using TinyTUI;
using TinyTUI.Components;
using TinyTUI.Input;
using TinyTUI.Overlay;
using TinyTUI.Rendering;
using TinyTUI.Runtime;
using TinyTUI.Stdio;
using TinyTUI.Stdout;
using TinyTUI.Text;

using var terminalInput = new ConsoleTerminalInput();
var terminalOutput = new ConsoleTerminalOutput();
var parser = new DefaultInputParser();
var textMeasurer = new TerminalTextMeasurer();
var renderer = new DifferentialRenderer(terminalOutput, textMeasurer);
using var runtime = new TuiRuntime(terminalInput, parser, renderer);

var done = new ManualResetEventSlim();
var eventsText = new Text("最近事件:\n- 无");
var statusText = new Text();
var editorHistory = new List<string> { "history: first command", "history: second command" };
var loader = new Loader(textMeasurer) { Message = "运行中" };
using var loaderCancellation = new CancellationTokenSource();
var input = new TinyTUI.Components.Input(textMeasurer) { Prompt = "请输入: " };
IOverlayHandle? tipHandle = null;

input.OnChanged = value => UpdateStatus(statusText, value, textMeasurer, renderer);
input.OnSubmitted = value =>
{
    switch (value.Trim())
    {
        case "/help":
            AddEvent(eventsText, "Overlay: help opened");
            runtime.ShowOverlay(
                new HelpOverlay(runtime, textMeasurer),
                new OverlayOptions
                {
                    Width = OverlaySize.Percent(45),
                    MinWidth = 42,
                    Anchor = OverlayAnchor.TopRight,
                    Margin = new OverlayMargin(1),
                });
            break;
        case "/tip":
            tipHandle?.Hide();
            tipHandle = runtime.ShowOverlay(
                new TipOverlay(textMeasurer),
                OverlayOptions.NonCapturingTooltip());
            AddEvent(eventsText, "Overlay: non-capturing tip opened");
            break;
        case "/select":
            AddEvent(eventsText, "Overlay: select opened");
            runtime.ShowOverlay(
                new SelectOverlay(runtime, message => AddEvent(eventsText, message), textMeasurer),
                new OverlayOptions
                {
                    Width = 34,
                    Anchor = OverlayAnchor.LeftCenter,
                    Margin = new OverlayMargin(1),
                    MaxHeight = 9,
                });
            break;
        case "/edit":
            AddEvent(eventsText, "Overlay: editor opened");
            runtime.ShowOverlay(
                new EditorOverlay(runtime, editorHistory, message => AddEvent(eventsText, message), textMeasurer),
                new OverlayOptions
                {
                    Width = OverlaySize.Percent(70),
                    MinWidth = 52,
                    Anchor = OverlayAnchor.BottomCenter,
                    Margin = new OverlayMargin(1),
                });
            break;
        case "":
            AddEvent(eventsText, "Submitted empty input");
            break;
        default:
            AddEvent(eventsText, $"Submitted: {value}");
            break;
    }

    input.Clear();
};
input.OnCanceled = () => done.Set();

UpdateStatus(statusText, input.Value, textMeasurer, renderer);

var page = new Container();
AddAll(
    page,
    new Text("TinyTUI 基础组件示例"),
    new Text("======================"),
    new Text(
        "操作说明\n" +
        "- 输入文本后 Enter 提交\n" +
        "- /help 打开帮助弹层\n" +
        "- /tip 打开不抢焦点的右上角提示\n" +
        "- /select 打开可交互选择列表\n" +
        "- /edit 打开需要焦点的多行编辑器\n" +
        "- Esc 退出"),
    new Text(),
    new Box(statusText, textMeasurer) { Title = "状态" },
    new Text(),
    new Box(new Container { Children = { loader, input } }, textMeasurer) { Title = "Input" },
    new Text(),
    new Box(eventsText, textMeasurer) { Title = "事件" });

runtime.Add(page);
runtime.SetFocus(input);
terminalOutput.ShowCursor();

var loaderTask = RunLoaderAsync(loader, runtime, loaderCancellation.Token);

try
{
    runtime.Start();
    done.Wait();
}
finally
{
    StopLoader(loaderCancellation, loaderTask);
    runtime.Stop();
    terminalOutput.ShowCursor();
    terminalOutput.Write("\r\n");
    terminalOutput.Flush();
}

static async Task RunLoaderAsync(Loader loader, ITuiRuntime runtime, CancellationToken cancellationToken)
{
    try
    {
        while (!cancellationToken.IsCancellationRequested)
        {
            await Task.Delay(180, cancellationToken).ConfigureAwait(false);
            loader.Tick();
            runtime.RequestRender();
        }
    }
    catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
    {
    }
}

static void StopLoader(CancellationTokenSource cancellation, Task loaderTask)
{
    cancellation.Cancel();
    loaderTask.Wait(TimeSpan.FromSeconds(1));
}

