import Foundation

// Entspricht den Schemas des Backends (backend/app/schemas.py).

struct TokenResponse: Codable {
    let accessToken: String
    let role: String
    let username: String

    enum CodingKeys: String, CodingKey {
        case accessToken = "access_token"
        case role, username
    }
}

struct MeResponse: Codable {
    let id: Int
    let username: String
    let role: String

    var isAdmin: Bool { role == "admin" }
}

struct Unit: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
    let kind: String
    let factor: Double
    /// Eingebaute Einheiten lassen sich umbenennen, aber nicht loeschen.
    let isBuiltin: Bool

    enum CodingKeys: String, CodingKey {
        case id, name, kind, factor
        case isBuiltin = "is_builtin"
    }
}

struct BarcodeEntry: Codable, Identifiable, Hashable {
    let id: Int
    let code: String
    let note: String?
}

struct Product: Codable, Identifiable, Hashable {
    let id: Int
    let barcode: String?
    let name: String
    let brand: String?
    let imageUrl: String?
    let baseUnit: String
    let packageSize: Double?
    let packageLabel: String?
    let groupId: Int?
    let minStock: Double?
    let stock: Double
    let expiredCount: Int
    let kind: String
    let unitName: String
    let unitFactor: Double
    let barcodes: [BarcodeEntry]
    /// Welche MHD-Genauigkeit bei diesem Produkt ueblich ist ("day"/"month").
    let datePrecision: String?
    /// Kategorie: reine Ordnungshilfe fuer die Artikelliste (nicht die Gruppe).
    let categoryId: Int?
    let categoryName: String?
    /// Mindestbestand in der erfassten Einheit, fuer die Anzeige.
    let minStockDisplay: Double?
    let minStockUnitLabel: String?
    /// Verwaltungsart aus der Kategorie: "food" (Chargen+MHD) oder "object" (Menge je Ort).
    let tracking: String?
    /// Nur fuer Gegenstaende: Bezugsquelle und Onlineshop-Link.
    let shopId: Int?
    let shopName: String?
    let productUrl: String?
    /// Selbst definierte Feldwerte: {feld_id (als Text): Wert}.
    let fieldValues: [String: String?]?
    /// Gegenstand als Einzelstücke (Items mit UID/QR) statt als Menge geführt.
    let individual: Bool?
    /// Mindestbestand je Lagerort (zusaetzlich zum globalen Mindestbestand).
    let locationMinStocks: [LocationMinStock]?

    enum CodingKeys: String, CodingKey {
        case id, barcode, name, brand, stock, kind, barcodes, tracking, individual
        case locationMinStocks = "location_min_stocks"
        case datePrecision = "date_precision"
        case categoryId = "category_id"
        case categoryName = "category_name"
        case minStockDisplay = "min_stock_display"
        case minStockUnitLabel = "min_stock_unit_label"
        case imageUrl = "image_url"
        case baseUnit = "base_unit"
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case groupId = "group_id"
        case minStock = "min_stock"
        case expiredCount = "expired_count"
        case unitName = "unit_name"
        case unitFactor = "unit_factor"
        case shopId = "shop_id"
        case shopName = "shop_name"
        case productUrl = "product_url"
        case fieldValues = "field_values"
    }

    /// Gegenstand (Menge je Lagerort) statt Lebensmittel (Chargen/MHD)?
    var isObject: Bool { tracking == "object" }
    /// Gegenstand, der als Einzelstücke (UID/QR) geführt wird?
    var isIndividual: Bool { individual == true }

    /// Bezeichnung der Artikeleinheit (Gebinde, sonst Produkteinheit).
    var articleUnitLabel: String {
        if let size = packageSize, size > 0 { return packageLabel ?? "Packung" }
        return unitName
    }

