using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xunit;
using xUnitStudy.Model;

namespace xUnitStudy.WebApi.Test
{
    /// <summary>
    /// https://xunit.github.io/docs/comparisons
    /// </summary>
    [Trait("测试断言分组", "默认组")]
    public class UseXUnitAssertTest : IDisposable
    {
        #region 准备
        public UseXUnitAssertTest()
        {

        }
        #endregion

        

        #region Equal
        [Fact]
        public void Equal_String_Test()
        {
            Assert.Equal("ping", "ping");
        }

        /// <summary>
        /// 断言 string 相等
        /// 设置大小写、行尾符、空白符号 比较选项
        /// </summary>
        [Fact]
        public void Equal_String_Ignore_Test()
        {
            //ignoreCase:忽略字符大小写差异.如果为true,比较时忽略字符大小写
            Assert.Equal("ABcdEF", "abcdef", ignoreCase: true);

            //ignoreLineEndingDifferences：忽略行尾结束符差异。设置为true，则将\rn、\r和\n视为等效。
            Assert.Equal("One line\r\n", "one line\n", ignoreCase: true, ignoreLineEndingDifferences: true);

            //ignoreWhiteSpaceDifferences：忽略"空白"(空格、Tab)差异。设置为true，则将空格和制表符（以任何非零量）视为等效。
            Assert.Equal("One line\r", "one    line\n", ignoreCase: true, ignoreLineEndingDifferences: true, ignoreWhiteSpaceDifferences: true);
        }

        [Fact]
        public void Equal_Double_Test()
        {
            //注意：先舍入，然后再比较
            //舍入规则：四舍五入
            //精度范围[0,15]位小数

            Assert.Equal(1.14d, 1.11d, precision: 1);
            Assert.Equal(1.15d, 1.19d, precision: 1);

            Assert //1.14d 约等于1.1 而1.15d 约等于1.2 所以不相等
                  .NotEqual(1.14d, 1.15d, precision: 1);

            //四舍五入到2位小数精度，相等
            Assert.Equal(2.123d, 2.124d, 2);

            //四舍五入到3位小数精度，相等
            Assert.Equal(3.1234d, 3.1231d, 3);

            //四舍五入到4位小数精度，不等
            Assert.NotEqual(3.12345d, 3.12349d, 4);

            //四舍五入到整数，相等
            Assert.Equal(15d, 15.111d, precision: 0);

            //没有小数位，四舍五入到整数
            Assert.Equal(15d, 15d, precision: 0);
        }

        [Fact]
        public void Equal_Decimal_Test()
        {
            //注意：先舍入，然后再比较
            //舍入规则：四舍五入
            //精度范围[0,15]位小数

            Assert.Equal(1.14M, 1.11M, precision: 1);
            Assert.Equal(1.15M, 1.19M, precision: 1);

            Assert //1.14M 约等于1.1 而1.15M 约等于1.2 所以不相等
                  .NotEqual(1.14M, 1.15M, precision: 1);

            //四舍五入到2位小数精度，相等
            Assert.Equal(2.123M, 2.124M, 2);

            //四舍五入到3位小数精度，相等
            Assert.Equal(3.1234M, 3.1231M, 3);

            //四舍五入到4位小数精度，不等
            Assert.NotEqual(3.12345M, 3.12349M, 4);

            //四舍五入到整数，相等
            Assert.Equal(15M, 15.111M, precision: 0);

            //没有小数位，四舍五入到整数
            Assert.Equal(15M, 15M, precision: 0);
        }

        [Fact]
        public void Equal_Datetime_Test()
        {
            Assert.Equal(DateTime.Now, DateTime.Now.AddSeconds(1), TimeSpan.FromSeconds(2));
            Assert.Equal(DateTime.Now, DateTime.Now.AddMinutes(1), TimeSpan.FromMinutes(2));
        }

        /// <summary>
        /// Equal 泛型版本
        /// 泛型版基本上都有简化写法
        /// </summary>
        [Fact]
        public void Equal_Generic_T_Test()
        {
            //形如：Assert.Equal<T>(Expected T, Actual T);
            //常见类型都可以简化，或是有更好的非泛型版，此时，一般用非泛型版

            Assert.Equal<string>("ping", "ping");
            Assert  //基本使用非泛型版本
                   .Equal("ping", "ping");

            Assert.Equal<int>(3, 3);
            Assert //简化为
                   .Equal(3, 3);

