using Prism.Mvvm;
using Prism.Commands;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Windows;
using TeamAAS.FlowEditor.Models;
using TeamAAS.FlowEngine.Execution;
using TeamAAS.Dialogs;
using TeamAAS.FlowEngine;
using TeamAAS.FlowEditor.Execution;

namespace TeamAAS.FlowEditor
{

    /// <summary>
    /// 流程编辑器外壳 ViewModel：管理多 Tab 流程
    /// </summary>
    public class FlowEditorShellViewModel : TeamAAS.BindableBase
    {
        public ObservableCollection<FlowTabItem> FlowTabs => PluginLoader.Instance.FlowTabs;

        private FlowTabItem _activeTab;
        public FlowTabItem ActiveTab
        {
            get => _activeTab;
            set
            {
                if (_activeTab != null) _activeTab.IsActive = false;
                if (SetProperty(ref _activeTab, value))
                {
                    if (_activeTab != null) _activeTab.IsActive = true;
                    RaisePropertyChanged(nameof(ActiveEditorVm));
                }
            }
        }

        public FlowEditorViewModel ActiveEditorVm => ActiveTab?.EditorVm;

        // 流程结构变化（新建/删除/重命名 Tab）——关闭的 Tab 不再参与 per-tab 脏检查，需单独记录
        private bool _structureChanged;

        private bool _isReadOnly;
        /// <summary>只读监控模式（运行产品运行中）：由 ProductManager/ProductViewModel 设置并传播到所有 Tab</summary>
        public bool IsReadOnly
        {
            get => _isReadOnly;
            set
            {
                if (SetProperty(ref _isReadOnly, value))
                    ApplyReadOnlyToTabs();
            }
        }

        private bool _isMonitorMode;
        /// <summary>是否监控运行中流程（勾选后挂接 RunTabs，否则独立编辑）</summary>
        public bool IsMonitorMode
        {
            get => _isMonitorMode;
            private set => SetProperty(ref _isMonitorMode, value);
        }

        /// <summary>切换监控模式（开/关）</summary>
        public DelegateCommand ToggleMonitorCommand { get; }

        private bool _isMonitorOptionAvailable;
        /// <summary>「监控当前流程」选项是否可用（当前产品==运行产品且正在运行）</summary>
        public bool IsMonitorOptionAvailable
        {
            get => _isMonitorOptionAvailable;
            private set => SetProperty(ref _isMonitorOptionAvailable, value);
        }

        /// <summary>把当前只读状态应用到所有流程 Tab（切换产品/新增 Tab 后调用）</summary>
        public void ApplyReadOnlyToTabs()
        {
            foreach (var tab in FlowTabs)
                tab.EditorVm?.SetReadOnly(_isReadOnly);
        }

        /// <summary>是否存在未保存的修改（流程内容修改 + 流程增删/改名）</summary>
        public bool HasUnsavedChanges =>
            _structureChanged || FlowTabs.Any(t => t.EditorVm != null && t.EditorVm.IsDirty);

        /// <summary>保存后清除所有流程的修改标记</summary>
        public void MarkAllClean()
        {
            _structureChanged = false;
            foreach (var tab in FlowTabs)
                tab.EditorVm?.MarkClean();
        }

        public DelegateCommand AddFlowCommand { get; }
        public DelegateCommand<FlowTabItem> CloseFlowCommand { get; }
        public DelegateCommand<FlowTabItem> RenameFlowCommand { get; }
        public DelegateCommand<FlowTabItem> OpenTabPropertiesCommand { get; }
        public DelegateCommand ImportFlowCommand { get; }
        public DelegateCommand ExportFlowCommand { get; }

        public FlowEditorShellViewModel()
        {
            if (FlowTabs.Count == 0)
            {
                var defaultTab = new FlowTabItem("流程1");
                FlowTabs.Add(defaultTab);
                ActiveTab = defaultTab;
            }
            else
            {
                ActiveTab = FlowTabs[0];
            }

