public async Task <PhotoModel> GetPhotoById(PhotoId photoId, UserId currentUserId)
{
PhotoModel result = null;
bool photoIsLikedByCurrentUser = false;
logWriter.LogInformation($"{nameof(GetPhotoById)}({nameof(photoId)} = '{photoId}')");
var request = new BatchGetItemRequest
{
RequestItems = new Dictionary <string, KeysAndAttributes>
{
{
tableName,
new KeysAndAttributes
{
Keys = new List <Dictionary <string, AttributeValue> >
{
Mappers.PhotoModel.ToDbKey(new PhotoModel {
PhotoId = photoId
}),
Mappers.PhotoLike.ToDbKey(new PhotoLikeRecord
{
PhotoId = photoId,
UserId = currentUserId
})
}
}
}
}
};
logWriter.LogInformation($"Batch get keys:\n{JsonConvert.SerializeObject(request)}");
try
{
var getItemResponse = await dynamoDbCore.BatchGetItem(request);
foreach (var item in getItemResponse.SelectMany(r => r.Value))
{
logWriter.LogInformation($"Record type: {item[FieldMappings.RecordType].S}");
switch (item[FieldMappings.RecordType].S.ToLowerInvariant())
{
case "photo":
result = Mappers.PhotoModel.FromDbItem(item);
break;
case "photolike":
photoIsLikedByCurrentUser = true;
break;
}
}
if (result != null)
{
result.PhotoIsLikedByCurrentUser = photoIsLikedByCurrentUser;
}
return(result);
}
catch (Exception ex)
{
logWriter.LogError(ex, $"{nameof(GetPhotoById)}({nameof(photoId)} = '{photoId}'):\n{ex.ToString()}");
throw;
}
}
private async Task RemoveLikeRecord(UserId userId, PhotoId photoId)
{
BatchGetItemRequest request = new BatchGetItemRequest
{
RequestItems = new Dictionary <string, KeysAndAttributes>
{
{ tableName, new KeysAndAttributes {
Keys = new[] {
Mappers.PhotoModel.ToDbKey(new PhotoModel {
PhotoId = photoId
}),
Mappers.PhotoLike.ToDbKey(new PhotoLikeRecord {
PhotoId = photoId, UserId = userId
})
}.ToList()
} }
}
};
var items = await dynamoDbCore.BatchGetItem(request);
PhotoModel photo = null;
PhotoLikeRecord likeRecord = null;
foreach (var item in items[tableName])
{
switch (item[FieldMappings.RecordType].S.ToLower())
{
case "photo":
photo = Mappers.PhotoModel.FromDbItem(item);
break;
case "photolike":
likeRecord = Mappers.PhotoLike.FromDbItem(item);
break;
}
}
if (likeRecord == null)
{
return;
}
logWriter.LogInformation($"{nameof(RemoveLikeRecord)}({nameof(userId)} = '{userId}', {nameof(photoId)} = '{photoId}')");
var scoreDelta = scoreCalculator.GetLikeScore(likeRecord) * -1;
var deleteItemRequest = new DeleteItemRequest(
tableName,
Mappers.PhotoLike.ToDbKey(new PhotoLikeRecord
{
UserId = userId,
PhotoId = photoId,
CreatedTime = system.Time.UtcNow
}));
try
{
await dynamoDbCore.DeleteItem(deleteItemRequest);
await UpdateLikeCountAndScore(photo, -1, scoreDelta);
}
catch (Exception ex)
{
logWriter.LogError(ex, $"Error in {nameof(RemoveLikeRecord)}({nameof(userId)} = '{userId}', {nameof(photoId)} = '{photoId}'):\n{ex.ToString()}");
throw;
}
}