added repository interfaces for all models

added Completion model

SurveyLib.Core/Models/Answer.cs

@@ -2,11 +2,10 @@ namespace SurveyLib.Core.Models;
 
 public class Answer
 {
-    public int TryId { get; set; }
-    public int SurveyId { get; set; }
+    public int CompletionId { get; set; }
     public int QuestionId { get; set; }
     public string AnswerText { get; set; }
 
-    public Survey Survey { get; set; }
+    public Completion Completion { get; set; }
     public QuestionBase Question { get; set; }
 }

SurveyLib.Core/Models/Completion.cs

@@ -0,0 +1,10 @@
+namespace SurveyLib.Core.Models;
+
+public class Completion
+{
+    public int Id { get; set; }
+    public int SurveyId { get; set; }
+    public DateTime FinishedAt { get; set; }
+
+    public Survey Survey { get; set; }
+}

SurveyLib.Core/Models/QuestionBase.cs

@@ -2,7 +2,7 @@ namespace SurveyLib.Core.Models;
 
 public class QuestionBase
 {
-    public int Id { get; set; } // TODO: А ведь их наверное много будет, вдруг int однажды не хватит...
+    public int Id { get; set; }
     public int SurveyId { get; set; }
     public string Title { get; set; }
 

SurveyLib.Core/Models/Survey.cs

@@ -7,5 +7,5 @@ public class Survey
     public string Description { get; set; }
 
     public ICollection<QuestionBase> Questions { get; set; }
-    public ICollection<Answer> Answers { get; set; }
+    public ICollection<Completion> Completions { get; set; }
 }