DateTime? BeginYear { get; set; }

    /// <summary>
    /// End year
    /// </summary>
    [HtmlAttributeName(END_YEAR_ATTRIBUTE_NAME)]
    public DateTime? EndYear { get; set; }

    /// <summary>
    /// Selected day
    /// </summary>
    [HtmlAttributeName(SELECTED_DATE_ATTRIBUTE_NAME)]
    public DateTime? SelectedDate { get; set; }

    /// <summary>
    /// Wrap tags
    /// </summary>
    [HtmlAttributeName(WRAP_TAGS_ATTRIBUTE_NAME)]
    public string WrapTags { get; set; }

    /// <summary>
    /// ViewContext
    /// </summary>
    [HtmlAttributeNotBound]
    [ViewContext]
    public ViewContext ViewContext { get; set; }

    #endregion
}