// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Generic;
using System.Linq;
using Xunit.Abstractions;
using Xunit.Sdk;
 
namespace Microsoft.DotNet.XUnitExtensions
{
    public class ConditionalTheoryDiscoverer : TheoryDiscoverer
    {
        private readonly Dictionary<IMethodInfo, string> _conditionCache;
 
        public ConditionalTheoryDiscoverer(IMessageSink diagnosticMessageSink) : base(diagnosticMessageSink)
        {
            _conditionCache = new Dictionary<IMethodInfo, string>();
        }
 
        protected override IEnumerable<IXunitTestCase> CreateTestCasesForTheory(ITestFrameworkDiscoveryOptions discoveryOptions, ITestMethod testMethod, IAttributeInfo theoryAttribute)
        {
            if (ConditionalTestDiscoverer.TryEvaluateSkipConditions(discoveryOptions, DiagnosticMessageSink, testMethod, theoryAttribute.GetConstructorArguments().ToArray(), out string skipReason, out ExecutionErrorTestCase errorTestCase))
            {
                return skipReason != null
                   ? new[] { new SkippedTestCase(skipReason, DiagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), discoveryOptions.MethodDisplayOptionsOrDefault(), testMethod) }
                   : new IXunitTestCase[] { new SkippedTheoryTestCase(DiagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), discoveryOptions.MethodDisplayOptionsOrDefault(), testMethod) }; // Theory skippable at runtime.
            }
 
            return new IXunitTestCase[] { errorTestCase };
        }
 
        protected override IEnumerable<IXunitTestCase> CreateTestCasesForDataRow(ITestFrameworkDiscoveryOptions discoveryOptions, ITestMethod testMethod, IAttributeInfo theoryAttribute, object[] dataRow)
        {
            IMethodInfo methodInfo = testMethod.Method;
            List<IXunitTestCase> skippedTestCase = new List<IXunitTestCase>();
 
            if (!_conditionCache.TryGetValue(methodInfo, out string skipReason))
            {
                if (!ConditionalTestDiscoverer.TryEvaluateSkipConditions(discoveryOptions, DiagnosticMessageSink, testMethod, theoryAttribute.GetConstructorArguments().ToArray(), out skipReason, out ExecutionErrorTestCase errorTestCase))
                {
                    return new IXunitTestCase[] { errorTestCase };
                }
 
                _conditionCache.Add(methodInfo, skipReason);
 
                if (skipReason != null)
                {
                    // If this is the first time we evalute the condition we return a SkippedTestCase to avoid printing a skip for every inline-data.
                    skippedTestCase.Add(new SkippedTestCase(skipReason, DiagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), discoveryOptions.MethodDisplayOptionsOrDefault(), testMethod));
                }
            }
 
            return skipReason != null ?
                        (IEnumerable<IXunitTestCase>)skippedTestCase
                        : new [] { new SkippedFactTestCase(DiagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), discoveryOptions.MethodDisplayOptionsOrDefault(), testMethod, dataRow) }; // Test case skippable at runtime.
        }
    }
}