import Foundation
import SwiftData

// CloudKit-compatible (2.0): no unique constraints, inline defaults everywhere,
// and the relationship stored as optional (CloudKit requires it). `slots` keeps
// its name so existing stores lightweight-migrate; use `slotList` in code.
@Model
final class WeekPlan {
    var id: UUID = UUID()
    var weekStartDate: Date = Date()
    var createdAt: Date = Date()
    var updatedAt: Date = Date()
    var userRating: Int = 0   // 0 = unrated, 1 = liked, -1 = disliked

    /// Per-week overrides of the global schedule (2.1.1, premium). nil = follow
    /// `AppSettings`. Optional so existing stores lightweight-migrate and
    /// CloudKit accepts the new attributes.
    var includeWeekendsOverride: Bool?
    /// Comma-separated MealType raw values, chronological. nil = follow settings.
    var mealTypesOverrideRaw: String?

    @Relationship(deleteRule: .cascade)
    var slots: [MealSlot]? = []

    /// Non-optional facade over the CloudKit-required optional relationship.
    var slotList: [MealSlot] {
        get { slots ?? [] }
        set { slots = newValue }
    }

    /// The meal types this week overrides the global setting with, or nil when
    /// it follows `AppSettings.activeMealTypes`.
    var mealTypesOverride: [MealType]? {
        get {
            guard let raw = mealTypesOverrideRaw else { return nil }
            let types = raw.split(separator: ",").compactMap { MealType(rawValue: String($0)) }
            guard !types.isEmpty else { return nil }
            return MealType.allCases.filter { types.contains($0) }
        }
        set {
            guard let newValue else {
                mealTypesOverrideRaw = nil
                return
            }
            let ordered = MealType.allCases.filter { newValue.contains($0) }
            // An empty selection would leave the week with no slots at all;
            // treat it as "no override" instead.
            mealTypesOverrideRaw = ordered.isEmpty ? nil : ordered.map(\.rawValue).joined(separator: ",")
        }
    }

    var hasScheduleOverride: Bool {
        includeWeekendsOverride != nil || mealTypesOverrideRaw != nil
    }

    func clearScheduleOverride() {
        includeWeekendsOverride = nil
        mealTypesOverrideRaw = nil
    }

    init(
        id: UUID = UUID(),
        weekStartDate: Date,
        slots: [MealSlot] = [],
        createdAt: Date = Date(),
        updatedAt: Date = Date()
    ) {
        self.id = id
        self.weekStartDate = weekStartDate
        self.slots = slots
        self.createdAt = createdAt
        self.updatedAt = updatedAt
        self.userRating = 0
    }
}