Trio/FreeAPS/Sources/APS/Storage/GlucoseStorage.swift

import AVFAudio
import CoreData
import Foundation
import SwiftDate
import SwiftUI
import Swinject

protocol GlucoseStorage {
    func storeGlucose(_ glucose: [BloodGlucose])
    func syncDate() -> Date
    func filterTooFrequentGlucose(_ glucose: [BloodGlucose], at: Date) -> [BloodGlucose]
    func lastGlucoseDate() -> Date
    func isGlucoseFresh() -> Bool
    func nightscoutGlucoseNotUploaded() -> [BloodGlucose]
    func nightscoutCGMStateNotUploaded() -> [NigtscoutTreatment]
    func nightscoutManualGlucoseNotUploaded() -> [NigtscoutTreatment]
    var alarm: GlucoseAlarm? { get }
    func fetchGlucose() -> [GlucoseStored]
}

final class BaseGlucoseStorage: GlucoseStorage, Injectable {
    private let processQueue = DispatchQueue(label: "BaseGlucoseStorage.processQueue")
    @Injected() private var storage: FileStorage!
    @Injected() private var broadcaster: Broadcaster!
    @Injected() private var settingsManager: SettingsManager!

    let coredataContext = CoreDataStack.shared.newTaskContext()

    private enum Config {
        static let filterTime: TimeInterval = 3.5 * 60
    }

    init(resolver: Resolver) {
        injectServices(resolver)
    }

    private var glucoseFormatter: NumberFormatter {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.maximumFractionDigits = 0
        if settingsManager.settings.units == .mmolL {
            formatter.maximumFractionDigits = 1
        }
        formatter.decimalSeparator = "."
        return formatter
    }

    func storeGlucose(_ glucose: [BloodGlucose]) {
        processQueue.sync {
            debug(.deviceManager, "Start storage of glucose data")

            self.coredataContext.perform {
                let datesToCheck: Set<Date?> = Set(glucose.compactMap { $0.dateString as Date? })
                let fetchRequest: NSFetchRequest<NSFetchRequestResult> = GlucoseStored.fetchRequest()
                fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
                    NSPredicate(format: "date IN %@", datesToCheck),
                    NSPredicate.predicateForOneDayAgo
                ])
                fetchRequest.propertiesToFetch = ["date"]
                fetchRequest.resultType = .dictionaryResultType

                var existingDates = Set<Date>()
                do {
                    let results = try self.coredataContext.fetch(fetchRequest) as? [NSDictionary]
                    existingDates = Set(results?.compactMap({ $0["date"] as? Date }) ?? [])
                } catch {
                    debugPrint("Failed to fetch existing glucose dates: \(error)")
                }

                var filteredGlucose = glucose.filter { !existingDates.contains($0.dateString) }

                // prepare batch insert
                let batchInsert = NSBatchInsertRequest(
                    entity: GlucoseStored.entity(),
                    managedObjectHandler: { (managedObject: NSManagedObject) -> Bool in
                        guard let glucoseEntry = managedObject as? GlucoseStored, !filteredGlucose.isEmpty else {
                            return true // Stop if there are no more items
                        }
                        let entry = filteredGlucose.removeFirst()
                        glucoseEntry.id = UUID()
                        glucoseEntry.glucose = Int16(entry.glucose ?? 0)
                        glucoseEntry.date = entry.dateString
                        glucoseEntry.direction = entry.direction?.symbol
                        return false // Continue processing
                    }
                )

                // process batch insert
                do {
                    try self.coredataContext.execute(batchInsert)
                    debugPrint("Glucose Storage: \(#function) \(DebuggingIdentifiers.succeeded) saved glucose to Core Data")

                    // Send notification for triggering a fetch in Home State Model to update the Glucose Array
                    /// This is necessary because changes only get merged automatically into the viewContext because of the Persistent History Tracking
                    /// But I do not want to fetch on the Main Thread using the @FetchRequest property, I also can not use the FetchedResultsController because of the architecture of the State Model (it must inherit from BaseStateModel and therefore can not inherit from NSObject as well) and because of the fact that I am using a batch insert here there are no notifications sent from the managedObjectContext because changes are directly stored in the persistent container
                    Foundation.NotificationCenter.default.post(name: .didPerformBatchInsert, object: nil)
                } catch {
                    debugPrint(
                        "Glucose Storage: \(#function) \(DebuggingIdentifiers.failed) failed to execute batch insert: \(error)"
                    )
                }

