//
//  DataController.swift
//  Feels
//
//  SwiftData controller replacing Core Data PersistenceController.
//

import SwiftData
import SwiftUI

@MainActor
final class DataController: ObservableObject {
    static let shared = DataController()

    private(set) var container: ModelContainer

    var modelContext: ModelContext {
        container.mainContext
    }

    private var useCloudKit: Bool {
        GroupUserDefaults.groupDefaults.bool(forKey: UserDefaultsStore.Keys.useCloudKit.rawValue)
    }

    // Listeners for data changes (keeping existing pattern)
    var switchContainerListeners = [(() -> Void)]()
    private var editedDataClosure = [() -> Void]()

    // Computed properties for earliest/latest entries
    var earliestEntry: MoodEntryModel? {
        var descriptor = FetchDescriptor<MoodEntryModel>(
            sortBy: [SortDescriptor(\.forDate, order: .forward)]
        )
        descriptor.fetchLimit = 1
        return try? modelContext.fetch(descriptor).first
    }

    var latestEntry: MoodEntryModel? {
        var descriptor = FetchDescriptor<MoodEntryModel>(
            sortBy: [SortDescriptor(\.forDate, order: .reverse)]
        )
        descriptor.fetchLimit = 1
        return try? modelContext.fetch(descriptor).first
    }

    private init() {
        let cloudKit = GroupUserDefaults.groupDefaults.bool(forKey: UserDefaultsStore.Keys.useCloudKit.rawValue)
        container = SharedModelContainer.create(useCloudKit: cloudKit)
    }

    // MARK: - Container Switching (for CloudKit toggle)

    func switchContainer() {
        save()
        container = SharedModelContainer.create(useCloudKit: useCloudKit)
        for listener in switchContainerListeners {
            listener()
        }
    }

    // MARK: - Listener Management

    func addNewDataListener(closure: @escaping (() -> Void)) {
        editedDataClosure.append(closure)
    }

    func saveAndRunDataListeners() {
        save()
        for closure in editedDataClosure {
            closure()
        }
    }

    func save() {
        guard modelContext.hasChanges else { return }
        do {
            try modelContext.save()
        } catch {
            print("Failed to save context: \(error)")
        }
    }
}