    /// Faktor, um Basiseinheiten in Artikeleinheiten umzurechnen.
    var articleUnitFactor: Double {
        if let size = packageSize, size > 0 { return size }
        return unitFactor == 0 ? 1 : unitFactor
    }

    var stockInArticleUnits: Double { stock / articleUnitFactor }

    /// Wie es um den Mindestbestand steht. Beides in Basiseinheiten verglichen.
    enum StockLevel { case none, ok, close, below }

    var stockLevel: StockLevel {
        guard let minimum = minStock, minimum > 0 else { return .none }
        if stock < minimum { return .below }
        // Weniger als ein Viertel Luft: bald nachkaufen.
        return stock < minimum * 1.25 ? .close : .ok
    }
}

/// Mindestbestand eines Produkts/einer Gruppe an einem Lagerort (Anzeige).
struct LocationMinStock: Codable, Hashable, Identifiable {
    let locationId: String
    let locationName: String?
    let minStock: Double
    var id: String { locationId }

    enum CodingKeys: String, CodingKey {
        case minStock = "min_stock"
        case locationId = "location_id"
        case locationName = "location_name"
    }
}

/// Ein Mindestbestand-Eintrag zum Speichern (Menge in Artikeleinheiten).
struct LocationMinStockIn: Codable {
    let locationId: String
    let minStock: Double

    enum CodingKeys: String, CodingKey {
        case minStock = "min_stock"
        case locationId = "location_id"
    }
}

/// Auswahleintrag fuer Einheiten.
///
/// Anzeige und uebertragener Wert sind bewusst getrennt: Das Backend kennt
/// fuer das Gebinde nur das Schluesselwort "package" (siehe
/// services/conversion.py). Die Bezeichnung "Glas" oder "Dose" ist reine
/// Anzeige - wird sie mitgeschickt, antwortet der Server
/// "Unbekannte Einheit: Glas".
struct UnitOption: Hashable, Identifiable {
    let value: String
    let label: String
    var id: String { value }

    static let packageValue = "package"
}

struct LookupResult: Codable {
    let found: Bool
    let existingProduct: Product?
    let suggestion: Suggestion?
    /// Gruppe: nur gesetzt, wenn der Code dort ausdruecklich hinterlegt ist.
    let groupId: Int?
    let groupName: String?
    /// Kategorie: aus der Open-Food-Facts-Einordnung vorgeschlagen.
    let categoryId: Int?
    let categoryName: String?

    enum CodingKeys: String, CodingKey {
        case found, suggestion
        case existingProduct = "existing_product"
        case groupId = "group_id"
        case groupName = "group_name"
        case categoryId = "category_id"
        case categoryName = "category_name"
    }

    struct Suggestion: Codable {
        let barcode: String?
        let name: String
        let brand: String?
        let imageUrl: String?
        let baseUnit: String?
        let packageSize: Double?
        let quantityText: String?

        enum CodingKeys: String, CodingKey {
            case barcode, name, brand
            case imageUrl = "image_url"
            case baseUnit = "base_unit"
            case packageSize = "package_size"
            case quantityText = "quantity_text"
        }
    }
}

struct Lot: Codable, Identifiable, Hashable {
    let id: Int
    let productId: Int
    let quantity: Double
    let bestBefore: String?
    let bestBeforePrecision: String?
    let locationId: String?

    enum CodingKeys: String, CodingKey {
        case id, quantity
        case productId = "product_id"
        case bestBefore = "best_before"
        case bestBeforePrecision = "best_before_precision"
        case locationId = "location_id"
    }
}

struct StorageLocation: Codable, Identifiable, Hashable {
    let id: String
    let name: String
    let parentId: String?

    enum CodingKeys: String, CodingKey {
        case id, name
        case parentId = "parent_id"
    }
}

struct CheckInLine: Codable {
    let quantity: Double
    let bestBefore: String?
    let bestBeforePrecision: String
    let locationId: String?