            Assert.Equal<long>(3L, 3L);
            Assert //简化为
                   .Equal(3L, 3L);

            Assert.Equal<double>(5.5d, 5.5d);
            Assert //简化为
                   .Equal(5.5d, 5.5d);

            Assert.Equal<decimal>(5.5M, 5.5M);
            Assert //简化为
                   .Equal(5.5M, 5.5M);

            Assert.Equal<DateTime>(DateTime.Now.Date, DateTime.Now.Date);
            Assert //简化为
                   .Equal(DateTime.Now.Date, DateTime.Now.Date);

            //类或其它自定义结构比较，可以使用

            var obj = new object();
            Assert.Equal<object>(obj, obj);
            Assert //简化为
                   .Equal(obj, obj);
        }

        /// <summary>
        /// Equal 实现了IEqualityComparer接口的泛型版本
        /// </summary>
        [Fact]
        public void Equal_Generic_IEqualityComparer_Test()
        {
            //形如：Assert.Equal<T>(Expected T, Actual T,IEqualityComparer comparer);
            //实现 IEqualityComparer 接口

            var expected = new AssertEqualDemo() { Id = 1, Name = "zhansan" };
            var actual = new AssertEqualDemo() { Id = 1, Name = "lisi" };

            //实现 IEqualityComparer 接口的，可以是被比较对象自己实现接口，也可以是单独的类。
            var comparer = new AssertEqualDemo();

            Assert.Equal<AssertEqualDemo>(expected, actual, comparer);
            Assert.//可以简写为
                Equal(expected, actual, comparer);

            //id不一样，则不相等
            expected.Id = 3;
            Assert.NotEqual(expected, actual, comparer);
        }

        /// <summary>
        /// 实现IEnumerable接口对象的 Equal比较
        /// </summary>
        [Fact]
        public void Equal_Generic_IEnumerable_Test()
        {
            //对实现IEnumerable接口的对象进行 Equal比较
            //形如：Equal<T>(IEnumerable<T> expected, IEnumerable<T> actual)；

            List<string> expected = new List<string>() { "first", "second" };
            List<string> actual = new List<string>() { "first", "second" };

            Assert.Equal<List<string>>(expected, actual);
            Assert.//简写为
                 Equal(expected, actual);
        }

        /// <summary>
        /// 实现IEnumerable接口对象的 Equal 比较
        /// 传入实现IEqualityComparer接口的比较器
        /// </summary>
        [Fact]
        public void Equal_Generic_IEnumerable_IEqualityComparer_Test()
        {
            //对实现IEnumerable接口的对象进行 Equal比较
            //形如：Equal<T>(IEnumerable<T> expected, IEnumerable<T> actual，IEqualityComparer comparer)
            //传入实现了 IEqualityComparer 接口的比较参数

            var expected = new List<AssertEqualDemo>()
            {
                new AssertEqualDemo() { Id = 1, Name = "zhansan" },
                new AssertEqualDemo() { Id = 2, Name = "lis" },
            };
            var actual = new List<AssertEqualDemo>()
            {
                new AssertEqualDemo() { Id = 1, Name = "wangwu" },
                new AssertEqualDemo() { Id = 2, Name = "zhaoliu" },
            };

            //实现 IEqualityComparer 接口的，可以是被比较对象自己实现接口，也可以是单独的类。
            var comparer = new AssertEqualDemo();

            Assert.Equal<AssertEqualDemo>(expected, actual, comparer);
            Assert.//可以简写为
                Equal(expected, actual, comparer);

            //id不一样，则不相等
            expected[0].Id = 100;
            Assert.NotEqual(expected, actual, comparer);
        }
        #endregion

        #region NotEqual
        [Fact]
        public void NotEqual_String_Test()
        {
            Assert.NotEqual("ping", "ack");
        }

        [Fact]
        public void NotEqual_Double_Test()
        {
            //注意：先舍入，然后再比较
            //舍入规则：四舍五入
            //精度范围[0,15]位小数

            Assert //1.14d 约等于1.1 而1.15d 约等于1.2 所以不相等
                  .NotEqual(1.14d, 1.15d, precision: 1);

            //舍入到2位小数精度，相等
            Assert.NotEqual(2.124d, 2.126d, 2);

            //舍入到3位小数精度，相等
            Assert.NotEqual(3.1234d, 3.1239d, 3);

            //舍入到4位小数精度，不等
            Assert.NotEqual(3.12346d, 3.12341d, 4);

