import Foundation public struct ProviderTokenAccount: Codable, Identifiable, Sendable {    public let id: UUID    public let label: String    public let token: String    public let addedAt: TimeInterval    public let lastUsed: TimeInterval?     public init(id: UUID, label: String, token: String, addedAt: TimeInterval, lastUsed: TimeInterval?) {        self.id = id        self.label = label        self.token = token        self.addedAt = addedAt        self.lastUsed = lastUsed    }     public var displayName: String {        self.label    }} public struct ProviderTokenAccountData: Codable, Sendable {    public let version: Int    public let accounts: [ProviderTokenAccount]    public let activeIndex: Int     public init(version: Int, accounts: [ProviderTokenAccount], activeIndex: Int) {        self.version = version        self.accounts = accounts        self.activeIndex = activeIndex    }     public func clampedActiveIndex() -> Int {        guard !self.accounts.isEmpty else { return 0 }        return min(max(self.activeIndex, 0), self.accounts.count - 1)    }} private struct ProviderTokenAccountsFile: Codable {    let version: Int    let providers: [String: ProviderTokenAccountData]} public protocol ProviderTokenAccountStoring: Sendable {    func loadAccounts() throws -> [UsageProvider: ProviderTokenAccountData]    func storeAccounts(_ accounts: [UsageProvider: ProviderTokenAccountData]) throws    func ensureFileExists() throws -> URL} public struct FileTokenAccountStore: ProviderTokenAccountStoring, @unchecked Sendable {    private let fileURL: URL    private let fileManager: FileManager     public init(fileURL: URL = Self.defaultURL(), fileManager: FileManager = .default) {        self.fileURL = fileURL        self.fileManager = fileManager    }     public func loadAccounts() throws -> [UsageProvider: ProviderTokenAccountData] {        guard self.fileManager.fileExists(atPath: self.fileURL.path) else { return [:] }        let data = try Data(contentsOf: self.fileURL)        let decoder = JSONDecoder()        let decoded = try decoder.decode(ProviderTokenAccountsFile.self, from: data)        var result: [UsageProvider: ProviderTokenAccountData] = [:]        for (key, value) in decoded.providers {            guard let provider = UsageProvider(rawValue: key) else { continue }            result[provider] = value        }        return result    }     public func storeAccounts(_ accounts: [UsageProvider: ProviderTokenAccountData]) throws {        let payload = ProviderTokenAccountsFile(            version: 1,            providers: Dictionary(uniqueKeysWithValues: accounts.map { ($0.key.rawValue, $0.value) }))        let encoder = JSONEncoder()        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]        let data = try encoder.encode(payload)        let directory = self.fileURL.deletingLastPathComponent()        if !self.fileManager.fileExists(atPath: directory.path) {            try self.fileManager.createDirectory(at: directory, withIntermediateDirectories: true)        }        try data.write(to: self.fileURL, options: [.atomic])        try self.applySecurePermissionsIfNeeded()    }     public func ensureFileExists() throws -> URL {        if self.fileManager.fileExists(atPath: self.fileURL.path) { return self.fileURL }        try self.storeAccounts([:])        return self.fileURL    }     private func applySecurePermissionsIfNeeded() throws {        #if os(macOS)        try self.fileManager.setAttributes([            .posixPermissions: NSNumber(value: Int16(0o600)),        ], ofItemAtPath: self.fileURL.path)        #endif    }     public static func defaultURL() -> URL {        let base = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask).first            ?? FileManager.default.homeDirectoryForCurrentUser        return base            .appendingPathComponent("CodexBar", isDirectory: true)            .appendingPathComponent("token-accounts.json")    }}