import XCTest

/// 画笔面板打开时，工具未选中应保留手机横屏单页的连续竖滑；
/// 选中任一绘图工具后，单指手势只能用于绘制，不能触发阅读器滚动。
final class PDFDrawingModeTests: XCTestCase {
    private let app = XCUIApplication()

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

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

    func testLandscapeSinglePageScrollsOnlyWhenDrawingToolIsDeselected() {
        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 横屏阅读页面未出现")
        XCTAssertTrue(waitForLandscapeLayout(), "PDF 未进入横屏单页布局")

        app.showReaderChromeIfNeeded(requiredButtonIDs: [IDs.pdfDrawing])
        let drawing = app.buttons[IDs.pdfDrawing]
        XCTAssertTrue(drawing.waitForExistence(timeout: 5), "画笔入口未出现")
        drawing.tap()

        let pen = app.buttons[IDs.pdfDrawingPen]
        let eraser = app.buttons[IDs.pdfDrawingEraser]
        XCTAssertTrue(pen.waitForExistence(timeout: 5), "画笔工具未出现")
        XCTAssertTrue(eraser.exists, "橡皮擦工具未出现")

        let firstScrollablePage = app.currentDemoReaderState()?.page
        XCTAssertNotNil(firstScrollablePage, "未取得初始 PDF 页码")
        guard let firstScrollablePage else { return }
        XCTAssertTrue(
            scrollToAnotherPage(content, from: firstScrollablePage),
            "未选中工具时，手机横屏单页无法连续竖滑"
        )

        let lockedPage = app.currentDemoReaderState()?.page
        XCTAssertNotNil(lockedPage, "滚动后未取得 PDF 页码")
        guard let lockedPage else { return }

        pen.tap()
        assertPageRemains(lockedPage, afterSwiping: content, message: "选中画笔后仍触发了页面滚动")

        eraser.tap()
        assertPageRemains(lockedPage, afterSwiping: content, message: "切换至橡皮擦后仍触发了页面滚动")

        eraser.tap()
        XCTAssertTrue(
            scrollToAnotherPage(content, from: lockedPage),
            "取消橡皮擦选中后，手机横屏单页没有恢复连续竖滑"
        )
    }

    /// 放大状态下同一规则：未选中工具单指拖动画面，选中画笔后单指只用于绘制。
    func testZoomedPageDragsOnlyWhenDrawingToolIsDeselected() {
        app.launchAndOpenSampleBook(bookTitleQuery: "英汉大词典", displayType: "pagecurl")
        app.waitForReader()

        let content = app.otherElements[IDs.readerContent].firstMatch
        XCTAssertTrue(content.waitForExistence(timeout: 8), "PDF 阅读页面未出现")

        app.showReaderChromeIfNeeded(requiredButtonIDs: [IDs.pdfDrawing])
        let drawing = app.buttons[IDs.pdfDrawing]
        XCTAssertTrue(drawing.waitForExistence(timeout: 5), "画笔入口未出现")
        drawing.tap()

        let pen = app.buttons[IDs.pdfDrawingPen]
        XCTAssertTrue(pen.waitForExistence(timeout: 5), "画笔工具未出现")

        // 未选中工具 → 双指放大
        content.pinch(withScale: 2.5, velocity: 1)
        RunLoop.current.run(until: Date().addingTimeInterval(1.0))
        let zoomedFrame = content.frame
        XCTAssertGreaterThan(zoomedFrame.width, app.windows.firstMatch.frame.width * 1.2, "画笔面板打开时无法双指放大页面")

        // 未选中工具 → 单指拖动应移动页面
        let start = content.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5))
        let end = content.coordinate(withNormalizedOffset: CGVector(dx: 0.3, dy: 0.3))
        start.press(forDuration: 0.05, thenDragTo: end)
        RunLoop.current.run(until: Date().addingTimeInterval(0.8))
        let draggedFrame = content.frame
        XCTAssertNotEqual(draggedFrame.origin, zoomedFrame.origin, "未选中工具时，放大页面无法单指拖动")

        // 选中画笔 → 单指应绘制而非拖动
        pen.tap()
        let frameBeforeStroke = content.frame
        let strokeStart = content.coordinate(withNormalizedOffset: CGVector(dx: 0.45, dy: 0.45))
        let strokeEnd = content.coordinate(withNormalizedOffset: CGVector(dx: 0.6, dy: 0.6))
        strokeStart.press(forDuration: 0.05, thenDragTo: strokeEnd)
        RunLoop.current.run(until: Date().addingTimeInterval(0.8))
        XCTAssertEqual(content.frame.origin, frameBeforeStroke.origin, "选中画笔后，单指仍拖动了放大页面而不是绘制")
    }

    private func waitForLandscapeLayout() -> Bool {
        let deadline = Date().addingTimeInterval(8)
        while Date() < deadline {
            let frame = app.windows.firstMatch.frame
            if frame.width > frame.height { return true }
            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
        }
        return false
    }

    private func scrollToAnotherPage(_ content: XCUIElement, from page: Int) -> Bool {
        let window = app.windows.firstMatch
        for _ in 0..<5 {
            // 从屏幕上半部拖动，避开底部画笔工具条区域。
            let start = window.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.35))
            let end = window.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.05))
            start.press(forDuration: 0.05, thenDragTo: end, withVelocity: .fast, thenHoldForDuration: 0)
            let deadline = Date().addingTimeInterval(1.5)
            while Date() < deadline {
                if let current = app.currentDemoReaderState()?.page, current != page { return true }
                RunLoop.current.run(until: Date().addingTimeInterval(0.1))
            }
        }
        return false
    }

    private func assertPageRemains(_ page: Int, afterSwiping content: XCUIElement, message: String) {
        for _ in 0..<3 { content.swipeUp() }
        RunLoop.current.run(until: Date().addingTimeInterval(0.8))
        XCTAssertEqual(app.currentDemoReaderState()?.page, page, message)
    }
}