public class LinkIndexProvider()

in src/infra/docs-lambda-index-publisher/LinkIndexProvider.cs [18:80]
60 lines of code
5 McCabe index (conditional complexity)

public class LinkIndexProvider(IAmazonS3 s3Client, ILambdaLogger logger, string bucketName, string key)
{
	private string? _etag;
	private LinkReferenceRegistry? _linkIndex;

	private async Task<LinkReferenceRegistry> GetLinkIndex()
	{
		var getObjectRequest = new GetObjectRequest
		{
			BucketName = bucketName,
			Key = key
		};
		logger.LogInformation("Getting link index from s3://{bucketName}/{key}", bucketName, key);
		var getObjectResponse = await s3Client.GetObjectAsync(getObjectRequest);
		await using var stream = getObjectResponse.ResponseStream;
		_etag = getObjectResponse.ETag;
		logger.LogInformation("Successfully got link index from s3://{bucketName}/{key}", bucketName, key);
		_linkIndex = LinkReferenceRegistry.Deserialize(stream);
		return _linkIndex;
	}

	public async Task UpdateLinkIndexEntry(LinkRegistryEntry linkRegistryEntry)
	{
		_linkIndex ??= await GetLinkIndex();
		if (_linkIndex.Repositories.TryGetValue(linkRegistryEntry.Repository, out var existingEntry))
		{
			var newEntryIsNewer = DateTime.Compare(linkRegistryEntry.UpdatedAt, existingEntry[linkRegistryEntry.Branch].UpdatedAt) > 0;
			if (newEntryIsNewer)
			{
				existingEntry[linkRegistryEntry.Branch] = linkRegistryEntry;
				logger.LogInformation("Updated existing entry for {repository}@{branch}", linkRegistryEntry.Repository, linkRegistryEntry.Branch);
			}
			else
				logger.LogInformation("Skipping update for {repository}@{branch} because the existing entry is newer", linkRegistryEntry.Repository, linkRegistryEntry.Branch);
		}
		else
		{
			_linkIndex.Repositories.Add(linkRegistryEntry.Repository, new Dictionary<string, LinkRegistryEntry>
			{
				{ linkRegistryEntry.Branch, linkRegistryEntry }
			});
			logger.LogInformation("Added new entry for {repository}@{branch}", linkRegistryEntry.Repository, linkRegistryEntry.Branch);
		}
	}

	public async Task Save()
	{
		if (_etag == null || _linkIndex == null)
			throw new InvalidOperationException("You must call UpdateLinkIndexEntry() before Save()");
		var json = LinkReferenceRegistry.Serialize(_linkIndex);
		logger.LogInformation("Saving link index to s3://{bucketName}/{key}", bucketName, key);
		var putObjectRequest = new PutObjectRequest
		{
			BucketName = bucketName,
			Key = key,
			ContentBody = json,
			ContentType = "application/json",
			IfMatch = _etag // Only update if the ETag matches. Meaning the object has not been changed in the meantime.
		};
		_ = await s3Client.PutObjectAsync(putObjectRequest);
		logger.LogInformation("Successfully saved link index to s3://{bucketName}/{key}", bucketName, key);
	}
}