using Microsoft.EntityFrameworkCore;
using Tiku.Application.Learning;
using Tiku.Infrastructure.Persistence;

namespace Tiku.Infrastructure.Learning;

internal sealed class StudentLearningCatalogService(
    ILearningAccessPersistence access,
    IEffectiveLearningAccessService effectiveAccess) : IStudentLearningCatalogService
{
    public async Task<StudentLearningCatalogItem> GetAsync(
        LearningActor actor,
        Guid businessLineId,
        CancellationToken cancellationToken = default)
    {
        var snapshot = await effectiveAccess.GetSnapshotAsync(actor, businessLineId, cancellationToken);
        var manifestIds = snapshot.ManifestVersionIds.ToArray();
        var rows = await access.ProductManifestResources.AsNoTracking()
            .Where(item => item.TenantId == actor.TenantId &&
                           manifestIds.Contains(item.ProductAccessManifestVersionId))
            .OrderBy(item => item.SortOrder)
            .ThenBy(item => item.Id)
            .ToArrayAsync(cancellationToken);
        var resources = rows
            .GroupBy(item => new { item.ResourceType, item.ResourceId })
            .Select(group =>
            {
                var first = group.OrderBy(item => item.SortOrder).ThenBy(item => item.Id).First();
                return new StudentCatalogResourceItem(
                    first.ResourceType,
                    first.ResourceId,
                    string.IsNullOrWhiteSpace(first.DisplayName)
                        ? first.ResourceType.ToString()
                        : first.DisplayName,
                    first.SortOrder,
                    group.Select(item => item.ProductAccessManifestVersionId).Distinct().Order().ToArray());
            })
            .OrderBy(item => item.SortOrder)
            .ThenBy(item => item.DisplayName)
            .ThenBy(item => item.ResourceId)
            .ToArray();
        return new StudentLearningCatalogItem(
            businessLineId,
            snapshot.PrimaryProfileVersionId,
            snapshot.AlternateProfileVersionIds.Order().ToArray(),
            resources,
            snapshot.GrantVersion,
            snapshot.ContentVersion);
    }
}