import Foundation
import SwiftData

// CloudKit-compatible (2.0): no unique constraints, inline defaults everywhere.
@Model
final class AppSettings {
    var mealWindows: String = "dinnerOnly" // legacy: "dinnerOnly", "lunchOnly", "both"
    var includeWeekends: Bool = true
    var language: String = "system"

    /// Comma-separated MealType raw values, in chronological order (2.0).
    /// nil = derive from the legacy `mealWindows` field (pre-2.0 installs).
    var enabledMealTypesRaw: String?

    var calendarId: String?
    var syncEnabled: Bool = false
    var syncMode: String? // "weekComplete", "manual"
    var lunchTime: Date = AppSettings.defaultTime(hour: 14)
    var dinnerTime: Date = AppSettings.defaultTime(hour: 21)
    var breakfastTime: Date? // optional: pre-2.0 stores lack it
    var snackTime: Date?
    var eventDuration: Int = 60
    var eventPrefix: String = "🍽️"
    var reminderMinutesBefore: Int?
    var iCloudSyncEnabled: Bool?
    var weekExportStyle: String?
    /// Show dish photos as planner card backgrounds (2.0). Optional for
    /// CloudKit/migration compatibility; resolves to true.
    var showDishPhotosInPlanner: Bool?

    var isPremium: Bool = false
    var onboardingCompleted: Bool = false

    init() {
        self.mealWindows = "dinnerOnly"
        self.includeWeekends = true
        self.language = "system"
        self.calendarId = nil
        self.syncEnabled = false
        self.syncMode = CalendarSyncMode.weekComplete.rawValue
        // Default lunch time 14:00
        var lunchComponents = DateComponents()
        lunchComponents.hour = 14
        lunchComponents.minute = 0
        self.lunchTime = Calendar.current.date(from: lunchComponents) ?? Date()
        // Default dinner time 21:00
        var dinnerComponents = DateComponents()
        dinnerComponents.hour = 21
        dinnerComponents.minute = 0
        self.dinnerTime = Calendar.current.date(from: dinnerComponents) ?? Date()
        self.eventDuration = 60
        self.eventPrefix = "🍽️"
        self.reminderMinutesBefore = nil
        self.iCloudSyncEnabled = true
        self.weekExportStyle = nil
        self.isPremium = false
        self.onboardingCompleted = false
    }

    var mealWindowsEnum: MealWindows {
        get { MealWindows(rawValue: mealWindows) ?? .dinnerOnly }
        set { mealWindows = newValue.rawValue }
    }

    var languageEnum: AppLanguage {
        get { AppLanguage(rawValue: language) ?? .system }
        set { language = newValue.rawValue }
    }

    var syncModeEnum: CalendarSyncMode {
        get { CalendarSyncMode(rawValue: syncMode ?? "") ?? .weekComplete }
        set { syncMode = newValue.rawValue }
    }

    var iCloudSyncEnabledResolved: Bool {
        get { iCloudSyncEnabled ?? true }
        set { iCloudSyncEnabled = newValue }
    }

    var showDishPhotosInPlannerResolved: Bool {
        get { showDishPhotosInPlanner ?? true }
        set { showDishPhotosInPlanner = newValue }
    }

    var weekExportStyleEnum: WeekExportStyle {
        get { WeekExportStyle(rawValue: weekExportStyle ?? "") ?? .defaultStyle }
        set { weekExportStyle = newValue.rawValue }
    }

    /// The meal types the user plans, in chronological order. Single source of
    /// truth for slot generation, calendar rows, exports and the widget.
    /// Falls back to the legacy `mealWindows` for pre-2.0 installs.
    var activeMealTypes: [MealType] {
        get {
            if let raw = enabledMealTypesRaw {
                let types = raw.split(separator: ",").compactMap { MealType(rawValue: String($0)) }
                if !types.isEmpty {
                    return MealType.allCases.filter { types.contains($0) }
                }
            }
            switch mealWindowsEnum {
            case .dinnerOnly: return [.dinner]
            case .lunchOnly: return [.lunch]
            case .both: return [.lunch, .dinner]
            }
        }
        set {
            let ordered = MealType.allCases.filter { newValue.contains($0) }
            enabledMealTypesRaw = ordered.isEmpty
                ? MealType.dinner.rawValue
                : ordered.map(\.rawValue).joined(separator: ",")
            // Keep the legacy field roughly coherent for pre-2.0 code paths.
            if ordered.contains(.lunch) && ordered.contains(.dinner) {
                mealWindowsEnum = .both
            } else if ordered.contains(.lunch) {
                mealWindowsEnum = .lunchOnly
            } else {
                mealWindowsEnum = .dinnerOnly
            }
        }
    }

