import Foundation
import SwiftUI

extension Notification.Name {
    static let snackbarDidChange = Notification.Name("snackbarDidChange")
}

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

    @Published var current: SnackbarMessage?

    private var dismissTask: Task<Void, Never>?

    func show(
        title: String,
        style: SnackbarStyle = .info,
        icon: String? = nil,
        duration: TimeInterval = 3.5,
        action: (() -> Void)? = nil
    ) {
        dismissTask?.cancel()
        current = SnackbarMessage(
            title: title,
            style: style,
            iconSystemName: icon,
            duration: duration,
            action: action
        )

        dismissTask = Task { [weak self] in
            let nanos = UInt64(max(0.2, duration) * 1_000_000_000)
            try? await Task.sleep(nanoseconds: nanos)
            guard !Task.isCancelled else { return }
            self?.dismiss(animated: true)
        }
    }

    func handleTap() {
        let action = current?.action
        dismiss(animated: true)
        action?()
    }

    func dismiss(animated: Bool) {
        dismissTask?.cancel()
        dismissTask = nil
        if animated {
            withAnimation(.spring(response: 0.3, dampingFraction: 0.9)) {
                current = nil
            }
        } else {
            current = nil
        }
    }
}

enum SnackbarStyle: Sendable {
    case info
    case success
    case warning
    case error

    var backgroundColor: Color {
        switch self {
        case .info: return Color(hex: "#3B93F7")
        case .success: return Color(hex: "#2E7D32")
        case .warning: return Color(hex: "#C77700")
        case .error: return Color(hex: "#C62828")
        }
    }
}

struct SnackbarMessage: Identifiable {
    let id = UUID()
    let title: String
    let style: SnackbarStyle
    let iconSystemName: String?
    let duration: TimeInterval
    let action: (() -> Void)?
}