            AddFlowCommand = new DelegateCommand(AddFlow);
            CloseFlowCommand = new DelegateCommand<FlowTabItem>(CloseFlow);
            RenameFlowCommand = new DelegateCommand<FlowTabItem>(tab => RenameFlow(tab));
            OpenTabPropertiesCommand = new DelegateCommand<FlowTabItem>(OpenTabProperties);
            // 导入/导出逻辑统一在 FlowEditorViewModel 的命令里，Shell 只做转发（只读模式下禁用导入）
            ImportFlowCommand = new DelegateCommand(
                () => ActiveEditorVm?.ImportFlowCommand?.Execute(),
                () => ActiveEditorVm != null && !IsReadOnly);
            ExportFlowCommand = new DelegateCommand(() => ActiveEditorVm?.ExportFlowCommand?.Execute());
            ToggleMonitorCommand = new DelegateCommand(ToggleMonitor);

            // 订阅运行态重载事件：监控中主界面重载流程时自动同步显示
            FlowRunner.Instance.RunTabsRefreshed += OnRunTabsRefreshed;
        }

        /// <summary>切换监控模式入口</summary>
        private void ToggleMonitor()
        {
            if (IsMonitorMode) ExitMonitor();
            else EnterMonitor();
        }

        /// <summary>进入监控模式：必要时提示保存当前编辑，再挂接运行态 RunTabs</summary>
        private void EnterMonitor()
        {
            // 运行态未启动 → 提示并 return
            if (!FlowRunner.Instance.IsRunning || FlowRunner.Instance.RunTabs.Count == 0)
            {
                DialogHelper.Info("当前没有正在运行的流程，无法监控");
                return;
            }
            // 当前产品 != 运行产品 → 提示保存后切换（点否不保存但仍然切到运行产品监控）
            if (!string.Equals(ProductManager.Instance.CurrentProductName,
                               FlowRunner.Instance.RunProductName, StringComparison.Ordinal))
            {
                if (HasUnsavedChanges)
                {
                    bool save = DialogHelper.ConfirmYesNo("切换到运行产品需先保存当前方案，是否保存？", "保存确认");
                    if (save) SaveAllModifiedTabs();
                }
                ProductManager.Instance.SwitchProduct(FlowRunner.Instance.RunProductName, this);
            }
            else if (HasUnsavedChanges)
            {
                // 当前产品 == 运行产品：点否也进入监控，但不保存
                bool save = DialogHelper.ConfirmYesNo("进入监控前是否保存当前修改？", "保存确认");
                if (save) SaveAllModifiedTabs();
            }
            AttachRunTabs();
            IsMonitorMode = true;
            IsReadOnly = true;
        }

        /// <summary>退出监控模式：恢复编辑态（从磁盘重载副本）</summary>
        private void ExitMonitor()
        {
            IsMonitorMode = false;
            IsReadOnly = false;
            DetachAndReloadFromDisk();
        }

        /// <summary>
        /// 根据"当前产品 == 运行产品 且 正在运行"刷新监控选项可用性，并自动同步监控状态：
        /// - 满足条件 → 选项可用；若当前不在监控则自动进入监控
        /// - 不满足   → 选项禁用；若当前在监控则自动退出
        /// 该方法由 ProductManager.SwitchProduct/SwitchProductAsync、ProductViewModel.RefreshRunState 调用。
        /// 注意：本方法不直接调 EnterMonitor（避免与 EnterMonitor 内部的 SwitchProduct 互相递归），
        ///       而是设置 IsMonitorMode 标志后再调，让 EnterMonitor 看到 IsMonitorMode=true 时跳过自动调用。
        /// </summary>
        public void ApplyMonitorAvailability()
        {
            bool available = !string.IsNullOrEmpty(ProductManager.Instance.CurrentProductName)
                             && string.Equals(ProductManager.Instance.CurrentProductName,
                                              FlowRunner.Instance.RunProductName, StringComparison.Ordinal)
                             && FlowRunner.Instance.IsRunning;
            IsMonitorOptionAvailable = available;
            try
            {
                if (!available && IsMonitorMode)
                {
                    // 当前产品不再是运行产品或运行已停止 → 退出监控
                    ExitMonitor();
                }
                else if (available && !IsMonitorMode)
                {
                    // 切到运行产品且正在运行 → 默认进入监控模式。
                    // 先置 IsMonitorMode=true 防止 EnterMonitor 内部调 SwitchProduct 时
                    // 其末尾的 ApplyMonitorAvailability 再次触发 EnterMonitor（无限递归）。
                    IsMonitorMode = true;
                    EnterMonitor();
                }
            }
            catch (Exception ex)
            {
                // 监控自动切换失败不应导致整个应用闪退
                IsMonitorMode = false;
                IsReadOnly = false;
                TeamAAS.AppLogger.Error("ApplyMonitorAvailability 自动监控失败", ex, nameof(FlowEditorShellViewModel));
            }
        }

