using System.Globalization;
using System.Text;
using YKanBan.Export;
using YKanBan.Models;

namespace YKanBan.Tests.Export;

/// <summary>
/// Tests for the Markdown exporter. Mutates the global
/// <see cref="Resources.Culture"/>, therefore marked do-not-parallelize.
/// Expected documents are assembled from the same ResX template keys as the
/// exporter (plus fixed fixture values), so no localized text is hard-coded
/// here.
/// </summary>
[TestClass]
[DoNotParallelize]
public class MarkdownExporterTests
{
    private static readonly DateTimeOffset ExportedAt = new(2026, 9, 30, 14, 25, 37, TimeSpan.Zero);

    /// <summary>
    /// Builds a local wall-clock moment, matching the exporter's conversion path.
    /// </summary>
    /// <param name="year">The year.</param>
    /// <param name="month">The month.</param>
    /// <param name="day">The day.</param>
    /// <param name="hour">The hour.</param>
    /// <param name="minute">The minute.</param>
    /// <returns>The local time.</returns>
    private static DateTimeOffset Local(int year, int month, int day, int hour, int minute) =>
        new DateTimeOffset(new DateTime(year, month, day, hour, minute, 0)).ToLocalTime();

    /// <summary>
    /// Converts a local wall-clock time to Unix seconds.
    /// </summary>
    /// <param name="year">The year.</param>
    /// <param name="month">The month.</param>
    /// <param name="day">The day.</param>
    /// <param name="hour">The hour.</param>
    /// <param name="minute">The minute.</param>
    /// <returns>The Unix timestamp.</returns>
    private static long UnixTimeOf(int year, int month, int day, int hour, int minute) =>
        Local(year, month, day, hour, minute).ToUnixTimeSeconds();

    /// <summary>
    /// Builds the board fixture: one working column with two cards, one empty column and two tags.
    /// </summary>
    /// <returns>The columns, cards and tag/usage tuples.</returns>
    private static (IReadOnlyList<ColumnModel> Columns, IReadOnlyList<CardModel> Cards, IReadOnlyList<(TagModel, long)> Tags) CreateBoard()
    {
        long created = UnixTimeOf(2026, 9, 1, 10, 0);
        long updated = UnixTimeOf(2026, 9, 28, 18, 30);

        var columns = new List<ColumnModel>
        {
            new(1, "In Progress", "The work column", 100, 100),
            new(2, "Empty", string.Empty, 100, 100),
        };
        var bug = new TagModel(1, "bug", RgbColor.Parse("#ff0000"), string.Empty);
        var ui = new TagModel(2, "ui", RgbColor.Parse("#00ff00"), "Interface work");
        var cards = new List<CardModel>
        {
            new(61, 1, "Fix login", "Body text", created, updated, [bug, ui]),
            new(62, 1, string.Empty, string.Empty, created, updated, []),
        };
        var tags = new List<(TagModel, long)> { (bug, 1), (ui, 1) };
        return (columns, cards, tags);
    }

    /// <summary>
    /// Renders the fixture board with the exporter under the current culture.
    /// </summary>
    /// <returns>The produced Markdown document.</returns>
    private static string ExportBoard()
    {
        (IReadOnlyList<ColumnModel> columns, IReadOnlyList<CardModel> cards, IReadOnlyList<(TagModel, long)> tags) = CreateBoard();
        return MarkdownExporter.Export("MyRepo", columns, cards, tags, ExportedAt);
    }

    /// <summary>
    /// Assembles the expected document from the ResX template keys under the current culture.
    /// </summary>
    /// <param name="culture">The UI culture.</param>
    /// <returns>The expected Markdown document.</returns>
    private static string BuildExpected(CultureInfo culture)
    {
        string created = Local(2026, 9, 1, 10, 0).ToString(Resources.Export_CardTimePattern, culture);
        string updated = Local(2026, 9, 28, 18, 30).ToString(Resources.Export_CardTimePattern, culture);

        var builder = new StringBuilder();

