private bool CreateUser(MlContext ctx, out string msg)
{
if (!VerifyInput(out msg))
{
return(false);
}
var user = ctx.Users.FirstOrDefault(t => t.Username.Equals(Username));
if (user != null)
{
msg = "User already exists";
return(false);
}
user = new User {
Username = Username
};
try {
ctx.Users.Add(user);
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "User created";
return(true);
}
private bool DeleteUser(MlContext ctx, out string msg)
{
var user = ctx.Users.FirstOrDefault(t => t.Id.Equals(Id));
if (user == null)
{
msg = "No such user";
return(false);
}
if (user.IsAdmin)
{
msg = "Cannot delete an administrative user";
return(false);
}
try {
ctx.Users.Remove(user);
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "User deleted";
return(true);
}
public void GetWatchedSubmissions(MlContext ctx)
{
WatchedSubmissions = ctx.Submissions
.Where(t => t.IsWatched)
.Include(t => t.User)
.ToList();
}
public void GetPlannedSubmissions(MlContext ctx, string username)
{
PlannedSubmissions = ctx.Submissions
.Where(t => !t.IsWatched)
.Include(t => t.User)
.Include(t => t.Votes)
.ThenInclude(t => t.User)
.ToList();
// Count votes
PlannedSubmissions.ForEach(t => t.UpVotes = t.Votes.Count(u => u.Value == 1));
PlannedSubmissions.ForEach(t => t.DownVotes = t.Votes.Count(u => u.Value == -1));
PlannedSubmissions.ForEach(t => t.Seen = t.Votes.Count(u => u.Value == 0));
// Find submissions the current user has voted for
if (username != null)
{
PlannedSubmissions.ForEach(t =>
t.UserHasVotedFor = t.Votes.Any(u => u.Value == 1 && u.User.Username.Equals(username)));
PlannedSubmissions.ForEach(t =>
t.UserHasVotedAgainst = t.Votes.Any(u => u.Value == -1 && u.User.Username.Equals(username)));
PlannedSubmissions.ForEach(t =>
t.UserHasSeen = t.Votes.Any(u => u.Value == 0 && u.User.Username.Equals(username)));
}
// Sort by total sum of votes
PlannedSubmissions.Sort((j, i) => (i.UpVotes - i.DownVotes - i.Seen)
.CompareTo(j.UpVotes - j.DownVotes - j.Seen));
}
private bool VoteSubmission(MlContext ctx, string username, int value, out string msg)
{
var userId = ctx.Users.First(t => t.Username.Equals(username)).Id;
var vote = ctx.Votes.FirstOrDefault(t => t.UserId == userId && t.SubmissionId == Id);
// Vote didn't exist
if (vote == null)
{
vote = new Vote {
SubmissionId = Id,
Value = value,
UserId = userId
};
// Attempt to add to database
try {
ctx.Votes.Add(vote);
ctx.SaveChanges();
} catch {
msg = "An error occurred while adding the vote";
return(false);
}
msg = "Successfully added vote";
return(true);
}
// Remove vote from database
if (vote.Value == value)
{
try {
ctx.Votes.Remove(vote);
ctx.SaveChanges();
msg = "Successfully removed the vote";
return(true);
} catch {
msg = "An error occurred while adding the vote";
return(false);
}
}
// Attempt to update vote
try {
vote.Value = value;
ctx.Votes.Update(vote);
ctx.SaveChanges();
} catch {
msg = "An error occurred while adding the vote";
return(false);
}
msg = "Successfully updated the vote";
return(true);
}
public void Train(string trainingFileName, string testingFileName)
{
if (!File.Exists(trainingFileName))
{
Console.WriteLine($"Failed to find training data file ({trainingFileName}");
return;
}
if (!File.Exists(testingFileName))
{
Console.WriteLine($"Failed to find test data file ({testingFileName}");
return;
}
var trainingDataView = GetDataView(trainingFileName);
var options = new MatrixFactorizationTrainer.Options
{
MatrixColumnIndexColumnName = UserIDEncoding,
MatrixRowIndexColumnName = MusicIDEncoding,
LabelColumnName = "Label",
NumberOfIterations = 20,
ApproximationRank = 10,
Quiet = false
};
var trainingPipeLine = trainingDataView.Transformer.Append(MlContext.Recommendation().Trainers.MatrixFactorization(options));
ITransformer trainedModel = trainingPipeLine.Fit(trainingDataView.DataView);
MlContext.Model.Save(trainedModel, trainingDataView.DataView.Schema, ModelPath);
Console.WriteLine($"Model saved to {ModelPath}{Environment.NewLine}");
var testingDataView = GetDataView(testingFileName, true);
var testSetTransform = trainedModel.Transform(testingDataView.DataView);
var modelMetrics = MlContext.Recommendation().Evaluate(testSetTransform);
Console.WriteLine($"Matrix Factorization Evaluation:{Environment.NewLine}{Environment.NewLine}" +
$"Loss Function: {modelMetrics.LossFunction:F3}{Environment.NewLine}" +
$"Mean Absolute Error: {modelMetrics.MeanAbsoluteError:F3}{Environment.NewLine}" +
$"Mean Squared Error: {modelMetrics.MeanSquaredError:F3}{Environment.NewLine}" +
$"R Squared: {modelMetrics.RSquared:F3}{Environment.NewLine}" +
$"Root Mean Squared Error: {modelMetrics.RootMeanSquaredError:F3}");
}
public bool DoAction(MlContext ctx, string username, out string msg)
{
switch (Action)