    enum CodingKeys: String, CodingKey {
        case quantity
        case bestBefore = "best_before"
        case bestBeforePrecision = "best_before_precision"
        case locationId = "location_id"
    }
}

struct BatchCheckInRequest: Codable {
    let productId: Int
    let unit: String
    let lines: [CheckInLine]

    enum CodingKeys: String, CodingKey {
        case unit, lines
        case productId = "product_id"
    }
}

struct CheckOutRequest: Codable {
    let productId: Int
    let quantity: Double
    let unit: String
    let lotId: Int?

    enum CodingKeys: String, CodingKey {
        case quantity, unit
        case productId = "product_id"
        case lotId = "lot_id"
    }
}

struct StockResponse: Codable {
    let productStock: Double

    enum CodingKeys: String, CodingKey {
        case productStock = "product_stock"
    }
}

struct NewProductRequest: Codable {
    let barcode: String?
    let name: String
    let brand: String?
    let imageUrl: String?
    let baseUnit: String
    let packageSize: Double?
    let packageLabel: String?
    let datePrecision: String
    let groupId: Int?
    let categoryId: Int?
    var individual: Bool? = nil

    enum CodingKeys: String, CodingKey {
        case barcode, name, brand, individual
        case imageUrl = "image_url"
        case baseUnit = "base_unit"
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case datePrecision = "date_precision"
        case groupId = "group_id"
        case categoryId = "category_id"
    }
}

// MARK: - Listen (Einkaufsliste, bald ablaufend)

struct ShoppingItem: Codable, Identifiable {
    let productId: Int
    let name: String
    let baseUnit: String
    let packageSize: Double?
    let stock: Double
    let minStock: Double
    let deficit: Double

    var id: Int { productId }

    enum CodingKeys: String, CodingKey {
        case name, stock, deficit
        case productId = "product_id"
        case baseUnit = "base_unit"
        case packageSize = "package_size"
        case minStock = "min_stock"
    }
}

struct GroupShoppingItem: Codable, Identifiable {
    let groupId: Int
    let name: String
    let stock: Double
    let minStock: Double
    let deficit: Double
    let unitName: String
    let productCount: Int

    var id: Int { groupId }

    enum CodingKeys: String, CodingKey {
        case name, stock, deficit
        case groupId = "group_id"
        case minStock = "min_stock"
        case unitName = "unit_name"
        case productCount = "product_count"
    }
}

// MARK: - Bedarfe je Lagerort

struct LocationNeedProduct: Codable, Identifiable {
    let productId: Int
    let name: String
    let unitLabel: String
    let stock: Double
    let minStock: Double
    let deficit: Double

    var id: Int { productId }

    enum CodingKeys: String, CodingKey {
        case name, stock, deficit
        case productId = "product_id"
        case unitLabel = "unit_label"
        case minStock = "min_stock"
    }
}

struct LocationNeedGroup: Codable, Identifiable {
    let groupId: Int
    let name: String
    let unitName: String
    let stock: Double
    let minStock: Double
    let deficit: Double

    var id: Int { groupId }

    enum CodingKeys: String, CodingKey {
        case name, stock, deficit
        case groupId = "group_id"
        case unitName = "unit_name"
        case minStock = "min_stock"
    }
}

struct LocationNeeds: Codable, Identifiable {
    let locationId: String
    let locationName: String
    let products: [LocationNeedProduct]
    let groups: [LocationNeedGroup]

    var id: String { locationId }

    enum CodingKeys: String, CodingKey {
        case products, groups
        case locationId = "location_id"
        case locationName = "location_name"
    }
}

struct ExpiringItem: Codable, Identifiable {
    let lotId: Int
    let productId: Int
    let productName: String
    let quantity: Double
    let baseUnit: String
    let bestBefore: String
    let bestBeforePrecision: String?
    let daysLeft: Int
    let packageSize: Double?
    let packageLabel: String?
    let unitName: String
    let unitFactor: Double

    var id: Int { lotId }

    enum CodingKeys: String, CodingKey {
        case quantity
        case lotId = "lot_id"
        case productId = "product_id"
        case productName = "product_name"
        case baseUnit = "base_unit"
        case bestBefore = "best_before"
        case bestBeforePrecision = "best_before_precision"
        case daysLeft = "days_left"
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case unitName = "unit_name"
        case unitFactor = "unit_factor"
    }
}

