using System;
using System.Globalization;
using System.Linq;
using System.Numerics;

using NUnit.Framework;
using Python.Runtime;

namespace Python.EmbeddingTest
{
    public class TestPyInt
    {
        [Test]
        public void TestCtorInt()
        {
            const int i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorUInt()
        {
            const uint i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorLong()
        {
            const long i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorULong()
        {
            const ulong i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorShort()
        {
            const short i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorUShort()
        {
            const ushort i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorByte()
        {
            const byte i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorSByte()
        {
            const sbyte i = 5;
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(i));
        }

        [Test]
        public void TestCtorPyObject()
        {
            var i = new PyInt(5);
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(5));
        }

        [Test]
        public void TestCtorBadPyObject()
        {
            var i = new PyString("Foo");
            PyInt a = null;

            var ex = Assert.Throws(() => a = new PyInt(i));

            StringAssert.StartsWith("object is not an int", ex.Message);
            Assert.IsNull(a);
        }

        [Test]
        public void TestCtorString()
        {
            const string i = "5";
            var a = new PyInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(5));
        }

        [Test]
        public void TestCtorBadString()
        {
            const string i = "Foo";
            PyInt a = null;

            var ex = Assert.Throws(() => a = new PyInt(i));

            StringAssert.StartsWith("invalid literal for int", ex.Message);
            Assert.IsNull(a);
        }

        [Test]
        public void TestIsIntTypeTrue()
        {
            var i = new PyInt(5);
            Assert.True(PyInt.IsIntType(i));
        }

        [Test]
        public void TestIsIntTypeFalse()
        {
            var s = new PyString("Foo");
            Assert.False(PyInt.IsIntType(s));
        }

        [Test]
        public void TestAsIntGood()
        {
            var i = new PyInt(5);
            var a = PyInt.AsInt(i);
            Assert.That(a.ToInt32(), Is.EqualTo(5));
        }

        [Test]
        public void TestAsIntBad()
        {
            var s = new PyString("Foo");
            PyInt a = null;

            var ex = Assert.Throws(() => a = PyInt.AsInt(s));
            StringAssert.StartsWith("invalid literal for int", ex.Message);
            Assert.IsNull(a);
        }

        [Test]
        public void TestConvertToInt32()
        {
            var a = new PyInt(5);
            Assert.IsInstanceOf(typeof(int), a.ToInt32());
            Assert.That(a.ToInt32(), Is.EqualTo(5));
        }

        [Test]
        public void TestConvertToInt16()
        {
            var a = new PyInt(5);
            Assert.IsInstanceOf(typeof(short), a.ToInt16());
            Assert.That(a.ToInt16(), Is.EqualTo(5));
        }

        [Test]
        public void TestConvertToInt64()
        {
            long val = 5 + (long)int.MaxValue;
            var a = new PyInt(val);
            Assert.IsInstanceOf(typeof(long), a.ToInt64());
            Assert.That(a.ToInt64(), Is.EqualTo(val));
        }

        [Test]
        public void ToBigInteger()
        {
            int[] simpleValues =
            {
                0, 1, 2,
                0x10,
                0x79,
                0x80,
                0x81,
                0xFF,
                0x123,
                0x8000,
                0x1234,
                0x8001,
                0x4000,
                0xFF,
            };
            simpleValues = simpleValues.Concat(simpleValues.Select(v => -v)).ToArray();

            var expected = simpleValues.Select(v => new BigInteger(v)).ToArray();
            var actual = simpleValues.Select(v => new PyInt(v).ToBigInteger()).ToArray();

            Assert.That(actual, Is.EqualTo(expected));
        }

        [Test]
        public void CompareTo()
        {
            var v = new PyInt(42);

            #region Signed
            Assert.That(v.CompareTo(42L), Is.EqualTo(0));
            Assert.That(v.CompareTo(42), Is.EqualTo(0));
            Assert.That(v.CompareTo((short)42), Is.EqualTo(0));
            Assert.That(v.CompareTo((sbyte)42), Is.EqualTo(0));

            Assert.That(v.CompareTo(41L), Is.EqualTo(1));
            Assert.That(v.CompareTo(41), Is.EqualTo(1));
            Assert.That(v.CompareTo((short)41), Is.EqualTo(1));
            Assert.That(v.CompareTo((sbyte)41), Is.EqualTo(1));

            Assert.That(v.CompareTo(43L), Is.EqualTo(-1));
            Assert.That(v.CompareTo(43), Is.EqualTo(-1));
            Assert.That(v.CompareTo((short)43), Is.EqualTo(-1));
            Assert.That(v.CompareTo((sbyte)43), Is.EqualTo(-1));
            #endregion Signed

            #region Unsigned
            Assert.That(v.CompareTo(42UL), Is.EqualTo(0));
            Assert.That(v.CompareTo(42U), Is.EqualTo(0));
            Assert.That(v.CompareTo((ushort)42), Is.EqualTo(0));
            Assert.That(v.CompareTo((byte)42), Is.EqualTo(0));

            Assert.That(v.CompareTo(41UL), Is.EqualTo(1));
            Assert.That(v.CompareTo(41U), Is.EqualTo(1));
            Assert.That(v.CompareTo((ushort)41), Is.EqualTo(1));
            Assert.That(v.CompareTo((byte)41), Is.EqualTo(1));

            Assert.That(v.CompareTo(43UL), Is.EqualTo(-1));
            Assert.That(v.CompareTo(43U), Is.EqualTo(-1));
            Assert.That(v.CompareTo((ushort)43), Is.EqualTo(-1));
            Assert.That(v.CompareTo((byte)43), Is.EqualTo(-1));
            #endregion Unsigned
        }

        [Test]
        public void Equals()
        {
            var v = new PyInt(42);

            #region Signed
            Assert.True(v.Equals(42L));
            Assert.True(v.Equals(42));
            Assert.True(v.Equals((short)42));
            Assert.True(v.Equals((sbyte)42));

            Assert.False(v.Equals(41L));
            Assert.False(v.Equals(41));
            Assert.False(v.Equals((short)41));
            Assert.False(v.Equals((sbyte)41));
            #endregion Signed

            #region Unsigned
            Assert.True(v.Equals(42UL));
            Assert.True(v.Equals(42U));
            Assert.True(v.Equals((ushort)42));
            Assert.True(v.Equals((byte)42));

            Assert.False(v.Equals(41UL));
            Assert.False(v.Equals(41U));
            Assert.False(v.Equals((ushort)41));
            Assert.False(v.Equals((byte)41));
            #endregion Unsigned
        }

        [Test]
        public void ToBigIntegerLarge()
        {
            BigInteger val = BigInteger.Pow(2, 1024) + 3;
            var pyInt = new PyInt(val);
            Assert.That(pyInt.ToBigInteger(), Is.EqualTo(val));
            val = -val;
            pyInt = new PyInt(val);
            Assert.That(pyInt.ToBigInteger(), Is.EqualTo(val));
        }
    }
}