import Foundation

/// The physical range band a user is open to connecting within.
///
/// Each tier maps to a different sensing technology. The tiers are ordered so
/// higher tiers *include* lower ones (being open "in the area" also means
/// you're open "nearby" and "right here").
enum DistanceTier: Int, CaseIterable, Identifiable, Codable {
    /// 0–9 m. Ultra-wideband (Nearby Interaction). "This exact person."
    case rightHere = 1

    /// 10–100 m. Bluetooth Low Energy / iBeacon. "This room, this block."
    case nearby = 2

    /// 100 m–50 mi. Server-relayed, opt-in coarse location. "This neighborhood."
    case inTheArea = 3

    var id: Int { rawValue }

    var title: String {
        switch self {
        case .rightHere: return "Right Here"
        case .nearby:    return "Nearby"
        case .inTheArea: return "In the Area"
        }
    }

    var subtitle: String {
        switch self {
        case .rightHere: return "0–9 m · UWB"
        case .nearby:    return "10–100 m · BLE"
        case .inTheArea: return "100 m–50 mi · Network"
        }
    }

    /// The primary engine used for this tier.
    var engine: ProximityEngine {
        switch self {
        case .rightHere: return .uwb
        case .nearby:    return .ble
        case .inTheArea: return .beacon
        }
    }

    /// Higher tiers include lower ones.
    func includes(_ other: DistanceTier) -> Bool {
        self.rawValue >= other.rawValue
    }
}