using NozCli.Core.Models;
using NozCli.Repl;
using Spectre.Console;

namespace NozCli.Commands;

public class LsCommand : ICommand
{
    public string Name        => "ls";
    public string Description => "List notes and folders at current path";
    public string Usage       => "ls [-la]";

    public async Task ExecuteAsync(string[] args, ReplContext ctx, CancellationToken ct = default)
    {
        var flags    = string.Concat(args.Where(a => a.StartsWith('-')).SelectMany(a => a.TrimStart('-')));
        var detailed = flags.Contains('l');
        var depth    = ctx.CurrentSubPath is null ? 0 : ctx.CurrentSubPath.Split('/').Length;

        var (subFolders, directNotes) = Partition(ctx, depth);

        if (!detailed)
        {
            RenderShort(ctx, subFolders, directNotes, depth);
            return;
        }

        RenderLong(ctx, subFolders, directNotes, depth);
        await Task.CompletedTask;
    }

    // ── Short view ───────────────────────────────────────────────────────────────

    private static void RenderShort(ReplContext ctx, List<string> folders, List<NoteInfo> notes, int depth)
    {
        AnsiConsole.WriteLine();
        foreach (var f in folders)
            AnsiConsole.MarkupLine($"  [grey46]▸[/]  [white]{Markup.Escape(f)}/[/]");

        if (folders.Count > 0 && notes.Count > 0)
            AnsiConsole.WriteLine();

        foreach (var n in notes)
        {
            var (color, dot) = Style(n.Status);
            var name = ctx.SlugRelative(n.Slug).Split('/')[depth];
            AnsiConsole.MarkupLine($"  [{color}]{dot}[/]  [white]{Markup.Escape(name)}[/]");
        }
        AnsiConsole.WriteLine();
    }

    // ── Long view ────────────────────────────────────────────────────────────────

    private static void RenderLong(ReplContext ctx, List<string> folders, List<NoteInfo> notes, int depth)
    {
        var term     = Math.Max(Console.WindowWidth, 72);
        var nameCol  = Math.Clamp(term / 3, 20, 36);
        var titleCol = Math.Max(16, term - nameCol - 32);

        var table = new Table()
            .BorderStyle(new Style(new Color(50, 50, 65)))
            .Border(TableBorder.Simple)
            .Expand()
            .AddColumn(new TableColumn("[dim]  [/]")          { Width = 3,        NoWrap = true })
            .AddColumn(new TableColumn("[dim grey]name[/]")   { Width = nameCol,  NoWrap = true })
            .AddColumn(new TableColumn("[dim grey]status[/]") { Width = 10,       NoWrap = true })
            .AddColumn(new TableColumn("[dim grey]lang[/]")   { Width = 5,        NoWrap = true })
            .AddColumn(new TableColumn("[dim grey]date[/]")   { Width = 12,       NoWrap = true })
            .AddColumn(new TableColumn("[dim grey]title[/]")  { NoWrap = true });

        foreach (var folder in folders)
        {
            var folderNotes = ctx.CurrentTopic is null
                ? ctx.NoteCache.Where(n => string.Equals(n.Topic, folder, StringComparison.OrdinalIgnoreCase)).ToList()
                : ctx.NotesInView().Where(n =>
                {
                    var rel = ctx.SlugRelative(n.Slug);
                    return rel.StartsWith(folder + "/") || rel == folder;
                }).ToList();

            var count    = folderNotes.Count;
            var countStr = $"{count} {(count == 1 ? "note" : "notes")}";
            var minibar  = string.Concat(folderNotes.Select(n =>
            {
                var (c, d) = Style(n.Status);
                return $"[{c} dim]{d}[/]";
            }));

            table.AddRow(
                "[grey46]▸[/]",
                $"[bold white]{Markup.Escape(Truncate(folder, nameCol - 1))}/[/]",
                $"[dim]{countStr}[/]",
                "", "",
                minibar
            );
        }

        if (folders.Count > 0 && notes.Count > 0)
            table.AddEmptyRow();

        foreach (var note in notes)
        {
            var (color, dot) = Style(note.Status);
            var name  = Truncate(ctx.SlugRelative(note.Slug).Split('/')[depth], nameCol);
            var title = Truncate(note.Title, titleCol);
            var date  = FormatDate(note.Date);

            table.AddRow(
                $"[{color}]{dot}[/]",
                $"[white]{Markup.Escape(name)}[/]",
                $"[{color} dim]{note.Status}[/]",
                $"[dim]{note.Lang}[/]",
                $"[dim grey]{date}[/]",
                $"[dim]{Markup.Escape(title)}[/]"
            );
        }

        AnsiConsole.WriteLine();
        AnsiConsole.Write(table);

        var total = folders.Count + notes.Count;
        AnsiConsole.MarkupLine($"[dim grey]  {total} {(total == 1 ? "item" : "items")}[/]\n");
    }

    // ── Helpers ──────────────────────────────────────────────────────────────────

    private static (List<string> folders, List<NoteInfo> notes) Partition(ReplContext ctx, int depth)
    {
        if (ctx.CurrentTopic is null)
            return (ctx.FoldersInView().OrderBy(f => f).ToList(), []);

        var inView = ctx.NotesInView().ToList();

        var notes = inView
            .Where(n => ctx.SlugRelative(n.Slug).Split('/').Length == depth + 1)
            .OrderBy(n => ctx.SlugRelative(n.Slug).Split('/')[depth])
            .ToList();

        var noteSlugs = notes
            .Select(n => ctx.SlugRelative(n.Slug).Split('/')[depth])
            .ToHashSet(StringComparer.OrdinalIgnoreCase);

        var folders = inView
            .Where(n => ctx.SlugRelative(n.Slug).Split('/').Length > depth + 1)
            .Select(n => ctx.SlugRelative(n.Slug).Split('/')[depth])
            .Distinct(StringComparer.OrdinalIgnoreCase)
            .Where(seg => !noteSlugs.Contains(seg))
            .OrderBy(f => f)
            .ToList();

        return (folders, notes);
    }

    private static (string color, string dot) Style(string status) => status switch
    {
        "seed"      => ("yellow",  "◦"),
        "budding"   => ("magenta", "◈"),
        "evergreen" => ("cyan",    "◉"),
        _           => ("grey",    "○"),
    };

    private static string FormatDate(string? date)
    {
        if (date is null) return "—";
        if (DateTime.TryParse(date, out var d)) return d.ToString("yyyy-MM-dd");
        return date.Length > 10 ? date[..10] : date;
    }

    private static string Truncate(string s, int max) =>
        s.Length <= max ? s : s[..(max - 1)] + "…";
}