using Sdt.Config;
using Spectre.Console;

namespace Sdt.Tui;

public sealed class WorkspaceScreen
{
    private readonly WorkspaceConfig _workspace;
    private readonly string _workspaceRoot;
    private readonly string _currentProjectRoot;

    public WorkspaceScreen(WorkspaceConfig workspace, string workspaceRoot, string currentProjectRoot)
    {
        _workspace = workspace;
        _workspaceRoot = workspaceRoot;
        _currentProjectRoot = currentProjectRoot;
    }

    /// <summary>
    /// Shows the project switcher. Returns the absolute path to the selected project root,
    /// or null if the user cancelled.
    /// </summary>
    public string? SelectProject()
    {
        AnsiConsole.Clear();
        AnsiConsole.Write(Theme.SectionRule("WORKSPACE — " + _workspace.Name));
        AnsiConsole.WriteLine();

        var projects = _workspace.Projects;
        if (projects.Count == 0)
        {
            AnsiConsole.MarkupLine(Theme.Warn("No projects defined in sdt-workspace.json."));
            AnsiConsole.MarkupLine(Theme.Faint("Add entries to the \"projects\" array."));
            AnsiConsole.MarkupLine("\n" + Theme.Faint("Press any key to go back..."));
            Console.ReadKey(intercept: true);
            return null;
        }

        // Build choice list with current project marked
        var choices = new List<WorkspaceMenuItem>();
        foreach (var proj in projects)
        {
            var absPath = WorkspaceLoader.ResolveProjectRoot(_workspaceRoot, proj);
            var devtoolPath = Path.Combine(absPath, "devtool.json");
            var isCurrent = string.Equals(absPath, _currentProjectRoot, StringComparison.OrdinalIgnoreCase);
            var exists = File.Exists(devtoolPath);

            var label = isCurrent
                ? $"[bold {Theme.GreenBold}]► {Markup.Escape(proj.Name)}[/]  [{Theme.GreenDim}](current)[/]"
                : $"[{Theme.Green}]  {Markup.Escape(proj.Name)}[/]";

            var desc = !exists
                ? $"  [{Theme.Red}]devtool.json not found[/]"
                : string.IsNullOrWhiteSpace(proj.Description)
                    ? $"  [{Theme.GreenDim}]{Markup.Escape(absPath)}[/]"
                    : $"  [{Theme.GreenDim}]{Markup.Escape(proj.Description)}[/]";

            choices.Add(new WorkspaceMenuItem(label + "\n" + desc, absPath, exists && !isCurrent));
        }

        choices.Add(new WorkspaceMenuItem($"[{Theme.GreenDim}]← Cancel[/]", null, true));

        // Show project table for overview
        var table = new Table()
            .Border(TableBorder.Rounded)
            .BorderStyle(Theme.DimStyle)
            .AddColumn(new TableColumn($"[{Theme.Amber}]Project[/]"))
            .AddColumn(new TableColumn($"[{Theme.Amber}]Path[/]"))
            .AddColumn(new TableColumn($"[{Theme.Amber}]Status[/]").Width(12));

        foreach (var proj in projects)
        {
            var absPath = WorkspaceLoader.ResolveProjectRoot(_workspaceRoot, proj);
            var isCurrent = string.Equals(absPath, _currentProjectRoot, StringComparison.OrdinalIgnoreCase);
            var hasConfig = File.Exists(Path.Combine(absPath, "devtool.json"));

            table.AddRow(
                isCurrent
                    ? $"[bold {Theme.GreenBold}]► {Markup.Escape(proj.Name)}[/]"
                    : Theme.G(proj.Name),
                Theme.Faint(proj.Path),
                hasConfig ? Theme.Ok("ready") : Theme.Fail("no config"));
        }

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

        var switchable = choices.Where(c => c.Selectable).ToList();
        if (switchable.Count == 1) // only Cancel
        {
            AnsiConsole.MarkupLine(Theme.Warn("No other projects available to switch to."));
            AnsiConsole.MarkupLine("\n" + Theme.Faint("Press any key to go back..."));
            Console.ReadKey(intercept: true);
            return null;
        }

        var selected = AnsiConsole.Prompt(
            new SelectionPrompt<WorkspaceMenuItem>()
                .Title($"[{Theme.Green}]Switch to project:[/]")
                .PageSize(15)
                .UseConverter(m => m.Display)
                .AddChoices(switchable));

        return selected.AbsPath; // null = cancelled
    }

    private sealed record WorkspaceMenuItem(string Display, string? AbsPath, bool Selectable);
}