using FsCheck;
using FsCheck.Xunit;
using HuangyanParking.Domain.Utils;

namespace HuangyanParking.Tests;

/// <summary>
/// 券码和UID生成的属性测试
/// </summary>
public class CouponCodeAndUidPropertyTests
{
    /// <summary>
    /// Feature: huangyan-parking-points, Property 1: 券码格式正确性
    /// 对于任意生成的券码，长度为9位，由字母+数字组成，首字符不为'0'
    /// Validates: Requirements 16.1, 16.2
    /// </summary>
    [Property(MaxTest = 100)]
    public bool CouponCode_ShouldHaveValidFormat()
    {
        var code = CouponCodeGenerator.Generate();

        // 长度为9位
        if (code.Length != 9) return false;

        // 首字符不为'0'
        if (code[0] == '0') return false;

        // 所有字符由字母+数字组成
        return code.All(c => char.IsLetterOrDigit(c));
    }

    /// <summary>
    /// Feature: huangyan-parking-points, Property 2: 券码唯一性
    /// 对于任意批量生成的N个券码，所有券码互不相同
    /// Validates: Requirements 16.3
    /// </summary>
    [Property(MaxTest = 100)]
    public bool CouponCodes_ShouldBeUnique(PositiveInt countWrapper)
    {
        // 限制批量数量在2-50之间
        var count = Math.Clamp(countWrapper.Get, 2, 50);
        var codes = Enumerable.Range(0, count)
            .Select(_ => CouponCodeGenerator.Generate())
            .ToList();
        return codes.Distinct().Count() == codes.Count;
    }

    /// <summary>
    /// Feature: huangyan-parking-points, Property 3: UID格式正确性
    /// 对于任意生成的UID，长度为6位，纯数字，首位不为0
    /// Validates: Requirements 1.3
    /// </summary>
    [Property(MaxTest = 100)]
    public bool Uid_ShouldHaveValidFormat()
    {
        var uid = UidGenerator.Generate();

        // 长度为6位
        if (uid.Length != 6) return false;

        // 首位不为0
        if (uid[0] == '0') return false;

        // 纯数字
        return uid.All(c => char.IsDigit(c));
    }
}