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
}

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?

    enum CodingKeys: String, CodingKey {
        case id, barcode, name, brand, stock, kind, barcodes
        case datePrecision = "date_precision"
        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"
    }

    /// 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 }
}

/// 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?
    let groupId: Int?
    let groupName: String?

    enum CodingKeys: String, CodingKey {
        case found, suggestion
        case existingProduct = "existing_product"
        case groupId = "group_id"
        case groupName = "group_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: Int?

    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: Int
    let name: String
    let parentId: Int?

    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: Int?

    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?

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

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?
    /// Kategorie (heisst in der API weiterhin group_id).
    var groupId: Int?

    enum CodingKeys: String, CodingKey {
        case name, brand
        case packageSize = "package_size"
        case packageLabel = "package_label"
        case datePrecision = "date_precision"
        case groupId = "group_id"
    }

    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)
    }
}

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
}

/// Kategorie (heisst in der Datenbank und in der API weiterhin "group";
/// nur die Beschriftung in der Oberflaeche wurde auf "Kategorie" geaendert).
struct GroupItem: Codable, Identifiable, Hashable {
    let id: Int
    let name: String
}