using Microsoft.Extensions.Logging;
using MongoDB.Driver;
using StellaOps.Scheduler.Storage.Mongo.Internal;

namespace StellaOps.Scheduler.Storage.Mongo.Migrations;

internal sealed class EnsureSchedulerCollectionsMigration : ISchedulerMongoMigration
{
    private readonly ILogger<EnsureSchedulerCollectionsMigration> _logger;

    public EnsureSchedulerCollectionsMigration(ILogger<EnsureSchedulerCollectionsMigration> logger)
        => _logger = logger ?? throw new ArgumentNullException(nameof(logger));

    public string Id => "20251019_scheduler_collections_v1";

    public async ValueTask ExecuteAsync(SchedulerMongoContext context, CancellationToken cancellationToken)
    {
        ArgumentNullException.ThrowIfNull(context);

        var requiredCollections = new[]
        {
            context.Options.SchedulesCollection,
            context.Options.RunsCollection,
            context.Options.ImpactSnapshotsCollection,
            context.Options.AuditCollection,
            context.Options.LocksCollection,
            context.Options.MigrationsCollection
        };

        var cursor = await context.Database
            .ListCollectionNamesAsync(cancellationToken: cancellationToken)
            .ConfigureAwait(false);

        var existing = await cursor.ToListAsync(cancellationToken).ConfigureAwait(false);

        foreach (var collection in requiredCollections)
        {
            if (existing.Contains(collection, StringComparer.Ordinal))
            {
                continue;
            }

            _logger.LogInformation("Creating Scheduler Mongo collection '{CollectionName}'.", collection);
            await context.Database.CreateCollectionAsync(collection, cancellationToken: cancellationToken).ConfigureAwait(false);
        }
    }
}