prep the field for building the select statement next.

2018-03-12 22:26:41 -05:00
parent 436bd5ab98
commit 30d1d9072b
4 changed files with 135 additions and 13 deletions
@@ -1,11 +1,112 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text;

 namespace PoweredSoft.DynamicLinq.Fluent
 {
+    public class SelectPart
+    {
+        public string Path { get; set; }
+        public string PropertyName { get; set; }
+        public SelectTypes SelectType { get; set; }
+    }
+
    public class SelectBuilder
    {
+        public List<SelectPart> Parts = new List<SelectPart>();

+        public bool Empty => Parts?.Count == 0;
+
+        protected void throwIfUsedOrEmpty(string propertyName)
+        {
+            if (string.IsNullOrEmpty(propertyName))
+                throw new ArgumentNullException($"{propertyName} cannot end up be empty.");
+
+            if (Parts.Any(t => t.PropertyName == propertyName))
+                throw new Exception($"{propertyName} is already used");
+        }
+
+        public SelectBuilder Key(string propertyName, string path = null)
+        {
+            if (propertyName == null)
+                propertyName = path.Split('.').LastOrDefault();
+
+            throwIfUsedOrEmpty(propertyName);
+
+            Parts.Add(new SelectPart
+            {
+                Path = path == null ? "Key" : $"Key.{path}",
+                PropertyName = propertyName,
+                SelectType = SelectTypes.Key
+            });
+
+            return this;
+        }
+
+        public SelectBuilder Count(string propertyName)
+        {
+            throwIfUsedOrEmpty(propertyName);
+            Parts.Add(new SelectPart
+            {
+                PropertyName = propertyName,
+                SelectType = SelectTypes.Count
+            });
+            return this;
+        }
+
+        public SelectBuilder LongCount(string propertyName)
+        {
+            throwIfUsedOrEmpty(propertyName);
+            Parts.Add(new SelectPart
+            {
+                PropertyName = propertyName,
+                SelectType = SelectTypes.LongCount
+            });
+            return this;
+        }
+
+        public SelectBuilder Sum(string path, string propertyName = null)
+        {
+            if (propertyName == null)
+                propertyName = path.Split('.').LastOrDefault();
+
+            throwIfUsedOrEmpty(propertyName);
+
+            Parts.Add(new SelectPart
+            {
+                Path = path,
+                PropertyName = propertyName,
+                SelectType = SelectTypes.Sum
+            });
+            return this;
+        }
+
+        public SelectBuilder Average(string path, string propertyName = null)
+        {
+            if (propertyName == null)
+                propertyName = path.Split('.').LastOrDefault();
+
+            throwIfUsedOrEmpty(propertyName);
+
+            Parts.Add(new SelectPart
+            {
+                Path = path,
+                PropertyName = propertyName,
+                SelectType = SelectTypes.Average
+            });
+            return this;
+        }
+
+        public SelectBuilder ToList(string propertyName)
+        {
+            throwIfUsedOrEmpty(propertyName);
+            Parts.Add(new SelectPart
+            {
+                PropertyName = propertyName,
+                SelectType = SelectTypes.ToList
+            });
+            return this;
+        }
    }
 }