{
case "upvote":
return(VoteSubmission(ctx, username, 1, out msg));
case "downvote":
return(VoteSubmission(ctx, username, -1, out msg));
case "seen":
return(VoteSubmission(ctx, username, 0, out msg));
default:
msg = "Invalid action";
return(false);
}
}
public bool DoAction(MlContext ctx, out string msg)
{
switch (Action)
{
case "delete":
return(DeleteUser(ctx, out msg));
case "reset":
return(ResetPassword(ctx, out msg));
case "create":
return(CreateUser(ctx, out msg));
default:
msg = "Invalid action";
return(false);
}
}
public bool DoAction(MlContext ctx, out string msg)
{
switch (Action)
{
case "delete":
return(DeleteSubmission(ctx, out msg));
case "reset":
return(ResetVotes(ctx, out msg));
case "watched":
return(ToggleWatched(ctx, out msg));
default:
msg = "Invalid action";
return(false);
}
}
public bool Login(MlContext ctx, out User user, out string msg)
{
user = null;
if (!VerifyInput(out msg))
{
return(false);
}
user = ctx.Users.FirstOrDefault(t => t.Username.Equals(Username));
if (user == null)
{
msg = "No user by that name";
return(false);
}
// If user has no password set, treat is as registration
if (string.IsNullOrEmpty(user.Secret))
{
user.Secret = Utility.Security.HashPassword(Password);
try {
ctx.Users.Update(user);
ctx.SaveChanges();
} catch (Exception ex) {
msg = ex.Message;
return(false);
}
msg = "Account created";
return(true);
}
if (!Utility.Security.VerifyHashedPassword(user.Secret, Password))
{
msg = "Invalid login credentials";
return(false);
}
msg = "Successfully logged in";
return(true);
}
private bool ResetVotes(MlContext ctx, out string msg)
{
var submission = ctx.Submissions.FirstOrDefault(t => t.Id.Equals(Id));
if (submission == null)
{
msg = "No such submission";
return(false);
}
try {
ctx.Votes.RemoveRange(ctx.Votes.Where(t => t.SubmissionId.Equals(submission.Id)));
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "Successfully reset votes";
return(true);
}
private bool DeleteSubmission(MlContext ctx, out string msg)
{
var submission = ctx.Submissions.FirstOrDefault(t => t.Id.Equals(Id));
if (submission == null)
{
msg = "No such submission";
return(false);
}
try {
ctx.Submissions.Remove(submission);
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "Submission deleted";
return(true);
}
private bool ResetPassword(MlContext ctx, out string msg)
{
var user = ctx.Users.FirstOrDefault(t => t.Id.Equals(Id));
if (user == null)
{
msg = "No such user";
return(false);
}
try {
user.Secret = null;
ctx.Users.Update(user);
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "User's password reset";
return(true);
}
private bool ToggleWatched(MlContext ctx, out string msg)
{
var submission = ctx.Submissions.FirstOrDefault(t => t.Id.Equals(Id));
if (submission == null)
{
msg = "No such submission";
return(false);
}
submission.IsWatched = !submission.IsWatched;
try {
ctx.Submissions.Update(submission);
ctx.SaveChanges();
} catch (Exception e) {
msg = e.Message;
return(false);
}
msg = "Successfully toggled watched state";
return(true);
}
public void GetSubmissions(MlContext ctx)
{
Submissions = ctx.Submissions
.Include(t => t.User)
.ToList();
}
public void GetUsers(MlContext ctx)
{
Users = ctx.Users.ToList();
}
public bool AddToDb(MlContext ctx, string username, out string msg)
{
// Extract id from user-provided url
int id;
try {
id = int.Parse(UrlRegex.Match(Url).Groups[2].Value);
} catch {
msg = "Invalid URL";
return(false);
}
// Check if the submission already exists. Prevents api spam
// I'd use .Any() but it's throwing a lot of `InvalidOperationException: No coercion operator is defined
// between types 'System.Int16' and 'System.Boolean'.` exceptions so I went with the gimmicky option due to
// time constraints
if (ctx.Submissions.Where(t => t.Id == id).ToList().Any())
{
msg = "Movie already exists";
return(false);
}
// Attempt to get movie details from external API
Entry entry;
try {
entry = ApiConnector.AsyncGet(id).Result;
if (entry == null)
{
throw new Exception();
}
} catch {
msg = "An error occurred while fetching the data";
return(false);
}
// Attempt to add to database
try {
ctx.Submissions.Add(new Submission {
Id = entry.MalId,
UserId = ctx.Users.First(t => t.Username.Equals(username)).Id,
Url = Url,
Title = entry.Title,
Duration = entry.Duration,
Episodes = entry.Episodes,
ImageUrl = entry.ImageUrl,
Score = entry.Score,
Type = entry.Type,
TrailerUrl = entry.TrailerUrl,
Rating = entry.Rating,
Synopsis = entry.Synopsis,
Genres = entry.Genres.Select(t => t.Name).Aggregate((i, j) => i + ", " + j)
});
ctx.SaveChanges();
} catch (Exception ex) {
msg = ex.Message;
msg = "An exception occurred while processing the request";
return(false);
}
msg = "Successfully added";
return(true);
}
