using CentronSoftware.Centron.Controls.PositionGrid.Helpers;
using CentronSoftware.Centron.Controls.PositionGrid.Interfaces;

namespace Centron.Tests.Controls.PositionGrid
{
    /// <summary>
    /// Tests for the indent normalization of a cut-out of positions that is pasted into the receipt
    /// </summary>
    public class PasteIndentNormalizerTests
    {
        private static (ReceiptArticleKind kind, bool? isExpanded, int indent) Position(int indent)
            => (ReceiptArticleKind.Article, null, indent);

        private static (ReceiptArticleKind kind, bool? isExpanded, int indent) PartListHead(int indent)
            => (ReceiptArticleKind.Article, true, indent);

        private static (ReceiptArticleKind kind, bool? isExpanded, int indent) Title(int indent)
            => (ReceiptArticleKind.Titleposition, true, indent);

        [Fact]
        public void CalculateIndents_TitleIndentDoesNotAffectFollowingPartList()
        {
            // A title with a non-zero source indent must not stay the indent reference for the
            // positions after it, otherwise the following part-list head pushes currentIndent below
            // zero and its child ends up at indent 0 instead of 1.
            var positions = new[]
            {
                Title(2),
                PartListHead(0),
                Position(1),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 0, 1 }, indents);
        }

        [Fact]
        public void CalculateIndents_TitleResetsIndentOfPrecedingPartList()
        {
            var positions = new[]
            {
                PartListHead(0),
                Position(1),
                Title(0),
                Position(0),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 1, 0, 0 }, indents);
        }

        [Fact]
        public void CalculateIndents_RebasesCutOutTakenFromInsideAPartList()
        {
            // Cut-out starts at indent 2 because it was copied out of a nested part-list.
            var positions = new[]
            {
                PartListHead(2),
                Position(3),
                Position(3),
                Position(2),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 1, 1, 0 }, indents);
        }

        [Fact]
        public void CalculateIndents_KeepsNestedPartLists()
        {
            var positions = new[]
            {
                PartListHead(0),
                PartListHead(1),
                Position(2),
                Position(1),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 1, 2, 1 }, indents);
        }

        [Fact]
        public void CalculateIndents_ClosesAllPartListsLeftAtOnce()
        {
            // The last position leaves three part-lists at the same time and therefore belongs back
            // on the top level.
            var positions = new[]
            {
                PartListHead(0),
                PartListHead(1),
                PartListHead(2),
                Position(0),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 1, 2, 0 }, indents);
        }

        [Fact]
        public void CalculateIndents_ClosesPartListsUpToTheRemainingLevel()
        {
            // The cut-out drops from indent 3 back to indent 1, so only the two inner part-lists are
            // closed and the position stays inside the outermost one.
            var positions = new[]
            {
                PartListHead(0),
                PartListHead(1),
                PartListHead(2),
                Position(3),
                Position(1),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 1, 2, 3, 1 }, indents);
        }

        [Fact]
        public void CalculateIndents_FlatPositionsStayAtZero()
        {
            var positions = new[]
            {
                Position(0),
                Position(0),
                Position(0),
            };

            var indents = PasteIndentNormalizer.CalculateIndents(positions);

            Assert.Equal(new[] { 0, 0, 0 }, indents);
        }
    }
}