/// <summary>
/// Calculate the hash tags trend score and save. Maintain the link between a has tag and meme
/// NOTE: A meme's hash tag list never changes.
/// </summary>
/// <param name="hashTag"></param>
/// <param name="memeId"></param>
/// <param name="previousMemeTrendScore"></param>
/// <param name="newMemeTrendScore"></param>
/// <returns></returns>
public IHashTag SaveMemeTags(string hashTag, string memeId, double previousMemeTrendScore, double newMemeTrendScore)
{
string id = hashTag.ToLower();
// Get from repository or create new if doesn't exist
IHashTag tag = repository.GetHashTag(id) ?? new HashTag {
Id = id, Name = hashTag
};
// Update the score of the hash tag to account for the memes new score
tag.TrendScoreOfAllMemes += newMemeTrendScore - previousMemeTrendScore;
// Save hash tag in repository
var savedHashTag = repository.Save(tag);
// Maintain a link between the hash tag and meme
repository.Save(new HashTagMeme(tag.Id, memeId, newMemeTrendScore));
return(savedHashTag);
}
/// <summary>
/// Save the hashtag
/// </summary>
/// <param name="hashTag"></param>
/// <returns></returns>
public IHashTag Save(IHashTag hashTag)
{
hashTagCollection.Save(hashTag.ToBsonDocument());
return(hashTag);
}
/// <summary>
/// Get a hashtag by name (ID is hash tag name)
/// </summary>
/// <param name="hashTagName"></param>
/// <returns></returns>
public IHashTag GetHashTag(string hashTagName)
{
IHashTag hashTag = hashTagCollection.FindOne(Query <HashTag> .EQ(e => e.Id, hashTagName));
return(hashTag);
}
