using AutoMapper;
using DigitalData.MessagingService.Application.Common.Dto.MailSearch;
using DigitalData.MessagingService.Application.Common.Interfaces.Repositories;
using DigitalData.MessagingService.Domain.Entities;
using DigitalData.MessagingService.Infrastructure.Persistence;
using Microsoft.EntityFrameworkCore;

namespace DigitalData.MessagingService.Infrastructure.Repositories;

public class ReceivedEmailRepository(MessagingServiceDbContext Context, IMapper Mapper) : Repository<ReceivedEmail>(Context, Mapper), IReceivedEmailRepository
{
    public async Task<IEnumerable<ReceivedEmail>> FindAsync(MailSearchFilter mailSearchFilter, EmailAccount? accountQuery = null, CancellationToken cancellationToken = default)
    {
        var query = DbSet.AsNoTracking();

        // ── Account filter ─────────────────────────────────────────────────────
        if (accountQuery is not null)
            query = query.Where(x => x.AccountId == accountQuery.Id);

        // ── Flag filters ───────────────────────────────────────────────────────
        if (mailSearchFilter.UnseenOnly)
            query = query.Where(x => !x.IsSeen);

        // ── Text filters ───────────────────────────────────────────────────────
        if (!string.IsNullOrWhiteSpace(mailSearchFilter.SubjectContains))
            query = query.Where(x => x.Subject.Contains(mailSearchFilter.SubjectContains));

        if (!string.IsNullOrWhiteSpace(mailSearchFilter.SenderContains))
            query = query.Where(x => x.From.Contains(mailSearchFilter.SenderContains));

        if (!string.IsNullOrWhiteSpace(mailSearchFilter.BodyContains))
            query = query.Where(x => x.TextBody.Contains(mailSearchFilter.BodyContains)
                                  || x.HtmlBody.Contains(mailSearchFilter.BodyContains));

        // ── UID filter ─────────────────────────────────────────────────────────
        if (mailSearchFilter.Uid is { } uid)
        {
            if (uid.Absolute.HasValue)
                query = query.Where(x => x.Uid == uid.Absolute.Value);
            else
            {
                if (uid.Min.HasValue)
                    query = query.Where(x => x.Uid >= uid.Min.Value);
                if (uid.Max.HasValue)
                    query = query.Where(x => x.Uid <= uid.Max.Value);
            }
        }

        // ── Date filter ────────────────────────────────────────────────────────
        if (mailSearchFilter.Date is { } date)
        {
            if (date.After.HasValue)
                query = query.Where(x => x.Date >= date.After.Value);
            if (date.Before.HasValue)
                query = query.Where(x => x.Date <= date.Before.Value);
        }

        // ── Attachments ────────────────────────────────────────────────────────
        if (mailSearchFilter.WithAttachments)
            query = query.Include(x => x.Attachments);

        // ── Sort ───────────────────────────────────────────────────────────────
        query = mailSearchFilter.SortOrder == MailSortOrder.OldestFirst
            ? query.OrderBy(x => x.Date)
            : query.OrderByDescending(x => x.Date);

        // ── Limit ──────────────────────────────────────────────────────────────
        if (mailSearchFilter.MaxCount.HasValue)
            query = query.Take(mailSearchFilter.MaxCount.Value);

        // ── RecipientContains: To/Cc are IEnumerable<string> (nvarchar(max)) ──
        // EF Core cannot translate collection predicates on these columns to SQL.
        // Materialization is deferred until after other DB-side filters narrow the set.
        var results = await query.ToListAsync(cancellationToken);

        if (!string.IsNullOrWhiteSpace(mailSearchFilter.RecipientContains))
            results = [.. results
                .Where(x => x.To.Any(t => t.Contains(mailSearchFilter.RecipientContains, StringComparison.OrdinalIgnoreCase))
                          || x.Cc.Any(c => c.Contains(mailSearchFilter.RecipientContains, StringComparison.OrdinalIgnoreCase)))];

        return results;
    }
}