//
//  ServicesMALocaleManager.swift
//  Mobile Music Assistant
//
//  Created by Sven Hanold on 09.04.26.
//

import SwiftUI

// MARK: - Supported Languages

enum SupportedLanguage: String, CaseIterable, Identifiable {
    case en = "en"
    case de = "de"
    case fr = "fr"
    case es = "es"

    var id: String { rawValue }

    /// Native display name (endonym) — always shown in the language's own script
    var endonym: String {
        switch self {
        case .en: return "English"
        case .de: return "Deutsch"
        case .fr: return "Français"
        case .es: return "Español"
        }
    }
}

// MARK: - Locale Manager

@Observable
class MALocaleManager {
    /// nil means "System" (no override — iOS uses device language)
    var selectedLanguageCode: String? {
        didSet {
            if let code = selectedLanguageCode {
                UserDefaults.standard.set(code, forKey: "appLanguageOverride")
            } else {
                UserDefaults.standard.removeObject(forKey: "appLanguageOverride")
            }
        }
    }

    init() {
        selectedLanguageCode = UserDefaults.standard.string(forKey: "appLanguageOverride")
    }

    /// The locale to inject into the environment. nil = let iOS choose.
    var overrideLocale: Locale? {
        guard let code = selectedLanguageCode else { return nil }
        return Locale(identifier: code)
    }
}

// MARK: - Environment Key

private struct LocaleManagerKey: EnvironmentKey {
    static let defaultValue = MALocaleManager()
}

extension EnvironmentValues {
    var localeManager: MALocaleManager {
        get { self[LocaleManagerKey.self] }
        set { self[LocaleManagerKey.self] = newValue }
    }
}

// MARK: - Locale Applied Modifier

struct LocaleAppliedModifier: ViewModifier {
    @Environment(\.localeManager) var localeManager

    func body(content: Content) -> some View {
        content.environment(\.locale, localeManager.overrideLocale ?? .current)
    }
}

extension View {
    func applyLocale() -> some View {
        modifier(LocaleAppliedModifier())
    }
}