using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace JJServiceManager
{
    /// <summary>서비스 한 개의 로그 파일 보기 (상단 정보줄 + 로그 목록)</summary>
    public sealed class LogTailView : DockPanel, IDisposable
    {
        private readonly LogTailer _tailer;
        private readonly TextBlock _path;
        private readonly LogPanel _panel;

        public ServiceEntry Entry { get; }

        /// <summary>인코딩을 바꾸면 설정 저장용으로 호출됨</summary>
        public event Action EntryChanged;

        public LogTailView(ServiceEntry entry)
        {
            Entry = entry;
            LastChildFill = true;

            // ── 상단 정보줄
            var bar = new Border
            {
                Background = Brushes2.Make("#F1F8FB"),
                BorderBrush = Brushes2.Make("#B0BEC5"),
                BorderThickness = new Thickness(0, 0, 0, 1),
                Padding = new Thickness(6, 4, 6, 4),
                Margin = new Thickness(0, 0, 0, 4)
            };
            SetDock(bar, Dock.Top);

            var grid = new Grid();
            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });

            var title = new TextBlock
            {
                Text = entry.DisplayName,
                FontWeight = FontWeights.Bold,
                FontSize = 14,
                VerticalAlignment = VerticalAlignment.Center,
                Margin = new Thickness(0, 0, 12, 0),
                Foreground = Brushes2.Make("#155E75")
            };
            Grid.SetColumn(title, 0);

            _path = new TextBlock
            {
                Text = (entry.LogIsFolder ? "폴더: " : "파일: ") + entry.LogPath,
                Foreground = Brushes.Gray,
                VerticalAlignment = VerticalAlignment.Center,
                TextTrimming = TextTrimming.CharacterEllipsis
            };
            Grid.SetColumn(_path, 1);

            var encLabel = new TextBlock { Text = "인코딩", VerticalAlignment = VerticalAlignment.Center, Margin = new Thickness(10, 0, 4, 0) };
            Grid.SetColumn(encLabel, 2);

            var enc = new ComboBox { Width = 90, VerticalAlignment = VerticalAlignment.Center };
            enc.Items.Add(new ComboBoxItem { Content = "자동", Tag = "auto" });
            enc.Items.Add(new ComboBoxItem { Content = "UTF-8", Tag = "utf-8" });
            enc.Items.Add(new ComboBoxItem { Content = "CP949", Tag = "cp949" });
            enc.SelectedIndex = (entry.LogEncoding ?? "auto") switch { "utf-8" => 1, "cp949" => 2, _ => 0 };
            Grid.SetColumn(enc, 3);

            var open = new Button { Content = "탐색기에서 열기", Margin = new Thickness(6, 0, 0, 0) };
            Grid.SetColumn(open, 4);
            open.Click += (s, e) => OpenInExplorer();

            grid.Children.Add(title);
            grid.Children.Add(_path);
            grid.Children.Add(encLabel);
            grid.Children.Add(enc);
            grid.Children.Add(open);
            bar.Child = grid;
            Children.Add(bar);

            // ── 로그 목록
            _panel = new LogPanel { ShowTimestamp = false, MaxLines = 50000 };
            Children.Add(_panel);

            _tailer = new LogTailer(entry, (lines, level) => _panel.AddMany(lines, level));
            _tailer.FileChanged += f => Dispatcher.BeginInvoke(new Action(() =>
            {
                _path.Text = entry.LogIsFolder ? $"폴더: {entry.LogPath}  →  {Path.GetFileName(f)}" : "파일: " + f;
                _path.ToolTip = f;
            }));

            enc.SelectionChanged += (s, e) =>
            {
                if (enc.SelectedItem is ComboBoxItem item)
                {
                    entry.LogEncoding = (string)item.Tag;
                    EntryChanged?.Invoke();
                    _panel.Add("──────── 인코딩 변경: " + item.Content + " ────────", LogLevel.Notice);
                    _tailer.Reload();
                }
            };

