using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Admin.Store.Game.Search;

public sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        var query = db.Game.AsNoTracking().AsQueryable();

        if (!string.IsNullOrWhiteSpace(request.Keyword))
        {
            var kw = request.Keyword.Trim();

            query = request.Search switch
            {
                1 => int.TryParse(kw, out var id) ? query.Where(c => c.ID == id) : query.Where(c => false),
                2 => query.Where(c => c.KorName.Contains(kw)),
                3 => query.Where(c => c.EngName != null && c.EngName.Contains(kw)),
                4 => query.Where(c => c.Code != null && c.Code.Contains(kw)),
                5 => query.Where(c => c.Publisher.Contains(kw)),
                _ => query.Where(c =>
                    c.KorName.Contains(kw)
                    || (c.EngName != null && c.EngName.Contains(kw))
                    || (c.Code != null && c.Code.Contains(kw))
                    || c.Publisher.Contains(kw))
            };
        }

        if (DateTime.TryParse(request.StartAt, out var startAt))
        {
            query = query.Where(c => c.CreatedAt >= startAt);
        }

        if (DateTime.TryParse(request.EndAt, out var endAt))
        {
            query = query.Where(c => c.CreatedAt <= endAt);
        }

        if (request.IsActive.HasValue)
        {
            query = query.Where(c => c.IsActive == request.IsActive.Value);
        }

        var total = await query.CountAsync(ct);

        var list = await query
            .OrderBy(c => c.Order)
            .ThenByDescending(c => c.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(c => new
            {
                c.ID,
                c.Code,
                c.KorName,
                c.EngName,
                c.Publisher,
                c.Thumbnail,
                c.CommissionRate,
                c.Link,
                c.IsActive,
                c.Order,
                ProductCount = db.Product.Count(p => p.GameID == c.ID),
                c.UpdatedAt,
                c.CreatedAt
            })
            .ToListAsync(ct);

        var startNum = total - ((request.Page - 1) * request.PerPage);

        return new Response(
            total,
            [.. list.Select((c, i) => new Response.Row(
                Num: startNum - i,
                c.ID,
                c.Code,
                c.KorName,
                c.EngName,
                c.Publisher,
                c.Thumbnail,
                c.CommissionRate,
                c.Link,
                c.IsActive,
                c.Order,
                c.ProductCount,
                c.UpdatedAt,
                c.CreatedAt
            ))]
        );
    }
}