using System;
using Glass.Typesetting;
using UnitTestSharp;

namespace Glass.UnitTests.Typesetting
{
    public class WordEndMetricsTests : TestFixture
    {
        public static MeasuredWord Word(int trailingSpaces = 0, LineBreakEnding ending = LineBreakEnding.Plain,
            bool isMandatory = false, short endKerning = 0)
        {
            return new MeasuredWord(new LineBreak(9, isMandatory, trailingSpaces, ending), contentWidth: 20,
                leadingKerning: 0, endKerning);
        }

        public static readonly WordEndMetrics Ends = new WordEndMetrics(WordMeasurerTests.TestFont());

        public class CtorTests : TestFixture
        {
            public void NullFont_Throws()
            {
                CheckThrow(typeof(ArgumentNullException));
                new WordEndMetrics(null);
            }

            public void FromAlreadyLookedUpPieces_MatchesConstructingFromTheFont()
            {
                SpriteFontDefinition font = WordMeasurerTests.TestFont();
                var fromFont = new WordEndMetrics(font);
                var fromPieces = new WordEndMetrics(font.MetricsTable, font.KerningTable, font.MetricsTable[' ']);

                MeasuredWord spaces = Word(trailingSpaces: 1, endKerning: -2);
                MeasuredWord hyphen = Word(ending: LineBreakEnding.SoftHyphen, endKerning: -1);

                CheckEqual(fromFont.TrailingWidthOf(spaces), fromPieces.TrailingWidthOf(spaces));
                CheckEqual(fromFont.HyphenWidthOf(hyphen), fromPieces.HyphenWidthOf(hyphen));
            }
        }

        public class TrailingWidthOfTests : TestFixture
        {
            public void NoSpaces_IsZero()
            {
                CheckEqual(0, Ends.TrailingWidthOf(Word(endKerning: -2)));
            }

            public void OneSpace_IsTheSpaceAndTheKerningIntoIt()
            {
                CheckEqual(-2 + WordMeasurerTests.SpaceWidth,
                    Ends.TrailingWidthOf(Word(trailingSpaces: 1, endKerning: -2)));
            }

            public void SeveralSpaces_KernBetweenEachOther()
            {
                var ends = new WordEndMetrics(WordMeasurerTests.TestFont(kerningBetweenSpaces: -1));

                CheckEqual(-2 + 3 * WordMeasurerTests.SpaceWidth + 2 * -1,
                    ends.TrailingWidthOf(Word(trailingSpaces: 3, endKerning: -2)));
            }
        }

        public class HyphenWidthOfTests : TestFixture
        {
            public void SoftHyphen_IsTheHyphenAndTheKerningIntoIt()
            {
                CheckEqual(-1 + WordMeasurerTests.HyphenWidth,
                    Ends.HyphenWidthOf(Word(ending: LineBreakEnding.SoftHyphen, endKerning: -1)));
            }

            public void MandatoryBreakAfterASoftHyphen_ShowsNoHyphen()
            {
                CheckEqual(0,
                    Ends.HyphenWidthOf(Word(ending: LineBreakEnding.SoftHyphen, isMandatory: true, endKerning: -1)));
            }

            public void NoSoftHyphen_IsZero()
            {
                CheckEqual(0, Ends.HyphenWidthOf(Word(trailingSpaces: 1, endKerning: -1)));
            }
        }
    }
}