import Foundation
import Observation
import VelodyDomain
import VelodyNetworking
import VelodyPersistence
import VelodySync

@MainActor
@Observable
final class iPhoneLibraryViewModel {
    var tracks: [LibraryTrack] = []
    var syncStatus = "Offline library not synced yet"

    private let store: any LocalLibraryStore
    private let syncCoordinator: PlaceholderSyncCoordinator
    private var hasLoaded = false

    init() {
        let repository = Self.makeTrackRepository()
        let environment = ServerEnvironment(
            baseURL: ServerEnvironment.defaultLocalBaseURL,
            appVersion: "0.1.0"
        )
        let apiClient = StubVelodyAPIClient(environment: environment)
        self.store = repository
        self.syncCoordinator = PlaceholderSyncCoordinator(
            apiClient: apiClient,
            store: repository
        )
    }

    func loadIfNeeded() async {
        guard !hasLoaded else { return }
        hasLoaded = true

        do {
            let persistedTracks = try await store.loadTracks()
            if !persistedTracks.isEmpty {
                tracks = persistedTracks
                syncStatus = "Loaded \(persistedTracks.count) cached track(s) from local storage."
            }
        } catch {
            syncStatus = "Failed to load cached catalog: \(error.localizedDescription)"
        }

        await refreshSync()
    }

    func refreshSync() async {
        do {
            let result = try await syncCoordinator.performInitialSync()
            tracks = result.tracks
            syncStatus = result.statusMessage
        } catch {
            syncStatus = "Sync placeholder failed: \(error.localizedDescription)"
        }
    }

    private static func makeTrackRepository() -> any TrackRepository {
        if let repository = try? SwiftDataTrackRepository() {
            return repository
        }

        return InMemoryTrackRepository()
    }
}