// MARK: - Aenderungen

/// Die Felder, die das Produktformular der App besitzt (PATCH).
///
/// Bewusst mit eigener Kodierung: Swift laesst `nil`-Optionals sonst einfach
/// weg, und das Backend wertet nur mitgeschickte Felder aus. Leeren waere damit
/// unmoeglich - "keine Kategorie" oder eine geloeschte Marke wuerden stumm
/// verpuffen. Felder, die die App nicht bearbeitet (etwa der Mindestbestand),
/// stehen deshalb gar nicht erst hier drin.
struct ProductUpdateRequest: Encodable {
    var name: String?
    var brand: String?
    var packageSize: Double?
    var packageLabel: String?
    var datePrecision: String?
    var groupId: Int?
    var categoryId: Int?
    // Nur fuer Gegenstaende (Standard nil = nicht mitschicken bei fieldValues).
    var shopId: Int? = nil
    var productUrl: String? = nil
    var fieldValues: [String: String?]? = nil

    enum CodingKeys: String, CodingKey {
        case name, brand
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case datePrecision = "date_precision"
        case groupId = "group_id"
        case categoryId = "category_id"
        case shopId = "shop_id"
        case productUrl = "product_url"
        case fieldValues = "field_values"
    }

    func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(name, forKey: .name)
        try container.encode(brand, forKey: .brand)
        try container.encode(packageSize, forKey: .packageSize)
        try container.encode(packageLabel, forKey: .packageLabel)
        try container.encode(datePrecision, forKey: .datePrecision)
        try container.encode(groupId, forKey: .groupId)
        try container.encode(categoryId, forKey: .categoryId)
        try container.encode(shopId, forKey: .shopId)
        try container.encode(productUrl, forKey: .productUrl)
        // Feldwerte nur senden, wenn gesetzt – sonst nichts an den Feldern ändern.
        if let fieldValues { try container.encode(fieldValues, forKey: .fieldValues) }
    }
}

struct LotUpdateRequest: Codable {
    var quantity: Double?
    var bestBefore: String?
    var bestBeforePrecision: String?

    enum CodingKeys: String, CodingKey {
        case quantity
        case bestBefore = "best_before"
        case bestBeforePrecision = "best_before_precision"
    }
}

/// Ein Eintrag aus /settings (Schluessel/Wert).
struct SettingEntry: Codable {
    let key: String
    let value: String
}

/// Gruppe: fasst Bestaende mehrerer Marken zusammen (z.B. "Mehl").
struct GroupItem: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
}

/// Kategorie: ordnet die Artikelliste und bestimmt die Verwaltungsart
/// ("food"/"object"), verschachtelbar (Suesswaren -> Schokolade).
struct CategoryItem: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
    let parentId: Int?
    let tracking: String?

    enum CodingKeys: String, CodingKey {
        case id, name, tracking
        case parentId = "parent_id"
    }

    var isObject: Bool { tracking == "object" }
}

// MARK: - Hierarchische Stammdaten

/// Gemeinsame Form baumartiger Stammdaten (Kategorien, Lagerorte): eine flache
/// Liste mit Eltern-Verweis, aus der sich der Baum aufbauen lässt.
protocol TreeItem: Identifiable {
    var name: String { get }
    var parentId: ID? { get }
}

extension CategoryItem: TreeItem {}
extension StorageLocation: TreeItem {}

/// Shop / Bezugsquelle fuer Gegenstaende ("gekauft bei").
struct ShopItem: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
    let website: String?
    let productCount: Int?

