import SwiftUI
import ComposeApp

struct ResidenceDetailView: View {
    let residenceId: Int32

    @StateObject private var viewModel = ResidenceViewModel()
    @StateObject private var taskViewModel = TaskViewModel()
    @ObservedObject private var dataManager = DataManagerObservable.shared

    // Use TaskViewModel's state instead of local state
    private var tasksResponse: TaskColumnsResponse? { taskViewModel.tasksResponse }
    private var isLoadingTasks: Bool { taskViewModel.isLoadingTasks }
    private var tasksError: String? { taskViewModel.tasksError }

    @State private var contractors: [ContractorSummary] = []
    @State private var isLoadingContractors = false
    @State private var contractorsError: String?

    @State private var showAddTask = false
    @State private var showEditResidence = false
    @State private var showEditTask = false
    @State private var showManageUsers = false
    @State private var selectedTaskForEdit: TaskResponse?
    @State private var selectedTaskForComplete: TaskResponse?
    @State private var selectedTaskForArchive: TaskResponse?
    @State private var showArchiveConfirmation = false

    @State private var hasAppeared = false
    @State private var showReportAlert = false
    @State private var showReportConfirmation = false
    @State private var showDeleteConfirmation = false
    @State private var isDeleting = false
    @State private var showingUpgradePrompt = false
    @State private var upgradeTriggerKey = ""
    @StateObject private var subscriptionCache = SubscriptionCacheWrapper.shared

    @Environment(\.dismiss) private var dismiss

    // Check if current user is the owner of the residence
    private func isCurrentUserOwner(of residence: ResidenceResponse) -> Bool {
        guard let currentUser = dataManager.currentUser else {
            return false
        }
        return Int(residence.ownerId) == Int(currentUser.id)
    }

    var body: some View {
        ZStack {
            WarmGradientBackground()

            mainContent
        }
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            leadingToolbar
            trailingToolbar
        }

        // MARK: Alerts
        .alert(L10n.Residences.generateReport, isPresented: $showReportConfirmation) {
            Button(L10n.Common.cancel, role: .cancel) {
                showReportConfirmation = false
            }
            Button(L10n.Residences.generate) {
                viewModel.generateTasksReport(residenceId: residenceId, email: "")
                showReportConfirmation = false
            }
        } message: {
            Text(L10n.Residences.generateReportMessage)
        }

        .alert(L10n.Residences.deleteTitle, isPresented: $showDeleteConfirmation) {
            Button(L10n.Common.cancel, role: .cancel) { }
                .accessibilityIdentifier(AccessibilityIdentifiers.Alert.cancelButton)
            Button(L10n.Common.delete, role: .destructive) {
                deleteResidence()
            }
            .accessibilityIdentifier(AccessibilityIdentifiers.Alert.deleteButton)
        } message: {
            if let residence = viewModel.selectedResidence {
                Text("\(L10n.Residences.deleteConfirmMessage)")
            }
        }

        .alert(L10n.Residences.maintenanceReport, isPresented: $showReportAlert) {
            Button(L10n.Common.ok, role: .cancel) { }
        } message: {
            Text(viewModel.reportMessage ?? "")
        }
        
        // MARK: Sheets
        .sheet(isPresented: $showAddTask) {
            AddTaskView(residenceId: residenceId, isPresented: $showAddTask)
        }
        .sheet(isPresented: $showEditResidence) {
            if let residence = viewModel.selectedResidence {
                EditResidenceView(residence: residence, isPresented: $showEditResidence)
            }
        }
        .sheet(isPresented: $showEditTask) {
            if let task = selectedTaskForEdit {
                EditTaskView(task: task, isPresented: $showEditTask)
            }
        }
        .sheet(item: $selectedTaskForComplete) { task in
            CompleteTaskView(task: task) { updatedTask in
                print("DEBUG: onComplete callback called")
                print("DEBUG: updatedTask is nil: \(updatedTask == nil)")
                if let updatedTask = updatedTask {
                    print("DEBUG: updatedTask.id = \(updatedTask.id)")
                    print("DEBUG: updatedTask.kanbanColumn = \(updatedTask.kanbanColumn ?? "nil")")
                    updateTaskInKanban(updatedTask)
                }
                selectedTaskForComplete = nil
            }
        }
        .sheet(isPresented: $showManageUsers) {
            if let residence = viewModel.selectedResidence {
                ManageUsersView(
                    residenceId: residence.id,
                    residenceName: residence.name,
                    isPrimaryOwner: isCurrentUserOwner(of: residence),
                    residenceOwnerId: residence.ownerId,
                    residence: residence
                )
            }
        }