            //舍入到整数，相等
            Assert.NotEqual(16d, 15.111d, precision: 0);

            //没有小数位，舍入到整数
            Assert.NotEqual(16d, 160d, precision: 0);
        }
        
        [Fact]
        public void NotEqual_Decimal_Test()
        {
            //注意：先舍入，然后再比较
            //舍入规则：四舍五入
            //精度范围[0,15]位小数

            Assert //1.14M 约等于1.1 而1.15M 约等于1.2 所以不相等
                  .NotEqual(1.14M, 1.15M, precision: 1);

            //四舍五入到2位小数精度，不等
            Assert.NotEqual(2.123M, 2.129M, 2);

            //四舍五入到3位小数精度，不等
            Assert.NotEqual(3.1234M, 3.1236M, 3);

            //四舍五入到4位小数精度，不等
            Assert.NotEqual(3.12345M, 3.12349M, 4);

            //四舍五入到整数，不等
            Assert.NotEqual(15M, 15.501M, precision: 0);

            //没有小数位，四舍五入到整数
            Assert.NotEqual(29M, 15M, precision: 0);
        }

        [Fact]
        public void NotEqual_Generic_T_Test()
        {
            //形如：Assert.NotEqual<T>(Expected T, Actual T);

            Assert.NotEqual<string>("ping", "ack");
            Assert  //基本使用非泛型版本
                   .NotEqual("ping", "ack");

            Assert.NotEqual<int>(3, 4);
            Assert //简化为
                   .NotEqual(3, 4);

            Assert.NotEqual<long>(3L, 4L);
            Assert //简化为
                   .NotEqual(3L, 4L);

            Assert.NotEqual<double>(5.5d, 6.5d);
            Assert //简化为
                   .NotEqual(5.5d, 6.5d);

            Assert.NotEqual<decimal>(5.5M, 5.6M);
            Assert //简化为
                   .NotEqual(5.5M, 6.5M);

            Assert.NotEqual<DateTime>(DateTime.Now.Date, DateTime.Now.Date.AddDays(1));
            Assert //简化为
                   .NotEqual(DateTime.Now.Date, DateTime.Now.Date.AddDays(1));

            //类或其它自定义结构比较，可以使用

            var obj = new object();
            var obj2 = new object();
            Assert.NotEqual<object>(obj, obj2);
            Assert //简化为
                   .NotEqual(obj, obj2);
        }

        [Fact]
        public void NotEqual_Generic_IEqualityComparer_Test()
        {
            //形如：Assert.NotEqual<T>(Expected T, Actual T,IEqualityComparer comparer);
            //实现 IEqualityComparer 接口

            var expected = new AssertEqualDemo() { Id = 1, Name = "zhansan" };
            var actual = new AssertEqualDemo() { Id = 1, Name = "lishi" };

            //实现 IEqualityComparer 接口的，可以是被比较对象自己实现接口，也可以是单独的类。
            var comparer = new AssertEqualDemo();

            Assert.Equal<AssertEqualDemo>(expected, actual, comparer);
            Assert.//可以简写为
                   Equal(expected, actual, comparer);

            //id不一样，则不相等
            expected.Id = 3;
            Assert.NotEqual(expected, actual, comparer);
        }

        [Fact]
        public void NotEqual_Generic_IEnumerable_Test()
        {
            //对实现IEnumerable接口的对象进行 Equal比较
            //形如：NotEqual<T>(IEnumerable<T> expected, IEnumerable<T> actual)

            List<string> expected = new List<string>() { "first", "second","third" };
            List<string> actual = new List<string>() { "first", "second" };

            Assert.NotEqual<List<string>>(expected, actual);
            Assert.//简写为
                  NotEqual(expected, actual);
        }

        [Fact]
        public void NotEqual_Generic_IEnumerable_IEqualityComparer_Test()
        {
            //对实现IEnumerable接口的对象进行 Equal比较
            //形如：NotEqual<T>(IEnumerable<T> expected, IEnumerable<T> actual，IEqualityComparer comparer)
            //传入实现了 IEqualityComparer 接口的比较参数

            var expected = new List<AssertEqualDemo>()
            {
                new AssertEqualDemo() { Id = 1, Name = "zhansan" },
                new AssertEqualDemo() { Id = 2, Name = "lis" },
            };
            var actual = new List<AssertEqualDemo>()
            {
                new AssertEqualDemo() { Id = 1, Name = "wangwu" },
                new AssertEqualDemo() { Id = 2, Name = "zhaoliu" },
            };

