import SwiftUI
import UIKit

struct UserCreatorChatRoomView: View {
    @StateObject private var viewModel = UserCreatorChatRoomViewModel()
    @State private var messageText = ""

    private let roomId: Int?
    private let creatorId: Int?

    init(roomId: Int) {
        self.roomId = roomId
        self.creatorId = nil
    }

    init(creatorId: Int) {
        self.roomId = nil
        self.creatorId = creatorId
    }

    var body: some View {
        BaseView(isLoading: $viewModel.isLoading) {
            VStack(spacing: 0) {
                headerView

                messageListView
                    .frame(maxWidth: .infinity, maxHeight: .infinity)

                inputBarView
            }
            .background(Color.black.ignoresSafeArea())
        }
        .onAppear(perform: enterRoom)
        .onDisappear { viewModel.leaveAndClose() }
        .sodaToast(
            isPresented: $viewModel.isShowPopup,
            message: viewModel.errorMessage,
            autohideIn: 2
        )
    }

    private var headerView: some View {
        HStack(spacing: SodaSpacing.s12) {
            Image("ic_back")
                .resizable()
                .frame(width: 24, height: 24)
                .onTapGesture { AppState.shared.back() }

            DownsampledKFImage(
                url: URL(string: viewModel.opponentProfileImageUrl ?? ""),
                size: CGSize(width: 36, height: 36)
            )
            .clipShape(Circle())

            Text(viewModel.opponentNickname)
                .appFont(size: 14, weight: .bold)
                .foregroundColor(.white)
                .lineLimit(1)
                .truncationMode(.tail)

            Spacer(minLength: 0)
        }
        .padding(.horizontal, SodaSpacing.s16)
        .padding(.vertical, SodaSpacing.s8)
        .frame(width: screenSize().width, height: 60)
        .background(Color.black)
    }

    private var messageListView: some View {
        GeometryReader { geometry in
            ScrollViewReader { proxy in
                ScrollView(.vertical, showsIndicators: false) {
                    LazyVStack(spacing: SodaSpacing.s16) {
                        if viewModel.isLoadingNextPage {
                            ProgressView()
                                .progressViewStyle(.circular)
                                .tint(Color.soda400)
                                .padding(.vertical, SodaSpacing.s12)
                        }

                        ForEach(textMessages) { message in
                            UserCreatorChatTextMessageItemView(message: message)
                                .id(message.id)
                                .onAppear {
                                    if message.id == textMessages.first?.id {
                                        viewModel.loadMore()
                                    }
                                }
                        }
                    }
                    .padding(.horizontal, SodaSpacing.s24)
                    .padding(.vertical, SodaSpacing.s12)
                    .background(
                        GeometryReader { contentGeometry in
                            Color.clear.preference(
                                key: UserCreatorChatContentHeightPreferenceKey.self,
                                value: contentGeometry.size.height
                            )
                        }
                    )
                    .frame(minHeight: geometry.size.height, alignment: .bottom)
                }
                .onPreferenceChange(UserCreatorChatContentHeightPreferenceKey.self) { contentHeight in
                    guard contentHeight <= geometry.size.height else { return }
                    viewModel.loadMore()
                }
                .onChange(of: textMessages.last?.id) { _ in
                    scrollToBottom(proxy)
                }
                .onChange(of: viewModel.socketState) { state in
                    guard state == .joined else { return }
                    scrollToBottom(proxy)
                }
            }
        }
    }

    private var inputBarView: some View {
        HStack(spacing: SodaSpacing.s8) {
            ZStack(alignment: .leading) {
                if messageText.isEmpty {
                    Text(I18n.UserCreatorChat.messagePlaceholder)
                        .appFont(size: 14, weight: .regular)
                        .foregroundColor(Color.gray500)
                }

                TextField("", text: $messageText)
                    .appFont(size: 14, weight: .regular)
                    .foregroundColor(.white)
                    .accentColor(Color.soda400)
                    .disabled(isInputEnabled == false)
                    .onSubmit { sendText() }
            }
            .padding(.horizontal, SodaSpacing.s16)
            .padding(.vertical, SodaSpacing.s12)
            .background(Color.gray900)
            .cornerRadius(999)

            Button(action: sendText) {
                Image("ic_message_send")
                    .resizable()
                    .frame(width: 24, height: 24)
                    .opacity(isSendEnabled ? 1 : 0.4)
            }
            .buttonStyle(.plain)
            .disabled(isSendEnabled == false)
        }
        .padding(.horizontal, SodaSpacing.s12)
        .padding(.vertical, SodaSpacing.s12)
        .frame(width: screenSize().width)
        .background(Color.black)
    }

    private var textMessages: [UserCreatorChatDisplayMessage] {
        viewModel.messages.filter { $0.messageType == "TEXT" }
    }

    private var isInputEnabled: Bool {
        viewModel.socketState == .joined
    }

    private var isSendEnabled: Bool {
        isInputEnabled && messageText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty == false
    }

    private func enterRoom() {
        if let roomId {
            viewModel.enter(roomId: roomId)
        } else if let creatorId {
            viewModel.enter(creatorId: creatorId)
        }
    }

    private func sendText() {
        let trimmedText = messageText.trimmingCharacters(in: .whitespacesAndNewlines)
        guard isInputEnabled, trimmedText.isEmpty == false else { return }
        UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
        viewModel.sendText(trimmedText)
        messageText = ""
    }

    private func scrollToBottom(_ proxy: ScrollViewProxy) {
        guard let lastMessage = textMessages.last else { return }
        withAnimation(.easeOut(duration: 0.3)) {
            proxy.scrollTo(lastMessage.id, anchor: .bottom)
        }
    }
}

private struct UserCreatorChatContentHeightPreferenceKey: PreferenceKey {
    static var defaultValue: CGFloat = 0

    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
        value = nextValue()
    }
}

struct UserCreatorChatRoomView_Previews: PreviewProvider {
    static var previews: some View {
        UserCreatorChatRoomView(roomId: 1)
    }
}