feat: ToStringOut() for series

src/_common/Enums.cs

@@ -206,6 +206,27 @@ public enum MaType
     WMA
 }
 
+/// <summary>
+/// String output format type.
+/// </summary>
+public enum OutType
+{
+    /// <summary>
+    /// Fixed width format.
+    /// </summary>
+    FixedWidth,
+
+    /// <summary>
+    /// Comma-separated values format.
+    /// </summary>
+    CSV,
+
+    /// <summary>
+    /// JSON format.
+    /// </summary>
+    JSON
+}
+
 /// <summary>
 /// Period size, usually referring to the time period represented in a quote candle.
 /// </summary>

src/_common/Generics/StringOut.cs

@@ -0,0 +1,96 @@
+using System.Text;
+using System.Text.Json;
+
+namespace Skender.Stock.Indicators;
+
+/// <summary>
+/// Provides extension methods for converting ISeries lists to formatted strings.
+/// </summary>
+public static class StringOut
+{
+    /// <summary>
+    /// Converts an IEnumerable of ISeries to a formatted string.
+    /// </summary>
+    /// <typeparam name="T">The type of the elements in the list.</typeparam>
+    /// <param name="list">The list of elements to convert.</param>
+    /// <param name="outType">The output format type.</param>
+    /// <param name="limitQty">The maximum number of elements to include in the output.</param>
+    /// <param name="startIndex">The starting index of the elements to include in the output.</param>
+    /// <param name="endIndex">The ending index of the elements to include in the output.</param>
+    /// <returns>A formatted string representing the list of elements.</returns>
+    public static string ToStringOut<T>(this IEnumerable<T> list, OutType outType = OutType.FixedWidth, int? limitQty = null, int? startIndex = null, int? endIndex = null) where T : ISeries
+    {
+        if (list == null || !list.Any())
+        {
+            return string.Empty;
+        }
+
+        var limitedList = list;
+
+        if (limitQty.HasValue)
+        {
+            limitedList = limitedList.Take(limitQty.Value);
+        }
+
+        if (startIndex.HasValue && endIndex.HasValue)
+        {
+            limitedList = limitedList.Skip(startIndex.Value).Take(endIndex.Value - startIndex.Value + 1);
+        }
+
+        switch (outType)
+        {
+            case OutType.CSV:
+                return ToCsv(limitedList);
+            case OutType.JSON:
+                return ToJson(limitedList);
+            case OutType.FixedWidth:
+            default:
+                return ToFixedWidth(limitedList);
+        }
+    }
+
+    private static string ToCsv<T>(IEnumerable<T> list) where T : ISeries
+    {
+        var sb = new StringBuilder();
+        var properties = typeof(T).GetProperties();
+
+        sb.AppendLine(string.Join(",", properties.Select(p => p.Name)));
+
+        foreach (var item in list)
+        {
+            sb.AppendLine(string.Join(",", properties.Select(p => p.GetValue(item))));
+        }
+
+        return sb.ToString();
+    }
+
+    private static string ToJson<T>(IEnumerable<T> list) where T : ISeries
+    {
+        return JsonSerializer.Serialize(list);
+    }
+
+    private static string ToFixedWidth<T>(IEnumerable<T> list) where T : ISeries
+    {
+        var sb = new StringBuilder();
+        var properties = typeof(T).GetProperties();
+
+        var headers = properties.Select(p => p.Name).ToArray();
+        var values = list.Select(item => properties.Select(p => p.GetValue(item)?.ToString() ?? string.Empty).ToArray()).ToArray();
+
+        var columnWidths = new int[headers.Length];
+
+        for (int i = 0; i < headers.Length; i++)
+        {
+            columnWidths[i] = Math.Max(headers[i].Length, values.Max(row => row[i].Length));
+        }
+
+        sb.AppendLine(string.Join(" ", headers.Select((header, index) => header.PadRight(columnWidths[index]))));
+
+        foreach (var row in values)
+        {
+            sb.AppendLine(string.Join(" ", row.Select((value, index) => value.PadRight(columnWidths[index]))));
+        }
+
+        return sb.ToString();
+    }
+}