static void UpdateStatus(
    Text statusText,
    string inputValue,
    ITextMeasurer textMeasurer,
    DifferentialRenderer renderer)
{
    statusText.Value = string.Join(
        '\n',
        $"当前输入 = \"{inputValue}\"",
        $"当前输入宽度 = {textMeasurer.GetWidth(inputValue)}",
        $"字符串 \"abc中文😀xyz\" 宽度 = {textMeasurer.GetWidth("abc中文😀xyz")}",
        $"截断到 8 列 = \"{textMeasurer.Truncate("abc中文😀xyz", 8)}\"",
        $"全量重绘次数 = {renderer.FullRedrawCount}",
        $"差分重绘次数 = {renderer.DifferentialRedrawCount}");
}

static void AddEvent(Text eventsText, string message)
{
    var lines = eventsText.Value.Split('\n').Skip(1).Append($"- {message}").TakeLast(8);
    eventsText.Value = "最近事件:\n" + string.Join('\n', lines);
}

static void AddAll(Container container, params IComponent[] components)
{
    foreach (var component in components) container.Add(component);
}

file sealed class HelpOverlay(ITuiRuntime runtime, ITextMeasurer textMeasurer) : IInputComponent
{
    private readonly Box _box = new(
        new Text(
            "Overlay 示例\n" +
            "\n" +
            "- 这个弹层由 Runtime 显示\n" +
            "- OverlayManager 会把它合成到基础页面上\n" +
            "- 显示时焦点会切到弹层\n" +
            "- 关闭后焦点会恢复到输入框\n" +
            "\n" +
            "按 Enter 或 Esc 关闭"),
        textMeasurer)
    {
        Title = "Help",
    };

    public IReadOnlyList<string> Render(int width) => _box.Render(width);

    public void HandleInput(TuiInputEvent input)
    {
        if (input is { Kind: TuiInputEventKind.Key, Value: KeyNames.Enter or KeyNames.Escape })
        {
            runtime.HideOverlay();
        }
    }
}

file sealed class TipOverlay(ITextMeasurer textMeasurer) : IComponent
{
    private readonly Box _box = new(
        new Text(
            "这是 non-capturing overlay\n" +
            "打开后输入框仍然接收键盘输入\n" +
            "再次输入 /tip 会替换当前提示"),
        textMeasurer)
    {
        Title = "Tip",
    };

    public IReadOnlyList<string> Render(int width) => _box.Render(width);
}

file sealed class SelectOverlay : IInputComponent
{
    private readonly ITuiRuntime _runtime;
    private readonly Action<string> _addEvent;
    private readonly SelectList _selectList;
    private readonly Box _box;

    public SelectOverlay(ITuiRuntime runtime, Action<string> addEvent, ITextMeasurer textMeasurer)
    {
        _runtime = runtime;
        _addEvent = addEvent;
        _selectList = new SelectList(textMeasurer) { Height = 5 };
        _selectList.SetItems(["Text", "Input", "Editor", "SelectList", "Markdown", "Loader", "Overlay"]);
        _selectList.OnSubmitted = (item, _) =>
        {
            _addEvent($"Selected: {item}");
            _runtime.HideOverlay();
        };
        _selectList.OnCanceled = _runtime.HideOverlay;
        _box = new Box(_selectList, textMeasurer) { Title = "SelectList" };
    }

    public IReadOnlyList<string> Render(int width) => _box.Render(width);

    public void HandleInput(TuiInputEvent input) => _selectList.HandleInput(input);
}

file sealed class EditorOverlay : IInputComponent
{
    private readonly ITuiRuntime _runtime;
    private readonly List<string> _history;
    private readonly Action<string> _addEvent;
    private readonly Editor _editor;
    private readonly Box _box;

    public EditorOverlay(ITuiRuntime runtime, List<string> history, Action<string> addEvent, ITextMeasurer textMeasurer)
    {
        _runtime = runtime;
        _history = history;
        _addEvent = addEvent;
        _editor = new Editor(textMeasurer)
        {
            Height = 6,
            Placeholder = "在这里输入内容",
            OnCanceled = SubmitAndClose,
        };
        _editor.SetHistory(_history);
        _box = new Box(
            new Container
            {
                Children =
                {
                    new Text(
                        "Ctrl+A/E 行首行尾 Ctrl+Left/Right 按词移动\n" +
                        "Ctrl+Backspace/Delete 按词删除 Ctrl+Z/Y 撤销重做\n" +
                        "空内容时 Up/Down 浏览历史 Esc 提交并关闭"),
                    new Text(),
                    _editor,
                },
            },
            textMeasurer)
        {
            Title = "Editor",
        };
    }

    public IReadOnlyList<string> Render(int width) => _box.Render(width);

    public void HandleInput(TuiInputEvent input)
    {
        if (input is { Kind: TuiInputEventKind.Key, Value: KeyNames.Escape })
        {
            SubmitAndClose();
            return;
        }

        _editor.HandleInput(input);
    }

    private void SubmitAndClose()
    {
        var value = _editor.Value.Trim();
        if (value.Length > 0)
        {
            _history.Remove(value);
            _history.Insert(0, value);
        }

        _addEvent($"Edited {Math.Max(1, _editor.Value.Split('\n').Length)} line(s)");
        _runtime.HideOverlay();
    }
}