import SwiftUI
import Foundation

// 搜索历史记录管理器（保持不变）
class SearchHistoryManager {
    static let shared = SearchHistoryManager()
    private let userDefaultsKey = "search_history"
    private let maxHistoryCount = 50
    
    var history: [String] {
        UserDefaults.standard.array(forKey: userDefaultsKey) as? [String] ?? []
    }
    
    func addHistory(_ query: String) {
        var newHistory = history
        if let index = newHistory.firstIndex(of: query) {
            newHistory.remove(at: index)
        }
        newHistory.insert(query, at: 0)
        if newHistory.count > maxHistoryCount {
            newHistory = Array(newHistory.prefix(maxHistoryCount))
        }
        UserDefaults.standard.set(newHistory, forKey: userDefaultsKey)
    }
    
    func removeHistory(_ query: String) {
        var newHistory = history
        if let index = newHistory.firstIndex(of: query) {
            newHistory.remove(at: index)
            UserDefaults.standard.set(newHistory, forKey: userDefaultsKey)
        }
    }
    
    func clearAllHistory() {
        UserDefaults.standard.removeObject(forKey: userDefaultsKey)
    }
}

// 修改后的搜索视图（实现数字ID直接导航）
struct SearchView: View {
    @State private var searchQuery: String = ""
    @State private var searchResults: [AlbumItem] = []
    @State private var isSearching: Bool = false
    @State private var showAlert: Bool = false
    @State private var alertMessage: String = ""
    @State private var searchHistory: [String] = []
    // 添加导航路径状态，用于编程式导航
    @State private var navigationPath = NavigationPath()
    
    var body: some View {
        // 使用带路径的NavigationStack以支持编程式导航
        NavigationStack(path: $navigationPath) {
            Form {
                Section(header: Text("Jetson Media")) {
                    HStack {
                        TextField("输入搜索内容或ID", text: $searchQuery)
                            .textFieldStyle(RoundedBorderTextFieldStyle())
                            .onChange(of: searchQuery) {
                                if $0.isEmpty {
                                    loadHistory()
                                }
                            }
                        
                        Button(action: performSearch) {
                            if isSearching {
                                ProgressView()
                            } else {
                                Image(systemName: "magnifyingglass")
                            }
                        }
                        .disabled(searchQuery.isEmpty || isSearching)
                    }
                }
                
                // 搜索历史区域（保持不变）
                if searchQuery.isEmpty && !searchHistory.isEmpty {
                    Section(header: HStack {
                        Text("搜索历史")
                        Spacer()
                        Button("清除全部") {
                            SearchHistoryManager.shared.clearAllHistory()
                            loadHistory()
                        }
                        .foregroundColor(.red)
                        .font(.subheadline)
                    }) {
                        ForEach(searchHistory, id: \.self) { query in
                            HStack {
                                Text(query)
                                    .foregroundColor(.primary)
                                    .frame(maxWidth: .infinity, alignment: .leading)
                                    .onTapGesture {
                                        searchQuery = query
                                        performSearch()
                                    }
                                
                                Button(action: {
                                    SearchHistoryManager.shared.removeHistory(query)
                                    loadHistory()
                                }) {
                                    Image(systemName: "xmark.circle.fill")
                                        .foregroundColor(.gray)
                                }
                                .buttonStyle(PlainButtonStyle())
                            }
                        }
                    }
                }
                
                // 搜索结果区域（保持不变）
                if !searchResults.isEmpty {
                    Section(header: Text("搜索结果")) {
                        ForEach(searchResults, id: \.album_id) { item in
                            NavigationLink(destination: PhotoView(albumId: item.album_id)) {
                                VStack(alignment: .leading) {
                                    Text(item.title)
                                        .font(.headline)
                                    Text("ID: \(item.album_id)")
                                        .font(.subheadline)
                                        .foregroundColor(.gray)
                                }
                            }
                        }
                    }
                }
            }
            .navigationTitle("搜索")
            .onAppear {
                loadHistory()
            }
            // 定义导航目的地
            .navigationDestination(for: Int.self) { albumId in
                PhotoView(albumId: String(albumId))
            }
        }
        .alert(isPresented: $showAlert) {
            Alert(title: Text("提示"), message: Text(alertMessage), dismissButton: .default(Text("确定")))
        }
    }
    
    private func loadHistory() {
        searchHistory = SearchHistoryManager.shared.history
    }
    
    private func performSearch() {
        guard !searchQuery.isEmpty else { return }
        
        // 首先检查搜索内容是否为数字
        if let albumId = Int(searchQuery) {
            // 如果是数字，直接导航到对应的ID页面
            SearchHistoryManager.shared.addHistory(searchQuery)
            loadHistory()
            navigationPath.append(albumId)
            return
        }
        
        // 如果不是数字，执行正常搜索流程
        SearchHistoryManager.shared.addHistory(searchQuery)
        loadHistory()
        
        isSearching = true
        searchResults = []
        
        let encodedQuery = searchQuery.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? searchQuery
        let urlString = Config.shared.apiURL(
            path: "\(Config.Path.search)?search_query=\(encodedQuery)&page=1"
        )
        guard let url = URL(string: urlString) else {
            showAlert(message: "无效的URL")
            isSearching = false
            return
        }
        
        let task = URLSession.shared.dataTask(with: url) { data, response, error in
            DispatchQueue.main.async {
                self.isSearching = false
                
                if let error = error {
                    self.showAlert(message: "搜索失败: \(error.localizedDescription)")
                    return
                }
                
                guard let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 else {
                    self.showAlert(message: "服务器返回错误")
                    return
                }
                
                guard let data = data else {
                    self.showAlert(message: "没有接收到数据")
                    return
                }
                
                do {
                    let decoder = JSONDecoder()
                    self.searchResults = try decoder.decode([AlbumItem].self, from: data)
                } catch {
                    print("解码错误: \(error)")
                    self.showAlert(message: "解析数据失败: \(error.localizedDescription)")
                }
            }
        }
        task.resume()
    }
    
    private func showAlert(message: String) {
        alertMessage = message
        showAlert = true
    }
}