        .alert("Archive Task", isPresented: $showArchiveConfirmation) {
            Button("Cancel", role: .cancel) {
                selectedTaskForArchive = nil
            }
            Button("Archive", role: .destructive) {
                if let task = selectedTaskForArchive {
                    taskViewModel.archiveTask(id: task.id) { _ in
                        loadResidenceTasks()
                    }
                    selectedTaskForArchive = nil
                }
            }
        } message: {
            if let task = selectedTaskForArchive {
                Text("Are you sure you want to archive \"\(task.title)\"? You can unarchive it later from archived tasks.")
            }
        }
        .sheet(isPresented: $showingUpgradePrompt) {
            UpgradePromptView(triggerKey: upgradeTriggerKey.isEmpty ? "add_11th_task" : upgradeTriggerKey, isPresented: $showingUpgradePrompt)
        }

        // MARK: onChange & lifecycle
        .onChange(of: viewModel.reportMessage) { message in
            if message != nil {
                showReportAlert = true
            }
        }
        .onChange(of: viewModel.selectedResidence) { residence in
            if residence != nil {
                hasAppeared = true
            }
        }
        .onChange(of: showAddTask) { isShowing in
            if !isShowing {
                loadResidenceTasks(forceRefresh: true)
            }
        }
        .onChange(of: showEditResidence) { isShowing in
            if !isShowing {
                loadResidenceData()
            }
        }
        .onChange(of: showEditTask) { isShowing in
            if !isShowing {
                loadResidenceTasks(forceRefresh: true)
            }
        }
        .onAppear {
            loadResidenceData()
        }
        .handleErrors(
            error: viewModel.errorMessage,
            onRetry: { loadResidenceData() }
        )
    }
}

// MARK: - Main Content

private extension ResidenceDetailView {
    @ViewBuilder
    var mainContent: some View {
        if !hasAppeared || viewModel.isLoading {
            loadingView
        } else if let residence = viewModel.selectedResidence {
            contentView(for: residence)
        }
    }
    
    var loadingView: some View {
        StandardLoadingView(message: L10n.Residences.loadingResidence)
    }
    
    @ViewBuilder
    func contentView(for residence: ResidenceResponse) -> some View {
        ScrollView(showsIndicators: false) {
            VStack(spacing: OrganicSpacing.comfortable) {
                PropertyHeaderCard(residence: residence)
                    .padding(.horizontal, 16)
                    .padding(.top, 8)

                tasksSection
                    .padding(.horizontal, 16)

                contractorsSection
                    .padding(.horizontal, 16)
            }
            .padding(.bottom, OrganicSpacing.airy)
        }
    }
    
    @ViewBuilder
    var tasksSection: some View {
        if let tasksResponse = tasksResponse {
            TasksSectionContainer(
                tasksResponse: tasksResponse,
                taskViewModel: taskViewModel,
                selectedTaskForEdit: $selectedTaskForEdit,
                showEditTask: $showEditTask,
                selectedTaskForComplete: $selectedTaskForComplete,
                selectedTaskForArchive: $selectedTaskForArchive,
                showArchiveConfirmation: $showArchiveConfirmation,
                reloadTasks: { loadResidenceTasks(forceRefresh: true) }
            )
        } else if isLoadingTasks {
            ProgressView(L10n.Residences.loadingTasks)
        } else if let tasksError = tasksError {
            Text("\(L10n.Residences.errorLoadingTasks): \(tasksError)")
                .foregroundColor(Color.appError)
                .padding()
        }
    }

