using System.Collections.Generic;
using System.Linq;
using NUnit.Framework;
using StardewModdingAPI;
using StardewModdingAPI.Toolkit.Framework.Clients.Wiki;

namespace SMAPI.Tests.WikiClient
{
    /// <summary>Unit tests for <see cref="ChangeDescriptor"/>.</summary>
    [TestFixture]
    internal class ChangeDescriptorTests
    {
        /*********
        ** Unit tests
        *********/
        /****
        ** Constructor
        ****/
        [Test(Description = "Assert that Parse sets the expected values for valid and invalid descriptors.")]
        public void Parse_SetsExpectedValues_Raw()
        {
            // arrange
            string rawDescriptor = "-Nexus:2400,    -B, XX → YY, Nexus:451,+A, XXX → YYY, invalidA →, → invalidB";
            string[] expectedAdd = new[] { "Nexus:451", "A" };
            string[] expectedRemove = new[] { "Nexus:2400", "B" };
            IDictionary<string, string> expectedReplace = new Dictionary<string, string>
            {
                ["XX"] = "YY",
                ["XXX"] = "YYY"
            };
            string[] expectedErrors = new[]
            {
                "Failed parsing ' invalidA →': can't map to a blank value. Use the '-value' format to remove a value.",
                "Failed parsing ' → invalidB': can't map from a blank old value. Use the '+value' format to add a value."
            };

            // act
            ChangeDescriptor parsed = ChangeDescriptor.Parse(rawDescriptor, out string[] errors);

            // assert
            Assert.That(parsed.Add, Is.EquivalentTo(expectedAdd), $"{nameof(parsed.Add)} doesn't match the expected value.");
            Assert.That(parsed.Remove, Is.EquivalentTo(expectedRemove), $"{nameof(parsed.Replace)} doesn't match the expected value.");
            Assert.That(parsed.Replace, Is.EquivalentTo(expectedReplace), $"{nameof(parsed.Replace)} doesn't match the expected value.");
            Assert.That(errors, Is.EquivalentTo(expectedErrors), $"{nameof(errors)} doesn't match the expected value.");
        }

        [Test(Description = "Assert that Parse sets the expected values for descriptors when a format callback is specified.")]
        public void Parse_SetsExpectedValues_Formatted()
        {
            // arrange
            string rawDescriptor = "-1.0.1,    -2.0-beta, 1.00 → 1.0, 1.0.0,+2.0-beta.15, 2.0 → 2.0-beta, invalidA →, → invalidB";
            string[] expectedAdd = new[] { "1.0.0", "2.0.0-beta.15" };
            string[] expectedRemove = new[] { "1.0.1", "2.0.0-beta" };
            IDictionary<string, string> expectedReplace = new Dictionary<string, string>
            {
                ["1.00"] = "1.0.0",
                ["2.0.0"] = "2.0.0-beta"
            };
            string[] expectedErrors = new[]
            {
                "Failed parsing ' invalidA →': can't map to a blank value. Use the '-value' format to remove a value.",
                "Failed parsing ' → invalidB': can't map from a blank old value. Use the '+value' format to add a value."
            };

            // act
            ChangeDescriptor parsed = ChangeDescriptor.Parse(
                rawDescriptor,
                out string[] errors,
                formatValue: raw => SemanticVersion.TryParse(raw, out ISemanticVersion version)
                    ? version.ToString()
                    : raw
            );

            // assert
            Assert.That(parsed.Add, Is.EquivalentTo(expectedAdd), $"{nameof(parsed.Add)} doesn't match the expected value.");
            Assert.That(parsed.Remove, Is.EquivalentTo(expectedRemove), $"{nameof(parsed.Replace)} doesn't match the expected value.");
            Assert.That(parsed.Replace, Is.EquivalentTo(expectedReplace), $"{nameof(parsed.Replace)} doesn't match the expected value.");
            Assert.That(errors, Is.EquivalentTo(expectedErrors), $"{nameof(errors)} doesn't match the expected value.");
        }

        [Test(Description = "Assert that Apply returns the expected value for the given descriptor.")]