    enum CodingKeys: String, CodingKey {
        case id, name, website
        case productCount = "product_count"
    }
}

/// Selbst definiertes Feld einer Kategorie (inkl. der geerbten).
struct FieldDefinition: Codable, Identifiable, Hashable {
    let id: Int
    let categoryId: Int
    let label: String
    let key: String
    let fieldType: String
    let unit: String?
    let options: [String]
    let required: Bool
    let position: Int
    let isBuiltin: Bool
    let inherited: Bool

    enum CodingKeys: String, CodingKey {
        case id, label, key, unit, options, required, position, inherited
        case categoryId = "category_id"
        case fieldType = "field_type"
        case isBuiltin = "is_builtin"
    }
}

// MARK: - Gegenstaende: Bestandsbuchungen

struct ObjectCheckInRequest: Codable {
    let productId: Int
    let quantity: Double
    let unit: String
    let locationId: String?

    enum CodingKeys: String, CodingKey {
        case quantity, unit
        case productId = "product_id"
        case locationId = "location_id"
    }
}

struct RelocateRequest: Codable {
    let productId: Int
    let quantity: Double
    let fromLocationId: String?
    let toLocationId: String?

    enum CodingKeys: String, CodingKey {
        case quantity
        case productId = "product_id"
        case fromLocationId = "from_location_id"
        case toLocationId = "to_location_id"
    }
}

struct RemoveRequest: Codable {
    let productId: Int
    let quantity: Double
    let locationId: String?
    let reason: String
    let note: String?

    enum CodingKeys: String, CodingKey {
        case quantity, reason, note
        case productId = "product_id"
        case locationId = "location_id"
    }
}

struct RemovalStat: Codable, Identifiable, Hashable {
    let reason: String
    let quantity: Double
    let count: Int
    var id: String { reason }
}

struct RemovalHistoryItem: Codable, Identifiable, Hashable {
    let reason: String
    let quantity: Double
    let locationId: String?
    let locationName: String?
    let note: String?
    let username: String?
    let createdAt: String
    var id: String { "\(reason)-\(createdAt)-\(quantity)" }

    enum CodingKeys: String, CodingKey {
        case reason, quantity, note, username
        case locationId = "location_id"
        case locationName = "location_name"
        case createdAt = "created_at"
    }
}

struct RemovalSummary: Codable {
    let stats: [RemovalStat]
    let history: [RemovalHistoryItem]
}

/// Anzeige-Bezeichnungen der Entnahmegruende.
enum RemovalReasons {
    static let all: [(value: String, label: String)] = [
        ("broken", "kaputt"),
        ("lost", "verloren"),
        ("given_away", "verschenkt"),
        ("sold", "verkauft"),
        ("used_up", "aufgebraucht"),
        ("other", "sonstiges"),
    ]
    static func label(_ value: String) -> String {
        all.first { $0.value == value }?.label ?? value
    }
}

// MARK: - Einzelstücke (Items mit UID/QR)

struct ItemDocument: Codable, Identifiable, Hashable {
    let id: Int
    let filename: String
    let contentType: String
    let uploadedAt: String

    enum CodingKeys: String, CodingKey {
        case id, filename
        case contentType = "content_type"
        case uploadedAt = "uploaded_at"
    }
}

struct Item: Codable, Identifiable, Hashable {
    let id: Int
    let uid: String
    let productId: Int
    let locationId: String?
    let locationName: String?
    let shopId: Int?
    let shopName: String?
    let acquiredOn: String?      // "yyyy-MM-dd"
    let warrantyUntil: String?
    let note: String?
    let priceCents: Int?
    let currency: String?
    let createdAt: String
    let productName: String?
    let productBrand: String?
    let documents: [ItemDocument]

    enum CodingKeys: String, CodingKey {
        case id, uid, note, currency, documents
        case productId = "product_id"
        case locationId = "location_id"
        case locationName = "location_name"
        case shopId = "shop_id"
        case shopName = "shop_name"
        case acquiredOn = "acquired_on"
        case warrantyUntil = "warranty_until"
        case priceCents = "price_cents"
        case createdAt = "created_at"
        case productName = "product_name"
        case productBrand = "product_brand"
    }
}