    @ViewBuilder
    var contractorsSection: some View {
        VStack(alignment: .leading, spacing: 16) {
            // Section Header
            HStack(alignment: .center, spacing: 12) {
                ZStack {
                    Circle()
                        .fill(Color.appPrimary.opacity(0.12))
                        .frame(width: 40, height: 40)

                    Image(systemName: "person.2.fill")
                        .font(.system(size: 16, weight: .semibold))
                        .foregroundColor(Color.appPrimary)
                }

                Text(L10n.Residences.contractors)
                    .font(.system(size: 20, weight: .bold, design: .rounded))
                    .foregroundColor(Color.appTextPrimary)

                Spacer()
            }
            .padding(.top, 8)

            if isLoadingContractors {
                HStack {
                    Spacer()
                    ProgressView()
                        .tint(Color.appPrimary)
                    Spacer()
                }
                .padding(OrganicSpacing.cozy)
            } else if let error = contractorsError {
                Text("\(L10n.Common.error): \(error)")
                    .foregroundColor(Color.appError)
                    .padding()
            } else if contractors.isEmpty {
                // Empty state with organic styling
                OrganicEmptyState(
                    icon: "person.crop.circle.badge.plus",
                    title: L10n.Residences.noContractors,
                    subtitle: L10n.Residences.addContractorsPrompt,
                    blobVariation: 1
                )
            } else {
                // Contractors list
                VStack(spacing: 12) {
                    ForEach(contractors, id: \.id) { contractor in
                        NavigationLink(destination: ContractorDetailView(contractorId: contractor.id)) {
                            ContractorCard(
                                contractor: contractor,
                                onToggleFavorite: {
                                    // Could implement toggle favorite here if needed
                                }
                            )
                        }
                        .buttonStyle(OrganicCardButtonStyle())
                    }
                }
            }
        }
    }
}

// MARK: - Organic Card Button Style

private struct OrganicCardButtonStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .scaleEffect(configuration.isPressed ? 0.98 : 1.0)
            .opacity(configuration.isPressed ? 0.9 : 1.0)
            .animation(.easeOut(duration: 0.15), value: configuration.isPressed)
    }
}

// MARK: - Toolbars

private extension ResidenceDetailView {
    @ToolbarContentBuilder
    var leadingToolbar: some ToolbarContent {
        ToolbarItem(placement: .navigationBarLeading) {
            if viewModel.selectedResidence != nil {
                Button(L10n.Common.edit) {
                    showEditResidence = true
                }
                .accessibilityIdentifier(AccessibilityIdentifiers.Residence.editButton)
            }
        }
    }
    
    @ToolbarContentBuilder
    var trailingToolbar: some ToolbarContent {
        ToolbarItemGroup(placement: .navigationBarTrailing) {
            if viewModel.selectedResidence != nil {
                Button {
                    showReportConfirmation = true
                } label: {
                    if viewModel.isGeneratingReport {
                        ProgressView()
                    } else {
                        Image(systemName: "doc.text")
                    }
                }
                .disabled(viewModel.isGeneratingReport)
            }

            // Manage Users button (owner only) - includes share code generation and easy share
            if let residence = viewModel.selectedResidence, isCurrentUserOwner(of: residence) {
                Button {
                    if subscriptionCache.canShareResidence() {
                        showManageUsers = true
                    } else {
                        upgradeTriggerKey = "share_residence"
                        showingUpgradePrompt = true
                    }
                } label: {
                    Image(systemName: "person.2")
                }
            }

            Button {
                // Check LIVE task count before adding
                let totalTasks = tasksResponse?.columns.reduce(0) { $0 + $1.tasks.count } ?? 0
                if subscriptionCache.shouldShowUpgradePrompt(currentCount: totalTasks, limitKey: "tasks") {
                    upgradeTriggerKey = "add_11th_task"
                    showingUpgradePrompt = true
                } else {
                    showAddTask = true
                }
            } label: {
                Image(systemName: "plus")
            }
            .accessibilityIdentifier(AccessibilityIdentifiers.Task.addButton)

            if let residence = viewModel.selectedResidence, isCurrentUserOwner(of: residence) {
                Button {
                    showDeleteConfirmation = true
                } label: {
                    Image(systemName: "trash")
                        .foregroundStyle(Color.appError)
                }
                .accessibilityIdentifier(AccessibilityIdentifiers.Residence.deleteButton)
            }
        }
    }
}

