//
//  NetworkView.swift
//  punchnet
import SwiftUI
import Observation

// 资源展示模式
enum NetworkShowMode: String, CaseIterable {
    case resource = "访问资源"
    case device = "成员设备"
}

// MARK: - 网络连接状态
enum NetworkConnectionPhase {
    case disconnected
    case connecting
    case connected
    case disconnecting
}

// MARK: - 主网络视图
struct NetworkView: View {
    @Environment(AppContext.self) var appContext: AppContext
    @Environment(\.openWindow) var openWindow
    
    @State private var networkModel = NetworkModel()
    
    var body: some View {
        @Bindable var networkModel = self.networkModel
        
        VStack(spacing: 0) {
            // 1. 头部区域 (Header)
            HStack(spacing: 16) {
                NetworkStatusBar(model: self.networkModel)
                
                Spacer()
                
                if self.networkModel.shouldShowModePicker {
                    Picker("", selection: $networkModel.showMode) {
                        ForEach(NetworkShowMode.allCases, id: \.self) {
                            Text($0.rawValue).tag($0)
                        }
                    }
                    .pickerStyle(.segmented)
                    .frame(width: 160)
                }
                
                Button {
                    openWindow(id: "settings")
                } label: {
                    Image(systemName: "slider.horizontal.3")
                        .font(.system(size: 14))
                        .foregroundColor(.secondary)
                }
                .buttonStyle(.plain)
                .help("配置中心")
            }
            .padding(.horizontal, 20)
            .padding(.vertical, 14)
            .background(VisualEffectView(material: .headerView, blendingMode: .withinWindow))
            
            Divider()
            
            // 2. 内容区域 (Content)
            Group {
                switch self.networkModel.phase {
                case .connecting, .disconnecting:
                    NetworkWaitAuthView(phase: self.networkModel.phase)
                case .connected:
                    NetworkConnectedView(model: self.networkModel)
                case .disconnected:
                    NetworkDisconnectedView(model: self.networkModel)
                }
            }
            .frame(maxWidth: .infinity, maxHeight: .infinity)
            .background(VisualEffectView(material: .windowBackground, blendingMode: .behindWindow))
        }
        .frame(minWidth: 700, minHeight: 500) // 适当调大宽度以适应 SplitView
        .task {
            await self.networkModel.activate(appContext: self.appContext)
        }
        .alert("提示", isPresented: self.errorPresented) {
            Button("确定", role: .cancel) {
                self.networkModel.clearError()
            }
        } message: {
            Text(self.networkModel.errorMessage ?? "")
        }
    }
    
    private var errorPresented: Binding<Bool> {
        Binding(
            get: { self.networkModel.errorMessage != nil },
            set: { isPresented in
                if !isPresented {
                    self.networkModel.clearError()
                }
            }
        )
    }
}

private struct NetworkStatusBar: View {
    var model: NetworkModel

    var body: some View {
        let isOnBinding = Binding(
            get: { self.model.isTunnelEnabled },
            set: { newValue in
                Task { @MainActor in
                    await self.model.setConnectionEnabled(newValue)
                }
            }
        )
        
        HStack(spacing: 12) {
            // 左侧：状态指示器与文字
            HStack(spacing: 20) {
                ZStack {
                    Circle()
                        .fill(self.model.isTunnelEnabled ? Color.green.opacity(0.15) : Color.primary.opacity(0.05))
                        .frame(width: 36, height: 36)
                    
                    Image(systemName: self.model.isTunnelEnabled ? "checkmark.shield.fill" : "shield.slash.fill")
                        .symbolRenderingMode(.hierarchical)
                        .foregroundStyle(self.model.isTunnelEnabled ? Color.green : Color.secondary)
                        .font(.system(size: 16))
                }
                
                VStack(alignment: .leading, spacing: 1) {
                    if let networkSession = self.model.networkSession {
                        Text(networkSession.networkName)
                            .font(.system(size: 12, weight: .semibold))
                        
                        Text("局域网IP: \(self.model.networkContext?.ip ?? "0.0.0.0")")
                            .font(.system(size: 10, design: .monospaced))
                            .foregroundColor(.secondary)
                    } else {
                        Text("未登录网络")
                            .font(.system(size: 12, weight: .semibold))
                        
                        Text("登录后可建立连接")
                            .font(.system(size: 10))
                            .foregroundColor(.secondary)
                    }
                }
            }
            
            if self.model.networkSession != nil {
                exitNodeMenu
            }
            
            // 右侧：Switch 开关
            // 注意：这里使用 Binding 手动接管连接/断开逻辑
            Toggle("", isOn: isOnBinding)
                .toggleStyle(.switch)
                .controlSize(.small) // macOS 顶部栏或面板推荐使用 small 尺寸
                .disabled(self.model.phase == .connecting || self.model.phase == .disconnecting || self.model.networkSession == nil)
        }
        .padding(.vertical, 5)
    }
    
    private var exitNodeMenu: some View {
        Menu {
            Button {
                Task { @MainActor in
                    await self.model.updateExitNodeSelection(nil)
                }
            } label: {
                if self.model.selectedExitNode == nil {
                    Label("不设置出口节点", systemImage: "checkmark")
                } else {
                    Text("不设置出口节点")
                }
            }
            
            if !self.model.exitNodeOptions.isEmpty {
                Divider()
                
                ForEach(self.model.exitNodeOptions) { option in
                    Button {
                        Task { @MainActor in
                            await self.model.updateExitNodeSelection(option.ip)
                        }
                    } label: {
                        if self.model.selectedExitNode?.ip == option.ip {
                            Label(option.nodeNameWithIp, systemImage: "checkmark")
                        } else {
                            Text(option.nodeNameWithIp)
                        }
                    }
                }
            }
        } label: {
            HStack(spacing: 10) {
                VStack(alignment: .leading, spacing: 3) {
                    Text("出口节点")
                        .font(.system(size: 10, weight: .medium))
                        .foregroundColor(.secondary)
                    
                    Text(self.model.exitNodeTitle)
                        .font(.system(size: 12, weight: .semibold))
                        .foregroundColor(.primary)
                        .lineLimit(1)
                    
                    Text(self.model.exitNodeSubtitle)
                        .font(.system(size: 10, design: .monospaced))
                        .foregroundColor(.secondary)
                        .lineLimit(1)
                }
                
                Spacer(minLength: 0)
                
                if self.model.isUpdatingExitNode {
                    ProgressView()
                        .controlSize(.small)
                } else {
                    Image(systemName: "chevron.down")
                        .font(.system(size: 10, weight: .semibold))
                        .foregroundColor(.secondary)
                }
            }
            .padding(.horizontal, 12)
            .padding(.vertical, 8)
            .frame(width: 220, alignment: .leading)
            .background(
                RoundedRectangle(cornerRadius: 12, style: .continuous)
                    .fill(Color.primary.opacity(0.04))
            )
            .overlay(
                RoundedRectangle(cornerRadius: 12, style: .continuous)
                    .stroke(Color.primary.opacity(0.06), lineWidth: 1)
            )
        }
        .buttonStyle(.plain)
        .disabled(!self.model.canSelectExitNode)
        .opacity(self.model.canSelectExitNode ? 1 : 0.7)
        .help(self.model.exitNodeHelpText)
    }
}