/// Antwort nach dem Beleg-Upload – mit den aus dem PDF geschätzten Werten.
/// Aus einem Beleg-PDF geschätzte Werte (Analyse ohne Speichern).
struct DocumentSuggestions: Codable {
    var suggestedWarrantyUntil: String? = nil
    var suggestedPriceCents: Int? = nil
    var suggestedPriceCandidates: [Int] = []
    var suggestedAcquiredOn: String? = nil
    var suggestedShopId: Int? = nil
    var suggestedShopName: String? = nil

    enum CodingKeys: String, CodingKey {
        case suggestedWarrantyUntil = "suggested_warranty_until"
        case suggestedPriceCents = "suggested_price_cents"
        case suggestedPriceCandidates = "suggested_price_candidates"
        case suggestedAcquiredOn = "suggested_acquired_on"
        case suggestedShopId = "suggested_shop_id"
        case suggestedShopName = "suggested_shop_name"
    }

    init() {}

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        suggestedWarrantyUntil = try c.decodeIfPresent(String.self, forKey: .suggestedWarrantyUntil)
        suggestedPriceCents = try c.decodeIfPresent(Int.self, forKey: .suggestedPriceCents)
        suggestedPriceCandidates = try c.decodeIfPresent([Int].self, forKey: .suggestedPriceCandidates) ?? []
        suggestedAcquiredOn = try c.decodeIfPresent(String.self, forKey: .suggestedAcquiredOn)
        suggestedShopId = try c.decodeIfPresent(Int.self, forKey: .suggestedShopId)
        suggestedShopName = try c.decodeIfPresent(String.self, forKey: .suggestedShopName)
    }
}

struct ItemDocumentUpload: Codable {
    let id: Int
    let suggestions: DocumentSuggestions

    enum IdKey: String, CodingKey { case id }

    init(from decoder: Decoder) throws {
        id = try decoder.container(keyedBy: IdKey.self).decode(Int.self, forKey: .id)
        suggestions = try DocumentSuggestions(from: decoder)
    }
}

struct ItemCreateRequest: Codable {
    let count: Int
    let locationId: String?
    let shopId: Int?
    let acquiredOn: String?
    let warrantyUntil: String?
    let note: String?
    var priceCents: Int? = nil
    var currency: String? = nil

    enum CodingKeys: String, CodingKey {
        case count, note, currency
        case locationId = "location_id"
        case shopId = "shop_id"
        case acquiredOn = "acquired_on"
        case warrantyUntil = "warranty_until"
        case priceCents = "price_cents"
    }
}

struct ItemUpdateRequest: Encodable {
    var locationId: String?
    var shopId: Int?
    var acquiredOn: String?
    var warrantyUntil: String?
    var note: String?
    var priceCents: Int?
    var currency: String?

    enum CodingKeys: String, CodingKey {
        case note, currency
        case locationId = "location_id"
        case shopId = "shop_id"
        case acquiredOn = "acquired_on"
        case warrantyUntil = "warranty_until"
        case priceCents = "price_cents"
    }

    // Immer alle Felder senden (auch null), damit sich ein Feld leeren lässt.
    func encode(to encoder: Encoder) throws {
        var c = encoder.container(keyedBy: CodingKeys.self)
        try c.encode(locationId, forKey: .locationId)
        try c.encode(shopId, forKey: .shopId)
        try c.encode(acquiredOn, forKey: .acquiredOn)
        try c.encode(warrantyUntil, forKey: .warrantyUntil)
        try c.encode(note, forKey: .note)
        try c.encode(priceCents, forKey: .priceCents)
        try c.encode(currency, forKey: .currency)
    }
}

struct ItemRemoveRequest: Codable {
    let reason: String
    let note: String?
}

