import SwiftUI
import UniformTypeIdentifiers

enum SheetType {
    case export(Data)
    case importData
}

struct SettingsView: View {
    @EnvironmentObject var dataManager: ClimbingDataManager
    @State private var activeSheet: SheetType?

    var body: some View {
        List {
            SyncSection()
                .environmentObject(dataManager.syncService)

            DataManagementSection(
                activeSheet: $activeSheet
            )

            AppInfoSection()
        }
        .navigationTitle("Settings")
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                if dataManager.isSyncing {
                    HStack(spacing: 2) {
                        ProgressView()
                            .progressViewStyle(CircularProgressViewStyle(tint: .blue))
                            .scaleEffect(0.6)
                    }
                    .padding(.horizontal, 6)
                    .padding(.vertical, 3)
                    .background(
                        Circle()
                            .fill(.regularMaterial)
                    )
                    .transition(.scale.combined(with: .opacity))
                    .animation(
                        .easeInOut(duration: 0.2), value: dataManager.isSyncing
                    )
                }
            }
        }
        .sheet(
            item: Binding<SheetType?>(
                get: { activeSheet },
                set: { activeSheet = $0 }
            )
        ) { sheetType in
            switch sheetType {
            case .export(let data):
                ExportDataView(data: data)
            case .importData:
                ImportDataView()
            }
        }
    }
}

extension SheetType: Identifiable {
    var id: String {
        switch self {
        case .export: return "export"
        case .importData: return "import"
        }
    }
}

struct DataManagementSection: View {
    @EnvironmentObject var dataManager: ClimbingDataManager
    @Binding var activeSheet: SheetType?
    @State private var showingResetAlert = false
    @State private var isExporting = false

    var body: some View {
        Section("Data Management") {
            // Export Data
            Button(action: {
                exportDataAsync()
            }) {
                HStack {
                    if isExporting {
                        ProgressView()
                            .scaleEffect(0.8)
                        Text("Exporting...")
                            .foregroundColor(.secondary)
                    } else {
                        Image(systemName: "square.and.arrow.up")
                            .foregroundColor(.blue)
                        Text("Export Data")
                    }
                    Spacer()
                }
            }
            .disabled(isExporting)
            .foregroundColor(.primary)

            // Import Data
            Button(action: {
                activeSheet = .importData
            }) {
                HStack {
                    Image(systemName: "square.and.arrow.down")
                        .foregroundColor(.green)
                    Text("Import Data")
                    Spacer()
                }
            }
            .foregroundColor(.primary)

            // Reset All Data
            Button(action: {
                showingResetAlert = true
            }) {
                HStack {
                    Image(systemName: "trash")
                        .foregroundColor(.red)
                    Text("Reset All Data")
                    Spacer()
                }
            }
            .foregroundColor(.red)
        }
        .alert("Reset All Data", isPresented: $showingResetAlert) {
            Button("Cancel", role: .cancel) {}
            Button("Reset", role: .destructive) {
                dataManager.resetAllData()
            }
        } message: {
            Text(
                "Are you sure you want to reset all data? This will permanently delete:\n\n• All gyms and their information\n• All problems and their images\n• All climbing sessions\n• All attempts and progress data\n\nThis action cannot be undone. Consider exporting your data first."
            )
        }
    }

    private func exportDataAsync() {
        isExporting = true
        Task {
            let data = await MainActor.run { dataManager.exportData() }
            isExporting = false
            if let data = data {
                activeSheet = .export(data)
            }
        }
    }
}

struct AppInfoSection: View {
    private var appVersion: String {
        Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "Unknown"
    }

    private var buildNumber: String {
        Bundle.main.infoDictionary?["CFBundleVersion"] as? String ?? "Unknown"
    }

    var body: some View {
        Section("App Information") {
            HStack {
                Image("MountainsIcon")
                    .resizable()
                    .frame(width: 24, height: 24)
                VStack(alignment: .leading) {
                    Text("OpenClimb")
                        .font(.headline)
                    Text("Track your climbing progress")
                        .font(.caption)
                        .foregroundColor(.secondary)
                }
                Spacer()
            }

