// MyPass/ViewModels/VaultViewModel.swift
import Foundation
import Combine
import MyPassCore

@MainActor
final class VaultViewModel: ObservableObject {
    @Published var searchQuery: String = ""
    @Published var selectedGroupIds: Set<UUID> = []
    @Published var lastToggledGroupId: UUID?
    @Published var errorMessage: String?

    let session: VaultSession
    private var sessionCancellable: AnyCancellable?

    init(session: VaultSession) {
        self.session = session
        sessionCancellable = session.objectWillChange.sink { [weak self] in
            self?.objectWillChange.send()
        }
    }

    /// All entries in the vault, flattened with their group breadcrumb, before any filtering.
    private var allFlatEntries: [FlatEntry] {
        guard let root = session.database?.root else { return [] }
        return flattenEntries(in: root)
    }

    /// Entries after applying the group filter, then the search filter (AND semantics).
    var displayedEntries: [FlatEntry] {
        var entries = allFlatEntries
        if !selectedGroupIds.isEmpty {
            entries = entries.filter { selectedGroupIds.contains($0.parentGroupId) }
        }
        if !searchQuery.isEmpty {
            let q = searchQuery.lowercased()
            entries = entries.filter {
                $0.entry.title.lowercased().contains(q)
                || $0.entry.username.lowercased().contains(q)
                || $0.entry.url.lowercased().contains(q)
            }
        }
        return entries
    }

    func deleteEntry(_ flatEntry: FlatEntry) {
        Task {
            do { try session.deleteEntry(id: flatEntry.entry.id, fromGroupId: flatEntry.parentGroupId) }
            catch { errorMessage = error.localizedDescription }
        }
    }
}