import XCTest

final class ReaderToolbarTests: XCTestCase {
    private let app = XCUIApplication()

    override func setUpWithError() throws {
        continueAfterFailure = false
    }

    func testTapCenterShowsToolbars() {
        app.launchAndOpenSampleBook()
        app.waitForReader()

        app.showReaderChromeIfNeeded()

        XCTAssertTrue(app.otherElements[IDs.readerTopToolbar].waitForExistence(timeout: 5))
        XCTAssertTrue(app.otherElements[IDs.readerBottomToolbar].waitForExistence(timeout: 5))
        XCTAssertTrue(app.buttons[IDs.readerBack].exists)
        XCTAssertTrue(app.buttons[IDs.readerSettings].exists)
    }

    func testPDFTapCenterShowsAndHidesToolbars() {
        app.launchAndOpenSamplePDF()
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "mode=pdf") { $0.mode == "pdf" }

        app.showReaderChromeIfNeeded()
        XCTAssertTrue(app.otherElements[IDs.readerTopToolbar].waitForExistence(timeout: 3))
        XCTAssertTrue(app.otherElements[IDs.readerBottomToolbar].waitForExistence(timeout: 3))

        app.hideReaderChromeIfNeeded()
        XCTAssertFalse(app.buttons[IDs.readerBack].waitForExistence(timeout: 2), "PDF 点击内容区后工具栏应隐藏")
        app.waitForDemoReaderState(timeout: 5, description: "toolbar=hidden") { $0.toolbar == "hidden" }
    }

    func testPDFTocButtonOpensNavigationSheet() {
        app.launchAndOpenSamplePDF()
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "mode=pdf") { $0.mode == "pdf" }

        app.showReaderChromeIfNeeded(requiredButtonIDs: [IDs.readerToc])

        let tocButton = app.buttons[IDs.readerToc]
        XCTAssertTrue(tocButton.waitForExistence(timeout: 5))
        tocButton.tap()

        XCTAssertTrue(app.tables[IDs.readerTocTable].waitForExistence(timeout: 5), "PDF 目录面板未出现")
    }

    func testPDFSettingsPanelProvidesUsableOptions() {
        app.launchAndOpenSamplePDF()
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "mode=pdf") { $0.mode == "pdf" }

        app.showReaderChromeIfNeeded(requiredButtonIDs: [IDs.readerSettings])
        let settingsButton = app.buttons[IDs.readerSettings]
        XCTAssertTrue(settingsButton.waitForExistence(timeout: 5))
        settingsButton.tap()

        let settingsPanel = app.scrollViews[IDs.settingsScroll]
        XCTAssertTrue(settingsPanel.waitForExistence(timeout: 5), "PDF 设置面板未出现")
        XCTAssertTrue(app.sliders[IDs.settingsBrightness].waitForExistence(timeout: 3), "PDF 亮度设置未出现")
        XCTAssertTrue(app.segmentedControls[IDs.settingsDisplayType].waitForExistence(timeout: 3), "PDF 翻页方式设置未出现")
        XCTAssertTrue(app.buttons[IDs.settingsTheme(5)].waitForExistence(timeout: 3), "PDF 主题设置未出现")

        app.segmentedControls[IDs.settingsDisplayType].buttons["竖滑"].tap()
        app.buttons[IDs.settingsTheme(5)].tap()
        app.buttons[IDs.settingsDone].tap()
        app.waitForDemoReaderState(timeout: 5, description: "display changed") { $0.display == "verticalscroll" }
        app.waitForDemoReaderState(timeout: 5, description: "theme changed") { $0.fields["theme"] == "5" }
    }

    func testPDFLaunchHonorsDisplayTypeArgument() {
        app.launchAndOpenSampleBook(bookTitleQuery: "PDF测试文件", displayType: "verticalscroll")
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "PDF vertical launch mode") {
            $0.mode == "pdf" && $0.display == "verticalscroll"
        }
    }

