dimensionhub/dimensionhub/Views/Index/IndexMainView.swift

//
//  IndexMainView.swift
//  dimensionhub
//
//  Created by 安礼成 on 2025/4/8.
//
import SwiftUI
import Combine

// 首页的主要窗口
struct IndexMainView: View {
    @Environment(\.modelContext) private var modelContext
    @EnvironmentObject var appNavigation: AppNavigation
    @Environment(\.userId) private var userId
    
    @State var indexModel = IndexModel()
    @State private var scrollID: IndexModel.ScrollTarget? = nil
    
    // 提示信息
    @State var showPrompt: Bool = false
    @State var promptMessage: String = ""
    
    // 是否显示日期弹出层
    @State private var selectGroupId: String = ""
    @State private var showDateNavPopover: Bool = false
    
    // 刷新逻辑
    @State private var headerRefreshing: Bool = false
    @State private var footerRefreshing: Bool = false
    @State private var noMore: Bool = false
    
    @State private var scrollOffset: CGFloat = 0
    @State private var showFloatGroupLabel: Bool = false
    
    @State private var scrollHeight: Double = 0
    
    var body: some View {
        VStack(alignment: .center) {
            
            HStack(alignment: .center) {
                Text("亚次元")
                    .font(.system(size: 20, weight: .bold))
                    .padding([.top, .bottom], 5)
                Spacer()
                
                HStack {
                    Text("♡ \(indexModel.follow_num)")
                        .font(.system(size: 18))
                        .foregroundColor(.black)
                        .padding([.top, .bottom], 5)
                        .padding(.leading, 10)
                }
                .contentShape(Rectangle())
                .highPriorityGesture(
                    TapGesture().onEnded {
                        appNavigation.append(dest: .followList)
                    }
                )
                .zIndex(1)
                .task {
                    await indexModel.reloadFollowNum(userId: userId)
                }
            }
            .padding([.leading, .trailing], 15)
            .frame(height: 50)
            .background(Color(hex: "#F2F2F2"), ignoresSafeAreaEdges: .top)
            
            ScrollView(.vertical, showsIndicators: false) {
                ScrollViewOffsetReader(offset: $scrollOffset)
                
                MixGroupLabelView(fixedDramaGroup: indexModel.fixedDramaGroup) {
                    if let groupId = indexModel.fixedDramaGroup?.group_id {
                        selectGroupId = groupId
                        indexModel.selectedDate = groupId
                        showDateNavPopover = true
                    }
                }
                .opacity(!showFloatGroupLabel ? 1 : 0)
                
                // 基于日期的更新列表
                LazyVStack(alignment: .center, spacing: 10) {
                    ForEach(indexModel.dramaGroupElements, id: \.id) { item in
                        switch item.data {
                        case .label(let groupId, let groupName, _):
                            DramaGroupLabelView(group_name: groupName) {
                                selectGroupId = groupId
                                indexModel.selectedDate = groupId
                                showDateNavPopover = true
                            }
                            .id(item.id)
                        case .item(let groupId, let item, _):
                            DramaGroupItemView(groupId: groupId, item: item)
                                .id(item.id)
                        }
                    }
                }
                .scrollTargetLayout()
                                
                ProgressView()
            }
            .frame(width: 370)
            .coordinateSpace(name: "indexScrollView")
            .scrollPosition(id: $scrollID)
            .onChange(of: scrollOffset) {
                self.showFloatGroupLabel = scrollOffset < 0
                indexModel.offsetChanged(offset: scrollOffset)
            }
            .refreshable {
                guard !self.showDateNavPopover && !self.headerRefreshing else {
                    return
                }
                
                // 上拉刷新功能
                self.headerRefreshing = true
                Task {
                    await self.indexModel.loadPrevUpdateDramasTask(userId: self.userId) { anchorGroupElement in
                        DispatchQueue.main.async {
                            self.headerRefreshing = false
                        }
                    }
                }
            }
            .onChange(of: scrollID) { _, newValue in
                if let newValue {
                    indexModel.scrollIDPublisher.send((userId, newValue))
                }
            }
            .overlay(alignment: .topTrailing) {
                MixGroupLabelView(fixedDramaGroup: indexModel.fixedDramaGroup) {
                    if let groupId = indexModel.fixedDramaGroup?.group_id {
                        selectGroupId = groupId
                        indexModel.selectedDate = groupId
                        showDateNavPopover = true
                    }
                    
                }
                .opacity(showFloatGroupLabel ? 1 : 0)
            }
        }
        .ignoresSafeArea(edges: .bottom)
        .popover(isPresented: $showDateNavPopover) {
            DateNavView(selectGroupId: self.$selectGroupId, showDateNavPopover: $showDateNavPopover) { selectedDate in
                Task {
                    await indexModel.loadDateUpdateDramas(userId: self.userId, date: selectedDate)
                }
            }
        }
        .alert(isPresented: $showPrompt) {
            Alert(title: Text("提示"), message: Text(self.promptMessage), dismissButton: .default(Text("OK")))
        }
        .task {
            await self.indexModel.loadData(userId: self.userId)
            
            
        }
    }
    
    struct ScrollViewOffsetReader: View {
        @Binding var offset: CGFloat
        
        var body: some View {
            GeometryReader { geometry in
                Color.clear
                    .preference(
                        key: ScrollOffsetPreferenceKey.self,
                        value: geometry.frame(in: .named("indexScrollView")).origin.y
                    )
            }
            .frame(height: 0)
            .onPreferenceChange(ScrollOffsetPreferenceKey.self) { value in
                DispatchQueue.main.async {
                    self.offset = value
                }
            }
        }
    }

    struct ScrollOffsetPreferenceKey: PreferenceKey {
        static var defaultValue: CGFloat = 0
        
        static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
            value = nextValue()
        }
    }
    
}

extension IndexMainView {
    
    struct MixGroupLabelView: View {
        @EnvironmentObject var appNav: AppNavigation
        
        let fixedDramaGroup: IndexModel.UpdateDramaGroup?
        let onTap: () -> Void
        
        var body: some View {
            HStack(alignment: .center) {
                Button(action: {
                    appNav.append(dest: .search)
                }) {
                    Image(systemName: "magnifyingglass")
                        .font(.system(size: 20))
                }
                
                Spacer()
                
                if let fixedDramaGroup {
                    Text(fixedDramaGroup.group_name)
                        .font(.system(size: 18))
                        .fontWeight(.regular)
                        .onTapGesture {
                            onTap()
                        }
                }
            }
            .padding([.top, .bottom], 8)
            .background(.white)
        }
    }
    
    // 显示分组信息
    struct DramaGroupLabelView: View {
        let group_name: String
        var onTap: () -> Void
        
        var body: some View {
            VStack(alignment: .center, spacing: 10) {
                HStack {
                    Spacer()
                    Text(group_name)
                        .font(.system(size: 18))
                        .fontWeight(.regular)
                        .onTapGesture {
                            onTap()
                        }
                }
            }
        }
    }
    
    // 显示具体的item
    struct DramaGroupItemView: View {
        @EnvironmentObject var appNav: AppNavigation

        let groupId: String
        let item: IndexModel.UpdateDramaGroup.Item
        
        var body: some View {
            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)
                }
                .contentShape(Rectangle())
                .onTapGesture {
                    appNav.append(dest: .detail(id: item.id))
                }
        }
    }
    
}

#Preview {
    IndexMainView()
}