            HStack {
                Image(systemName: "info.circle")
                    .foregroundColor(.blue)
                Text("Version")
                Spacer()
                Text("\(appVersion) (\(buildNumber))")
                    .foregroundColor(.secondary)
            }
        }
    }
}

struct ExportDataView: View {
    let data: Data
    @Environment(\.dismiss) private var dismiss
    @State private var tempFileURL: URL?
    @State private var isCreatingFile = true

    var body: some View {
        NavigationView {
            VStack(spacing: 30) {
                if isCreatingFile {
                    // Loading state - more prominent
                    VStack(spacing: 20) {
                        ProgressView()
                            .scaleEffect(1.5)
                            .tint(.blue)

                        Text("Preparing Your Export")
                            .font(.title2)
                            .fontWeight(.semibold)

                        Text("Creating ZIP file with your climbing data and images...")
                            .font(.body)
                            .foregroundColor(.secondary)
                            .multilineTextAlignment(.center)
                            .padding(.horizontal)
                    }
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
                } else {
                    // Ready state
                    VStack(spacing: 20) {
                        Image(systemName: "checkmark.circle.fill")
                            .font(.system(size: 60))
                            .foregroundColor(.green)

                        Text("Export Ready!")
                            .font(.title)
                            .fontWeight(.bold)

                        Text(
                            "Your climbing data has been prepared for export. Use the share button below to save or send your data."
                        )
                        .multilineTextAlignment(.center)
                        .padding(.horizontal)

                        if let fileURL = tempFileURL {
                            ShareLink(
                                item: fileURL,
                                preview: SharePreview(
                                    "OpenClimb Data Export",
                                    image: Image("MountainsIcon"))
                            ) {
                                Label("Share Data", systemImage: "square.and.arrow.up")
                                    .font(.headline)
                                    .foregroundColor(.white)
                                    .frame(maxWidth: .infinity)
                                    .padding()
                                    .background(
                                        RoundedRectangle(cornerRadius: 12)
                                            .fill(.blue)
                                    )
                            }
                            .padding(.horizontal)
                            .buttonStyle(.plain)
                        }
                    }

                    Spacer()
                }
            }
            .padding()
            .navigationTitle("Export")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Done") {
                        dismiss()
                    }
                }
            }
            .onAppear {
                if tempFileURL == nil {
                    createTempFile()
                }
            }
            .onDisappear {
                // Delay cleanup to ensure sharing is complete
                DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
                    cleanupTempFile()
                }
            }
        }
    }

    private func createTempFile() {
        DispatchQueue.global(qos: .userInitiated).async {
            do {
                let formatter = ISO8601DateFormatter()
                formatter.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
                let isoString = formatter.string(from: Date())
                let timestamp = isoString.replacingOccurrences(of: ":", with: "-")
                    .replacingOccurrences(of: ".", with: "-")
                let filename = "openclimb_export_\(timestamp).zip"

                guard
                    let documentsURL = FileManager.default.urls(
                        for: .documentDirectory, in: .userDomainMask
                    ).first
                else {
                    print("Could not access Documents directory")
                    DispatchQueue.main.async {
                        self.isCreatingFile = false
                    }
                    return
                }
                let fileURL = documentsURL.appendingPathComponent(filename)

                // Write the ZIP data to the file
                try data.write(to: fileURL)

                DispatchQueue.main.async {
                    self.tempFileURL = fileURL
                    self.isCreatingFile = false
                }
            } catch {
                print("Failed to create export file: \(error)")
                DispatchQueue.main.async {
                    self.isCreatingFile = false
                }
            }
        }
    }

    private func cleanupTempFile() {
        if let fileURL = tempFileURL {
            // Clean up after a delay to ensure sharing is complete
            DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {
                try? FileManager.default.removeItem(at: fileURL)
                print("Cleaned up export file: \(fileURL.lastPathComponent)")
            }
        }
    }
}

struct SyncSection: View {
    @EnvironmentObject var syncService: SyncService
    @EnvironmentObject var dataManager: ClimbingDataManager
    @State private var showingSyncSettings = false
    @State private var showingDisconnectAlert = false