    func testPDFPageCurlSupportsPinchAndDraggingAfterDoubleTapZoom() {
        app.launchAndOpenSamplePDF(bookTitleQuery: "PDF测试文件")
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "PDF page curl") {
            $0.mode == "pdf" && $0.display == "pagecurl"
        }

        let content = app.otherElements[IDs.readerContent].firstMatch
        XCTAssertTrue(content.waitForExistence(timeout: 5), "PDF 阅读页面未出现")
        XCTAssertTrue(waitForViewport(content, timeout: 3) { $0.scale <= 1.05 }, "PDF 初始页面不是适配状态")

        content.pinch(withScale: 1.8, velocity: 1)
        XCTAssertTrue(waitForViewport(content, timeout: 3) { $0.scale >= 1.4 }, "仿真翻页下双指缩放未生效")
        assertReaderPageRemains(1, duration: 0.4)

        content.doubleTap()
        XCTAssertTrue(waitForViewport(content, timeout: 3) { $0.scale <= 1.05 }, "双击未能还原 PDF 页面")
        content.doubleTap()
        guard let beforeDrag = waitForStableViewport(content, timeout: 3, stableDuration: 0.3, where: { $0.scale >= 1.8 }) else {
            XCTFail("双击后 PDF 未进入稳定的放大状态")
            return
        }
        let dragStart = content.coordinate(withNormalizedOffset: CGVector(dx: 0.75, dy: 0.5))
        let dragEnd = content.coordinate(withNormalizedOffset: CGVector(dx: 0.25, dy: 0.5))
        dragStart.press(forDuration: 0.05, thenDragTo: dragEnd)
        let didMoveContent = waitForViewport(content, timeout: 3) {
            $0.scale >= 1.8 && $0.offsetX - beforeDrag.offsetX > 30
        }
        XCTAssertTrue(
            didMoveContent,
            "PDF 双击放大后无法拖动内容；拖动前=\(beforeDrag)，拖动后=\(String(describing: content.value))"
        )
        assertReaderPageRemains(1, duration: 0.4)
    }

    func testPDFPageCurlSingleFingerTurnsPageAtFittedScale() {
        app.launchAndOpenSamplePDF(bookTitleQuery: "PDF测试文件")
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "PDF page curl at page 1") {
            $0.mode == "pdf" && $0.display == "pagecurl" && $0.page == 1
        }

        let content = app.otherElements[IDs.readerContent].firstMatch
        XCTAssertTrue(content.waitForExistence(timeout: 5), "PDF 阅读页面未出现")
        XCTAssertTrue(waitForViewport(content, timeout: 3) { $0.scale <= 1.05 }, "PDF 初始页面不是适配状态")

        let dragStart = content.coordinate(withNormalizedOffset: CGVector(dx: 0.60, dy: 0.5))
        let dragEnd = content.coordinate(withNormalizedOffset: CGVector(dx: 0.20, dy: 0.5))
        dragStart.press(forDuration: 0.05, thenDragTo: dragEnd)
        app.waitForReaderPage(2, timeout: 5)
    }

    func testPDFSwitchingFromZoomedCurlKeepsScrollModeInteractive() {
        app.launchAndOpenSamplePDF(bookTitleQuery: "PDF测试文件")
        app.waitForReader()
        app.waitForDemoReaderState(timeout: 5, description: "PDF page curl at page 1") {
            $0.mode == "pdf" && $0.display == "pagecurl" && $0.page == 1
        }

        let content = app.otherElements[IDs.readerContent].firstMatch
        XCTAssertTrue(content.waitForExistence(timeout: 5), "PDF 阅读页面未出现")
        content.doubleTap()
        XCTAssertNotNil(
            waitForStableViewport(content, timeout: 3, stableDuration: 0.3, where: { $0.scale >= 1.8 }),
            "PDF 双击后未放大"
        )

