0.4.4

bilibili热搜组件

LanMountainDesktop/Services/CalculatorDataService.cs

@@ -0,0 +1,123 @@
+using System;
+using System.Globalization;
+
+namespace LanMountainDesktop.Services;
+
+public sealed class CalculatorDataService : ICalculatorDataService
+{
+    private const int MaxInputLength = 18;
+
+    public string ApplyInputToken(string currentInput, string token)
+    {
+        var normalized = NormalizeInput(currentInput);
+        if (string.IsNullOrWhiteSpace(token))
+        {
+            return normalized;
+        }
+
+        if (string.Equals(token, CalculatorInputTokens.Clear, StringComparison.OrdinalIgnoreCase))
+        {
+            return "0";
+        }
+
+        if (string.Equals(token, CalculatorInputTokens.Backspace, StringComparison.OrdinalIgnoreCase))
+        {
+            if (normalized.Length <= 1)
+            {
+                return "0";
+            }
+
+            var trimmed = normalized[..^1];
+            if (trimmed is "-" or "" or "-0")
+            {
+                return "0";
+            }
+
+            return trimmed;
+        }
+
+        if (string.Equals(token, CalculatorInputTokens.DecimalPoint, StringComparison.Ordinal))
+        {
+            if (normalized.Contains('.', StringComparison.Ordinal))
+            {
+                return normalized;
+            }
+
+            if (normalized.Length >= MaxInputLength)
+            {
+                return normalized;
+            }
+
+            return $"{normalized}.";
+        }
+
+        if (token is "00")
+        {
+            if (normalized == "0")
+            {
+                return "0";
+            }
+
+            if (normalized.Length + 2 > MaxInputLength)
+            {
+                return normalized;
+            }
+
+            return normalized + "00";
+        }
+
+        if (token.Length == 1 && char.IsDigit(token[0]))
+        {
+            if (normalized == "0")
+            {
+                return token;
+            }
+
+            if (normalized.Length >= MaxInputLength)
+            {
+                return normalized;
+            }
+
+            return normalized + token;
+        }
+
+        return normalized;
+    }
+
+    public decimal ParseAmountOrZero(string? inputText)
+    {
+        var normalized = NormalizeInput(inputText);
+        if (decimal.TryParse(
+            normalized,
+            NumberStyles.AllowLeadingSign | NumberStyles.AllowDecimalPoint,
+            CultureInfo.InvariantCulture,
+            out var amount))
+        {
+            return amount;
+        }
+
+        return 0m;
+    }
+
+    public string FormatAmount(decimal amount, int maxFractionDigits = 4)
+    {
+        var safeDigits = Math.Clamp(maxFractionDigits, 0, 8);
+        var pattern = safeDigits == 0 ? "0" : $"0.{new string('#', safeDigits)}";
+        return amount.ToString(pattern, CultureInfo.InvariantCulture);
+    }
+
+    private static string NormalizeInput(string? input)
+    {
+        if (string.IsNullOrWhiteSpace(input))
+        {
+            return "0";
+        }
+
+        var trimmed = input.Trim();
+        return trimmed switch
+        {
+            "-" or "-0" => "0",
+            _ => trimmed
+        };
+    }
+}