import XCTest
@testable import PureMac

final class AppLanguagePreferencesTests: XCTestCase {
    func testApplyCustomLanguageSetsAppleLanguagesAndPreservesLocale() {
        let context = makeDefaults()
        let defaults = context.defaults
        defaults.set("pt_BR", forKey: "AppleLocale")

        AppLanguagePreferences.apply(.english, defaults: defaults)

        XCTAssertEqual(defaults.array(forKey: "AppleLanguages") as? [String], ["en"])
        XCTAssertEqual(defaults.string(forKey: "AppleLocale"), "pt_BR")
    }

    func testApplySystemLanguageRemovesAppleLanguagesAndPreservesLocale() {
        let context = makeDefaults()
        let defaults = context.defaults
        defaults.set(["en"], forKey: "AppleLanguages")
        defaults.set("pt_BR", forKey: "AppleLocale")

        AppLanguagePreferences.apply(.system, defaults: defaults)

        XCTAssertNil(defaults.persistentDomain(forName: context.suiteName)?["AppleLanguages"])
        XCTAssertEqual(defaults.string(forKey: "AppleLocale"), "pt_BR")
    }

    private func makeDefaults() -> (defaults: UserDefaults, suiteName: String) {
        let suiteName = "PureMacTests.AppLanguagePreferences.\(UUID().uuidString)"
        let defaults = UserDefaults(suiteName: suiteName)!
        defaults.removePersistentDomain(forName: suiteName)
        return (defaults, suiteName)
    }
}