            //实现 IEqualityComparer 接口的，可以是被比较对象自己实现接口，也可以是单独的类。
            var comparer = new AssertEqualDemo();

            Assert.Equal<AssertEqualDemo>(expected, actual, comparer);
            Assert.//可以简写为
                Equal(expected, actual, comparer);

            //id不一样，则不相等
            expected[0].Id = 100;
            Assert.NotEqual(expected, actual, comparer);
        }
        #endregion

        #region Same
        [Fact]
        public void Same_String_Test()
        {
            //验证两个引用类型的对象，是同一个实例
            //注意：必须是引用类型，不能是值类型

            //特别注明：sting类型，虽然是引用类型，但是比较特殊。采取复制策略，相同值可以(不严谨的说法)认为引用相同
            string expected = "hell,world!";
            string actual = "hell,world!";
            Assert.Same(expected, actual);

            string expected2 = "hell,world!";
            string actual2 = expected2;
            Assert.Same(expected2, actual2);
        }

        [Fact]
        public void Same_Object_Test()
        {
            object obj1 = new object();
            object obj2 = new object();
            object obj3 = obj1;
            object obj4 = obj2;

            Assert.Same(obj1, obj3);
            Assert.Same(obj2, obj4);
        }

        [Fact]
        public void Same_Class_Test()
        {
            object obj1 = new AssertEqualDemo() { Id = 1, Name = "zhangsan" };
            object obj2 = new AssertEqualDemo() { Id = 1, Name = "zhangsan" };
            object obj3 = obj1;
            object obj4 = obj2;

            Assert.Same(obj1, obj3);
            Assert.Same(obj2, obj4);
        }
        #endregion

        #region NotSame
        [Fact]
        public void NotSame_String_Test()
        {
            //验证两个引用类型的对象，是同一个实例
            //注意：必须是引用类型，不能是值类型

            //特别注明：sting类型，虽然是引用类型，但是比较特殊。采取复制策略，相同值可以(不严谨的说法)认为引用相同
            string expected = "hell,world!";
            string actual = "I am chinese!";
            Assert.NotSame(expected, actual);

            Assert.NotSame("abc", "xyz");
        }

        [Fact]
        public void NotSame_Object_Test()
        {
            object obj1 = new object();
            object obj2 = new object();
            Object obj3 = obj2;

            Assert.NotSame(obj1, obj2);
            Assert.NotSame(obj1, obj3);
            Assert.NotSame(new object(), new object());
        }

        [Fact]
        public void NotSame_Class_Test()
        {
            object obj1 = new AssertEqualDemo() { Id = 1, Name = "zhangsan" };
            object obj2 = new AssertEqualDemo() { Id = 1, Name = "zhangsan" };
            object obj3 = obj1;
            object obj4 = obj2;

            Assert.NotSame(obj1, obj2);
            Assert.NotSame(obj3, obj4);
            Assert.NotSame(obj1, obj4);
            Assert.NotSame(obj2, obj3);
        }
        #endregion

        #region True
        [Fact]
        public void True_Condition_Test()
        {
            Assert.True(true);
            Assert.True("ping" == "ping");
            Assert.True(2 == 1 + 1);
            Assert.True("ping" == "ping" && 2 == 1 + 1);
        }

        [Fact]
        public void True_Nullable_Test()
        {
            bool? expected = null;
            Assert.True(!expected.HasValue);

            int? expected2 = null;
            Assert.True(expected2 == null);
            expected2 = 2;
            Assert.True(2 == expected2.Value);
        }

        [Fact]
        public void True_Message_Test()
        {
            Assert.True(true, "userMessage");
            Assert.True("ping" == "ping", "userMessage");
            Assert.True(2 == 1 + 1, "userMessage");

            int? nullableInt = null;
            Assert.True(null == nullableInt, "userMessage");
        }
        #endregion

        #region False
        [Fact]
        public void False_Condition_Test()
        {
            Assert.False(false);
            Assert.False("ping" == "ack");
            Assert.False(3 == 1+1);
            Assert.False("ping" == "ping" && 3 == 1 + 1);
        }

        [Fact]
        public void False_Nullable_Test()
        {
            bool? expected = null;
            Assert.False(expected.HasValue);

            int? expected2 = 3;
            Assert.False(expected2 == null);
            Assert.False(4 == expected2.Value);
        }

