// Auteur : Simon-Pierre Boucher — contact@spboucher.ai
// FavoritesStore.swift — favoris et collections UNIFIÉS (tous univers dans une
// même collection : « Déménagement à Val-d'Or » peut contenir un 4½, une auto
// et un resto). Persistance JSON locale (consultation hors ligne).
// Repris de l'app iOS KA, sans haptique.
import Foundation
import SwiftUI

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

    struct FavCollection: Identifiable, Codable, Hashable {
        var id: UUID = UUID()
        var name: String
        var items: [KAItem] = []
    }

    @Published private(set) var collections: [FavCollection] = [] {
        didSet { save() }
    }

    private var fileURL: URL {
        let dir = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
            .appendingPathComponent("KA", isDirectory: true)
        try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
        return dir.appendingPathComponent("ka-favoris.json")
    }

    init() {
        if let data = try? Data(contentsOf: fileURL),
           let saved = try? JSONDecoder().decode([FavCollection].self, from: data) {
            collections = saved
        }
        if collections.isEmpty {
            collections = [FavCollection(name: "Mes favoris")]
        }
    }

    private func save() {
        if let data = try? JSONEncoder().encode(collections) {
            try? data.write(to: fileURL, options: .atomic)
        }
    }

    // MARK: API

    var allItems: [KAItem] { collections.flatMap(\.items) }
    var count: Int { collections.reduce(0) { $0 + $1.items.count } }

    func isFavorite(_ item: KAItem) -> Bool {
        collections.contains { $0.items.contains { $0.id == item.id } }
    }

    func toggle(_ item: KAItem, in collectionID: UUID? = nil) {
        if isFavorite(item) {
            for i in collections.indices {
                collections[i].items.removeAll { $0.id == item.id }
            }
        } else {
            let idx = collections.firstIndex { $0.id == collectionID } ?? 0
            collections[idx].items.insert(item, at: 0)
        }
    }

    func addCollection(_ name: String) {
        let trimmed = name.trimmingCharacters(in: .whitespaces)
        guard !trimmed.isEmpty else { return }
        collections.append(FavCollection(name: trimmed))
    }

    func removeCollection(_ id: UUID) {
        guard collections.count > 1 else { return }
        collections.removeAll { $0.id == id }
    }

    func move(_ item: KAItem, to collectionID: UUID) {
        for i in collections.indices { collections[i].items.removeAll { $0.id == item.id } }
        if let idx = collections.firstIndex(where: { $0.id == collectionID }) {
            collections[idx].items.insert(item, at: 0)
        }
    }
}