// LoopFollow
// RemoteSettingsViewModel.swift

import Combine
import Foundation
import HealthKit

class RemoteSettingsViewModel: ObservableObject {
    @Published var remoteType: RemoteType
    @Published var user: String
    @Published var sharedSecret: String
    @Published var apnsKey: String
    @Published var keyId: String

    @Published var maxBolus: HKQuantity
    @Published var maxCarbs: HKQuantity
    @Published var maxProtein: HKQuantity
    @Published var maxFat: HKQuantity
    @Published var mealWithBolus: Bool
    @Published var mealWithFatProtein: Bool
    @Published var isTrioDevice: Bool = (Storage.shared.device.value == "Trio")
    @Published var isLoopDevice: Bool = (Storage.shared.device.value == "Loop")

    // MARK: - Return Notification Properties

    @Published var returnApnsKey: String
    @Published var returnKeyId: String

    // MARK: - Loop APNS Setup Properties

    @Published var loopDeveloperTeamId: String
    @Published var loopAPNSQrCodeURL: String
    @Published var productionEnvironment: Bool
    @Published var isShowingLoopAPNSScanner: Bool = false
    @Published var loopAPNSErrorMessage: String?
  
      // MARK: - QR Code Sharing Properties

    @Published var isShowingQRCodeScanner: Bool = false
    @Published var isShowingQRCodeDisplay: Bool = false
    @Published var qrCodeErrorMessage: String?

    // MARK: - URL/Token Validation Properties

    @Published var pendingSettings: RemoteCommandSettings?
    @Published var showURLTokenValidation: Bool = false
    @Published var validationMessage: String = ""
    @Published var shouldPromptForURL: Bool = false
    @Published var shouldPromptForToken: Bool = false

    let loopFollowTeamId: String = BuildDetails.default.teamID ?? "Unknown"

    /// Determines if the target app's Team ID is different from this app's build Team ID.
    var areTeamIdsDifferent: Bool {
        // Get LoopFollow's own Team ID from the build details.
        guard let loopFollowTeamID = BuildDetails.default.teamID, !loopFollowTeamID.isEmpty, loopFollowTeamID != "Unknown" else {
            return false
        }

        // The property `loopDeveloperTeamId` holds the value from `Storage.shared.teamId`
        let targetTeamId = loopDeveloperTeamId

        // Determine if a comparison is needed and perform it.
        switch remoteType {
        case .loopAPNS, .trc:
            // For both Loop and TRC, the target Team ID is in the same storage location.
            // If the target ID is empty, there's nothing to compare.
            guard !targetTeamId.isEmpty else {
                return false
            }
            // Return true if the IDs are different.
            return loopFollowTeamID != targetTeamId

        case .none, .nightscout:
            // For other remote types, this check is not applicable.
            return false
        }
    }

    // MARK: - Computed property for Loop APNS Setup validation

    var loopAPNSSetup: Bool {
        !keyId.isEmpty &&
            !apnsKey.isEmpty &&
            !loopDeveloperTeamId.isEmpty &&
            !loopAPNSQrCodeURL.isEmpty &&
            !Storage.shared.deviceToken.value.isEmpty &&
            !Storage.shared.bundleId.value.isEmpty
    }

    private var storage = Storage.shared
    private var cancellables = Set<AnyCancellable>()

    init() {
        // Initialize published properties from storage
        remoteType = storage.remoteType.value
        user = storage.user.value
        sharedSecret = storage.sharedSecret.value
        apnsKey = storage.apnsKey.value
        keyId = storage.keyId.value
        maxBolus = storage.maxBolus.value
        maxCarbs = storage.maxCarbs.value
        maxProtein = storage.maxProtein.value
        maxFat = storage.maxFat.value
        mealWithBolus = storage.mealWithBolus.value
        mealWithFatProtein = storage.mealWithFatProtein.value

        loopDeveloperTeamId = storage.teamId.value ?? ""
        loopAPNSQrCodeURL = storage.loopAPNSQrCodeURL.value
        productionEnvironment = storage.productionEnvironment.value

        returnApnsKey = storage.returnApnsKey.value
        returnKeyId = storage.returnKeyId.value

        setupBindings()
    }

    private func setupBindings() {
        // Basic property bindings
        $remoteType
            .dropFirst()
            .sink { [weak self] in self?.storage.remoteType.value = $0 }
            .store(in: &cancellables)

        $user
            .dropFirst()
            .sink { [weak self] in self?.storage.user.value = $0 }
            .store(in: &cancellables)

        $sharedSecret
            .dropFirst()
            .sink { [weak self] in self?.storage.sharedSecret.value = $0 }
            .store(in: &cancellables)

        $apnsKey
            .dropFirst()
            .sink { [weak self] newValue in
                // Validate and fix the APNS key format using the service
                let apnsService = LoopAPNSService()
                let fixedKey = apnsService.validateAndFixAPNSKey(newValue)
                self?.storage.apnsKey.value = fixedKey
            }
            .store(in: &cancellables)

        $keyId
            .dropFirst()
            .sink { [weak self] in self?.storage.keyId.value = $0 }
            .store(in: &cancellables)

        $maxBolus
            .dropFirst()
            .sink { [weak self] in self?.storage.maxBolus.value = $0 }
            .store(in: &cancellables)