            _tailer.Start();
        }

        /// <summary>로그 경로가 바뀌면 표시를 갱신하고 새 경로로 다시 읽음</summary>
        public void PathChanged()
        {
            _path.Text = (Entry.LogIsFolder ? "폴더: " : "파일: ") + Entry.LogPath;
            _path.ToolTip = null;
            _panel.Add("──────── 로그 경로 변경: " + Entry.LogPath + " ────────", LogLevel.Notice);
            _tailer.Reload();
        }

        private void OpenInExplorer()
        {
            try
            {
                var f = _tailer.CurrentFile;
                if (!string.IsNullOrEmpty(f) && File.Exists(f))
                    Process.Start(new ProcessStartInfo("explorer.exe", $"/select,\"{f}\"") { UseShellExecute = true });
                else if (Directory.Exists(Entry.LogPath))
                    Process.Start(new ProcessStartInfo("explorer.exe", $"\"{Entry.LogPath}\"") { UseShellExecute = true });
                else
                {
                    var dir = Path.GetDirectoryName(Entry.LogPath);
                    if (!string.IsNullOrEmpty(dir) && Directory.Exists(dir))
                        Process.Start(new ProcessStartInfo("explorer.exe", $"\"{dir}\"") { UseShellExecute = true });
                }
            }
            catch { }
        }

        public void Dispose() => _tailer.Dispose();
    }

    /// <summary>
    /// 로그창 띄우기:
    /// 1. 개별 창  2. 하나의 창에 탭  3. 창을 좌우로 나누어 비교
    /// </summary>
    public sealed class LogWindowManager
    {
        private readonly Func<AppSettings> _settings;
        private readonly Action _save;

        // 개별 창
        private readonly Dictionary<string, Window> _individual = new Dictionary<string, Window>(StringComparer.OrdinalIgnoreCase);

        // 탭
        private Window _tabWindow;
        private TabControl _tabs;

        // 좌우 분할
        private Window _splitWindow;
        private SplitPane _left, _right;

        public LogWindowManager(Func<AppSettings> settings, Action save)
        {
            _settings = settings;
            _save = save;
        }

        public void Open(ServiceEntry entry)
        {
            switch (_settings().LogWindowMode)
            {
                case LogWindowMode.Tabs: OpenTab(entry); break;
                case LogWindowMode.Split: OpenSplit(entry); break;
                default: OpenIndividual(entry); break;
            }
        }

        /// <summary>서비스 목록이 바뀌었을 때 (분할 창의 선택 목록 갱신)</summary>
        public void ServicesChanged()
        {
            _left?.RefreshChoices(LogServices());
            _right?.RefreshChoices(LogServices());
        }

        /// <summary>서비스의 로그 경로가 바뀌었을 때. 경로가 비었으면 그 서비스의 로그창을 닫음</summary>
        public void EntryPathChanged(ServiceEntry entry)
        {
            if (string.IsNullOrWhiteSpace(entry.LogPath))
            {
                Close(entry.ServiceName);
                ServicesChanged();
                return;
            }
            foreach (var v in OpenViews(entry.ServiceName)) v.PathChanged();
            ServicesChanged();
        }

        /// <summary>서비스가 목록에서 빠졌을 때 그 서비스의 로그창을 닫음</summary>
        public void Close(string serviceName)
        {
            if (_individual.TryGetValue(serviceName, out var w)) w.Close();

            if (_tabs != null)
            {
                foreach (var t in _tabs.Items.Cast<TabItem>().ToList())
                {
                    if (t.Content is LogTailView v && Same(v.Entry.ServiceName, serviceName))
                    {
                        v.Dispose();
                        _tabs.Items.Remove(t);
                    }
                }
                if (_tabs.Items.Count == 0) _tabWindow?.Close();
            }

            if (_left != null && _left.ShowsName(serviceName)) _left.Clear();
            if (_right != null && _right.ShowsName(serviceName)) _right.Clear();
        }

        private IEnumerable<LogTailView> OpenViews(string serviceName)
        {
            if (_individual.TryGetValue(serviceName, out var w) && w.Content is Border b && b.Child is LogTailView iv)
                yield return iv;
            if (_tabs != null)
                foreach (TabItem t in _tabs.Items)
                    if (t.Content is LogTailView tv && Same(tv.Entry.ServiceName, serviceName)) yield return tv;
            if (_left?.View != null && _left.ShowsName(serviceName)) yield return _left.View;
            if (_right?.View != null && _right.ShowsName(serviceName)) yield return _right.View;
        }

        private static bool Same(string a, string b) => string.Equals(a, b, StringComparison.OrdinalIgnoreCase);