    var body: some View {
        Section("Sync") {
            // Sync Status
            HStack {
                Image(
                    systemName: syncService.isConnected
                        ? "checkmark.circle.fill"
                        : syncService.isConfigured
                            ? "exclamationmark.triangle.fill"
                            : "exclamationmark.circle.fill"
                )
                .foregroundColor(
                    syncService.isConnected
                        ? .green
                        : syncService.isConfigured
                            ? .orange
                            : .red
                )
                VStack(alignment: .leading) {
                    Text("Sync Server")
                        .font(.headline)
                    Text(
                        syncService.isConnected
                            ? "Connected"
                            : syncService.isConfigured
                                ? "Configured - Not tested"
                                : "Not configured"
                    )
                    .font(.caption)
                    .foregroundColor(.secondary)
                }
                Spacer()
            }

            // Configure Server
            Button(action: {
                showingSyncSettings = true
            }) {
                HStack {
                    Image(systemName: "gear")
                        .foregroundColor(.blue)
                    Text("Configure Server")
                    Spacer()
                    Image(systemName: "chevron.right")
                        .font(.caption)
                        .foregroundColor(.secondary)
                }
            }
            .foregroundColor(.primary)

            if syncService.isConfigured {

                // Sync Now - only show if connected
                if syncService.isConnected {
                    Button(action: {
                        performSync()
                    }) {
                        HStack {
                            if syncService.isSyncing {
                                ProgressView()
                                    .scaleEffect(0.8)
                                Text("Syncing...")
                                    .foregroundColor(.secondary)
                            } else {
                                Image(systemName: "arrow.triangle.2.circlepath")
                                    .foregroundColor(.green)
                                Text("Sync Now")
                                Spacer()
                                if let lastSync = syncService.lastSyncTime {
                                    Text(
                                        RelativeDateTimeFormatter().localizedString(
                                            for: lastSync, relativeTo: Date())
                                    )
                                    .font(.caption)
                                    .foregroundColor(.secondary)
                                }
                            }
                        }
                    }
                    .disabled(syncService.isSyncing)
                    .foregroundColor(.primary)
                }

                // Auto-sync configuration - always visible for testing
                HStack {
                    VStack(alignment: .leading) {
                        Text("Auto-sync")
                        Text("Sync automatically on app launch and data changes")
                            .font(.caption)
                            .foregroundColor(.secondary)
                    }
                    Spacer()
                    Toggle(
                        "",
                        isOn: Binding(
                            get: { syncService.isAutoSyncEnabled },
                            set: { syncService.isAutoSyncEnabled = $0 }
                        )
                    )
                    .disabled(!syncService.isConnected)
                }
                .foregroundColor(.primary)

                // Disconnect option - only show if connected
                if syncService.isConnected {
                    Button(action: {
                        showingDisconnectAlert = true
                    }) {
                        HStack {
                            Image(systemName: "power")
                                .foregroundColor(.orange)
                            Text("Disconnect")
                            Spacer()
                        }
                    }
                    .foregroundColor(.primary)
                }

                if let error = syncService.syncError {
                    Text(error)
                        .font(.caption)
                        .foregroundColor(.red)
                        .padding(.leading, 24)
                }

            }
        }
        .sheet(isPresented: $showingSyncSettings) {
            SyncSettingsView()
                .environmentObject(syncService)
        }
        .alert("Disconnect from Server", isPresented: $showingDisconnectAlert) {
            Button("Cancel", role: .cancel) {}
            Button("Disconnect", role: .destructive) {
                syncService.disconnect()
            }
        } message: {
            Text(
                "This will sign you out but keep your server settings. You'll need to test the connection again to sync."
            )
        }
    }

    private func performSync() {
        Task {
            do {
                try await syncService.syncWithServer(dataManager: dataManager)
            } catch {
                print("Sync failed: \(error)")
            }
        }
    }
}