        app.showReaderChromeIfNeeded(requiredButtonIDs: [IDs.readerSettings])
        app.buttons[IDs.readerSettings].tap()
        XCTAssertTrue(app.scrollViews[IDs.settingsScroll].waitForExistence(timeout: 5), "PDF 设置面板未出现")
        app.segmentedControls[IDs.settingsDisplayType].buttons["横滑"].tap()
        app.buttons[IDs.settingsDone].tap()
        app.waitForDemoReaderState(timeout: 5, description: "display=horizontalscroll") {
            $0.display == "horizontalscroll" && $0.page == 1
        }

        let paging = app.collectionViews[IDs.readerPaging]
        XCTAssertTrue(paging.waitForExistence(timeout: 5), "PDF 横滑视图未出现")
        paging.swipeLeft()
        app.waitForReaderPage(2, timeout: 5)
    }

    private func waitForStableViewport(
        _ element: XCUIElement,
        timeout: TimeInterval,
        stableDuration: TimeInterval,
        where predicate: ((scale: Double, offsetX: Double, offsetY: Double)) -> Bool
    ) -> (scale: Double, offsetX: Double, offsetY: Double)? {
        let deadline = Date().addingTimeInterval(timeout)
        var previous: (scale: Double, offsetX: Double, offsetY: Double)?
        var stableSince: Date?

        repeat {
            guard let current = viewport(of: element), predicate(current) else {
                previous = nil
                stableSince = nil
                RunLoop.current.run(until: Date().addingTimeInterval(0.05))
                continue
            }

            if let previous,
               abs(current.scale - previous.scale) <= 0.01,
               abs(current.offsetX - previous.offsetX) <= 1,
               abs(current.offsetY - previous.offsetY) <= 1 {
                if let stableSince, Date().timeIntervalSince(stableSince) >= stableDuration {
                    return current
                }
            } else {
                stableSince = Date()
            }
            previous = current
            RunLoop.current.run(until: Date().addingTimeInterval(0.05))
        } while Date() < deadline
        return nil
    }

    private func assertReaderPageRemains(
        _ page: Int,
        duration: TimeInterval,
        file: StaticString = #filePath,
        line: UInt = #line
    ) {
        let deadline = Date().addingTimeInterval(duration)
        repeat {
            guard let state = app.currentDemoReaderState(), state.page == page else {
                XCTFail(
                    "PDF 手势后发生了意外翻页，当前状态：\(app.currentDemoReaderState()?.rawValue ?? "<missing>")",
                    file: file,
                    line: line
                )
                return
            }
            RunLoop.current.run(until: Date().addingTimeInterval(0.05))
        } while Date() < deadline
    }

    private func waitForViewport(
        _ element: XCUIElement,
        timeout: TimeInterval,
        predicate: ((scale: Double, offsetX: Double, offsetY: Double)) -> Bool
    ) -> Bool {
        let deadline = Date().addingTimeInterval(timeout)
        repeat {
            if let viewport = viewport(of: element), predicate(viewport) { return true }
            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
        } while Date() < deadline
        return false
    }

    private func viewport(of element: XCUIElement) -> (scale: Double, offsetX: Double, offsetY: Double)? {
        guard let value = element.value as? String else { return nil }
        let pattern = #"zoom=([0-9.]+) offset=(-?[0-9.]+),(-?[0-9.]+)"#
        guard let regex = try? NSRegularExpression(pattern: pattern),
              let match = regex.firstMatch(in: value, range: NSRange(value.startIndex..., in: value)),
              let scaleRange = Range(match.range(at: 1), in: value),
              let xRange = Range(match.range(at: 2), in: value),
              let yRange = Range(match.range(at: 3), in: value),
              let scale = Double(value[scaleRange]),
              let offsetX = Double(value[xRange]),
              let offsetY = Double(value[yRange]) else { return nil }
        return (scale, offsetX, offsetY)
    }
}