work-flow/src/Workflow.Domain/Expressions/Comparators/ValueComparatorHelper.cs

using System.Globalization;
using System.Text.Json;

namespace Workflow.Domain.Expressions.Comparators;

/// <summary>
/// 值对比器共享的静态工具方法。从 ConditionEvaluator 中提取，
/// 供所有内置对比器复用。
/// </summary>
public static class ValueComparatorHelper
{
    public static bool TryGetDecimal(object? value, out decimal result)
    {
        result = 0m;
        return value switch
        {
            decimal d => SetResult(d, out result),
            double db => SetResult((decimal)db, out result),
            float f => SetResult((decimal)f, out result),
            int i => SetResult((decimal)i, out result),
            long l => SetResult((decimal)l, out result),
            short s => SetResult((decimal)s, out result),
            byte b => SetResult((decimal)b, out result),
            uint ui => SetResult((decimal)ui, out result),
            ulong ul => SetResult((decimal)ul, out result),
            string str => decimal.TryParse(str, out result),
            JsonElement e => TryGetDecimalFromElement(e, out result),
            _ => false
        };
    }

    public static bool TryGetDecimalFromElement(JsonElement element, out decimal result)
    {
        result = 0m;
        if (element.ValueKind == JsonValueKind.Number)
            return element.TryGetDecimal(out result);

        if (element.ValueKind == JsonValueKind.String)
        {
            var str = element.GetString();
            return str is not null && decimal.TryParse(str, out result);
        }

        return false;
    }

    public static bool TryGetDateTime(object? value, out DateTime result)
    {
        result = DateTime.MinValue;
        return value switch
        {
            DateTime dt => SetResult(dt, out result),
            DateTimeOffset dto => SetResult(dto.UtcDateTime, out result),
            string s => DateTime.TryParse(s, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out result),
            JsonElement e => TryGetDateTimeFromElement(e, out result),
            _ => false
        };
    }

    public static bool TryGetDateTimeFromElement(JsonElement element, out DateTime result)
    {
        result = DateTime.MinValue;
        if (element.ValueKind == JsonValueKind.String)
        {
            var str = element.GetString();
            return str is not null && DateTime.TryParse(str, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out result);
        }
        return false;
    }

    public static bool TryGetBoolean(object? value, out bool result)
    {
        result = false;
        return value switch
        {
            bool b => SetResult(b, out result),
            string s => bool.TryParse(s, out result),
            JsonElement e => TryGetBooleanFromElement(e, out result),
            _ => false
        };
    }

    public static bool TryGetBooleanFromElement(JsonElement element, out bool result)
    {
        result = false;
        if (element.ValueKind == JsonValueKind.True) { result = true; return true; }
        if (element.ValueKind == JsonValueKind.False) { result = false; return true; }
        if (element.ValueKind == JsonValueKind.String)
        {
            var str = element.GetString();
            return str is not null && bool.TryParse(str, out result);
        }
        return false;
    }

    public static string? GetStringValue(object? value)
    {
        return value switch
        {
            null => null,
            string s => s,
            JsonElement e => e.ValueKind == JsonValueKind.String ? e.GetString() : e.GetRawText(),
            _ => value.ToString()
        };
    }

    public static bool TryGetDecimalFromCondition(object? conditionValue, out decimal result)
    {
        if (conditionValue is string s)
            return decimal.TryParse(s, NumberStyles.Number, CultureInfo.InvariantCulture, out result);
        return TryGetDecimal(conditionValue, out result);
    }

    public static bool TryGetDateTimeFromCondition(object? conditionValue, out DateTime result)
    {
        if (conditionValue is string s)
            return DateTime.TryParse(s, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out result);
        return TryGetDateTime(conditionValue, out result);
    }

    public static bool TryGetBooleanFromCondition(object? conditionValue, out bool result)
    {
        if (conditionValue is string s)
            return bool.TryParse(s, out result);
        return TryGetBoolean(conditionValue, out result);
    }

    private static bool SetResult<T>(T value, out T result)
    {
        result = value;
        return true;
    }
}