struct SyncSettingsView: View {
    @EnvironmentObject var syncService: SyncService
    @Environment(\.dismiss) private var dismiss
    @State private var serverURL: String = ""
    @State private var authToken: String = ""
    @State private var showingDisconnectAlert = false
    @State private var isTesting = false
    @State private var showingTestResult = false
    @State private var testResultMessage = ""

    var body: some View {
        NavigationView {
            Form {
                Section {
                    TextField("Server URL", text: $serverURL)
                        .textFieldStyle(.roundedBorder)
                        .keyboardType(.URL)
                        .autocapitalization(.none)
                        .disableAutocorrection(true)
                        .placeholder(when: serverURL.isEmpty) {
                            Text("http://your-server:8080")
                                .foregroundColor(.secondary)
                        }

                    TextField("Auth Token", text: $authToken)
                        .textFieldStyle(.roundedBorder)
                        .autocapitalization(.none)
                        .disableAutocorrection(true)
                        .placeholder(when: authToken.isEmpty) {
                            Text("your-secret-token")
                                .foregroundColor(.secondary)
                        }
                } header: {
                    Text("Server Configuration")
                } footer: {
                    Text(
                        "Enter your sync server URL and authentication token. You must test the connection before syncing is available."
                    )
                }

                Section {
                    Button(action: {
                        testConnection()
                    }) {
                        HStack {
                            if isTesting {
                                ProgressView()
                                    .scaleEffect(0.8)
                                Text("Testing...")
                                    .foregroundColor(.secondary)
                            } else {
                                Image(systemName: "network")
                                    .foregroundColor(.blue)
                                Text("Test Connection")
                                Spacer()
                                if syncService.isConnected {
                                    Image(systemName: "checkmark.circle.fill")
                                        .foregroundColor(.green)
                                }
                            }
                        }
                    }
                    .disabled(
                        isTesting
                            || serverURL.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
                            || authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
                    )
                    .foregroundColor(.primary)
                } header: {
                    Text("Connection")
                } footer: {
                    Text("Test the connection to verify your server settings before saving.")
                }

                Section {
                    Button("Disconnect from Server") {
                        showingDisconnectAlert = true
                    }
                    .foregroundColor(.orange)

                    Button("Clear Configuration") {
                        syncService.clearConfiguration()
                        serverURL = ""
                        authToken = ""
                    }
                    .foregroundColor(.red)
                } footer: {
                    Text(
                        "Disconnect will sign you out but keep settings. Clear Configuration removes all sync settings."
                    )
                }
            }
            .navigationTitle("Sync Settings")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        dismiss()
                    }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        let newURL = serverURL.trimmingCharacters(in: .whitespacesAndNewlines)
                        let newToken = authToken.trimmingCharacters(in: .whitespacesAndNewlines)

                        // Mark as disconnected if settings changed
                        if newURL != syncService.serverURL || newToken != syncService.authToken {
                            syncService.isConnected = false
                            UserDefaults.standard.set(false, forKey: "sync_is_connected")
                        }

                        syncService.serverURL = newURL
                        syncService.authToken = newToken
                        dismiss()
                    }
                    .fontWeight(.semibold)
                }
            }
        }
        .onAppear {
            serverURL = syncService.serverURL
            authToken = syncService.authToken
        }
        .alert("Disconnect from Server", isPresented: $showingDisconnectAlert) {
            Button("Cancel", role: .cancel) {}
            Button("Disconnect", role: .destructive) {
                syncService.disconnect()
                dismiss()
            }
        } message: {
            Text(
                "This will sign you out but keep your server settings. You'll need to test the connection again to sync."
            )
        }
        .alert("Connection Test", isPresented: $showingTestResult) {
            Button("OK") {}
        } message: {
            Text(testResultMessage)
        }
    }

    private func testConnection() {
        isTesting = true

        let testURL = serverURL.trimmingCharacters(in: .whitespacesAndNewlines)
        let testToken = authToken.trimmingCharacters(in: .whitespacesAndNewlines)

        // Store original values in case test fails
        let originalURL = syncService.serverURL
        let originalToken = syncService.authToken