        // null input
        [TestCase(null, "", ExpectedResult = null)]
        [TestCase(null, "+Nexus:2400", ExpectedResult = "Nexus:2400")]
        [TestCase(null, "-Nexus:2400", ExpectedResult = null)]

        // blank input
        [TestCase("", null, ExpectedResult = "")]
        [TestCase("", "", ExpectedResult = "")]

        // add value
        [TestCase("", "+Nexus:2400", ExpectedResult = "Nexus:2400")]
        [TestCase("Nexus:2400", "+Nexus:2400", ExpectedResult = "Nexus:2400")]
        [TestCase("Nexus:2400", "Nexus:2400", ExpectedResult = "Nexus:2400")]
        [TestCase("Nexus:2400", "+Nexus:2401", ExpectedResult = "Nexus:2400, Nexus:2401")]
        [TestCase("Nexus:2400", "Nexus:2401", ExpectedResult = "Nexus:2400, Nexus:2401")]

        // remove value
        [TestCase("", "-Nexus:2400", ExpectedResult = "")]
        [TestCase("Nexus:2400", "-Nexus:2400", ExpectedResult = "")]
        [TestCase("Nexus:2400", "-Nexus:2401", ExpectedResult = "Nexus:2400")]

        // replace value
        [TestCase("", "Nexus:2400 → Nexus:2401", ExpectedResult = "")]
        [TestCase("Nexus:2400", "Nexus:2400 → Nexus:2401", ExpectedResult = "Nexus:2401")]
        [TestCase("Nexus:1", "Nexus: 2400 → Nexus: 2401", ExpectedResult = "Nexus:1")]

        // complex strings
        [TestCase("", "+Nexus:A, Nexus:B, -Chucklefish:14, Nexus:2400 → Nexus:2401, Nexus:A→Nexus:B", ExpectedResult = "Nexus:A, Nexus:B")]
        [TestCase("Nexus:2400", "+Nexus:A, Nexus:B, -Chucklefish:14, Nexus:2400 → Nexus:2401, Nexus:A→Nexus:B", ExpectedResult = "Nexus:2401, Nexus:A, Nexus:B")]
        [TestCase("Nexus:2400, Nexus:2401, Nexus:B,Chucklefish:14", "+Nexus:A, Nexus:B, -Chucklefish:14, Nexus:2400 → Nexus:2401, Nexus:A→Nexus:B", ExpectedResult = "Nexus:2401, Nexus:2401, Nexus:B, Nexus:A")]
        public string Apply_Raw(string input, string descriptor)
        {
            var parsed = ChangeDescriptor.Parse(descriptor, out string[] errors);

            Assert.IsEmpty(errors, "Parsing the descriptor failed.");

            return parsed.ApplyToCopy(input);
        }

        [Test(Description = "Assert that ToString returns the expected normalized descriptors.")]
        [TestCase(null, ExpectedResult = "")]
        [TestCase("", ExpectedResult = "")]
        [TestCase("+   Nexus:2400", ExpectedResult = "+Nexus:2400")]
        [TestCase("  Nexus:2400  ", ExpectedResult = "+Nexus:2400")]
        [TestCase("-Nexus:2400", ExpectedResult = "-Nexus:2400")]
        [TestCase("  Nexus:2400   →Nexus:2401  ", ExpectedResult = "Nexus:2400 → Nexus:2401")]
        [TestCase("+Nexus:A, Nexus:B, -Chucklefish:14, Nexus:2400 → Nexus:2401, Nexus:A→Nexus:B", ExpectedResult = "+Nexus:A, +Nexus:B, -Chucklefish:14, Nexus:2400 → Nexus:2401, Nexus:A → Nexus:B")]
        public string ToString(string descriptor)
        {
            var parsed = ChangeDescriptor.Parse(descriptor, out string[] errors);

            Assert.IsEmpty(errors, "Parsing the descriptor failed.");

            return parsed.ToString();
        }
    }
}