//
//  WordsView.swift
//  AIGrammar
//
//  Created by oscar on 2024/3/27.
//

import SwiftUI
import ToastUI

struct WordsView: View {
    @EnvironmentObject var globalEnv: GlobalEnvironment  // 引入环境对象
    
    @State private var searchText = ""
    @State private var showingResults = false
    @State private var res = WordDetails()
    @State private var isLoading = false  // 控制加载指示器的显示
    @State private var showingToast = false  // 控制是否显示toast
    @State private var toastText = ""

    var body: some View {
        NavigationView {
            ZStack {
                // 设置背景色
                Color.pink.opacity(0.2).edgesIgnoringSafeArea(.all)
                
                VStack(spacing: 0) {
                    // 搜索框区域
                    HStack {
                        TextField("word", text: $searchText, onCommit: fetchWordData)
                        .padding(.horizontal, 40)
                        .padding(.vertical, 10)
                        .background(Color(.systemGray6))
                        .cornerRadius(8)
                        .font(.headline)
                        .overlay(
                            Image(systemName: "magnifyingglass")
                                .foregroundColor(.gray)
                                .frame(minWidth: 0, maxWidth: .infinity, alignment: .leading).padding(.leading, 8)
                        )
                        Spacer()
                        
                        Button("Cancel") {
                            self.searchText = ""
                            self.showingResults = false
                            self.hideKeyboard()
                        }
                    }
                    .background(Color(.systemPink).opacity(0.2))
                    .cornerRadius(5) // 边框圆角
                    .shadow(radius: 2) // 轻微阴影
                    .padding(8)
            
                    
                    // 使用 Spacer 来推动搜索框保持在顶部
                    if !showingResults {
                        Spacer()
                    }
                    
                    if showingResults {
                    // 结果显示区域
                        HStack {
                            List {
                                Section(header: Text("Definitions").font(.headline)) {
                                    ForEach(res.explanations, id: \.self) { definition in
                                        Text(definition)
                                            .font(.system(.subheadline))
                                            .padding(.leading, 4)
                                    }
                                }

                                Section(header: Text("Common Phrases").font(.headline)) {
                                    ForEach(res.phrases, id: \.self) { phrase in
                                        Text(phrase)
                                            .font(.system(.subheadline))
                                            .padding(.leading, 4)
                                    }
                                }

                                Section(header: Text("Synonyms").font(.system(size: UIFont.systemFontSize * 1.2))) {
                                    ForEach(res.synonyms, id: \.self) { synonym in
                                        Text(synonym)
                                            .font(.system(.subheadline))
                                            .padding(.leading, 4)
                                    }
                                }
                            }
                            .padding(8)
                            .cornerRadius(5) // 边框圆角
                            .frame(maxHeight: .infinity) // 限制ErrorCard占用半个屏幕 */
                        }
                        .listStyle(GroupedListStyle()) // 使用分组列表样式，以适应背景
                    }
                }
                .toast(isPresented: $showingToast, dismissAfter: globalEnvironment.toastPresentMsNormal) {
                    HStack {
                        Image(systemName: "exclamationmark.bubble")
                            .foregroundColor(.yellow)
                        Text(toastText)
                            .foregroundColor(.black)
                    }
                    .padding()
                    .background(Color.white)
                    .cornerRadius(8)
                    .shadow(radius: 10)
                }
                
                // 加载指示器
                if isLoading {
                    LoadingView()
                }
            }
            .onTapGesture {
                // 点击任何非TextField区域时收起键盘
                self.hideKeyboard()
                
            }
            .navigationBarTitle("Words", displayMode: .inline)
        }
        
    }
    
    private func hideKeyboard() {
        UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
    }
    
    // 模拟加载数据
    func loadData() {
        isLoading = true
    }
    func loadComplete(){
        isLoading = false
    }
    
    private func fetchWordData() {
        // 清除输入内容前后的空格
        let trimmedText = searchText.trimmingCharacters(in: .whitespacesAndNewlines)
        
        // 检查是否为空
        if trimmedText.isEmpty {
            showingToast = true
            toastText = "Please enter some text."
            return  // 提前返回，不执行网络请求
        }
        
        // 检查长度是否超过200个字符
        if trimmedText.count > globalEnvironment.MaxLenWords {
            showingToast = true
            toastText = "Input too long. Please re-enter the text."
            return  // 提前返回，不执行网络请求
        }
        
        // 检查是否含有非法字符
        let checkRes = CommonFunc.shared.validateInputEng(input: trimmedText, isSingleWord: true)
        if !checkRes.isValid {
            showingToast = true
            toastText = checkRes.message
            return
        }
        /*
        if trimmedText.range(of: "[^a-zA-Z]", options: .regularExpression) != nil {
            showingToast = true
            toastText = "Please enter valid characters."
            return  // 提前返回，不执行网络请求
        }
         */
        
        loadData()  // 添加提交的提示
        NetworkManager.shared.fetchWordDetails(inputText: trimmedText) { result in
            switch result {
            case .success(let wordDetails):
                DispatchQueue.main.async {
                    res = wordDetails
                    showingResults = true
                }
                logger.info("fetch words succ.", context: ["word":wordDetails.word, "explanations":wordDetails.explanations, "phrases":wordDetails.phrases, "synonyms":wordDetails.synonyms])
            case .failure(let error):
                switch error {
                case .businessError(let ret, let message):
                    // 业务错误，比如无免费可用次数等，需要处理逻辑。
                    logger.error("Business error - Ret: \(ret), Message: \(message)")
                    DispatchQueue.main.async {
                        showingToast = true
                        switch ret{
                        case globalEnvironment.RetCodeFreeLimited:
                            toastText = globalEnvironment.FreeLimitedToast
                        case globalEnvironment.RetCodeDirtyInput:
                            toastText = globalEnvironment.DirtyInputErrToast
                        default:
                            toastText = globalEnvironment.OtherServerErrToast
                        }
                    }
                case .other(let error):
                    logger.error("network error occurred: \(error.localizedDescription)")
                    DispatchQueue.main.async {
                        showingToast = true
                        toastText = globalEnvironment.NetWorkErrToast
                    }
                }
            }
            loadComplete()
        }
    }
}

struct WordsView_Previews: PreviewProvider {
    static var previews: some View {
        WordsView()
    }
}



#Preview {
    WordsView()
}