        Task {
            do {
                // Temporarily set the values for testing
                syncService.serverURL = testURL
                syncService.authToken = testToken

                try await syncService.testConnection()

                await MainActor.run {
                    isTesting = false
                    testResultMessage =
                        "Connection successful! You can now save and sync your data."
                    showingTestResult = true
                }
            } catch {
                // Restore original values if test failed
                syncService.serverURL = originalURL
                syncService.authToken = originalToken

                await MainActor.run {
                    isTesting = false
                    testResultMessage = "Connection failed: \(error.localizedDescription)"
                    showingTestResult = true
                }
            }
        }
    }
}

// Removed AutoSyncSettingsView - now using simple toggle in main settings

extension View {
    func placeholder<Content: View>(
        when shouldShow: Bool,
        alignment: Alignment = .leading,
        @ViewBuilder placeholder: () -> Content
    ) -> some View {

        ZStack(alignment: alignment) {
            placeholder().opacity(shouldShow ? 1 : 0)
            self
        }
    }
}

struct ImportDataView: View {
    @EnvironmentObject var dataManager: ClimbingDataManager
    @Environment(\.dismiss) private var dismiss
    @State private var isImporting = false
    @State private var importError: String?
    @State private var showingDocumentPicker = false

    var body: some View {
        NavigationView {
            VStack(spacing: 20) {
                Image(systemName: "square.and.arrow.down")
                    .font(.system(size: 60))
                    .foregroundColor(.green)

                Text("Import Data")
                    .font(.title)
                    .fontWeight(.bold)

                VStack(spacing: 12) {
                    Text("Import climbing data from a previously exported ZIP file.")
                        .multilineTextAlignment(.center)

                    Text("⚠️ Warning: This will replace all current data!")
                        .font(.subheadline)
                        .foregroundColor(.red)
                        .multilineTextAlignment(.center)
                }
                .padding(.horizontal)

                Button(action: {
                    showingDocumentPicker = true
                }) {
                    if isImporting {
                        HStack {
                            ProgressView()
                                .scaleEffect(0.8)
                            Text("Importing...")
                        }
                    } else {
                        Label("Select ZIP File to Import", systemImage: "folder.badge.plus")
                    }
                }
                .font(.headline)
                .foregroundColor(.white)
                .frame(maxWidth: .infinity)
                .padding()
                .background(
                    RoundedRectangle(cornerRadius: 12)
                        .fill(isImporting ? .gray : .green)
                )
                .padding(.horizontal)
                .disabled(isImporting)

                if let error = importError {
                    Text(error)
                        .foregroundColor(.red)
                        .padding()
                        .background(
                            RoundedRectangle(cornerRadius: 8)
                                .fill(.red.opacity(0.1))
                        )
                }

                Spacer()
            }
            .padding()
            .navigationTitle("Import Data")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Cancel") {
                        dismiss()
                    }
                }
            }
            .fileImporter(
                isPresented: $showingDocumentPicker,
                allowedContentTypes: [.zip, .archive],
                allowsMultipleSelection: false
            ) { result in
                switch result {
                case .success(let urls):
                    if let url = urls.first {
                        importData(from: url)
                    }
                case .failure(let error):
                    importError = "Failed to select file: \(error.localizedDescription)"
                }
            }
        }
    }

    private func importData(from url: URL) {
        isImporting = true
        importError = nil

        Task {
            do {
                // Access the security-scoped resource
                guard url.startAccessingSecurityScopedResource() else {
                    await MainActor.run {
                        isImporting = false
                        importError = "Failed to access selected file"
                    }
                    return
                }

                defer { url.stopAccessingSecurityScopedResource() }

                let data = try Data(contentsOf: url)
                try dataManager.importData(from: data)

                await MainActor.run {
                    isImporting = false
                    // Auto-close after successful import
                    DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
                        dismiss()
                    }
                }
            } catch {
                await MainActor.run {
                    isImporting = false
                    importError = "Import failed: \(error.localizedDescription)"
                }
            }
        }
    }
}

#Preview {
    SettingsView()
        .environmentObject(ClimbingDataManager.preview)
}