using System.Collections.Generic;
using System.Linq;
using AcDream.App.UI.Layout;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// <see cref="ChatTranscriptRenderer.WrapText"/> tests — moved here from
/// <c>ChatWindowControllerTests</c> (CH6a/b REJECT-review NIT 5: WrapText
/// itself moved off <c>ChatWindowController</c> onto
/// <see cref="ChatTranscriptRenderer"/> to close the circular dependency
/// where <see cref="ChatTranscriptRenderer.BuildLines"/> called back into
/// one of its own two consumers).
///
/// <para>
/// Campaign CH user-gate round 1, item F: <c>/help</c> (and "probably many
/// places") never split on embedded <c>'\n'</c> — the whole multi-line blob
/// rode the single early-out as ONE line. Split on <c>'\n'</c> first, then
/// word-wrap each segment; a single-segment text keeps the pre-existing
/// early-out behavior exactly.
/// </para>
/// </summary>
public class ChatTranscriptRendererTests
{
    private static float MeasureByCharCount(string s) => s.Length;

    [Fact]
    public void WrapText_EmbeddedNewlines_ProduceOneRenderedLinePerSegment()
    {
        string text = "line one\nline two\nline three";

        // maxW is generous — every segment fits without word-wrapping, so
        // this isolates the newline-split behavior specifically.
        var lines = new List<string>(ChatTranscriptRenderer.WrapText(text, 1000f, MeasureByCharCount));

        Assert.Equal(new[] { "line one", "line two", "line three" }, lines);
    }

    [Fact]
    public void WrapText_CarriageReturnNewline_NormalizesTheSameAsBareNewline()
    {
        string text = "line one\r\nline two";

        var lines = new List<string>(ChatTranscriptRenderer.WrapText(text, 1000f, MeasureByCharCount));

        Assert.Equal(new[] { "line one", "line two" }, lines);
    }

    [Fact]
    public void WrapText_SegmentLongerThanMaxWidth_StillWordWraps()
    {
        // Each segment is independently word-wrapped by the SAME algorithm
        // the single-line path always used — a multi-line server message
        // whose second line overflows the window still wraps that line.
        string text = "short\nthis segment is much too long to fit on one line";

        var lines = new List<string>(ChatTranscriptRenderer.WrapText(text, 10f, MeasureByCharCount));

        Assert.Equal("short", lines[0]);
        Assert.True(lines.Count > 2, "the long second segment should have wrapped into multiple lines");
        Assert.All(lines, line => Assert.True(MeasureByCharCount(line) <= 10f));
        Assert.Equal(
            "this segment is much too long to fit on one line",
            string.Join(" ", lines.Skip(1)));
    }

    [Fact]
    public void WrapText_SingleSegmentText_KeepsTheEarlyOutBehavior()
    {
        // No '\n' at all — the pre-existing single-line early-out path
        // (whole text fits => returned verbatim as one fragment) is
        // unchanged.
        string text = "no newlines here";

        var lines = new List<string>(ChatTranscriptRenderer.WrapText(text, 1000f, MeasureByCharCount));

        Assert.Equal(new[] { text }, lines);
    }

    [Fact]
    public void WrapText_ConsecutiveNewlines_ProduceABlankLine()
    {
        string text = "first\n\nthird";

        var lines = new List<string>(ChatTranscriptRenderer.WrapText(text, 1000f, MeasureByCharCount));

        Assert.Equal(new[] { "first", "", "third" }, lines);
    }
}