using Xunit;
using NozCli.Core.Config;
using NozCli.Core.Models;
using NozCli.Repl;

namespace NozCli.Tests;

public class ReplContextTests
{
    // Builds a ReplContext with a fixed NoteCache — no API calls made.
    private static ReplContext BuildCtx(params NoteInfo[] notes)
    {
        var cfg = new LocalConfig { ServerUrl = "http://localhost:9999", Token = "test" };
        var ctx = new ReplContext(null!, cfg);   // Api is null — not used in navigation
        ctx.NoteCache = [.. notes];
        return ctx;
    }

    private static NoteInfo Note(string slug, string topic, string status = "seed") =>
        new(slug, $"Title {slug}", status, topic, "de", false, null);

    // ── CurrentPath ──────────────────────────────────────────────────────────

    [Fact]
    public void CurrentPath_AtRoot_IsWave()
    {
        var ctx = BuildCtx();
        Assert.Equal("~", ctx.CurrentPath);
    }

    [Fact]
    public void CurrentPath_InTopic_ShowsTopic()
    {
        var ctx = BuildCtx(Note("psychologie/test", "psychologie"));
        ctx.NavigateTo("psychologie");
        Assert.Equal("~/psychologie", ctx.CurrentPath);
    }

    [Fact]
    public void CurrentPath_InSubfolder_ShowsFullPath()
    {
        var ctx = BuildCtx(Note("psychologie/sub/deep", "psychologie"));
        ctx.NavigateTo("psychologie");
        ctx.NavigateTo("sub");
        Assert.Equal("~/psychologie/sub", ctx.CurrentPath);
    }

    // ── FoldersInView ────────────────────────────────────────────────────────

    [Fact]
    public void FoldersInView_AtRoot_ReturnsDistinctTopics()
    {
        var ctx = BuildCtx(
            Note("psychologie/a", "psychologie"),
            Note("psychologie/b", "psychologie"),
            Note("biosysteme/c",  "biosysteme"));

        var folders = ctx.FoldersInView().OrderBy(f => f).ToList();
        Assert.Equal(["biosysteme", "psychologie"], folders);
    }

    [Fact]
    public void FoldersInView_InTopic_ReturnsSubfolders()
    {
        var ctx = BuildCtx(
            Note("psychologie/sub/note",  "psychologie"),
            Note("psychologie/flat-note", "psychologie"));

        ctx.NavigateTo("psychologie");
        var folders = ctx.FoldersInView().ToList();

        Assert.Contains("sub", folders);
        Assert.DoesNotContain("flat-note", folders);
    }

    // ── NavigateTo / NavigateUp ──────────────────────────────────────────────

    [Fact]
    public void NavigateTo_ValidTopic_ReturnsTrue()
    {
        var ctx = BuildCtx(Note("psychologie/test", "psychologie"));
        Assert.True(ctx.NavigateTo("psychologie"));
        Assert.Equal("psychologie", ctx.CurrentTopic);
    }

    [Fact]
    public void NavigateTo_UnknownTopic_ReturnsFalse()
    {
        var ctx = BuildCtx(Note("psychologie/test", "psychologie"));
        Assert.False(ctx.NavigateTo("doesnotexist"));
        Assert.Null(ctx.CurrentTopic);
    }

    [Fact]
    public void NavigateUp_FromTopic_ReturnsToRoot()
    {
        var ctx = BuildCtx(Note("psychologie/test", "psychologie"));
        ctx.NavigateTo("psychologie");
        ctx.NavigateUp();
        Assert.Null(ctx.CurrentTopic);
        Assert.Equal("~", ctx.CurrentPath);
    }

    [Fact]
    public void NavigateUp_FromSubfolder_ReturnsToTopic()
    {
        var ctx = BuildCtx(Note("psychologie/sub/deep", "psychologie"));
        ctx.NavigateTo("psychologie");
        ctx.NavigateTo("sub");
        ctx.NavigateUp();

        Assert.Equal("psychologie", ctx.CurrentTopic);
        Assert.Null(ctx.CurrentSubPath);
    }

    // ── SlugRelative ─────────────────────────────────────────────────────────

    [Fact]
    public void SlugRelative_InTopic_StripsTopicPrefix()
    {
        var ctx = BuildCtx(Note("psychologie/flow", "psychologie"));
        ctx.NavigateTo("psychologie");
        Assert.Equal("flow", ctx.SlugRelative("psychologie/flow"));
    }

    [Fact]
    public void SlugRelative_AtRoot_ReturnsFullSlug()
    {
        var ctx = BuildCtx(Note("psychologie/flow", "psychologie"));
        Assert.Equal("psychologie/flow", ctx.SlugRelative("psychologie/flow"));
    }

    // ── NotesInView ──────────────────────────────────────────────────────────

    [Fact]
    public void NotesInView_InTopic_FiltersCorrectly()
    {
        var ctx = BuildCtx(
            Note("psychologie/a", "psychologie"),
            Note("biosysteme/b",  "biosysteme"));

        ctx.NavigateTo("psychologie");
        var notes = ctx.NotesInView().ToList();

        Assert.Single(notes);
        Assert.Equal("psychologie/a", notes[0].Slug);
    }

    // ── ResolveSlug ──────────────────────────────────────────────────────────

    [Fact]
    public void ResolveSlug_ShortName_InTopic_ResolvesToFullSlug()
    {
        var ctx = BuildCtx(Note("psychologie/flow", "psychologie"));
        ctx.NavigateTo("psychologie");
        Assert.Equal("psychologie/flow", ctx.ResolveSlug("flow"));
    }

    [Fact]
    public void ResolveSlug_AlreadyFullSlug_ReturnsUnchanged()
    {
        var ctx = BuildCtx(Note("psychologie/flow", "psychologie"));
        Assert.Equal("psychologie/flow", ctx.ResolveSlug("psychologie/flow"));
    }
}