// MARK: - Uebersicht und Verlauf

/// Kennzahlen der Startseite (GET /dashboard/stats).
struct DashboardStats: Codable {
    let productsInStock: Int
    let articleUnits: Double
    let expiringSoon: Int
    let expired: Int
    let shoppingItems: Int
    let productsTotal: Int

    enum CodingKeys: String, CodingKey {
        case productsInStock = "products_in_stock"
        case articleUnits = "article_units"
        case expiringSoon = "expiring_soon"
        case expired
        case shoppingItems = "shopping_items"
        case productsTotal = "products_total"
    }
}

/// Ein Eintrag im Bewegungsverlauf (GET /movements).
struct Movement: Codable, Identifiable, Hashable {
    let id: Int
    let productId: Int
    let productName: String
    /// "in" oder "out"
    let type: String
    /// in Basiseinheiten
    let quantity: Double
    let baseUnit: String
    let unitUsed: String
    let username: String?
    let note: String?
    let createdAt: String
    let packageSize: Double?
    let packageLabel: String?
    let unitName: String
    let unitFactor: Double

    enum CodingKeys: String, CodingKey {
        case id, type, quantity, username, note
        case productId = "product_id"
        case productName = "product_name"
        case baseUnit = "base_unit"
        case unitUsed = "unit_used"
        case createdAt = "created_at"
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case unitName = "unit_name"
        case unitFactor = "unit_factor"
    }

    var isIncoming: Bool { type == "in" }
}

// MARK: - Dashboards

/// Eine Karte auf einem Dashboard.
///
/// `i` ist die Kennung **dieser** Karte, `type` ihre Art - erst dadurch kann
/// dieselbe Art mehrfach auf einem Dashboard liegen. `props` traegt, was nur
/// diese eine Karte angeht (etwa welcher Artikel gemeint ist).
struct DashboardCard: Codable, Identifiable, Hashable {
    let i: String
    let type: String
    let x: Int
    let y: Int
    let w: Int
    let h: Int
    let tage: Int?
    let props: CardProps?

    var id: String { i }

    /// Nur die Felder, die die App auswertet. Die Rasterangaben kommen aus der
    /// Web-Oberflaeche; hier bestimmen sie allein die Reihenfolge.
    struct CardProps: Codable, Hashable {
        let productId: Int?

        enum CodingKeys: String, CodingKey {
            case productId = "product_id"
        }
    }
}

struct Dashboard: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
    let position: Int
    let layout: [DashboardCard]
}

struct DashboardList: Codable {
    let dashboards: [Dashboard]
    let source: String
    let enforced: Bool
    let hasDefault: Bool

    enum CodingKeys: String, CodingKey {
        case dashboards, source, enforced
        case hasDefault = "has_default"
    }
}

// MARK: - Diagrammdaten (Übersicht)

/// Artikeleinheiten je Ablaufzustand (GET /dashboard/expiry-split).
struct ExpirySplit: Codable {
    let ok: Double
    let soon: Double
    let expired: Double
    let noDate: Double

    enum CodingKeys: String, CodingKey {
        case ok, soon, expired
        case noDate = "no_date"
    }
}

/// Anteil einer Kategorie am Bestand (GET /dashboard/by-category).
struct CategoryShare: Codable, Identifiable {
    let categoryId: Int?
    let name: String
    let articleUnits: Double
    let ok: Double
    let soon: Double
    let expired: Double
    let noDate: Double

    var id: Int { categoryId ?? -1 }

    enum CodingKeys: String, CodingKey {
        case name, ok, soon, expired
        case categoryId = "category_id"
        case articleUnits = "article_units"
        case noDate = "no_date"
    }
}

