import XCTest

/// 向后导航和显示模式切换测试
/// 覆盖：向右滑动回到上一页、阅读中途切换显示模式
final class NavigationBackwardTests: XCTestCase {

    private let app = XCUIApplication()

    override func setUpWithError() throws {
        continueAfterFailure = false
    }

    /// 向右滑动应返回上一页
    func testSwipeRightGoesToPreviousPage() throws {
        app.launchAndOpenSampleBook()
        app.waitForReader()

        // 先向左滑动两次前进
        let content = app.otherElements[IDs.readerContent].firstMatch
        guard content.waitForExistence(timeout: 5) else {
            throw XCTSkip("内容区域不存在")
        }

        content.swipeLeft()
        Thread.sleep(forTimeInterval: 0.5)
        content.swipeLeft()
        Thread.sleep(forTimeInterval: 0.5)

        // 记录当前页码
        let stateAfterForward = app.waitForDemoReaderState(timeout: 5, description: "page after forward") {
            ($0.page ?? 0) > 1
        }
        let pageAfterForward = stateAfterForward.page ?? 2
        XCTAssertGreaterThan(pageAfterForward, 1, "应已前进到第 2 页或更后")

        // 向右滑动返回
        content.swipeRight()
        Thread.sleep(forTimeInterval: 0.5)

        // 验证页码减少
        let stateAfterBack = app.waitForDemoReaderState(timeout: 5, description: "page after back") {
            ($0.page ?? 0) < pageAfterForward
        }
        XCTAssertLessThan(stateAfterBack.page ?? 0, pageAfterForward, "向右滑动后页码应减少")
    }

    /// 阅读中途切换显示模式
    func testDisplayTypeSwitchMidSession() throws {
        app.launchAndOpenSampleBook(displayType: "horizontalScroll")
        app.waitForReader()

        // 确认初始模式
        app.waitForDemoReaderState(timeout: 5, description: "initial horizontalScroll") {
            $0.display == "horizontalScroll"
        }

        // 打开设置面板
        app.showReaderChromeIfNeeded()
        let settingsButton = app.buttons[IDs.readerSettings]
        guard settingsButton.waitForExistence(timeout: 3) else {
            throw XCTSkip("设置按钮不存在")
        }
        settingsButton.tap()

        // 切换到垂直滚动
        let displayTypeButton = app.buttons[IDs.settingsDisplayType]
        guard displayTypeButton.waitForExistence(timeout: 3) else {
            throw XCTSkip("显示模式按钮不存在")
        }
        displayTypeButton.tap()

        // 关闭设置
        let doneButton = app.buttons[IDs.settingsDone]
        if doneButton.waitForExistence(timeout: 3) {
            doneButton.tap()
        }

        // 验证显示模式已切换
        app.waitForDemoReaderState(timeout: 5, description: "switched to verticalScroll") {
            $0.display == "verticalScroll"
        }
    }
}