        $maxCarbs
            .dropFirst()
            .sink { [weak self] in self?.storage.maxCarbs.value = $0 }
            .store(in: &cancellables)

        $maxProtein
            .dropFirst()
            .sink { [weak self] in self?.storage.maxProtein.value = $0 }
            .store(in: &cancellables)

        $maxFat
            .dropFirst()
            .sink { [weak self] in self?.storage.maxFat.value = $0 }
            .store(in: &cancellables)

        $mealWithBolus
            .dropFirst()
            .sink { [weak self] in self?.storage.mealWithBolus.value = $0 }
            .store(in: &cancellables)

        $mealWithFatProtein
            .dropFirst()
            .sink { [weak self] in self?.storage.mealWithFatProtein.value = $0 }
            .store(in: &cancellables)

        // Device type monitoring
        Storage.shared.device.$value
            .receive(on: DispatchQueue.main)
            .sink { [weak self] newValue in
                self?.isTrioDevice = (newValue == "Trio")
                self?.isLoopDevice = (newValue == "Loop")
            }
            .store(in: &cancellables)

        // Loop APNS bindings
        $loopDeveloperTeamId
            .dropFirst()
            .sink { [weak self] in self?.storage.teamId.value = $0 }
            .store(in: &cancellables)

        $loopAPNSQrCodeURL
            .dropFirst()
            .sink { [weak self] in self?.storage.loopAPNSQrCodeURL.value = $0 }
            .store(in: &cancellables)

        $productionEnvironment
            .dropFirst()
            .sink { [weak self] in self?.storage.productionEnvironment.value = $0 }
            .store(in: &cancellables)

        // Return notification bindings
        $returnApnsKey
            .dropFirst()
            .sink { [weak self] in self?.storage.returnApnsKey.value = $0 }
            .store(in: &cancellables)

        $returnKeyId
            .dropFirst()
            .sink { [weak self] in self?.storage.returnKeyId.value = $0 }
            .store(in: &cancellables)
    }

    func handleLoopAPNSQRCodeScanResult(_ result: Result<String, Error>) {
        DispatchQueue.main.async {
            switch result {
            case let .success(code):
                self.loopAPNSQrCodeURL = code
                // Set device type and remote type for Loop APNS
                Storage.shared.device.value = "Loop"
                Storage.shared.remoteType.value = .loopAPNS
                // Update view model properties
                self.remoteType = .loopAPNS
                self.isLoopDevice = true
                self.isTrioDevice = false
                LogManager.shared.log(category: .apns, message: "Loop APNS QR code scanned: \(code)")
            case let .failure(error):
                self.loopAPNSErrorMessage = "Scanning failed: \(error.localizedDescription)"
            }
            self.isShowingLoopAPNSScanner = false
        }
    }

    // MARK: - QR Code Sharing Methods

    func handleRemoteCommandQRCodeScanResult(_ result: Result<String, Error>) {
        DispatchQueue.main.async {
            switch result {
            case let .success(jsonString):
                if let settings = RemoteCommandSettings.decodeFromJSON(jsonString) {
                    if settings.isValid() {
                        // Check URL and token compatibility
                        let validation = settings.validateCompatibilityWithCurrentStorage()

                        if validation.isCompatible {
                            // No conflicts, apply settings directly
                            settings.applyToStorage()
                            self.updateViewModelFromStorage()
                            LogManager.shared.log(category: .remote, message: "Remote command settings imported from QR code")
                        } else {
                            // Conflicts detected, show validation view
                            self.pendingSettings = settings
                            self.validationMessage = validation.message
                            self.shouldPromptForURL = validation.shouldPromptForURL
                            self.shouldPromptForToken = validation.shouldPromptForToken
                            self.showURLTokenValidation = true
                        }
                    } else {
                        self.qrCodeErrorMessage = "Invalid remote command settings in QR code"
                    }
                } else {
                    self.qrCodeErrorMessage = "Failed to decode remote command settings from QR code"
                }
            case let .failure(error):
                self.qrCodeErrorMessage = "Scanning failed: \(error.localizedDescription)"
            }
            self.isShowingQRCodeScanner = false
        }
    }

    func generateQRCodeForCurrentSettings() -> String? {
        let settings = RemoteCommandSettings.fromCurrentStorage()
        return settings.encodeToJSON()
    }

    // MARK: - Public Methods for View Access

    /// Updates the view model properties from storage (accessible from view)
    func updateViewModelFromStorage() {
        let storage = Storage.shared
        remoteType = storage.remoteType.value
        user = storage.user.value
        sharedSecret = storage.sharedSecret.value
        apnsKey = storage.apnsKey.value
        keyId = storage.keyId.value
        maxBolus = storage.maxBolus.value
        maxCarbs = storage.maxCarbs.value
        maxProtein = storage.maxProtein.value
        maxFat = storage.maxFat.value
        mealWithBolus = storage.mealWithBolus.value
        mealWithFatProtein = storage.mealWithFatProtein.value
        loopDeveloperTeamId = storage.teamId.value ?? ""
        loopAPNSQrCodeURL = storage.loopAPNSQrCodeURL.value
        productionEnvironment = storage.productionEnvironment.value

        // Update device-related properties
        isTrioDevice = (storage.device.value == "Trio")
        isLoopDevice = (storage.device.value == "Loop")
    }
}