        /// <summary>保存所有已修改的流程 tab 到磁盘</summary>
        private void SaveAllModifiedTabs()
        {
            foreach (var tab in FlowTabs)
                if (tab.EditorVm != null && tab.EditorVm.IsDirty)
                    ProductManager.Instance.SaveFlow(ProductManager.Instance.CurrentProductName, tab);
            MarkAllClean();
        }

        /// <summary>
        /// 释放当前集合中的编辑态 Tab（插件 Dispose + Debug 注册表清理）。
        /// 跳过 FlowRunner.RunTabs 中的运行态 Tab——它们由 FlowRunner 拥有，可能正在执行，不能在此释放。
        /// </summary>
        private void DisposeEditTabs()
        {
            try
            {
                var runTabs = FlowRunner.Instance.RunTabs;
                var editTabs = FlowTabs.Where(t => t != null && !runTabs.Contains(t)).ToList();
                if (editTabs.Count > 0)
                    ProductManager.DisposeFlowTabs(editTabs);
            }
            catch (Exception ex)
            {
                TeamAAS.AppLogger.Error("释放编辑态流程 Tab 失败", ex, nameof(FlowEditorShellViewModel));
            }
        }

        /// <summary>挂接运行态 RunTabs 到当前编辑器（监控模式核心）</summary>
        private void AttachRunTabs()
        {
            // 释放被替换的编辑态 Tab，否则插件与 Debug 注册表引用会随每次进入监控持续泄漏
            DisposeEditTabs();
            // 进入监控＝换对象：完全清空 Debug 之前的编辑态集合（含子流程残留），
            // 此后编辑器挂的是 Main 的 RunTabs，看到的就是运行态数据
            ResultRegistry.Debug.ClearAllFlows();
            FlowTabs.Clear();
            foreach (var t in FlowRunner.Instance.RunTabs.ToList())
                FlowTabs.Add(t);
            if (FlowTabs.Count > 0) ActiveTab = FlowTabs[0];
        }

        /// <summary>从磁盘重载当前产品的编辑副本（退出监控时恢复编辑态）</summary>
        private void DetachAndReloadFromDisk()
        {
            var productName = ProductManager.Instance.CurrentProductName;
            // 退出监控时 FlowTabs 挂的是 RunTabs（由 FlowRunner 拥有），只解除引用不释放；
            // 非监控状态下的残留编辑 Tab 则正常释放
            DisposeEditTabs();
            // 退出监控＝换回编辑态对象：完全清空 Debug（含监控期与子流程残留），再从磁盘重载干净副本
            ResultRegistry.Debug.ClearAllFlows();
            FlowTabs.Clear();
            if (!string.IsNullOrEmpty(productName))
            {
                foreach (var t in ProductManager.Instance.LoadAllFlows(productName))
                    FlowTabs.Add(t);
            }
            if (FlowTabs.Count == 0)
            {
                var defaultTab = new FlowTabItem("流程1");
                FlowTabs.Add(defaultTab);
            }
            ActiveTab = FlowTabs.FirstOrDefault();
        }

