using Upsilon.BaseTypes;
using Upsilon.BaseTypes.Number;
using Upsilon.Evaluator;
using Xunit;

namespace UpsilonTests
{
    public class FunctionTests
    {
        [Fact]
        public void BasicFunctionTest()
        {
            const string input = @"
function testFunc ()
    a = 100
end
a = 50
testFunc()
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            var a = script.GetVariable<long>("a");
            Assert.Equal(100, a);
        }

        [Fact]
        public void ParameterTest()
        {
            const string input = @"
function testFunc (var1)
    a = var1
end
a = 50
testFunc(100)
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            var a = script.GetVariable<long>("a");
            Assert.Equal(100, a);
        }

        [Fact]
        public void ParameterBindTest()
        {
            const string input = @"
function testFunc (var1)
    var1 == true
end
testFunc(100)
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Single(script.Diagnostics.Messages);
            Assert.True(script.HasVariable("testFunc"));
        }

        [Fact]
        public void BindUnusedFunctions()
        {
            const string input = @"
function testFunc (var1)
    var1 == true
end
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            var val = script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            Assert.True(script.HasVariable("testFunc"));
        }

        [Fact]
        public void ReturnFromFunction()
        {
            const string input = @"
function testFunc ()
    return 5
end
a = testFunc()
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            var a = script.GetVariable<long>("a");
            Assert.Equal(5, a);
        }

        [Fact]
        public void ReturnFromFunctionOnce()
        {
            const string input = @"
function testFunc ()
    return 5
    return 10
end
a = testFunc()
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            var a = script.GetVariable<long>("a");
            Assert.Equal(5, a);
        }

        [Fact]
        public void ReturnFromFunctionNested()
        {
            const string input = @"
function testFunc ()
    if true then
        return 5
    end
    return 10
end
a = testFunc()
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            script.Evaluate();
            Assert.Empty(script.Diagnostics.Messages);
            var a = script.GetVariable<long>("a");
            Assert.Equal(5, a);
        }

        [Fact]
        public void ReturnFromScriptAsFunction()
        {
            const string input = @"
a = 100
return 60
a = 87
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            var result = script.Evaluate<long>();
            Assert.Empty(script.Diagnostics.Messages);
            Assert.Equal(60, result);
        }

        [Fact]
        public void ReturnFromCSharpCall()
        {
            const string input = @"
function testFunc ()
    return 100
end
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            var result = script.EvaluateFunction<long>("testFunc");
            Assert.Empty(script.Diagnostics.Messages);
            Assert.Equal(100, result);
        }

        [Fact]
        public void ReturnFromCSharpCallWithParameter()
        {
            const string input = @"
function testFunc (b)
    if b then
        return 100
    else
        return 50
    end
end
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            var result = script.EvaluateFunction<long>("testFunc", new object[] {true});
            Assert.Empty(script.Diagnostics.Messages);
            Assert.Equal(100, result);
            var result2 = script.EvaluateFunction<long>("testFunc", new object[] {false});
            Assert.Empty(script.Diagnostics.Messages);
            Assert.Equal(50, result2);

        }

        [Fact]
        public void ReturnFromCSharpCallWithParameters()
        {
            const string input = @"
function add (a, b)
    return a + b
end
";
            var script = new Script(input);
            Assert.Empty(script.Diagnostics.Messages);
            var result = script.EvaluateFunction<long>("add", new object[] {400, 128});
            Assert.Empty(script.Diagnostics.Messages);
            Assert.Equal(528, result);

        }

    }
}