        [Fact]
        public void False_Message_Test()
        {
            Assert.False(false, "userMessage");
            Assert.False("ping" == "ack", "userMessage");
            Assert.False(2 == 1 + 3, "userMessage");

            int? nullableInt = 3;
            Assert.False(null == nullableInt, "userMessage");
        }
        #endregion

        #region True|False 可替代断言
        /// <summary>
        /// 直接设置验证通过
        /// </summary>
        [Fact]
        public void Pass_Test()
        {
            Assert.True(true, "用True断言替代");
        }

        [Fact]
        public void Fail_Test()
        {
            //Assert.True(false, "用True断言替代");
        }

        /// <summary>
        /// 大于
        /// </summary>
        [Fact]
        public void GreaterThan_Test()
        {
            Assert //大于比较，用True(x > y) 替代
                  .True(2 > 1);

            int max = 5;
            int min = 2;

            Assert.True(max > min);
        }

        /// <summary>
        /// 小于
        /// </summary>
        [Fact]
        public void LessThan_Test()
        {
            Assert //小于比较，用True(x < y) 替代
                  .True(2 < 3);

            int max = 5;
            int min = 2;

            Assert.True(min < max);
        }

        [Fact]
        public void NaN_Test()
        {
            //NaN=Not a Number,是否不为数字

            //说明：在浮点数计算中，0除以0将得到NaN，正数除以0将得到PositiveInfinity,负数除以0将得到NegativeInfinity。
            //浮点数运算从不引发异常

            Assert.True(double.IsNaN(0 / 0d));

            Assert.True(double.IsPositiveInfinity(1 / 0d));

            Assert.True(double.IsNegativeInfinity(-1 / 0d));
            
        }
        #endregion

        [Fact]
        public void Empty_Test()
        {
            List<string> expected = new List<string>();

            Assert //针对于集合，为Empty,即是集合中元素的个数为0。但集合为空引用null值时将引发异常
                  .Empty(expected);
        }

        [Fact]
        public void NotEmpty_Test()
        {
            List<string> expected = new List<string>() { "first", "second" };

            Assert //针对于集合，不为Empty,即是集合中元素的个数大于0。集合为空引用null值时将引发异常
                  .NotEmpty(expected);
        }

        [Fact]
        public void Null_Test()
        {
            Assert //null值，空引用
                  .Null(null);

            string exp = null;
            Assert.Null(exp);

            List<string> list = null;
            Assert.Null(list);
        }

        [Fact]
        public void NotNull_Test()
        {
            Assert //null值，空引用
                  .NotNull(new object());

            Assert.NotNull("");
            Assert.NotNull(string.Empty);

            Assert.NotNull(new List<string>());

            Assert.NotNull(new List<string>() { "first", "second" });
        }

        [Fact]
        public void IsType_Test()
        {
            //此形式，只在泛型不能使用时，才使用；应优先使用泛型版。
            Assert.IsType(typeof(string), "aaaa");

            //泛型版
            Assert.IsType<string>("hell,world!");
            Assert.IsType<int>(2);
            Assert.IsType<long>(2L);
            Assert.IsType<double>(2d);
            Assert.IsType<decimal>(2M);
            Assert.IsType<DateTime>(DateTime.Now);
            Assert.IsType<AssertEqualDemo>(new AssertEqualDemo());
        }

        [Fact]
        public void IsNotType_Test()
        {
            //此形式，只在泛型不能使用时，才使用；应优先使用泛型版。
            Assert.IsNotType(typeof(string), 22);

            //泛型版
            Assert.IsNotType<string>(2);
            Assert.IsNotType<int>("hello");
            Assert.IsNotType<long>("521");
            Assert.IsNotType<double>(new object());
            Assert.IsNotType<decimal>("55555");
            Assert.IsNotType<DateTime>("2018-08-03");
            Assert.IsNotType<AssertEqualDemo>(new object());
        }

        [Fact]
        public void IsAssignableFrom_Test()
        {
            //可以从指定的类型派生
            Assert.IsAssignableFrom<object>(22);
        }

        [Fact]
        public void All_Test()
        {
            List<string> items = new List<string>() { "abc","ac","ad","adddeddd"};
            Assert.All<string>(items, f => f.StartsWith("a"));
        }

        #region 清理
        public void Dispose()
        {

        }
        #endregion
    }
}