using DynamicExpresso;
using OpenTap;
using OpenTap.Addin.Util;
using System;

namespace AddInPlugin.Util
{
    public class DefaultVariableResolver : IVariableResolver
    {

        private Interpreter GetInterpreter(TestPlanRun run, ITestStep step)
        {
            var target = new Interpreter();
            target.SetVariable("this", MethodUtil.Instance);
            target.SetVariable("FileGlobals", run?.FileGlobalsRuntime);
            target.SetVariable("StationGlobals", run?.StationGlobalsRuntime);
            target.SetVariable("Parameters", run?.ParametersRuntime);

            var context = step?.GetParent<ContextStep>();
            if (context != null)
            {
                target.SetVariable("Context", context.GetContextVariables());
            }
            return target;
        }

        public dynamic Resolve(TestPlanRun run, ITestStep step, string expr)
        {
            return Resolve(run, step, expr, typeof(void));
        }

        public T Resolve<T>(TestPlanRun run, ITestStep step, string expr)
        {
            return Resolve(run, step, expr, typeof(T));
        }

        public dynamic Resolve(TestPlanRun run, ITestStep step, string expr, Type targetType)
        {
            if (expr == null) return null;
            var target = GetInterpreter(run, step);
            if (targetType == typeof(string))
            {
                return target.Eval(expr)?.ToString();
            }
            return target.Eval(expr, targetType);
        }
    }
}