import Foundation

/// Snapshot of the week the iPhone pushes to the Watch (WatchConnectivity) and
/// the watch widget reads from the watch-side app group. Labels and day titles
/// arrive already localized — the watch never formats, only renders.
/// Member of the iOS app, watch app and watch widget targets.
struct WatchWeekPayload: Codable {
    struct Meal: Codable {
        let type: String    // MealType rawValue, for the icon
        let label: String   // localized ("Comida", "Cena"…)
        let name: String?   // dish (+ secondary), "Comer fuera", or nil if empty
    }

    struct Day: Codable {
        let dayOfWeek: Int  // 0=Monday … 6=Sunday
        let title: String   // localized short title ("Lun 8")
        let isToday: Bool
        let meals: [Meal]
    }

    let weekTitle: String   // localized week range ("8 – 14 sep")
    let days: [Day]
    let updatedAt: Date

    static let appGroupID = "group.com.alexandrevazquez.mealmood"
    static let storageKey = "watch_week_payload_v1"

    func encoded() -> Data? { try? JSONEncoder().encode(self) }

    static func decode(_ data: Data) -> WatchWeekPayload? {
        try? JSONDecoder().decode(WatchWeekPayload.self, from: data)
    }

    /// Reads the last snapshot stored on this device's app group.
    static func stored() -> WatchWeekPayload? {
        guard let data = UserDefaults(suiteName: appGroupID)?.data(forKey: storageKey) else { return nil }
        return decode(data)
    }

    func store() {
        UserDefaults(suiteName: Self.appGroupID)?.set(encoded(), forKey: Self.storageKey)
    }

    static func icon(for mealType: String) -> String {
        switch mealType {
        case "breakfast": return "cup.and.saucer.fill"
        case "lunch": return "sun.max.fill"
        case "snack": return "carrot.fill"
        case "dinner": return "moon.stars.fill"
        default: return "fork.knife"
        }
    }
}