        public void CloseAll()
        {
            foreach (var w in _individual.Values.ToList()) w.Close();
            _tabWindow?.Close();
            _splitWindow?.Close();
        }

        private List<ServiceEntry> LogServices()
            => _settings().Services.Where(s => !string.IsNullOrWhiteSpace(s.LogPath)).ToList();

        private LogTailView NewView(ServiceEntry entry)
        {
            var v = new LogTailView(entry);
            v.EntryChanged += _save;
            return v;
        }

        private static Window NewWindow(string title, object content, double w = 960, double h = 620)
        {
            var win = new Window
            {
                Title = title,
                Content = content,
                Width = w,
                Height = h,
                FontFamily = new FontFamily("Malgun Gothic"),
                FontSize = 13,
                Background = Brushes2.Make("#FAFAFA"),
                WindowStartupLocation = WindowStartupLocation.CenterScreen
            };
            AppIcon.Apply(win);
            return win;
        }

        private static void Activate(Window w)
        {
            if (w.WindowState == WindowState.Minimized) w.WindowState = WindowState.Normal;
            w.Show();
            w.Activate();
        }

        // ───────────────────────── 1. 개별 창 ─────────────────────────

        private void OpenIndividual(ServiceEntry entry)
        {
            if (_individual.TryGetValue(entry.ServiceName, out var existing))
            {
                Activate(existing);
                return;
            }
            var view = NewView(entry);
            var win = NewWindow($"로그 - {entry.DisplayName}", new Border { Padding = new Thickness(6), Child = view });
            win.Closed += (s, e) =>
            {
                view.Dispose();
                _individual.Remove(entry.ServiceName);
            };
            _individual[entry.ServiceName] = win;
            // 여러 창이 겹치지 않도록 조금씩 비켜서 띄움
            int n = _individual.Count - 1;
            win.WindowStartupLocation = WindowStartupLocation.Manual;
            win.Left = Math.Max(0, (SystemParameters.WorkArea.Width - win.Width) / 2 + n * 28 % 200);
            win.Top = Math.Max(0, (SystemParameters.WorkArea.Height - win.Height) / 2 + n * 28 % 200);
            Activate(win);
        }

        // ───────────────────────── 2. 탭 ─────────────────────────

        private void OpenTab(ServiceEntry entry)
        {
            if (_tabWindow == null)
            {
                _tabs = new TabControl { Margin = new Thickness(6) };
                _tabWindow = NewWindow("로그 (탭)", _tabs);
                _tabWindow.Closed += (s, e) =>
                {
                    foreach (TabItem t in _tabs.Items)
                        (t.Content as LogTailView)?.Dispose();
                    _tabs = null;
                    _tabWindow = null;
                };
            }

            foreach (TabItem t in _tabs.Items)
            {
                if (t.Content is LogTailView v && string.Equals(v.Entry.ServiceName, entry.ServiceName, StringComparison.OrdinalIgnoreCase))
                {
                    _tabs.SelectedItem = t;
                    Activate(_tabWindow);
                    return;
                }
            }

            var view = NewView(entry);
            var tab = new TabItem { Content = view };

            var header = new StackPanel { Orientation = Orientation.Horizontal };
            header.Children.Add(new TextBlock { Text = entry.DisplayName, VerticalAlignment = VerticalAlignment.Center });
            var close = new Button
            {
                Content = "✕",
                MinWidth = 0,
                MinHeight = 0,
                Padding = new Thickness(4, 0, 4, 0),
                Margin = new Thickness(8, 0, 0, 0),
                FontSize = 10,
                BorderThickness = new Thickness(0),
                Background = Brushes.Transparent,
                ToolTip = "탭 닫기"
            };
            close.Click += (s, e) =>
            {
                view.Dispose();
                _tabs.Items.Remove(tab);
                if (_tabs.Items.Count == 0) _tabWindow.Close();
            };
            header.Children.Add(close);
            tab.Header = header;

            _tabs.Items.Add(tab);
            _tabs.SelectedItem = tab;
            Activate(_tabWindow);
        }

        // ───────────────────────── 3. 좌우 분할 ─────────────────────────

        private void OpenSplit(ServiceEntry entry)
        {
            if (_splitWindow == null)
            {
                var grid = new Grid { Margin = new Thickness(6) };
                grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
                grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(6) });
                grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });

                _left = new SplitPane(NewView, "왼쪽");
                _right = new SplitPane(NewView, "오른쪽");
                _left.RefreshChoices(LogServices());
                _right.RefreshChoices(LogServices());

                var splitter = new GridSplitter
                {
                    Width = 6,
                    HorizontalAlignment = HorizontalAlignment.Stretch,
                    VerticalAlignment = VerticalAlignment.Stretch,
                    Background = Brushes2.Make("#CFD8DC"),
                    ResizeBehavior = GridResizeBehavior.PreviousAndNext
                };
                Grid.SetColumn(_left, 0);
                Grid.SetColumn(splitter, 1);
                Grid.SetColumn(_right, 2);
                grid.Children.Add(_left);
                grid.Children.Add(splitter);
                grid.Children.Add(_right);

                _splitWindow = NewWindow("로그 비교 (좌우)", grid, 1400, 700);
                _splitWindow.Closed += (s, e) =>
                {
                    _left.Dispose();
                    _right.Dispose();
                    _left = _right = null;
                    _splitWindow = null;
                };
            }

            if (!_left.Shows(entry) && !_right.Shows(entry))
            {
                if (_left.IsEmpty) _left.Show(entry);
                else if (_right.IsEmpty) _right.Show(entry);
                else _right.Show(entry);
            }
            Activate(_splitWindow);
        }

        /// <summary>좌우 분할 창의 한쪽</summary>
        private sealed class SplitPane : DockPanel, IDisposable
        {
            private readonly Func<ServiceEntry, LogTailView> _factory;
            private readonly ComboBox _combo;
            private readonly ContentControl _host;
            private LogTailView _view;
            private bool _updating;

            public bool IsEmpty => _view == null;
            public LogTailView View => _view;

            private readonly UIElement _placeholder;

            public SplitPane(Func<ServiceEntry, LogTailView> factory, string side)
            {
                _factory = factory;

                var top = new DockPanel { Margin = new Thickness(0, 0, 0, 4) };
                SetDock(top, Dock.Top);
                var lbl = new TextBlock { Text = side + " 서비스:", VerticalAlignment = VerticalAlignment.Center, Margin = new Thickness(0, 0, 6, 0) };
                SetDock(lbl, Dock.Left);
                _combo = new ComboBox { DisplayMemberPath = nameof(ServiceEntry.DisplayName), MinWidth = 200 };
                top.Children.Add(lbl);
                top.Children.Add(_combo);
                Children.Add(top);

                _placeholder = new TextBlock
                {
                    Text = "위에서 서비스를 선택하거나, 초기화면에서 Log 버튼을 누르세요.",
                    Foreground = Brushes.Gray,
                    HorizontalAlignment = HorizontalAlignment.Center,
                    VerticalAlignment = VerticalAlignment.Center
                };
                _host = new ContentControl { Content = _placeholder };
                Children.Add(_host);

                _combo.SelectionChanged += (s, e) =>
                {
                    if (_updating) return;
                    if (_combo.SelectedItem is ServiceEntry se) Show(se);
                };
            }

            public bool Shows(ServiceEntry e) => ShowsName(e.ServiceName);

            public bool ShowsName(string serviceName)
                => _view != null && string.Equals(_view.Entry.ServiceName, serviceName, StringComparison.OrdinalIgnoreCase);

            public void Clear()
            {
                _view?.Dispose();
                _view = null;
                _host.Content = _placeholder;
                _updating = true;
                _combo.SelectedItem = null;
                _updating = false;
            }

            public void Show(ServiceEntry entry)
            {
                _view?.Dispose();
                _view = _factory(entry);
                _host.Content = _view;
                SelectInCombo(entry);
            }

            public void RefreshChoices(List<ServiceEntry> services)
            {
                _updating = true;
                _combo.ItemsSource = services;
                _updating = false;
                if (_view != null) SelectInCombo(_view.Entry);
            }

            private void SelectInCombo(ServiceEntry entry)
            {
                _updating = true;
                _combo.SelectedItem = (_combo.ItemsSource as IEnumerable<ServiceEntry>)?
                    .FirstOrDefault(x => string.Equals(x.ServiceName, entry.ServiceName, StringComparison.OrdinalIgnoreCase));
                _updating = false;
            }

            public void Dispose() => _view?.Dispose();
        }
    }
}