import XCTest

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

    override func setUpWithError() throws {
        continueAfterFailure = false
    }

    func testVerticalScrollSwipeNavigation() throws {
        app.launchAndOpenSampleBook(displayType: "verticalscroll")
        app.waitForReader(timeout: 12)

        let paging = app.collectionViews[IDs.readerPaging]
        if paging.waitForExistence(timeout: 5) { paging.swipeUp() }

        app.waitForDemoReaderState(timeout: 5, description: "reader=opened") { $0.isOpened }
    }

    func testOpenAndCloseMultipleTimes() throws {
        for iteration in 1...3 {
            app.launchAndOpenSampleBook()
            app.waitForReader(timeout: 12)

            app.showReaderChromeIfNeeded()
            let backButton = app.buttons[IDs.readerBack]
            XCTAssertTrue(backButton.waitForExistence(timeout: 3), "返回按钮不存在")
            backButton.tap()

            let booksTable = app.tables[IDs.demoBooksTable]
            XCTAssertTrue(booksTable.waitForExistence(timeout: 5), "书列表未出现")
        }
    }

    func testRapidPageNavigation() throws {
        app.launchAndOpenSampleBook()
        app.waitForReader(timeout: 12)
        app.waitForReaderPage(1, timeout: 5)

        let paging = app.collectionViews[IDs.readerPaging]
        guard paging.waitForExistence(timeout: 5) else { throw XCTSkip("分页视图不存在") }

        for _ in 1...5 { paging.swipeLeft() }

        app.waitForDemoReaderState(timeout: 8, description: "reader=opened") { $0.isOpened }
    }

    func testSettingsPanelScrollReachesAllControls() throws {
        app.launchAndOpenSampleBook()
        app.waitForReader(timeout: 12)

        app.showReaderChromeIfNeeded()
        app.buttons[IDs.readerSettings].tap()

        let settingsScroll = app.scrollViews[IDs.settingsScroll]
        XCTAssertTrue(settingsScroll.waitForExistence(timeout: 5), "设置面板未出现")

        XCTAssertTrue(app.buttons[IDs.settingsFontIncrease].waitForExistence(timeout: 3))
        XCTAssertTrue(app.buttons[IDs.settingsBrightness].waitForExistence(timeout: 3))

        settingsScroll.swipeUp()
        XCTAssertTrue(app.segmentedControls[IDs.settingsDisplayType].waitForExistence(timeout: 5))

        settingsScroll.swipeUp()
        XCTAssertTrue(app.buttons[IDs.settingsTheme(5)].waitForExistence(timeout: 5))

        app.buttons[IDs.settingsDone].tap()
    }

    func testHTTPSExternalLinkShowsConfirmationAlert() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: "Web交互流式外链验证", displayType: "scroll")
        app.waitForReader(timeout: 20)

        let httpsLink = externalLinkElement(named: "HTTPS Link")
        guard httpsLink.waitForExistence(timeout: 8) else {
            throw XCTSkip("HTTPS 外链元素未暴露")
        }
        httpsLink.tap()

        XCTAssertTrue(app.alerts["打开外部链接"].waitForExistence(timeout: 5), "HTTPS 外链应弹出确认框")
        XCTAssertTrue(app.buttons["打开"].waitForExistence(timeout: 2), "确认框应提供打开按钮")
        app.buttons["取消"].tap()
    }

    func testMailtoExternalLinkBlockedByDefaultPolicy() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: "Web交互流式外链验证", displayType: "scroll")
        app.waitForReader(timeout: 20)

        let mailtoLink = externalLinkElement(named: "Mailto Link")
        guard mailtoLink.waitForExistence(timeout: 8) else {
            throw XCTSkip("Mailto 外链元素未暴露")
        }
        mailtoLink.tap()

        XCTAssertFalse(app.alerts["打开外部链接"].waitForExistence(timeout: 2), "默认策略下 mailto 不应弹出确认框")
        let state = app.waitForDemoReaderState(timeout: 5, description: "mailto activation recorded") { state in
            (state.externalLinks ?? 0) >= 1 && state.lastExternalURL != nil
        }
        XCTAssertTrue(state.lastExternalURL?.contains("mailto:test@example.com") == true, "应记录 mailto 激活但不继续打开")
    }

    func testLargeWebResourceUsesStreamingPath() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: "Web交互流式外链验证", displayType: "scroll")
        app.waitForReader(timeout: 20)

        let state = app.waitForDemoReaderState(timeout: 15, description: "streamedResources>0") { state in
            (state.streamedResources ?? 0) > 0
        }
        XCTAssertGreaterThan(state.streamedResources ?? 0, 0, "大资源应走流式传输路径")
    }

    func testInvalidEPUBReportsFailure() {
        app.launchAndOpenSampleBook(bookTitleQuery: "损坏结构样本", resetsReaderState: true)

        let state = app.waitForDemoReaderState(timeout: 12, description: "invalid epub failure") { state in
            state.lastError != nil && state.lastError != "none"
        }
        XCTAssertNotEqual(state.lastError, "none")
    }

    func testEmptyArchiveReportsFailure() {
        app.launchAndOpenSampleBook(bookTitleQuery: "空归档样本", resetsReaderState: true)

        let state = app.waitForDemoReaderState(timeout: 12, description: "empty archive failure") { state in
            state.lastError != nil && state.lastError != "none"
        }
        XCTAssertNotEqual(state.lastError, "none")
    }

    func testMissingSpineDocumentReportsFailure() {
        app.launchAndOpenSampleBook(bookTitleQuery: "缺失文件样本", resetsReaderState: true)

        let state = app.waitForDemoReaderState(timeout: 12, description: "missing file failure") { state in
            state.lastError != nil && state.lastError != "none"
        }
        XCTAssertNotEqual(state.lastError, "none")
    }

    private func externalLinkElement(named label: String) -> XCUIElement {
        let link = app.links[label]
        if link.exists {
            return link
        }
        let staticText = app.staticTexts[label]
        if staticText.exists {
            return staticText
        }
        return link
    }
}