using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using AutoFixture;
using AutoFixture.Kernel;
using AutoFixture.Xunit2;
using Bit.Test.Common.AutoFixture.Attributes;

namespace Bit.Test.Common.Helpers
{
    public static class BitAutoDataAttributeHelpers
    {
        public static IEnumerable<object[]> GetData(MethodInfo testMethod, IFixture fixture, object[] fixedTestParameters)
        {
            var methodParameters = testMethod.GetParameters();
            var classCustomizations = testMethod.DeclaringType.GetCustomAttributes<BitCustomizeAttribute>().Select(attr => attr.GetCustomization());
            var methodCustomizations = testMethod.GetCustomAttributes<BitCustomizeAttribute>().Select(attr => attr.GetCustomization());

            fixedTestParameters = fixedTestParameters ?? Array.Empty<object>();

            fixture = ApplyCustomizations(ApplyCustomizations(fixture, classCustomizations), methodCustomizations);
            var missingParameters = methodParameters.Skip(fixedTestParameters.Length).Select(p => CustomizeAndCreate(p, fixture));

            return new object[1][] { fixedTestParameters.Concat(missingParameters).ToArray() };
        }

        public static object CustomizeAndCreate(ParameterInfo p, IFixture fixture)
        {
            var customizations = p.GetCustomAttributes(typeof(CustomizeAttribute), false)
                .OfType<CustomizeAttribute>()
                .Select(attr => attr.GetCustomization(p));

            var context = new SpecimenContext(ApplyCustomizations(fixture, customizations));
            return context.Resolve(p);
        }

        public static IFixture ApplyCustomizations(IFixture fixture, IEnumerable<ICustomization> customizations)
        {
            var newFixture = new Fixture();

            foreach (var customization in fixture.Customizations.Reverse().Select(b => b.ToCustomization()))
            {
                newFixture.Customize(customization);
            }

            foreach (var customization in customizations)
            {
                newFixture.Customize(customization);
            }

            return newFixture;
        }
    }
}