using Microsoft.Extensions.Logging;
using System.Text.Json;

namespace StellaOps.Provcache.Valkey;

public sealed partial class ValkeyProvcacheStore
{
    public async ValueTask SetManyAsync(IEnumerable<ProvcacheEntry> entries, CancellationToken cancellationToken = default)
    {
        var entryList = entries.ToList();
        cancellationToken.ThrowIfCancellationRequested();
        if (entryList.Count == 0)
            return;

        try
        {
            var db = await GetDatabaseAsync(cancellationToken).ConfigureAwait(false);
            var batch = db.CreateBatch();
            var tasks = new List<Task>();
            var now = _timeProvider.GetUtcNow();

            foreach (var entry in entryList)
            {
                cancellationToken.ThrowIfCancellationRequested();
                var redisKey = BuildKey(entry.VeriKey);
                var value = JsonSerializer.Serialize(entry, _jsonOptions);

                var ttl = entry.ExpiresAt - now;
                if (ttl <= TimeSpan.Zero)
                    continue;

                if (ttl > _options.MaxTtl)
                    ttl = _options.MaxTtl;

                tasks.Add(batch.StringSetAsync(redisKey, value, ttl));
            }

            batch.Execute();
            await Task.WhenAll(tasks).ConfigureAwait(false);

            _logger.LogDebug("Batch stored {Count} cache entries", entryList.Count);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error in batch cache store");
            throw;
        }
    }
}