// MARK: - Data Loading

private extension ResidenceDetailView {
    func loadResidenceData() {
        viewModel.getResidence(id: residenceId)
        loadResidenceTasks()
        loadResidenceContractors()
    }
    
    func loadResidenceTasks(forceRefresh: Bool = false) {
        taskViewModel.loadTasks(residenceId: residenceId, forceRefresh: forceRefresh)
    }

    func updateTaskInKanban(_ updatedTask: TaskResponse) {
        taskViewModel.updateTaskInKanban(updatedTask)
    }

    func deleteResidence() {
        guard TokenStorage.shared.getToken() != nil else { return }

        isDeleting = true
        
        Task {
            do {
                let result = try await APILayer.shared.deleteResidence(
                    id: Int32(Int(residenceId))
                )
                
                await MainActor.run {
                    self.isDeleting = false
                    
                    if result is ApiResultSuccess<KotlinUnit> {
                        dismiss()
                    } else if let errorResult = result as? ApiResultError {
                        self.viewModel.errorMessage = ErrorMessageParser.parse(errorResult.message)
                    } else {
                        self.viewModel.errorMessage = "Failed to delete residence"
                    }
                }
            } catch {
                await MainActor.run {
                    self.isDeleting = false
                    self.viewModel.errorMessage = ErrorMessageParser.parse(error.localizedDescription)
                }
            }
        }
    }

    func loadResidenceContractors() {
        guard TokenStorage.shared.getToken() != nil else { return }

        isLoadingContractors = true
        contractorsError = nil

        Task {
            do {
                let result = try await APILayer.shared.getContractorsByResidence(
                    residenceId: Int32(Int(residenceId)),
                    forceRefresh: false
                )

                await MainActor.run {
                    if let successResult = result as? ApiResultSuccess<NSArray> {
                        self.contractors = (successResult.data as? [ContractorSummary]) ?? []
                        self.isLoadingContractors = false
                    } else if let errorResult = result as? ApiResultError {
                        self.contractorsError = errorResult.message
                        self.isLoadingContractors = false
                    } else {
                        self.contractorsError = "Failed to load contractors"
                        self.isLoadingContractors = false
                    }
                }
            } catch {
                await MainActor.run {
                    self.contractorsError = ErrorMessageParser.parse(error.localizedDescription)
                    self.isLoadingContractors = false
                }
            }
        }
    }
}

private struct TasksSectionContainer: View {
    let tasksResponse: TaskColumnsResponse

    @ObservedObject var taskViewModel: TaskViewModel
    @Binding var selectedTaskForEdit: TaskResponse?
    @Binding var showEditTask: Bool
    @Binding var selectedTaskForComplete: TaskResponse?
    @Binding var selectedTaskForArchive: TaskResponse?
    @Binding var showArchiveConfirmation: Bool

    let reloadTasks: () -> Void

    var body: some View {
        TasksSection(
            tasksResponse: tasksResponse,
            onEditTask: { task in
                selectedTaskForEdit = task
                showEditTask = true
            },
            onCancelTask: { task in
                taskViewModel.cancelTask(id: task.id) { _ in
                    reloadTasks()
                }
            },
            onUncancelTask: { taskId in
                taskViewModel.uncancelTask(id: taskId) { _ in
                    reloadTasks()
                }
            },
            onMarkInProgress: { taskId in
                taskViewModel.markInProgress(id: taskId) { success in
                    if success {
                        reloadTasks()
                    }
                }
            },
            onCompleteTask: { task in
                selectedTaskForComplete = task
            },
            onArchiveTask: { task in
                selectedTaskForArchive = task
                showArchiveConfirmation = true
            },
            onUnarchiveTask: { taskId in
                taskViewModel.unarchiveTask(id: taskId) { _ in
                    reloadTasks()
                }
            }
        )
    }
}


// MARK: - Preview

struct ResidenceDetailView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationView {
            ResidenceDetailView(residenceId: 1)
        }
    }
}