import Foundation
import Security

final class AppSettings: @unchecked Sendable {
    static let shared = AppSettings()
    private let defaults = UserDefaults.standard

    var localBinaryPath: String {
        get { defaults.string(forKey: "localBinaryPath") ?? "\(NSHomeDirectory())/Library/Application Support/WhisperKey/whisper-cli" }
        set { defaults.set(newValue, forKey: "localBinaryPath") }
    }
    var localModelPath: String {
        get { defaults.string(forKey: "localModelPath") ?? "\(NSHomeDirectory())/Library/Application Support/WhisperKey/ggml-large-v3-turbo.bin" }
        set { defaults.set(newValue, forKey: "localModelPath") }
    }
    var glossary: String {
        get { defaults.string(forKey: "glossary") ?? "CampusAgro, PocketBase, Caddy, SvelteKit, Bitrix, Hetzner, Timeweb, OpenAI, Codex, Claude, VLESS, Reality, Hiddify, CNS8000D, RX8000, RX8500, BX8000, BX8500, BX8500S" }
        set { defaults.set(newValue, forKey: "glossary") }
    }
    var removeFillers: Bool {
        get { defaults.object(forKey: "removeFillers") as? Bool ?? true }
        set { defaults.set(newValue, forKey: "removeFillers") }
    }
    var cloudModel: String {
        get { defaults.string(forKey: "cloudModel") ?? "gpt-4o-transcribe" }
        set { defaults.set(newValue, forKey: "cloudModel") }
    }

    func apiKey() -> String? { KeychainStore.read(account: "openai-api-key") }
    func saveAPIKey(_ value: String) throws { try KeychainStore.write(value, account: "openai-api-key") }
}

enum KeychainStore {
    private static let service = "com.romanv.WhisperKey"

    static func write(_ value: String, account: String) throws {
        let data = Data(value.utf8)
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
        ]
        SecItemDelete(query as CFDictionary)
        var add = query
        add[kSecValueData as String] = data
        let status = SecItemAdd(add as CFDictionary, nil)
        guard status == errSecSuccess else { throw WhisperKeyError.processFailed("Keychain: \(status)") }
    }

    static func read(account: String) -> String? {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
            kSecReturnData as String: true,
            kSecMatchLimit as String: kSecMatchLimitOne,
        ]
        var item: CFTypeRef?
        guard SecItemCopyMatching(query as CFDictionary, &item) == errSecSuccess,
              let data = item as? Data else { return nil }
        return String(data: data, encoding: .utf8)
    }
}