using System.Text.Json;
#if POSTGRES
using Events.EF.Data.Postgres;
#else
using Events.EF.Data.MSSQL;
#endif
using Events.EF.Models;
using Events.MVC.Models;
using Events.MVC.Models.Sports;
using Events.MVC.Util.Extensions;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using Sieve.Models;
using Sieve.Services;

namespace Events.MVC.Controllers;

public class SportsController : Controller
{
    private readonly EventsContext ctx;
    private readonly ISieveProcessor sieveProcessor;
    private readonly PagingSettings pagingSettings;

    public SportsController(EventsContext ctx, ISieveProcessor sieveProcessor, IOptions<PagingSettings> pagingSettings)
    {
        this.ctx = ctx;
        this.sieveProcessor = sieveProcessor;
        this.pagingSettings = pagingSettings.Value;
    }

    public async Task<IActionResult> Index(SieveModel sieveModel)
    {
        var viewModel = await BuildSportsListAsync(sieveModel);
        if (Request.Headers.ContainsKey(Constants.HtmxHeaders.Request))
        {
            return PartialView("_SportsList", viewModel);
        }

        return View(viewModel);
    }

    [HttpGet]
    public async Task<IActionResult> Row(int id)
    {
        var sport = await ctx.Sports
            .AsNoTracking()
            .FirstOrDefaultAsync(s => s.Id == id);

        if (sport is null)
        {
            return NotFound();
        }

        return PartialView("_SportRow", new SportViewModel
        {
            Id = sport.Id,
            Name = sport.Name
        });
    }

    [HttpGet]
    public async Task<IActionResult> EditRow(int id)
    {
        var sport = await ctx.Sports
            .AsNoTracking()
            .FirstOrDefaultAsync(s => s.Id == id);

        if (sport is null)
        {
            return NotFound();
        }

        return PartialView("_SportEditRow", new SportViewModel
        {
            Id = sport.Id,
            Name = sport.Name
        });
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Create(SportViewModel model, SieveModel sieveModel)
    {
        if (!ModelState.IsValid)
        {
            Response.Headers[Constants.HtmxHeaders.Retarget] = "#create-sport-form";
            Response.Headers[Constants.HtmxHeaders.Reswap] = Constants.HtmxSwap.OuterHtml;
            return PartialView("_CreateSportForm", model);
        }

        var sport = new Sport
        {
            Name = model.Name
        };
        ctx.Sports.Add(sport);
        await ctx.SaveChangesAsync();

        Response.Headers[Constants.HtmxHeaders.Trigger] = JsonSerializer.Serialize(new Dictionary<string, object?>
        {
            [Constants.HtmxEvents.SportCreated] = true,
            [Constants.HtmxEvents.ShowToast] = new
            {
                variant = Constants.ToastVariants.Success,
                title = Constants.ToastTitles.Success,
                message = $"Sport '{model.Name}' was added successfully."
            }
        });
        var viewModel = await BuildSportsListAsync(sieveModel);
        return PartialView("_SportsList", viewModel);
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Edit(int id, SportViewModel model)
    {
        if (id != model.Id)
        {
            return BadRequest();
        }

        if (!ModelState.IsValid)
        {
            return PartialView("_SportEditRow", model);
        }

        var existingSport = await ctx.Sports.FirstOrDefaultAsync(s => s.Id == id);
        if (existingSport is null)
        {
            return NotFound();
        }

        existingSport.Name = model.Name;
        await ctx.SaveChangesAsync();

        return PartialView("_SportRow", new SportViewModel
        {
            Id = existingSport.Id,
            Name = existingSport.Name
        });
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Delete(int id, SieveModel sieveModel)
    {
        var sport = await ctx.Sports
            .Include(s => s.Registrations)
            .FirstOrDefaultAsync(s => s.Id == id);

        if (sport is null)
        {
            return NotFound();
        }

        if (sport.Registrations.Count > 0)
        {
            Response.StatusCode = StatusCodes.Status409Conflict;
            return Content("The sport cannot be deleted because registrations exist.");
        }

        ctx.Sports.Remove(sport);
        var deletedName = sport.Name;
        await ctx.SaveChangesAsync();

        Response.Headers[Constants.HtmxHeaders.Trigger] = JsonSerializer.Serialize(new Dictionary<string, object?>
        {
            [Constants.HtmxEvents.ShowToast] = new
            {
                variant = Constants.ToastVariants.Success,
                title = Constants.ToastTitles.Success,
                message = $"Sport '{deletedName}' was deleted successfully."
            }
        });
        var viewModel = await BuildSportsListAsync(sieveModel);
        return PartialView("_SportsList", viewModel);
    }

    private async Task<PagedList<SportViewModel>> BuildSportsListAsync(SieveModel sieveModel)
    {
        sieveModel.SetDefaultPagingAndSorting(pagingSettings.PageSize, "Name");
        var normalizedFilters = sieveModel.Filters?.Trim() ?? string.Empty;
        var nameFilter = SieveModelExtensions.ExtractFilterValue(normalizedFilters, "Name");

        var baseQuery = ctx.Sports
            .Select(s => new SportViewModel
            {
                Id = s.Id,
                Name = s.Name
            });

        var totalCount = await baseQuery.CountAsync();
        var filteredCount = string.IsNullOrWhiteSpace(normalizedFilters)
            ? totalCount
            : await sieveProcessor
                .Apply(
                    sieveModel,
                    baseQuery,
                    applyFiltering: true,
                    applySorting: false,
                    applyPagination: false)
                .CountAsync();
        var pagingInfo = new PagingInfo
        {
            FilteredItemsCount = filteredCount,
            TotalItemsCount = totalCount,
            ItemsPerPage = sieveModel.PageSize!.Value,
            CurrentPage = sieveModel.Page!.Value,
            Sorts = sieveModel.Sorts ?? "Name",
            Filters = normalizedFilters,
            NameFilter = nameFilter
        };

        if (pagingInfo.CurrentPage > pagingInfo.TotalPages)
        {
            pagingInfo.CurrentPage = pagingInfo.TotalPages;
            sieveModel.Page = pagingInfo.CurrentPage;
        }

        var sports = await sieveProcessor
            .Apply(sieveModel, baseQuery)
            .ToListAsync();

        return new PagedList<SportViewModel>(sports, pagingInfo);
    }

}