using System;
using System.Globalization;
using Amphora;
using Glass.Text;
using UnitTestSharp;
using static Glass.Text.Plurals;
using static Glass.Text.Styles;

namespace Glass.UnitTests
{
    public class LocaleBehaviorTests : TestFixture
    {
        public static TextPieces Stock(long boxes)
        {
            return $"{Count(boxes)} boxes";
        }

        public class VersionTests : TestFixture
        {
            public void StartsAtZero()
            {
                CheckEqual(0, new LocaleBehavior().Version);
            }

            public void EveryAssignmentBumpsIt()
            {
                var locale = new LocaleBehavior();

                locale.NumberFormat = NumberFormat.Invariant;
                CheckEqual(1, locale.Version);

                locale.PluralRules = PluralRules.None;
                CheckEqual(2, locale.Version);

                locale.SetCulture(new CultureInfo("de-DE"));
                CheckEqual(3, locale.Version);
            }

            public void ARejectedAssignment_LeavesItAlone()
            {
                var locale = new LocaleBehavior();

                CheckThrow(typeof(ArgumentNullException));
                locale.NumberFormat = null;
                CheckThrow(typeof(ArgumentNullException));
                locale.PluralRules = null;
                CheckThrow(typeof(ArgumentNullException));
                locale.SetCulture(null);

                CheckEqual(0, locale.Version);
            }
        }

        public class NumberFormatTests : TestFixture
        {
            public void IsInvariantUnlessChanged()
            {
                CheckTrue(ReferenceEquals(NumberFormat.Invariant, new LocaleBehavior().NumberFormat));
            }

            public void Setting_IsKept()
            {
                NumberFormat format = NumberFormat.FromCulture(new CultureInfo("de-DE"));
                var locale = new LocaleBehavior { NumberFormat = format };

                CheckTrue(ReferenceEquals(format, locale.NumberFormat));
            }
        }

        public class PluralRulesTests : TestFixture
        {
            public void AreEnglishUnlessChanged()
            {
                CheckTrue(ReferenceEquals(PluralRules.English, new LocaleBehavior().PluralRules));
            }

            public void Setting_IsKept()
            {
                var locale = new LocaleBehavior { PluralRules = PluralRules.None };

                CheckTrue(ReferenceEquals(PluralRules.None, locale.PluralRules));
            }
        }

        public class SetCultureTests : TestFixture
        {
            public void TakesBothTheNumberFormatAndThePluralRules()
            {
                var locale = new LocaleBehavior();
                locale.SetCulture(new CultureInfo("de-DE"));

                CheckEqual(".", locale.NumberFormat.GroupSeparator);
                CheckEqual("de", locale.PluralRules.Tag);
            }
        }

        public class WriteTests : TestFixture
        {
            public void ALine_UsesTheNumberFormat()
            {
                var locale = new LocaleBehavior();
                locale.SetCulture(new CultureInfo("de-DE"));
                char[] scratch = null;

                CheckEqual("1.234 boxes", locale.Write(Stock(1234), ref scratch).ToString());
            }

            public void ALine_ChangesWithTheLocale()
            {
                var locale = new LocaleBehavior();
                char[] scratch = null;
                CheckEqual("1,234 boxes", locale.Write(Stock(1234), ref scratch).ToString());

                locale.SetCulture(new CultureInfo("de-DE"));

                CheckEqual("1.234 boxes", locale.Write(Stock(1234), ref scratch).ToString());
            }

            public void ALineWithSpans_FillsTheSpans()
            {
                var locale = new LocaleBehavior();
                var spans = new DynamicArray<StyleSpan>();
                char[] scratch = null;
                TextPieces line = $"{Bold(Count(1234))} boxes";

                StringView view = locale.Write(line, ref scratch, spans);

                CheckEqual("1,234 boxes", view.ToString());
                CheckEqual(1, spans.Count);
                CheckEqual(0, spans[0].Start);
                CheckEqual(5, spans[0].End);
            }

            public void APluralLine_ChoosesByTheRules()
            {
                var locale = new LocaleBehavior();
                char[] scratch = null;
                PluralLine line = Plural(Count(1), one: $"{Amount} box", other: $"{Amount} boxes");
                CheckEqual("1 box", locale.Write(line, ref scratch).ToString());

                locale.PluralRules = PluralRules.None;

                CheckEqual("1 boxes", locale.Write(line, ref scratch).ToString());
            }

            public void APluralLineWithSpans_FillsTheSpans()
            {
                var locale = new LocaleBehavior();
                var spans = new DynamicArray<StyleSpan>();
                char[] scratch = null;
                PluralLine line = Plural(Count(1), one: $"{Bold(Amount)} box", other: $"{Bold(Amount)} boxes");

                StringView view = locale.Write(line, ref scratch, spans);

                CheckEqual("1 box", view.ToString());
                CheckEqual(1, spans.Count);
            }
        }
    }
}