MNN/apps/iOS/MNNLLMChat/MNNLLMiOS/ModelList/Views/ModelListView.swift

//
//  ModelListView.swift
//  MNNLLMiOS
//
//  Created by 游薪渝(揽清) on 2025/1/3.
//

import SwiftUI

struct ModelListView: View {
    
    @State private var scrollOffset: CGFloat = 0
    @State private var showHelp = false
    @State private var showHistory = false
    @State private var selectedHistory: ChatHistory?
    @State private var histories: [ChatHistory] = []
    
    @StateObject private var viewModel = ModelListViewModel()
    
    var body: some View {
        ZStack {
            NavigationView {
                List {
                    SearchBar(text: $viewModel.searchText)
                        .listRowInsets(EdgeInsets())
                        .listRowSeparator(.hidden)
                        .padding(.horizontal)
                        
                    ForEach(viewModel.filteredModels, id: \.modelId) { model in
                        ModelRowView(model: model,
                                   downloadProgress: viewModel.downloadProgress[model.modelId] ?? 0,
                                   isDownloading: viewModel.currentlyDownloading == model.modelId,
                                   isOtherDownloading: viewModel.currentlyDownloading != nil) {
                            if model.isDownloaded {
                                viewModel.selectModel(model)
                            } else {
                                Task {
                                    await viewModel.downloadModel(model)
                                }
                            }
                        }
                        .swipeActions(edge: .trailing, allowsFullSwipe: false) {
                            if model.isDownloaded {
                                Button(role: .destructive) {
                                    Task {
                                        await viewModel.deleteModel(model)
                                    }
                                } label: {
                                    Label("Delete", systemImage: "trash")
                                }
                            }
                        }
                    }
                }
                .listStyle(.plain)
                .navigationTitle("Models")
                .navigationBarTitleDisplayMode(.large)
                .navigationBarItems(
                    leading: Button(action: {
                        showHistory.toggle()
                        updateHistory()
                    }) {
                        Image(systemName: "clock.arrow.circlepath")
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                            .frame(width: 22, height: 22)
                    },
                    trailing: Button(action: {
                        showHelp = true
                    }) {
                        Image(systemName: "questionmark.circle")
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                            .frame(width: 22, height: 22)
                    }
                )
                .sheet(isPresented: $showHelp) {
                    HelpView()
                }
                .refreshable {
                    await viewModel.fetchModels()
                }
                .alert("Error", isPresented: $viewModel.showError) {
                    Button("OK", role: .cancel) {}
                } message: {
                    Text(viewModel.errorMessage)
                }
                .background(
                    NavigationLink(
                        destination: {
                            if let selectedModel = viewModel.selectedModel {
                                return AnyView(LLMChatView(modelInfo: selectedModel))
                            } else if let selectedHistory = selectedHistory {
                                return AnyView(LLMChatView(modelInfo: ModelInfo(
                                    modelId: selectedHistory.modelId,
                                    createdAt: selectedHistory.createdAt.formatAgo(),
                                    downloads: 0,
                                    tags: [],
                                    isDownloaded: true
                                ), history: selectedHistory))
                            }
                            return AnyView(EmptyView())
                        }(),
                        isActive: Binding(
                            get: { viewModel.selectedModel != nil || selectedHistory != nil },
                            set: { if !$0 { viewModel.selectedModel = nil; selectedHistory = nil } }
                        )
                    ) {
                        EmptyView()
                    }
                )
            }
            .disabled(showHistory)
            
            
            if showHistory {
                Color.black.opacity(0.5)
                    .edgesIgnoringSafeArea(.all)
                    .onTapGesture {
                        withAnimation {
                            showHistory = false
                        }
                    }
            }
            
            SideMenuView(isOpen: $showHistory, selectedHistory: $selectedHistory, histories: $histories)
                .edgesIgnoringSafeArea(.all)
        }
        .onAppear {
            updateHistory()
        }
    }
    
    private func updateHistory() {
        histories = ChatHistoryManager.shared.getAllHistory()
    }
}