import Foundation

@dynamicMemberLookup
public struct Nutriments: Codable, Sendable {
	private var storage: [String: Double]

	public init(from decoder: Decoder) throws {
		let container = try decoder.container(keyedBy: AnyCodingKey.self)
		var dict = [String: Double]()
		for key in container.allKeys {
			if let val = try? container.decode(Double.self, forKey: key) {
				dict[key.stringValue] = val
			} else if let valStr = try? container.decode(
				String.self, forKey: key), let val = Double(valStr)
			{
				dict[key.stringValue] = val
			}
		}
		self.storage = dict
	}

	public func encode(to encoder: Encoder) throws {
		var container = encoder.container(keyedBy: AnyCodingKey.self)
		for (key, value) in storage {
			try container.encode(value, forKey: AnyCodingKey(stringValue: key))
		}
	}

	/// Access any nutrient dynamically (e.g. `nutriments.energyKcal`)
	public subscript(dynamicMember member: String) -> Double? {
		// Convert camelCase "energyKcal" to snake_case "energy-kcal" or "energy_kcal" logic if needed
		// For V2, OFF often returns "energy-kcal_100g"
		let snake = member.camelCaseToSnakeCase()
		return storage[snake] ?? storage["\(snake)_100g"]
			?? storage["\(snake)_value"]
	}

	// Specific standard getters
	public var energyKcal: Double? { self.storage["energy-kcal_100g"] }
	public var carbohydrates: Double? { self.storage["carbohydrates_100g"] }
	public var fat: Double? { self.storage["fat_100g"] }
	public var proteins: Double? { self.storage["proteins_100g"] }
	public var salt: Double? { self.storage["salt_100g"] }
}

// Helper for String extension used above
struct AnyCodingKey: CodingKey {
	var stringValue: String
	var intValue: Int?
	init(stringValue: String) { self.stringValue = stringValue }
	init?(intValue: Int) { return nil }
}