import Foundation

// MARK: - System info data models (read-only, no TCC)

struct SystemInfoItem: Codable, Equatable, Sendable {
    let macos_version: String
    let build: String?
    let uname: String?
    let hw_model: String?
    let cpu_brand: String?
    let is_macos_26_plus: Bool?
    let speech_analyzer_expected: String?
}

struct SpeechApiStatusItem: Codable, Equatable, Sendable {
    let system: SystemInfoItem
    let swift_availability: [String: String]? // minimal stub
    let conclusion: String
}

enum SystemProviderError: Error, Equatable, Sendable {
    case unavailable(String)
}

protocol SystemInfoProviding: Sendable {
    func getSystemInfo() throws -> SystemInfoItem
    func getSpeechApiStatus() throws -> SpeechApiStatusItem
}

// Production provider - reads sw_vers / uname / sysctl, no permission needed
struct ProductionSystemInfoProvider: SystemInfoProviding {
    func getSystemInfo() throws -> SystemInfoItem {
        let ver = ProcessInfo.processInfo.operatingSystemVersion
        let verString = "\(ver.majorVersion).\(ver.minorVersion).\(ver.patchVersion)"
        // Best-effort hw model / cpu / uname without spawning processes in Swift? Use sysctl/mib.
        var hwModel: String? = nil
        var cpuBrand: String? = nil
        var unameStr: String? = nil
        // Use ProcessInfo hostName as fallback for minimal
        // For hw.model, use sysctlbyname where possible - but keep simple fallback to avoid C interop complexity
        // We'll try reading via sysctl nametable via Foundation
        #if os(macOS)
        hwModel = sysctlString("hw.model")
        cpuBrand = sysctlString("machdep.cpu.brand_string")
        #endif
        let m = ver.majorVersion
        let is26 = m >= 26
        let expected = is26 ? "likely available (macOS 26+)" : "not available - requires macOS 26+"
        return SystemInfoItem(
            macos_version: verString,
            build: nil,
            uname: unameStr,
            hw_model: hwModel,
            cpu_brand: cpuBrand,
            is_macos_26_plus: is26,
            speech_analyzer_expected: expected
        )
    }

    func getSpeechApiStatus() throws -> SpeechApiStatusItem {
        let info = try getSystemInfo()
        let major = ProcessInfo.processInfo.operatingSystemVersion.majorVersion
        let conclusion: String
        if major >= 26 {
            conclusion = "macOS 26+ detected — SpeechAnalyzer/SpeechTranscriber should be available per Apple docs."
        } else {
            conclusion = "macOS \(info.macos_version) detected — SpeechAnalyzer requires macOS 26+."
        }
        return SpeechApiStatusItem(system: info, swift_availability: nil, conclusion: conclusion)
    }

    private func sysctlString(_ name: String) -> String? {
        var size = 0
        let rc1 = sysctlbyname(name, nil, &size, nil, 0)
        if rc1 != 0 { return nil }
        var buffer = [CChar](repeating: 0, count: size)
        let rc2 = sysctlbyname(name, &buffer, &size, nil, 0)
        if rc2 != 0 { return nil }
        return String(cString: buffer)
    }
}