namespace DodoSSH.Client.Ssh.Tests;

/// <summary>
/// Remote paths, permission bits and byte counts — the three things the file browser renders.
/// </summary>
/// <remarks>
/// Not in the SSH collection, so this class needs no container. Every case here is one where the obvious
/// implementation is wrong on Windows, at a filesystem root, or on a number that has just crossed a
/// threshold — which is to say, one that a listing of somebody's home directory would not reveal.
/// </remarks>
public sealed class RemotePathTests
{
    [Theory]
    [InlineData("/var/log", "syslog", "/var/log/syslog")]
    [InlineData("/", "etc", "/etc")]
    [InlineData("/home/dodo/", "notes", "/home/dodo/notes")]
    public void Combine_JoinsWithExactlyOneSeparator(string directory, string name, string expected)
    {
        // Deliberately not Path.Combine, which on Windows would yield "/var/log\syslog" — a path the remote
        // cannot resolve, failing as "no such file" somewhere the backslash is invisible.
        SftpPath.Combine(directory, name).ShouldBe(expected);
    }

    [Theory]
    [InlineData("/var/log/syslog", "/var/log")]
    [InlineData("/var/log", "/var")]
    [InlineData("/var", "/")]
    [InlineData("/", "/")]
    [InlineData("/var/log/", "/var")]
    public void Parent_StopsAtTheRoot(string path, string expected)
    {
        // The root is its own parent rather than null, which is what lets the breadcrumb's "up" be a plain
        // navigation with nothing above it to special-case.
        SftpPath.Parent(path).ShouldBe(expected);
    }

    [Theory]
    [InlineData("/var/log/syslog", "syslog")]
    [InlineData("/var/log/", "log")]
    [InlineData("/", "/")]
    public void Name_IsTheLastSegment(string path, string expected)
    {
        SftpPath.Name(path).ShouldBe(expected);
    }

    [Fact]
    public void Trail_NamesEverySegmentWithThePathThatReachesIt()
    {
        SftpPath.Trail("/var/log/nginx").ShouldBe(
            [("var", "/var"), ("log", "/var/log"), ("nginx", "/var/log/nginx")]);
    }

    [Fact]
    public void Trail_IsEmptyAtTheRoot()
    {
        // The root has no segment to name. The breadcrumb draws it as a leading separator, so a trail with a
        // phantom empty crumb in it would render as a button with no label.
        SftpPath.Trail("/").ShouldBeEmpty();
    }

    [Fact]
    public void PosixMode_RendersTheKindCharacterAndThreeTriples()
    {
        PosixMode.Format(
            SftpEntryKind.Directory,
            ownerRead: true, ownerWrite: true, ownerExecute: true,
            groupRead: true, groupWrite: false, groupExecute: true,
            othersRead: true, othersWrite: false, othersExecute: true)
            .ShouldBe("drwxr-xr-x");

        PosixMode.Format(
            SftpEntryKind.File,
            ownerRead: true, ownerWrite: true, ownerExecute: false,
            groupRead: true, groupWrite: false, groupExecute: false,
            othersRead: false, othersWrite: false, othersExecute: false)
            .ShouldBe("-rw-r-----");

        PosixMode.Format(
            SftpEntryKind.SymbolicLink,
            ownerRead: true, ownerWrite: true, ownerExecute: true,
            groupRead: true, groupWrite: true, groupExecute: true,
            othersRead: true, othersWrite: true, othersExecute: true)
            .ShouldBe("lrwxrwxrwx");
    }

    [Theory]
    [InlineData(0, "0 B")]
    [InlineData(1023, "1023 B")]
    [InlineData(1024, "1.0 KB")]
    [InlineData(10 * 1024, "10 KB")]
    [InlineData(1536 * 1024, "1.5 MB")]
    [InlineData(5L * 1024 * 1024 * 1024, "5.0 GB")]
    public void ByteSize_KeepsOneDecimalOnlyWhileItMeansSomething(long bytes, string expected)
    {
        // The boundary at ten is the whole rule: "9.4 MB" and "512 MB" carry the same information, and
        // "512.3 MB" claims a precision the figure does not have by the time it is that large.
        ByteSize.Format(bytes).ShouldBe(expected);
    }
}