        /// <summary>FlowRunner.RunTabsRefreshed 回调：监控模式下自动同步新运行态</summary>
        private void OnRunTabsRefreshed()
        {
            if (!IsMonitorMode) return;
            Application.Current?.Dispatcher.Invoke(AttachRunTabs);
        }

        public void AddFlow()
        {
            if (IsReadOnly) return; // 运行监控中禁止新增流程

            var name = GetUniqueFlowName("流程");
            var tab = new FlowTabItem(name);
            tab.EditorVm?.SetReadOnly(IsReadOnly);
            FlowTabs.Add(tab);
            ActiveTab = tab;
            _structureChanged = true; // 新增流程属于未保存修改
        }

        private string GetUniqueFlowName(string baseName)
        {
            int suffix = 1;
            var name = baseName + suffix;
            while (FlowTabs.Any(t => t.Name == name))
            {
                suffix++;
                name = baseName + suffix;
            }
            return name;
        }

        public void CloseFlow(FlowTabItem tab)
        {
            if (tab == null || FlowTabs.Count <= 1) return;
            if (IsReadOnly)
            {
                DialogHelper.Info("运行产品监控中，无法关闭流程");
                return;
            }

            // 关闭的流程如果有未保存修改，先确认是否放弃
            if (tab.EditorVm != null && tab.EditorVm.IsDirty)
            {
                bool discard = DialogHelper.ConfirmYesNo(
                    $"流程 \"{tab.Name}\" 有未保存的修改，关闭后将丢失这些修改，确定关闭吗？",
                    "关闭流程");
                if (!discard) return;
            }

            int idx = FlowTabs.IndexOf(tab);
            FlowTabs.Remove(tab);
            if (ActiveTab == tab)
            {
                int newIdx = Math.Min(idx, FlowTabs.Count - 1);
                ActiveTab = FlowTabs[newIdx];
            }

            _structureChanged = true; // 删除流程：保存时需要同步删除磁盘上的对应 .aas
        }

        public void RenameFlow(FlowTabItem tab, string newName = null)
        {
            if (tab == null) return;
            if (IsReadOnly)
            {
                DialogHelper.Info("运行产品监控中，无法重命名流程");
                return;
            }
            if (newName == null)
            {
                newName = ShowRenameDialog(tab.Name);
                if (string.IsNullOrWhiteSpace(newName)) return;
            }
            // 重名加序号（排除自身）
            if (FlowTabs.Any(t => t != tab && t.Name == newName))
                newName = GetUniqueFlowName(newName);
            tab.Name = newName;
            tab.Graph.GraphName = newName;
            // 同步所有节点的 FlowName
            foreach (var node in tab.Graph.Nodes)
            {
                node.FlowName = newName;
            }
            tab.EditorVm?.MarkDirty(); // 流程改名也属于未保存修改
        }

        public void OpenTabProperties(FlowTabItem tab)
        {
            if (tab == null) return;
            if (IsReadOnly)
            {
                DialogHelper.Info("运行产品监控中，无法修改流程属性");
                return;
            }
            // 调试：记录打开属性前的 TriggerType 值
            TeamAAS.AppLogger.Info($"OpenTabProperties: {tab.Name} 当前 TriggerType={tab.TriggerType}", "OpenTabProperties");
            if (DialogHelper.EditProperties(tab, $"流程属性 - {tab.Name}"))
            {
                // 调试：记录关闭对话框后的 TriggerType 值
                TeamAAS.AppLogger.Info($"OpenTabProperties: {tab.Name} 修改后 TriggerType={tab.TriggerType}", "OpenTabProperties");
                DialogHelper.Info($"已更新流程属性: {tab.Name}");
            }
        }

        private string ShowRenameDialog(string currentName)
        {
            return DialogHelper.Input("流程名称", "重命名流程", currentName);
        }
    }
}