// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.ComponentModel.DataAnnotations;
using Xunit;

namespace Microsoft.AspNetCore.Components.Forms
{
    public class EditContextDataAnnotationsExtensionsTest
    {
        [Fact]
        public void CannotUseNullEditContext()
        {
            var editContext = (EditContext)null;
            var ex = Assert.Throws<ArgumentNullException>(() => editContext.AddDataAnnotationsValidation());
            Assert.Equal("editContext", ex.ParamName);
        }

        [Fact]
        public void ReturnsEditContextForChaining()
        {
            var editContext = new EditContext(new object());
            var returnValue = editContext.AddDataAnnotationsValidation();
            Assert.Same(editContext, returnValue);
        }

        [Fact]
        public void GetsValidationMessagesFromDataAnnotations()
        {
            // Arrange
            var model = new TestModel { IntFrom1To100 = 101 };
            var editContext = new EditContext(model).AddDataAnnotationsValidation();

            // Act
            var isValid = editContext.Validate();

            // Assert
            Assert.False(isValid);

            Assert.Equal(new string[]
                {
                    "RequiredString:required",
                    "IntFrom1To100:range"
                },
                editContext.GetValidationMessages());

            Assert.Equal(new string[] { "RequiredString:required" },
                editContext.GetValidationMessages(editContext.Field(nameof(TestModel.RequiredString))));

            // This shows we're including non-[Required] properties in the validation results, i.e,
            // that we're correctly passing "validateAllProperties: true" to DataAnnotations
            Assert.Equal(new string[] { "IntFrom1To100:range" },
                editContext.GetValidationMessages(editContext.Field(nameof(TestModel.IntFrom1To100))));
        }

        [Fact]
        public void ClearsExistingValidationMessagesOnFurtherRuns()
        {
            // Arrange
            var model = new TestModel { IntFrom1To100 = 101 };
            var editContext = new EditContext(model).AddDataAnnotationsValidation();

            // Act/Assert 1: Initially invalid
            Assert.False(editContext.Validate());

            // Act/Assert 2: Can become valid
            model.RequiredString = "Hello";
            model.IntFrom1To100 = 100;
            Assert.True(editContext.Validate());
        }

        [Fact]
        public void NotifiesValidationStateChangedAfterObjectValidation()
        {
            // Arrange
            var model = new TestModel { IntFrom1To100 = 101 };
            var editContext = new EditContext(model).AddDataAnnotationsValidation();
            var onValidationStateChangedCount = 0;
            editContext.OnValidationStateChanged += (sender, eventArgs) => onValidationStateChangedCount++;

            // Act/Assert 1: Notifies after invalid results
            Assert.False(editContext.Validate());
            Assert.Equal(1, onValidationStateChangedCount);

            // Act/Assert 2: Notifies after valid results
            model.RequiredString = "Hello";
            model.IntFrom1To100 = 100;
            Assert.True(editContext.Validate());
            Assert.Equal(2, onValidationStateChangedCount);

            // Act/Assert 3: Notifies even if results haven't changed. Later we might change the
            // logic to track the previous results and compare with the new ones, but that's just
            // an optimization. It's legal to notify regardless.
            Assert.True(editContext.Validate());
            Assert.Equal(3, onValidationStateChangedCount);
        }

        [Fact]
        public void PerformsPerPropertyValidationOnFieldChange()
        {
            // Arrange
            var model = new TestModel { IntFrom1To100 = 101 };
            var independentTopLevelModel = new object(); // To show we can validate things on any model, not just the top-level one
            var editContext = new EditContext(independentTopLevelModel).AddDataAnnotationsValidation();
            var onValidationStateChangedCount = 0;
            var requiredStringIdentifier = new FieldIdentifier(model, nameof(TestModel.RequiredString));
            var intFrom1To100Identifier = new FieldIdentifier(model, nameof(TestModel.IntFrom1To100));
            editContext.OnValidationStateChanged += (sender, eventArgs) => onValidationStateChangedCount++;

            // Act/Assert 1: Notify about RequiredString
            // Only RequiredString gets validated, even though IntFrom1To100 also holds an invalid value
            editContext.NotifyFieldChanged(requiredStringIdentifier);
            Assert.Equal(1, onValidationStateChangedCount);
            Assert.Equal(new[] { "RequiredString:required" }, editContext.GetValidationMessages());

            // Act/Assert 2: Fix RequiredString, but only notify about IntFrom1To100
            // Only IntFrom1To100 gets validated; messages for RequiredString are left unchanged
            model.RequiredString = "This string is very cool and very legal";
            editContext.NotifyFieldChanged(intFrom1To100Identifier);
            Assert.Equal(2, onValidationStateChangedCount);
            Assert.Equal(new string[]
                {
                    "RequiredString:required",
                    "IntFrom1To100:range"
                },
                editContext.GetValidationMessages());

            // Act/Assert 3: Notify about RequiredString
            editContext.NotifyFieldChanged(requiredStringIdentifier);
            Assert.Equal(3, onValidationStateChangedCount);
            Assert.Equal(new[] { "IntFrom1To100:range" }, editContext.GetValidationMessages());
        }

        [Theory]
        [InlineData(nameof(TestModel.ThisWillNotBeValidatedBecauseItIsAField))]
        [InlineData(nameof(TestModel.ThisWillNotBeValidatedBecauseItIsInternal))]
        [InlineData("ThisWillNotBeValidatedBecauseItIsPrivate")]
        [InlineData("This does not correspond to anything")]
        [InlineData("")]
        public void IgnoresFieldChangesThatDoNotCorrespondToAValidatableProperty(string fieldName)
        {
            // Arrange
            var editContext = new EditContext(new TestModel()).AddDataAnnotationsValidation();
            var onValidationStateChangedCount = 0;
            editContext.OnValidationStateChanged += (sender, eventArgs) => onValidationStateChangedCount++;

            // Act/Assert: Ignores field changes that don't correspond to a validatable property
            editContext.NotifyFieldChanged(editContext.Field(fieldName));
            Assert.Equal(0, onValidationStateChangedCount);

            // Act/Assert: For sanity, observe that we would have validated if it was a validatable property
            editContext.NotifyFieldChanged(editContext.Field(nameof(TestModel.RequiredString)));
            Assert.Equal(1, onValidationStateChangedCount);
        }

        class TestModel
        {
            [Required(ErrorMessage = "RequiredString:required")] public string RequiredString { get; set; }

            [Range(1, 100, ErrorMessage = "IntFrom1To100:range")] public int IntFrom1To100 { get; set; }

#pragma warning disable 649
            [Required] public string ThisWillNotBeValidatedBecauseItIsAField;
            [Required] string ThisWillNotBeValidatedBecauseItIsPrivate { get; set; }
            [Required] internal string ThisWillNotBeValidatedBecauseItIsInternal { get; set; }
#pragma warning restore 649
        }
    }
}