import Darwin
import Foundation
import IOKit

enum Sysctl {
    static func int(_ name: String) -> Int? {
        var value: Int64 = 0
        var size = MemoryLayout<Int64>.size
        guard sysctlbyname(name, &value, &size, nil, 0) == 0 else { return nil }
        // 32 位值只写入低 4 字节
        return size == MemoryLayout<Int32>.size ? Int(Int32(truncatingIfNeeded: value)) : Int(value)
    }

    static func string(_ name: String) -> String? {
        var size = 0
        guard sysctlbyname(name, nil, &size, nil, 0) == 0, size > 0 else { return nil }
        var buffer = [CChar](repeating: 0, count: size)
        guard sysctlbyname(name, &buffer, &size, nil, 0) == 0 else { return nil }
        return String(nullTerminated: buffer)
    }
}

enum IORegistry {
    static func property(_ service: io_registry_entry_t, _ key: String) -> Any? {
        IORegistryEntryCreateCFProperty(service, key as CFString, kCFAllocatorDefault, 0)?.takeRetainedValue()
    }

    static func string(fromData value: Any?) -> String? {
        guard let data = value as? Data else { return value as? String }
        return String(decoding: data.prefix { $0 != 0 }, as: UTF8.self)
    }
}

extension String {
    init(nullTerminated buffer: [CChar]) {
        self = String(decoding: buffer.prefix { $0 != 0 }.map { UInt8(bitPattern: $0) }, as: UTF8.self)
    }
}