import XCTest
@testable import AIStudyApp

final class AppContextTests: XCTestCase {

    func test_appContext_platform_is_ios_or_ipados() {
        let ctx = AppContext.testValue()
        XCTAssertTrue(ctx.platform == "ios" || ctx.platform == "ipadOS",
                      "platform should be ios or ipadOS, got \(ctx.platform)")
    }

    func test_appContext_appVersion_notEmpty() {
        let ctx = AppContext.testValue()
        XCTAssertFalse(ctx.appVersion.isEmpty, "appVersion should not be empty")
    }

    func test_appContext_buildNumber_notEmpty() {
        let ctx = AppContext.testValue()
        XCTAssertFalse(ctx.buildNumber.isEmpty, "buildNumber should not be empty")
    }

    func test_appContext_timezoneOffset_isWithinRange() {
        let ctx = AppContext.testValue()
        // Valid range: -720 (UTC-12) to +840 (UTC+14)
        XCTAssertGreaterThanOrEqual(ctx.clientTimezoneOffsetMinutes, -720)
        XCTAssertLessThanOrEqual(ctx.clientTimezoneOffsetMinutes, 840)
    }

    func test_appContext_refreshed_updates_timezone() {
        var ctx = AppContext.testValue()
        ctx.clientTimezoneOffsetMinutes = 0
        let refreshed = ctx.refreshed()
        // refreshed should update from current timezone
        let expected = TimeZone.current.secondsFromGMT() / 60
        XCTAssertEqual(refreshed.clientTimezoneOffsetMinutes, expected)
    }

    func test_appContext_codable_roundtrip() throws {
        let ctx = AppContext(
            platform: "ios",
            appVersion: "1.2.3",
            buildNumber: "42",
            clientTimezoneOffsetMinutes: 480,
            locale: "zh-Hans_CN",
            deviceType: "phone",
            osVersion: "18.0"
        )
        let data = try JSONEncoder().encode(ctx)
        let decoded = try JSONDecoder().decode(AppContext.self, from: data)
        XCTAssertEqual(decoded.platform, "ios")
        XCTAssertEqual(decoded.appVersion, "1.2.3")
        XCTAssertEqual(decoded.buildNumber, "42")
        XCTAssertEqual(decoded.clientTimezoneOffsetMinutes, 480)
        XCTAssertEqual(decoded.locale, "zh-Hans_CN")
        XCTAssertEqual(decoded.deviceType, "phone")
        XCTAssertEqual(decoded.osVersion, "18.0")
    }

    func test_appContext_equatable() {
        let a = AppContext.testValue()
        let b = a
        XCTAssertEqual(a, b)
    }

    func test_appContext_no_token_field() {
        let ctx = AppContext.testValue()
        let mirror = Mirror(reflecting: ctx)
        let children = mirror.children.map { $0.label ?? "" }
        let hasToken = children.contains { $0.lowercased().contains("token") }
        XCTAssertFalse(hasToken, "AppContext should not contain token fields")
    }

    func test_appContext_no_privacy_field() {
        let ctx = AppContext.testValue()
        let mirror = Mirror(reflecting: ctx)
        let children = mirror.children.map { $0.label ?? "" }
        let privacyFields = ["idfa", "idfv", "advertising", "pushToken", "deviceId"]
        for field in privacyFields {
            let found = children.contains { $0.lowercased().contains(field.lowercased()) }
            XCTAssertFalse(found, "AppContext should not contain \(field)")
        }
    }
}

// MARK: - Test Helper

extension AppContext {
    static func testValue() -> Self {
        AppContext(
            platform: "ios",
            appVersion: Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "0.0.0",
            buildNumber: Bundle.main.object(forInfoDictionaryKey: "CFBundleVersion") as? String ?? "0",
            clientTimezoneOffsetMinutes: TimeZone.current.secondsFromGMT() / 60,
            locale: Locale.current.identifier,
            deviceType: "phone",
            osVersion: UIDevice.current.systemVersion
        )
    }
}