/// Ein Punkt des Bestandsverlaufs (GET /dashboard/timeline).
struct TimelinePoint: Codable, Identifiable {
    let at: String
    let articleUnits: Double

    var id: String { at }

    enum CodingKeys: String, CodingKey {
        case at
        case articleUnits = "article_units"
    }
}

/// Ein- und Auslagerungen je Zeitpunkt (GET /dashboard/activity).
struct ActivityPoint: Codable, Identifiable {
    let at: String
    let checkedIn: Int
    let checkedOut: Int

    var id: String { at }

    enum CodingKeys: String, CodingKey {
        case at
        case checkedIn = "checked_in"
        case checkedOut = "checked_out"
    }
}

// MARK: - Stammdaten

/// Gebinde (Packung, Glas, ...) mit Einzahl und Mehrzahl.
struct PackageType: Codable, Identifiable, Hashable {
    let id: Int
    let singular: String
    let plural: String
    let isBuiltin: Bool

    enum CodingKeys: String, CodingKey {
        case id, singular, plural
        case isBuiltin = "is_builtin"
    }
}

struct NewLocationRequest: Codable {
    let name: String
    let parentId: String?

    enum CodingKeys: String, CodingKey {
        case name
        case parentId = "parent_id"
    }
}

/// Lagerort umbenennen und/oder umhängen. `parentId` wird bewusst immer gesendet
/// (auch `null` = oberste Ebene), damit „auf oberste Ebene holen" ankommt.
struct LocationUpdateRequest: Codable {
    let name: String
    let parentId: String?

    enum CodingKeys: String, CodingKey {
        case name
        case parentId = "parent_id"
    }

    func encode(to encoder: Encoder) throws {
        var c = encoder.container(keyedBy: CodingKeys.self)
        try c.encode(name, forKey: .name)
        try c.encode(parentId, forKey: .parentId)  // encodet null bei nil
    }
}

/// Eigenes Feld einer Kategorie anlegen. `unit`/`options` werden immer
/// mitgeschickt; der Server ignoriert sie bei unpassendem Typ.
struct FieldDefinitionCreate: Codable {
    let categoryId: Int
    let label: String
    let fieldType: String
    let unit: String
    let options: [String]
    let required: Bool

    enum CodingKeys: String, CodingKey {
        case label, unit, options, required
        case categoryId = "category_id"
        case fieldType = "field_type"
    }
}

struct FieldDefinitionUpdate: Codable {
    let label: String
    let fieldType: String
    let unit: String
    let options: [String]
    let required: Bool

    enum CodingKeys: String, CodingKey {
        case label, unit, options, required
        case fieldType = "field_type"
    }
}

struct NewUnitRequest: Codable {
    let name: String
    let kind: String
    let factor: Double
}

struct NewPackageTypeRequest: Codable {
    let singular: String
    let plural: String
}

struct NewCategoryRequest: Codable {
    let name: String
    let parentId: Int?
    var tracking: String? = nil

    enum CodingKeys: String, CodingKey {
        case name, tracking
        case parentId = "parent_id"
    }
}

struct CategoryUpdateRequest: Codable {
    let name: String?
    let tracking: String?
}

struct NewShopRequest: Codable {
    let name: String
    let website: String?
}

struct ShopUpdateRequest: Codable {
    let name: String?
    let website: String?
}

/// Umbenennen von Stammdaten. Ein einzelnes Feld reicht, weil das Backend nur
/// mitgeschickte Schluessel auswertet.
struct RenameRequest: Codable {
    let name: String
}

struct PackageTypeUpdateRequest: Codable {
    let singular: String
    let plural: String
}

/// Neue Gruppe anlegen (nur fuer Administratoren).
struct NewGroupRequest: Codable {
    let name: String
    let minStock: Double?
    let minStockUnitId: Int?

    enum CodingKeys: String, CodingKey {
        case name
        case minStock = "min_stock"
        case minStockUnitId = "min_stock_unit_id"
    }
}