                debug(.deviceManager, "start storage cgmState")
                self.storage.transaction { storage in
                    let file = OpenAPS.Monitor.cgmState
                    var treatments = storage.retrieve(file, as: [NigtscoutTreatment].self) ?? []
                    var updated = false
                    for x in glucose {
                        debug(.deviceManager, "storeGlucose \(x)")
                        guard let sessionStartDate = x.sessionStartDate else {
                            continue
                        }
                        if let lastTreatment = treatments.last,
                           let createdAt = lastTreatment.createdAt,
                           // When a new Dexcom sensor is started, it produces multiple consecutive
                           // startDates. Disambiguate them by only allowing a session start per minute.
                           abs(createdAt.timeIntervalSince(sessionStartDate)) < TimeInterval(60)
                        {
                            continue
                        }
                        var notes = ""
                        if let t = x.transmitterID {
                            notes = t
                        }
                        if let a = x.activationDate {
                            notes = "\(notes) activated on \(a)"
                        }
                        let treatment = NigtscoutTreatment(
                            duration: nil,
                            rawDuration: nil,
                            rawRate: nil,
                            absolute: nil,
                            rate: nil,
                            eventType: .nsSensorChange,
                            createdAt: sessionStartDate,
                            enteredBy: NigtscoutTreatment.local,
                            bolus: nil,
                            insulin: nil,
                            notes: notes,
                            carbs: nil,
                            fat: nil,
                            protein: nil,
                            targetTop: nil,
                            targetBottom: nil
                        )
                        debug(.deviceManager, "CGM sensor change \(treatment)")
                        treatments.append(treatment)
                        updated = true
                    }
                    if updated {
                        // We have to keep quite a bit of history as sensors start only every 10 days.
                        storage.save(
                            treatments.filter
                                { $0.createdAt != nil && $0.createdAt!.addingTimeInterval(30.days.timeInterval) > Date() },
                            as: file
                        )
                    }
                }
            }
        }
    }

    func syncDate() -> Date {
        let fr = GlucoseStored.fetchRequest()
        fr.predicate = NSPredicate.predicateForOneDayAgo
        fr.sortDescriptors = [NSSortDescriptor(keyPath: \GlucoseStored.date, ascending: false)]
        fr.fetchLimit = 1

        var date: Date?
        coredataContext.performAndWait {
            do {
                let results = try self.coredataContext.fetch(fr)
                date = results.first?.date
            } catch let error as NSError {
                print("Fetch error: \(DebuggingIdentifiers.failed) \(error.localizedDescription), \(error.userInfo)")
            }
        }

        return date ?? .distantPast
    }

    func lastGlucoseDate() -> Date {
        let fr = GlucoseStored.fetchRequest()
        fr.predicate = NSPredicate.predicateForOneDayAgo
        fr.sortDescriptors = [NSSortDescriptor(keyPath: \GlucoseStored.date, ascending: false)]
        fr.fetchLimit = 1

        var date: Date?
        coredataContext.performAndWait {
            do {
                let results = try self.coredataContext.fetch(fr)
                date = results.first?.date
            } catch let error as NSError {
                print("Fetch error: \(DebuggingIdentifiers.failed) \(error.localizedDescription), \(error.userInfo)")
            }
        }

        return date ?? .distantPast
    }

    func isGlucoseFresh() -> Bool {
        Date().timeIntervalSince(lastGlucoseDate()) <= Config.filterTime
    }

    func filterTooFrequentGlucose(_ glucose: [BloodGlucose], at date: Date) -> [BloodGlucose] {
        var lastDate = date
        var filtered: [BloodGlucose] = []
        let sorted = glucose.sorted { $0.date < $1.date }

        for entry in sorted {
            guard entry.dateString.addingTimeInterval(-Config.filterTime) > lastDate else {
                continue
            }
            filtered.append(entry)
            lastDate = entry.dateString
        }

        return filtered
    }

    // MARK: - fetching non manual Glucose, manual Glucose and the last glucose value

    // TODO: -optimize this bullshit here...I would love to use the async/await pattern, but its simply not possible because you would need to change all the calls of the following functions and make them async...same shit with the NSAsynchronousFetchRequest
    /// its all done on a background thread and on a separate queue so hopefully its not too heavy
    /// also tried this but here again you need to make everything asynchronous...
    ///  let privateContext = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)
    /// privateContext.parent = coredataContext /// merges changes to the core data context
    ///
    func fetchGlucose() -> [GlucoseStored] {
        let predicate = NSPredicate.predicateForOneDayAgo
        return CoreDataStack.shared.fetchEntities(
            ofType: GlucoseStored.self,
            onContext: coredataContext,
            predicate: predicate,
            key: "date",
            ascending: false,
            fetchLimit: 288,
            batchSize: 50
        )
    }