tests/indicators/_common/Results/Result.Utilities.ToStringOut.Tests.cs

@@ -0,0 +1,256 @@
+namespace Tests.Common;
+
+[TestClass]
+public class ResultsToString : TestBase
+{
+    [TestMethod]
+    public void ToStringFixedWidth()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Macd");
+        output.Should().Contain("Histogram");
+        output.Should().Contain("Signal");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp      Macd        Histogram   Signal     ");
+        lines[1].Trim().Should().Be("2017-01-03     0.0000      0.0000      0.0000     ");
+    }
+
+    [TestMethod]
+    public void ToStringCSV()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.CSV);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp,Macd,Histogram,Signal");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp,Macd,Histogram,Signal");
+        lines[1].Trim().Should().Be("2017-01-03,0.0000,0.0000,0.0000");
+    }
+
+    [TestMethod]
+    public void ToStringJson()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.JSON);
+        Console.WriteLine(output);
+
+        output.Should().StartWith("[");
+        output.Should().EndWith("]");
+    }
+
+    [TestMethod]
+    public void ToStringWithLimitQty()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth, 4);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Macd");
+        output.Should().Contain("Histogram");
+        output.Should().Contain("Signal");
+
+        string[] lines = output.Split('\n');
+        lines.Length.Should().Be(5); // 1 header + 4 data rows
+    }
+
+    [TestMethod]
+    public void ToStringWithStartIndexAndEndIndex()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth, null, 2, 5);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Macd");
+        output.Should().Contain("Histogram");
+        output.Should().Contain("Signal");
+
+        string[] lines = output.Split('\n');
+        lines.Length.Should().Be(5); // 1 header + 4 data rows
+    }
+
+    [TestMethod]
+    public void ToStringOutOrderDateFirst()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        string[] lines = output.Split('\n');
+        string headerLine = lines[0];
+        string firstDataLine = lines[1];
+
+        headerLine.Should().StartWith("Timestamp");
+        firstDataLine.Should().StartWith("2017-01-03");
+    }
+
+    [TestMethod]
+    public void ToStringOutProperUseOfOutType()
+    {
+        string outputFixedWidth = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        string outputCSV = Quotes.ToMacd().ToStringOut(OutType.CSV);
+        string outputJSON = Quotes.ToMacd().ToStringOut(OutType.JSON);
+
+        outputFixedWidth.Should().Contain("Timestamp");
+        outputCSV.Should().Contain("Timestamp,Macd,Histogram,Signal");
+        outputJSON.Should().StartWith("[");
+        outputJSON.Should().EndWith("]");
+    }
+
+    [TestMethod]
+    public void ToStringOutDateFormatting()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        string[] lines = output.Split('\n');
+        string firstDataLine = lines[1];
+
+        firstDataLine.Should().StartWith("2017-01-03");
+    }
+
+    [TestMethod]
+    public void ToStringOutPerformance()
+    {
+        var watch = System.Diagnostics.Stopwatch.StartNew();
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        watch.Stop();
+        var elapsedMs = watch.ElapsedMilliseconds;
+
+        Console.WriteLine($"Elapsed time: {elapsedMs} ms");
+        elapsedMs.Should().BeLessThan(500); // Ensure performance is within acceptable limits
+    }
+
+    [TestMethod]
+    public void ToStringOutDifferentBaseListTypes()
+    {
+        string output = Quotes.ToCandle().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Open");
+        output.Should().Contain("High");
+        output.Should().Contain("Low");
+        output.Should().Contain("Close");
+        output.Should().Contain("Volume");
+        output.Should().Contain("Size");
+        output.Should().Contain("Body");
+        output.Should().Contain("UpperWick");
+        output.Should().Contain("LowerWick");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp      Open        High        Low         Close       Volume      Size        Body        UpperWick   LowerWick   ");
+        lines[1].Trim().Should().Be("2017-01-03     212.71      213.35      211.52      212.57      96708880    1.83        0.14        0.64        0.18        ");
+    }
+
+    [TestMethod]
+    public void ToStringOutWithMultipleIndicators()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Macd");
+        output.Should().Contain("Histogram");
+        output.Should().Contain("Signal");
+
+        output = Quotes.ToAdx().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Pdi");
+        output.Should().Contain("Mdi");
+        output.Should().Contain("Adx");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp      Pdi         Mdi         Adx         ");
+        lines[1].Trim().Should().Be("2017-01-03     0.0000      0.0000      0.0000      ");
+    }
+
+    [TestMethod]
+    public void ToStringOutWithUniqueHeadersAndValues()
+    {
+        string output = Quotes.ToMacd().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Macd");
+        output.Should().Contain("Histogram");
+        output.Should().Contain("Signal");
+
+        output = Quotes.ToAdx().ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Pdi");
+        output.Should().Contain("Mdi");
+        output.Should().Contain("Adx");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp      Pdi         Mdi         Adx         ");
+        lines[1].Trim().Should().Be("2017-01-03     0.0000      0.0000      0.0000      ");
+    }
+
+    [TestMethod]
+    public void ToStringOutWithListQuote()
+    {
+        string output = Quotes.ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Open");
+        output.Should().Contain("High");
+        output.Should().Contain("Low");
+        output.Should().Contain("Close");
+        output.Should().Contain("Volume");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp      Open        High        Low         Close       Volume      ");
+        lines[1].Trim().Should().Be("2017-01-03     212.71      213.35      211.52      212.57      96708880    ");
+    }
+
+    [TestMethod]
+    public void ToStringOutWithIntradayQuotes()
+    {
+        var intradayQuotes = new List<Quote>
+        {
+            new Quote(new DateTime(2023, 1, 1, 9, 30, 0), 100, 105, 95, 102, 1000),
+            new Quote(new DateTime(2023, 1, 1, 9, 31, 0), 102, 106, 96, 103, 1100),
+            new Quote(new DateTime(2023, 1, 1, 9, 32, 0), 103, 107, 97, 104, 1200),
+            new Quote(new DateTime(2023, 1, 1, 9, 33, 0), 104, 108, 98, 105, 1300),
+            new Quote(new DateTime(2023, 1, 1, 9, 34, 0), 105, 109, 99, 106, 1400)
+        };
+
+        string output = intradayQuotes.ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        output.Should().Contain("Timestamp");
+        output.Should().Contain("Open");
+        output.Should().Contain("High");
+        output.Should().Contain("Low");
+        output.Should().Contain("Close");
+        output.Should().Contain("Volume");
+
+        string[] lines = output.Split('\n');
+        lines[0].Trim().Should().Be("Timestamp           Open        High        Low         Close       Volume      ");
+        lines[1].Trim().Should().Be("2023-01-01 09:30    100.00      105.00      95.00       102.00      1000        ");
+    }
+
+    [TestMethod]
+    public void ToStringOutWith20Rows()
+    {
+        var quotes = new List<Quote>();
+        for (int i = 0; i < 20; i++)
+        {
+            quotes.Add(new Quote(new DateTime(2023, 1, 1, 9, 30, 0).AddMinutes(i), 100 + i, 105 + i, 95 + i, 102 + i, 1000 + i));
+        }
+
+        string output = quotes.ToStringOut(OutType.FixedWidth);
+        Console.WriteLine(output);
+
+        string[] lines = output.Split('\n');
+        lines.Length.Should().Be(21); // 1 header + 20 data rows
+    }
+}