using JSMR.Application.Circles.Queries.Search;
using JSMR.Application.Common.Search;
using JSMR.Infrastructure.Common.Queries;
using Microsoft.EntityFrameworkCore;
using System.Linq.Expressions;

namespace JSMR.Infrastructure.Data.Repositories.Circles;

public class CircleSearchProvider(AppDbContext context) : SearchProvider<CircleSearchItem, CircleSearchCriteria, CircleSortField, CircleSearchItem>, ICircleSearchProvider
{
    protected override IQueryable<CircleSearchItem> GetBaseQuery()
    {
        // Project from Circles so we can use correlated subqueries per CircleId.
        var q =
        from c in context.Circles.AsNoTracking()
        select new CircleSearchItem
        {
            CircleId = c.CircleId,
            Name = c.Name,
            MakerId = c.MakerId,
            Favorite = c.Favorite,
            Blacklisted = c.Blacklisted,
            Spam = c.Spam,

            // Aggregates
            Downloads = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .Select(v => (int?)v.Downloads)      // make nullable for Sum over empty set
                .Sum() ?? 0,

            Releases = context.VoiceWorks
                .Count(v => v.CircleId == c.CircleId && v.SalesDate != null),

            Pending = context.VoiceWorks
                .Count(v => v.CircleId == c.CircleId && v.ExpectedDate != null),

            FirstReleaseDate = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .Select(v => v.SalesDate)
                .Min(),

            LatestReleaseDate = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .Select(v => v.SalesDate)
                .Max(),

            // "Latest" by ProductId length, then value
            LatestProductId = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .OrderByDescending(v => v.ProductId.Length)
                .ThenByDescending(v => v.ProductId)
                .Select(v => v.ProductId)
                .FirstOrDefault(),

            // If you want these two in base query too:
            LatestVoiceWorkHasImage = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .OrderByDescending(v => v.ProductId.Length)
                .ThenByDescending(v => v.ProductId)
                .Select(v => (bool?)v.HasImage)
                .FirstOrDefault(),

            LatestVoiceWorkSalesDate = context.VoiceWorks
                .Where(v => v.CircleId == c.CircleId)
                .OrderByDescending(v => v.ProductId.Length)
                .ThenByDescending(v => v.ProductId)
                .Select(v => v.SalesDate)
                .FirstOrDefault()
        };

        return q;
    }

    protected override IQueryable<CircleSearchItem> ApplyFilters(IQueryable<CircleSearchItem> query, CircleSearchCriteria criteria)
    {
        if (!string.IsNullOrWhiteSpace(criteria.Name))
        {
            var term = $"%{criteria.Name.Trim()}%";

            query = query.Where(x =>
                EF.Functions.Like(x.Name, term) ||
                EF.Functions.Like(x.MakerId, term));
        }

        switch (criteria.Status)
        {
            case CircleStatus.NotBlacklisted:
                query = query.Where(x => !x.Blacklisted);
                break;
            case CircleStatus.Favorited:
                query = query.Where(x => x.Favorite);
                break;
            case CircleStatus.Blacklisted:
                query = query.Where(x => x.Blacklisted);
                break;
            case CircleStatus.Spam:
                query = query.Where(x => x.Spam);
                break;
        }

        return query;
    }

    protected override Expression<Func<CircleSearchItem, object>> GetSortExpression(CircleSortField field) => field switch
    {
        CircleSortField.Favorite => x => !x.Favorite,
        CircleSortField.Blacklisted => x => !x.Blacklisted,
        CircleSortField.Spam => x => !x.Spam,
        _ => x => x.Name
    };

    protected override IEnumerable<(Expression<Func<CircleSearchItem, object>> Selector, SortDirection Dir)> GetDefaultSortChain()
    {
        yield return (x => x.Name, SortDirection.Ascending);
        yield return (x => x.MakerId, SortDirection.Ascending);
    }

    protected override IQueryable<CircleSearchItem> GetSelectQuery(IOrderedQueryable<CircleSearchItem> query)
    {
        // Join to VoiceWorks by LatestProductId to fill HasImage / SalesDate
        var selected =
            from item in query
            join vw in context.VoiceWorks.AsNoTracking() on item.LatestProductId equals vw.ProductId into vws
            from latest in vws.DefaultIfEmpty()
            select new CircleSearchItem
            {
                CircleId = item.CircleId,
                Name = item.Name,
                MakerId = item.MakerId,
                Favorite = item.Favorite,
                Blacklisted = item.Blacklisted,
                Spam = item.Spam,
                Downloads = item.Downloads,
                Releases = item.Releases,
                Pending = item.Pending,
                FirstReleaseDate = item.FirstReleaseDate,
                LatestReleaseDate = item.LatestReleaseDate,
                LatestProductId = item.LatestProductId,
                LatestVoiceWorkHasImage = latest != null ? latest.HasImage : (bool?)null,
                LatestVoiceWorkSalesDate = latest != null ? latest.SalesDate : null
            };

        return selected;
    }
}