using System.Collections.Generic;
using System.Linq;
using Util.Helpers;
using Xunit;
using Xunit.Abstractions;

namespace Util.Tests.Helpers;

/// <summary>
/// 随机数操作测试
/// </summary>
public class RandomTest {
    /// <summary>
    /// 输出工具
    /// </summary>
    private readonly ITestOutputHelper _testOutputHelper;

    /// <summary>
    /// 测试初始化
    /// </summary>
    public RandomTest( ITestOutputHelper testOutputHelper ) {
        _testOutputHelper = testOutputHelper;
    }

    /// <summary>
    /// 测试从集合中随机获取值
    /// </summary>
    [Fact]
    public void TestGetValue() {
        var list = new List<int>();
        for ( int i = 0; i < 10; i++ ) {
            list.Add( i );
        }
        for ( int i = 0; i < 10; i++ ) {
            var a = Random.GetValue( list );
            var b = Random.GetValue( list );
            if ( a != b )
                return;
        }
        Assert.Fail( "fail" );
    }

    /// <summary>
    /// 测试从集合中随机获取值列表
    /// </summary>
    [Fact]
    public void TestGetValues_1() {
        var list = Enumerable.Range( 0, 10 );
        var result = Random.GetValues( list, 3 );
        Assert.Equal( 3, result.Count );
        Assert.True( result[0] >= 0 && result[0] < 10 );
        Assert.True( result[1] >= 0 && result[1] < 10 );
        Assert.True( result[2] >= 0 && result[2] < 10 );
    }

    /// <summary>
    /// 测试从集合中随机获取值列表 - 获取数量大于集合数量
    /// </summary>
    [Fact]
    public void TestGetValues_2() {
        var list = Enumerable.Range( 0, 3 );
        var result = Random.GetValues( list, 10 );
        Assert.Equal( 3, result.Count );
        Assert.True( result[0] >= 0 && result[0] < 3 );
        Assert.True( result[1] >= 0 && result[1] < 3 );
        Assert.True( result[2] >= 0 && result[2] < 3 );
    }

    /// <summary>
    /// 获取随机排序的集合
    /// </summary>
    [Fact]
    public void TestSort() {
        int[] input = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
        var list = Util.Helpers.Random.Sort( input );
        var result = list.Join();
        Assert.Equal( 10, list.Distinct().Count() );
        Assert.NotEqual( "1,2,3,4,5,6,7,8,9,10", result );
        _testOutputHelper.WriteLine( result );
    }
}