dimensionhub/dimensionhub/Views/Search/SearchView.swift

//
//  SearchView.swift
//  dimensionhub
//
//  Created by 安礼成 on 2025/4/1.
//

import SwiftUI

struct SearchView: View {
    @Environment(\.modelContext) var modelContext
    @Environment(\.userId) private var userId

    @Environment(\.dismiss) var dismiss
    @State var searchText: String = ""
    @State var searchModel = SearchModel()
    
    @State private var isSearching = false
    
    // 是否显示搜索结果
    @State private var showSearchResult: Bool = false
    
    // 键盘焦点的控制
    @State private var toolbarID = UUID()
    @State private var isFocused: Bool = true

    var body: some View {
        ScrollView(.vertical, showsIndicators: false) {
            LazyVStack(alignment: .center, spacing: 10) {
                ForEach(searchModel.dramaGroups, id: \.group_id) { group in
                    SearchDramaGroupView(group: group)
                }
            }
            .padding(.top, 8)
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .background(
            GestureObserver {
                // 当检测到系统返回手势时调用
                if isFocused {
                    isFocused = false
                }
            } onGestureCancelled: {
                if !isFocused && !showSearchResult {
                    isFocused = true
                }
            }
        )
        .onTapGesture {
            isFocused = false
        }
        .simultaneousGesture(
            DragGesture().onChanged{ _ in
                isFocused = false
            }
        )
        .overlay(alignment: .center) {
            Text("什么都没有找到")
                .font(.system(size: 18))
                .foregroundColor(Color(hex: "#333333"))
                .opacity(showSearchResult && searchModel.dramaGroups.isEmpty ? 1 : 0)
        }
        .navigationTitle("")
        .toolbar {
            ToolbarItem(placement: .principal) {
                SearchBar(isFirstResponder: $isFocused, searchText: $searchText) {
                    doSearch()
                }
                .frame(width: UIScreen.main.bounds.width * 0.8)
                .id(toolbarID)
            }
        }
        .onAppear {
            toolbarID = UUID()
        }
    }
    
    private func doSearch() {
        let trimmed = searchText.trimmingCharacters(in: .whitespacesAndNewlines)
        if !trimmed.isEmpty {
            Task.detached {
                await searchModel.search(userId: userId, name: trimmed)
                DispatchQueue.main.async {
                    // 显示搜索结果
                    self.showSearchResult = true
                }
            }
            
            // 可选：添加历史记录
            // let history = SearchHistory(keyword: trimmed, timestamp: Date())
            // modelContext.insert(history)
        }
    }
    
}

// 显示分组信息
struct SearchDramaGroupView: View {
    let group: SearchModel.DramaGroup
    
    var body: some View {
        LazyVStack(alignment: .center, spacing: 10) {
            ForEach(group.items, id: \.id) { item in
                NavigationLink(destination: DetailView(id: item.id, channelName: nil)) {
                    FlexImage(urlString: item.thumb, width: 370, height: 180, placeholder: "ph_img_big")
                        .frame(width: 370, height: 180)
                        .overlay(alignment: .topLeading) {
                            VStack(alignment: .leading, spacing: 8) {
                                Text(item.name)
                                    .font(.system(size: 16))
                                    .foregroundColor(.white)
                                    .lineLimit(1)
                                
                                Text(item.status)
                                    .font(.system(size: 12))
                                    .foregroundColor(.white)
                                    .lineLimit(1)
                            }
                            .padding(5)
                            .background(
                                Color.black.opacity(0.6)
                            )
                            .cornerRadius(5)
                            .padding(8)
                        }
                }
            }
        }
    }
}

struct GestureObserver: UIViewControllerRepresentable {
    var onGestureBegin: () -> Void
    var onGestureCancelled: () -> Void

    func makeUIViewController(context: Context) -> UIViewController {
        return context.coordinator
    }

    func updateUIViewController(_ uiViewController: UIViewController, context: Context) { }

    func makeCoordinator() -> Coordinator {
        Coordinator(onGestureBegin: onGestureBegin, onGestureCancelled: onGestureCancelled)
    }

    class Coordinator: UIViewController {
        var onGestureBegin: () -> Void
        var onGestureCancelled: () -> Void
        
        // 用来保存当前堆栈中的数量
        var initialStackCount: Int = 0
        
        // 保存起来
        var cacheNavigationController: UINavigationController?

        init(onGestureBegin: @escaping () -> Void, onGestureCancelled: @escaping () -> Void) {
            self.onGestureBegin = onGestureBegin
            self.onGestureCancelled = onGestureCancelled
            super.init(nibName: nil, bundle: nil)
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        override func viewDidAppear(_ animated: Bool) {
            super.viewDidAppear(animated)
            guard let nav = self.navigationController else {
                return
            }
            initialStackCount = nav.viewControllers.count
            
            self.cacheNavigationController = nav
            // 添加手势识别函数
            if let gesture = nav.interactivePopGestureRecognizer {
                gesture.addTarget(self, action: #selector(handleGesture(_:)))
            }
        }
        
        @objc func handleGesture(_ gesture: UIScreenEdgePanGestureRecognizer) {
            switch gesture.state {
            case .began:
                onGestureBegin()
            case .ended:
                if let nav = self.cacheNavigationController {
                    DispatchQueue.main.asyncAfter(deadline: .now() + 0.8) { [self] in
                        let afterCount = nav.viewControllers.count
                        if afterCount < initialStackCount {
                            // 页面真的 pop 出去了
                            print("pop out")
                        } else {
                            // 页面还在
                            onGestureCancelled()
                        }
                    }
                }
            case .cancelled, .failed:
                onGestureCancelled()
                
            default:
                break
            }
        }
    }
    
}


//
//#Preview {
//    SearchView()
//}