Add QueryResult

src/Models/QueryResult.cs

@@ -0,0 +1,101 @@
+using Behlog.Core.Validations;
+using Behlog.Extensions;
+
+namespace Behlog.Core.Models;
+
+/// <summary>
+/// Represents a collection of results from a Query. 
+/// </summary>
+/// <typeparam name="TResult">type of Query Results.</typeparam>
+public class QueryResult<TResult> where TResult : class
+{
+    private ICollection<ValidationError> _errors;
+
+    protected QueryResult()
+    {
+        _errors = new List<ValidationError>();
+        Results = new List<TResult>();
+    }
+
+    protected QueryResult(IEnumerable<TResult> results)
+    {
+        _errors = new List<ValidationError>();
+        if (results is null)
+            throw new ArgumentNullException(nameof(results));
+
+        Results = results.ToList();
+    }
+
+    public IReadOnlyCollection<TResult> Results { get; }
+
+    public bool HasError => _errors.Any();
+
+    public IReadOnlyCollection<ValidationError> Errors => _errors.ToList();
+
+    public long PageNumber { get; protected set; }
+
+    public int PageSize { get; protected set; }
+
+    public long TotalCount { get; protected set; }
+
+    public long TotalPages => TotalCount / PageSize;
+
+
+    public static QueryResult<TResult> Create()
+    {
+        return new QueryResult<TResult>();
+    }
+
+    public static QueryResult<TResult> Create(IEnumerable<TResult> results)
+    {
+        return new QueryResult<TResult>(results);
+    }
+
+    public QueryResult<TResult> WithPageSize(int pageSize = 10)
+    {
+        PageSize = pageSize;
+        return this;
+    }
+
+    public QueryResult<TResult> WithPageNumber(int pageNumber)
+    {
+        PageNumber = pageNumber;
+        return this;
+    }
+
+    public QueryResult<TResult> WithTotalCount(int totalCount)
+    {
+        TotalCount = totalCount;
+        return this;
+    }
+
+
+    public void AddError(ValidationError error)
+    {
+        error.ThrowExceptionIfArgumentIsNull(nameof(error));
+        _errors.Add(error);
+    }
+
+    public void AddErrors(IEnumerable<ValidationError> errors)
+    {
+        errors.ThrowExceptionIfArgumentIsNull(nameof(errors));
+        if(!errors.Any()) return;
+
+        foreach (var err in errors)
+        {
+            _errors.Add(err);
+        }
+    }
+
+    public QueryResult<TResult> WithError(ValidationError error)
+    {
+        AddError(error);
+        return this;
+    }
+
+    public QueryResult<TResult> WithErrors(IEnumerable<ValidationError> errors)
+    {
+        AddErrors(errors);
+        return this;
+    }
+}