using FastEndpoints;
using Microsoft.EntityFrameworkCore;
using Socialize.Api.Data;
using Socialize.Api.Infrastructure.Security;
using Socialize.Api.Modules.ReleaseCommunications.Contracts;
using Socialize.Api.Modules.ReleaseCommunications.Data;
using Socialize.Api.Modules.ReleaseCommunications.Services;

namespace Socialize.Api.Modules.ReleaseCommunications.Handlers;

internal class ListReleaseUpdatesHandler(AppDbContext dbContext)
    : EndpointWithoutRequest<IReadOnlyCollection<ReleaseUpdateDto>>
{
    public override void Configure()
    {
        Get("/api/release-updates");
        Options(o => o.WithTags("Release Communications"));
    }

    public override async Task HandleAsync(CancellationToken ct)
    {
        Guid userId = User.GetUserId();
        ReleaseUpdateAudienceContext audienceContext =
            await ReleaseUpdateVisibility.GetAudienceContextAsync(dbContext, User, userId, ct);

        List<ReleaseUpdate> updates = await dbContext.ReleaseUpdates
            .VisibleTo(audienceContext)
            .OrderByDescending(update => update.PublishedAt)
            .ThenByDescending(update => update.CreatedAt)
            .ToListAsync(ct);

        HashSet<Guid> readUpdateIds = await GetReadUpdateIdsAsync(userId, updates.Select(update => update.Id), ct);

        await SendOkAsync(
            updates.Select(update => update.ToDto(readUpdateIds.Contains(update.Id))).ToArray(),
            ct);
    }

    private async Task<HashSet<Guid>> GetReadUpdateIdsAsync(
        Guid userId,
        IEnumerable<Guid> updateIds,
        CancellationToken ct)
    {
        Guid[] ids = updateIds.ToArray();
        return await dbContext.ReleaseUpdateReadReceipts
            .Where(receipt => receipt.UserId == userId && ids.Contains(receipt.ReleaseUpdateId))
            .Select(receipt => receipt.ReleaseUpdateId)
            .ToHashSetAsync(ct);
    }
}