import XCTest

/// 固定布局（pre-paginated）书籍的旋转回归：
/// 每次旋转会使预加载缓存签名失效并批量丢弃 WKWebView 页面，
/// 历史上曾因 script message handler 保留环导致 WebView 泄漏累积，
/// 多次旋转后在 CA commit 阶段 abort（CA::Render::Encoder::grow）。
final class FixedLayoutRotationTests: XCTestCase {
    private let app = XCUIApplication()

    override func setUpWithError() throws {
        continueAfterFailure = false
        XCUIDevice.shared.orientation = .portrait
    }

    override func tearDownWithError() throws {
        XCUIDevice.shared.orientation = .portrait
    }

    func testFixedLayoutBookSurvivesRepeatedRotation() {
        app.launchAndOpenSampleBook(bookTitleQuery: "熊爷爷")
        app.waitForReader()

        for _ in 0..<3 {
            XCUIDevice.shared.orientation = .landscapeLeft
            RunLoop.current.run(until: Date().addingTimeInterval(2))
            let landscapeState = app.waitForDemoReaderState(
                timeout: 5,
                description: "固定版式横屏保持单页"
            ) { $0.pagesPerScreen == 1 }
            XCTAssertEqual(landscapeState.pagesPerScreen, 1, "交互型固定版式书横屏不应启用双页")
            XCUIDevice.shared.orientation = .portrait
            RunLoop.current.run(until: Date().addingTimeInterval(2))
        }

        XCTAssertEqual(app.state, .runningForeground, "反复旋转后 app 已退出（疑似崩溃）")
        app.waitForReader()
    }

    /// PDF 手机横屏必须在旋转完成的第一轮布局中立即成为全宽单页。
    /// 过去 flow layout 继续使用竖屏 itemSize，导致横屏首帧并排露出两页，
    /// 只有点击触发下一轮布局后才恢复。
    func testPDFLandscapeImmediatelyUsesSingleFullWidthPage() {
        app.launchAndOpenSampleBook(
            bookTitleQuery: "英汉大词典",
            displayType: "pagecurl"
        )
        app.waitForReader()

        XCUIDevice.shared.orientation = .landscapeLeft

        let content = app.otherElements[IDs.readerContent].firstMatch
        XCTAssertTrue(content.waitForExistence(timeout: 8), "PDF 阅读区域未出现")
        let deadline = Date().addingTimeInterval(8)
        while Date() < deadline {
            let windowWidth = app.windows.firstMatch.frame.width
            if windowWidth > 0, abs(content.frame.width - windowWidth) <= 1 {
                break
            }
            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
        }

        // 等待旋转动画和 PDF 页异步配置完成，避免只验证到过渡中的短暂正确状态。
        RunLoop.current.run(until: Date().addingTimeInterval(1.5))

        let windowFrame = app.windows.firstMatch.frame
        XCTAssertGreaterThan(windowFrame.width, windowFrame.height, "设备没有进入横屏")
        XCTAssertEqual(content.frame.width, windowFrame.width, accuracy: 1, "横屏首帧仍在使用竖屏页面宽度")
        // 横屏单页按宽度适配：cell 高度是纸张按全宽换算的实际高度，竖版纸张
        // 高于一屏，纵向超出部分由阅读器连续竖滑承接，因此不再等于窗口高度。
        XCTAssertGreaterThanOrEqual(
            content.frame.height,
            windowFrame.height - 1,
            "横屏单页高度应不小于一屏（宽度适配后的纸张高度）"
        )
    }

    func testFixedLayoutCachedPageCanReturnAfterPageTurn() {
        app.launchAndOpenSampleBook(bookTitleQuery: "熊爷爷")
        app.waitForReader()

        let content = app.otherElements[IDs.readerContent]
        XCTAssertTrue(content.waitForExistence(timeout: 5), "固定版式阅读区域未出现")
        let initialState = app.waitForDemoReaderState(timeout: 5, description: "固定版式初始页") {
            $0.page != nil
        }
        let initialPage = initialState.page ?? 0

        content.swipeLeft()
        let nextState = app.waitForDemoReaderState(timeout: 8, description: "固定版式向后翻页") { state in
            guard let page = state.page else { return false }
            return page != initialPage
        }

        content.swipeRight()
        let returnedState = app.waitForDemoReaderState(timeout: 8, description: "固定版式返回缓存页") {
            $0.page == initialPage
        }
        XCTAssertNotEqual(nextState.page, returnedState.page, "固定版式返回缓存页后页码未恢复")
        XCTAssertTrue(content.exists, "返回缓存页后阅读区域不应消失")
    }
}