        // Header: workspace name and the export timestamp.
        builder.AppendLine(string.Format(culture, Resources.Export_WorkspaceHeading, "MyRepo"));
        builder.AppendLine(string.Format(
            culture, Resources.Export_ExportedAtLine, ExportedAt.ToString(Resources.Export_TimePattern, culture)));
        builder.AppendLine();

        // First column with its two cards.
        builder.AppendLine(string.Format(culture, Resources.Export_ColumnHeading, "In Progress", 2));
        builder.AppendLine("The work column");
        builder.AppendLine();
        builder.AppendLine("### #61 Fix login");
        builder.AppendLine("Body text");
        builder.AppendLine(string.Format(culture, Resources.Export_TagsLine, "`bug` `ui`"));
        builder.AppendLine(string.Format(culture, Resources.Export_CreatedModifiedLine, created, updated));
        builder.AppendLine();
        builder.AppendLine("### #62");
        builder.AppendLine(string.Format(culture, Resources.Export_CreatedModifiedLine, created, updated));
        builder.AppendLine();

        // Empty column is kept.
        builder.AppendLine(string.Format(culture, Resources.Export_ColumnHeading, "Empty", 0));
        builder.AppendLine();

        // Tag summary table.
        builder.AppendLine(Resources.Export_TagsSummaryHeading);
        builder.AppendLine(Resources.Export_TagsTableHeader);
        builder.AppendLine("|---|---|---|---|");
        builder.AppendLine("| bug | #ff0000 |  | 1 |");
        builder.AppendLine("| ui | #00ff00 | Interface work | 1 |");

        return builder.ToString();
    }

    /// <summary>
    /// Normalizes CRLF line endings so expected and actual compare consistently.
    /// </summary>
    /// <param name="text">The text to normalize.</param>
    /// <returns>The text with normalized line endings.</returns>
    private static string Normalize(string text) => text.Replace("\r\n", "\n");

    /// <summary>
    /// Asserts that the exporter output matches the resource-built expected document.
    /// </summary>
    /// <param name="culture">The UI culture to test.</param>
    private static void AssertOutputMatches(CultureInfo culture)
    {
        CultureInfo? original = Resources.Culture;
        try
        {
            Resources.Culture = culture;
            Assert.AreEqual(Normalize(BuildExpected(culture)), Normalize(ExportBoard()));
        }
        finally
        {
            Resources.Culture = original;
        }
    }

    [TestMethod]
    public void EnglishOutputMatchesTemplate()
    {
        AssertOutputMatches(new CultureInfo("en"));
    }

    [TestMethod]
    public void ChineseOutputMatchesTemplate()
    {
        AssertOutputMatches(new CultureInfo("zh-Hans"));
    }

    [TestMethod]
    public void FileNameFollowsLanguage()
    {
        CultureInfo? original = Resources.Culture;
        try
        {
            Resources.Culture = new CultureInfo("en");
            Assert.AreEqual(
                string.Format(Resources.Culture, Resources.Export_FileNamePattern, "MyRepo", ExportedAt),
                MarkdownExporter.BuildFileName("MyRepo", ExportedAt));

            Resources.Culture = new CultureInfo("zh-Hans");
            Assert.AreEqual(
                string.Format(Resources.Culture, Resources.Export_FileNamePattern, "MyRepo", ExportedAt),
                MarkdownExporter.BuildFileName("MyRepo", ExportedAt));
        }
        finally
        {
            Resources.Culture = original;
        }
    }

    [TestMethod]
    public void TagTableCellsEscapePipesAndLineBreaks()
    {
        CultureInfo? original = Resources.Culture;
        try
        {
            Resources.Culture = new CultureInfo("en");
            var tag = new TagModel(1, "a|b", RgbColor.Parse("#112233"), "first\nsecond");
            string markdown = MarkdownExporter.Export(
                "W",
                [new ColumnModel(1, "C", string.Empty, 1, 1)],
                [],
                [(tag, 0L)],
                ExportedAt);

            StringAssert.Contains(markdown, "| a\\|b | #112233 | first second | 0 |");
        }
        finally
        {
            Resources.Culture = original;
        }
    }
}