using System.Windows;
using AxCopilot.SDK;
using AxCopilot.Services;
using AxCopilot.Themes;

namespace AxCopilot.Handlers;

/// <summary>
/// paste prefix 핸들러: 클립보드 히스토리를 순서대로 붙여넣습니다.
/// 예: paste / paste 3 1 5 / paste all
/// </summary>
public class PasteHandler : IActionHandler
{
    private readonly ClipboardHistoryService _history;

    public string? Prefix => "paste";

    public PluginMetadata Metadata => new(
        "순차 붙여넣기",
        "클립보드 히스토리를 순서대로 붙여넣기 (Paste Sequentially)",
        "1.0",
        "AX");

    public PasteHandler(ClipboardHistoryService historyService)
    {
        _history = historyService;
    }

    public Task<IEnumerable<LauncherItem>> GetItemsAsync(string query, CancellationToken ct)
    {
        var q = query.Trim();
        var items = new List<LauncherItem>();
        var history = _history.History.Where(e => e.IsText && !string.IsNullOrEmpty(e.Text)).ToList();

        if (history.Count == 0)
        {
            items.Add(new LauncherItem(
                "클립보드 히스토리가 비어 있습니다",
                "텍스트를 복사하면 사용할 수 있습니다",
                null, null, Symbol: Symbols.ClipPaste));
            return Task.FromResult<IEnumerable<LauncherItem>>(items);
        }

        if (!string.IsNullOrWhiteSpace(q) && q != "all")
        {
            var nums = q.Split(' ', StringSplitOptions.RemoveEmptyEntries);
            var indices = new List<int>();
            foreach (var n in nums)
            {
                if (int.TryParse(n, out int idx) && idx >= 1 && idx <= history.Count)
                    indices.Add(idx);
            }

            if (indices.Count > 0)
            {
                var preview = string.Join(" · ", indices.Select(i => $"#{i}"));
                var texts = indices.Select(i => history[i - 1].Text ?? "").ToList();
                var totalLen = texts.Sum(t => t.Length);

                items.Add(new LauncherItem(
                    $"순차 붙여넣기: {preview}",
                    $"{indices.Count}개 항목 · 총 {totalLen}자 · Enter로 순서대로 붙여넣기",
                    null, ("seq", texts), Symbol: Symbols.ClipPaste));

                for (int i = 0; i < indices.Count; i++)
                {
                    var entry = history[indices[i] - 1];
                    items.Add(new LauncherItem(
                        $"  {i + 1}. #{indices[i]}: {Truncate(entry.Preview, 60)}",
                        entry.RelativeTime,
                        null, null, Symbol: Symbols.History));
                }

                return Task.FromResult<IEnumerable<LauncherItem>>(items);
            }
        }

        if (q.Equals("all", StringComparison.OrdinalIgnoreCase))
        {
            var texts = history.Take(20).Select(e => e.Text ?? "").ToList();
            items.Add(new LauncherItem(
                $"전체 순차 붙여넣기 ({texts.Count}개)",
                $"Enter로 최근 {texts.Count}개 항목을 순서대로 붙여넣기",
                null, ("seq", texts), Symbol: Symbols.ClipPaste));
            return Task.FromResult<IEnumerable<LauncherItem>>(items);
        }

        items.Add(new LauncherItem(
            "순차 붙여넣기 번호를 입력하세요",
            "예: paste 3 1 5 · paste all",
            null, null, Symbol: Symbols.ClipPaste));

        for (int i = 0; i < Math.Min(history.Count, 15); i++)
        {
            var entry = history[i];
            var pinMark = entry.IsPinned ? "\uD83D\uDCCC " : "";
            items.Add(new LauncherItem(
                $"  #{i + 1}  {pinMark}{Truncate(entry.Preview, 50)}",
                $"{entry.RelativeTime}  ·  {entry.CopiedAt:MM/dd HH:mm}",
                null, ("single", entry.Text ?? ""), Symbol: Symbols.History));
        }

        return Task.FromResult<IEnumerable<LauncherItem>>(items);
    }

    public async Task ExecuteAsync(LauncherItem item, CancellationToken ct)
    {
        if (item.Data is ("single", string singleText))
        {
            await PasteTexts([singleText], ct);
        }
        else if (item.Data is ("seq", List<string> texts))
        {
            await PasteTexts(texts, ct);
        }
    }

    private async Task PasteTexts(List<string> texts, CancellationToken ct)
    {
        if (texts.Count == 0) return;

        try
        {
            var prevWindow = WindowTracker.PreviousWindow;
            if (prevWindow == IntPtr.Zero) return;

            _history.SuppressNextCapture();

            var restored = await ForegroundPasteHelper.RestoreWindowAsync(prevWindow, ct, initialDelayMs: 260);
            if (!restored)
                return;

            foreach (var text in texts)
            {
                if (ct.IsCancellationRequested) break;

                _history.SuppressNextCapture();
                Application.Current.Dispatcher.Invoke(() => Clipboard.SetText(text));
                await Task.Delay(50, ct);

                await ForegroundPasteHelper.PasteClipboardAsync(prevWindow, ct, initialDelayMs: 0);
                await Task.Delay(200, ct);
            }

            NotificationService.Notify("paste", $"{texts.Count}개 항목 붙여넣기 완료");
        }
        catch (OperationCanceledException) { }
        catch (Exception ex)
        {
            NotificationService.Notify("paste", $"붙여넣기 실패: {ex.Message}");
        }
    }

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