    /// Event start time for a meal type (calendar sync). Breakfast/snack get
    /// sensible defaults on pre-2.0 stores that never set them.
    func time(for mealType: MealType) -> Date {
        switch mealType {
        case .breakfast: return breakfastTime ?? Self.defaultTime(hour: 8)
        case .lunch: return lunchTime
        case .snack: return snackTime ?? Self.defaultTime(hour: 17)
        case .dinner: return dinnerTime
        }
    }

    static func defaultTime(hour: Int) -> Date {
        var components = DateComponents()
        components.hour = hour
        components.minute = 0
        return Calendar.current.date(from: components) ?? Date()
    }
}

enum MealWindows: String, CaseIterable {
    case dinnerOnly
    case lunchOnly
    case both

    var localizedKey: String {
        switch self {
        case .dinnerOnly: return "meal_windows_dinner_only"
        case .lunchOnly: return "meal_windows_lunch_only"
        case .both: return "meal_windows_both"
        }
    }

    var icon: String {
        switch self {
        case .dinnerOnly: return "moon.stars.fill"
        case .lunchOnly: return "sun.max.fill"
        case .both: return "sun.and.horizon.fill"
        }
    }
}

enum AppLanguage: String, CaseIterable {
    case system
    case spanish
    case english
    case french
    case german
    case italian
    case portugueseBrazil

    var displayName: String {
        switch self {
        case .system: return "System"
        case .spanish: return "Español"
        case .english: return "English"
        case .french: return "Français"
        case .german: return "Deutsch"
        case .italian: return "Italiano"
        case .portugueseBrazil: return "Português (Brasil)"
        }
    }

    var localeIdentifier: String {
        switch self {
        case .system: return resolved().localeIdentifier
        case .spanish: return "es"
        case .english: return "en"
        case .french: return "fr"
        case .german: return "de"
        case .italian: return "it"
        case .portugueseBrazil: return "pt-BR"
        }
    }

    func resolved() -> AppLanguage {
        if self != .system { return self }
        let localeIdentifier = Locale.current.identifier.lowercased()

        if localeIdentifier.hasPrefix("es") { return .spanish }
        if localeIdentifier.hasPrefix("fr") { return .french }
        if localeIdentifier.hasPrefix("de") { return .german }
        if localeIdentifier.hasPrefix("it") { return .italian }
        if localeIdentifier.hasPrefix("pt") { return .portugueseBrazil }
        return .english
    }
}

enum MealType: String, Codable, CaseIterable {
    // Declaration order is chronological — allCases drives row/slot ordering.
    case breakfast
    case lunch
    case snack
    case dinner

    var icon: String {
        switch self {
        case .breakfast: return "cup.and.saucer.fill"
        case .lunch: return "sun.max.fill"
        case .snack: return "carrot.fill"
        case .dinner: return "moon.stars.fill"
        }
    }

    var localizedKey: String {
        switch self {
        case .breakfast: return "breakfast"
        case .lunch: return "lunch"
        case .snack: return "snack"
        case .dinner: return "dinner"
        }
    }

    /// Chronological position, used to order slots within a day.
    var order: Int {
        MealType.allCases.firstIndex(of: self) ?? 0
    }
}

enum CalendarSyncMode: String, CaseIterable {
    case weekComplete
    case manual

    var localizedKey: String {
        switch self {
        case .weekComplete: return "settings_sync_mode_week_complete"
        case .manual: return "settings_sync_mode_manual"
        }
    }
}

enum WeekExportStyle: String, CaseIterable {
    case defaultStyle
    case schoolTimetable
    case vertical

    var localizedKey: String {
        switch self {
        case .defaultStyle: return "share_export_style_default"
        case .schoolTimetable: return "share_export_style_school"
        case .vertical: return "share_export_style_vertical"
        }
    }
}