    func fetchManualGlucose() -> [GlucoseStored] {
        let predicate = NSPredicate.manualGlucose
        return CoreDataStack.shared.fetchEntities(
            ofType: GlucoseStored.self,
            onContext: coredataContext,
            predicate: predicate,
            key: "date",
            ascending: false,
            fetchLimit: 288,
            batchSize: 50
        )
    }

    func fetchLatestGlucose() -> GlucoseStored? {
        let predicate = NSPredicate.predicateFor20MinAgo
        return CoreDataStack.shared.fetchEntities(
            ofType: GlucoseStored.self,
            onContext: coredataContext,
            predicate: predicate,
            key: "date",
            ascending: false,
            fetchLimit: 1
        ).first
    }

    private func processManualGlucose() -> [BloodGlucose] {
        coredataContext.performAndWait {
            let fetchedResults = fetchManualGlucose()
            let glucoseArray = fetchedResults.map { result in
                BloodGlucose(
                    date: Decimal(result.date?.timeIntervalSince1970 ?? Date().timeIntervalSince1970) * 1000,
                    dateString: result.date ?? Date(),
                    unfiltered: Decimal(result.glucose),
                    filtered: Decimal(result.glucose),
                    noise: nil,
                    type: ""
                )
            }
            return glucoseArray
        }
    }

    private func processGlucose() -> [BloodGlucose] {
        coredataContext.performAndWait {
            let results = self.fetchGlucose()
            let glucoseArray = results.map { result in
                BloodGlucose(
                    date: Decimal(result.date?.timeIntervalSince1970 ?? Date().timeIntervalSince1970) * 1000,
                    dateString: result.date ?? Date(),
                    unfiltered: Decimal(result.glucose),
                    filtered: Decimal(result.glucose),
                    noise: nil,
                    type: ""
                )
            }
            return glucoseArray
        }
    }

    func nightscoutGlucoseNotUploaded() -> [BloodGlucose] {
        let uploaded = storage.retrieve(OpenAPS.Nightscout.uploadedGlucose, as: [BloodGlucose].self) ?? []
        let recentGlucose = processGlucose()

        return Array(Set(recentGlucose).subtracting(Set(uploaded)))
    }

    func nightscoutCGMStateNotUploaded() -> [NigtscoutTreatment] {
        let uploaded = storage.retrieve(OpenAPS.Nightscout.uploadedCGMState, as: [NigtscoutTreatment].self) ?? []
        let recent = storage.retrieve(OpenAPS.Monitor.cgmState, as: [NigtscoutTreatment].self) ?? []
        return Array(Set(recent).subtracting(Set(uploaded)))
    }

    func nightscoutManualGlucoseNotUploaded() -> [NigtscoutTreatment] {
        let uploaded = (storage.retrieve(OpenAPS.Nightscout.uploadedGlucose, as: [BloodGlucose].self) ?? [])
            .filter({ $0.type == GlucoseType.manual.rawValue })

        let recent = processManualGlucose()
        let filtered = Array(Set(recent).subtracting(Set(uploaded)))
        let manualReadings = filtered.map { item -> NigtscoutTreatment in
            NigtscoutTreatment(
                duration: nil, rawDuration: nil, rawRate: nil, absolute: nil, rate: nil, eventType: .capillaryGlucose,
                createdAt: item.dateString, enteredBy: "iAPS", bolus: nil, insulin: nil, notes: "iAPS User", carbs: nil,
                fat: nil,
                protein: nil, foodType: nil, targetTop: nil, targetBottom: nil, glucoseType: "Manual",
                glucose: settingsManager.settings
                    .units == .mgdL ? (glucoseFormatter.string(from: Int(item.glucose ?? 100) as NSNumber) ?? "")
                    : (glucoseFormatter.string(from: Decimal(item.glucose ?? 100).asMmolL as NSNumber) ?? ""),
                units: settingsManager.settings.units == .mmolL ? "mmol" : "mg/dl"
            )
        }
        return manualReadings
    }

    var alarm: GlucoseAlarm? {
        /// glucose can not be older than 20 minutes due to the predicate in the fetch request
        coredataContext.performAndWait {
            guard let glucose = fetchLatestGlucose() else { return nil }

            let glucoseValue = glucose.glucose

            if Decimal(glucoseValue) <= settingsManager.settings.lowGlucose {
                return .low
            }

            if Decimal(glucoseValue) >= settingsManager.settings.highGlucose {
                return .high
            }

            return nil
        }
    }
}

protocol GlucoseObserver {
    func glucoseDidUpdate(_ glucose: [BloodGlucose])
}

enum GlucoseAlarm {
    case high
    case low

    var displayName: String {
        switch self {
        case .high:
            return NSLocalizedString("LOWALERT!", comment: "LOWALERT!")
        case .low:
            return NSLocalizedString("HIGHALERT!", comment: "HIGHALERT!")
        }
    }
}