import XCTest

final class ConfigurableWindowTests: XCTestCase {
    private let app = XCUIApplication()
    private let largeBookQuery = "凡人修仙传"

    override func setUpWithError() throws {
        continueAfterFailure = false
    }

    func testWindowSize5PreloadsMoreChapters() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: largeBookQuery, resetsReaderState: true, windowSize: 5)
        app.waitForReader(timeout: 20)

        let state = app.waitForDemoReaderState(timeout: 15, description: "window=5 预加载更多章节") { state in
            state.mode == "bookPageMap" && state.knownChapters != nil
        }

        XCTAssertEqual(state.windowSize, 5, "windowSize 应为 5")
        XCTAssertTrue((state.knownChapters ?? 0) >= 3, "window=5 首开应至少预加载 3 章（当前章 + 相邻），实际=\(state.knownChapters ?? 0)")
        XCTAssertTrue(app.otherElements[IDs.readerContent].waitForExistence(timeout: 5), "window=5 首开应可阅读")
    }

    func testWindowSize3MinimumWorks() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: largeBookQuery, resetsReaderState: true, windowSize: 3)
        app.waitForReader(timeout: 20)

        let state = app.waitForDemoReaderState(timeout: 15, description: "window=3 最小窗口") { state in
            state.mode == "bookPageMap" && state.knownChapters != nil
        }

        XCTAssertEqual(state.windowSize, 3, "windowSize 应为 3")
        XCTAssertTrue(app.otherElements[IDs.readerContent].waitForExistence(timeout: 5), "window=3 应可阅读")
    }

    func testWindowSize15MaximumWorks() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: largeBookQuery, resetsReaderState: true, windowSize: 15)
        app.waitForReader(timeout: 20)

        let state = app.waitForDemoReaderState(timeout: 15, description: "window=15 最大窗口") { state in
            state.mode == "bookPageMap" && state.knownChapters != nil
        }

        XCTAssertEqual(state.windowSize, 15, "windowSize 应为 15")
        XCTAssertTrue((state.knownChapters ?? 0) >= 3, "window=15 首开应预加载多章")
        XCTAssertTrue(app.otherElements[IDs.readerContent].waitForExistence(timeout: 5), "window=15 应可阅读")
    }

    func testWindowSize5ChapterNavigationSmooth() throws {
        app.launchAndOpenSampleBook(bookTitleQuery: largeBookQuery, resetsReaderState: true, windowSize: 5)
        app.waitForReader(timeout: 20)

        _ = app.waitForDemoReaderState(timeout: 15, description: "等待首章加载") { state in
            state.mode == "bookPageMap" && (state.page ?? 0) >= 1
        }

        let paging = app.collectionViews[IDs.readerPaging]
        XCTAssertTrue(paging.waitForExistence(timeout: 5), "分页视图不存在")

        // 快速连续翻页，window=5 应该有更多章在缓存中
        for _ in 0..<6 {
            paging.swipeLeft()
            RunLoop.current.run(until: Date().addingTimeInterval(0.3))
        }

        let afterSwipe = app.currentDemoReaderState()
        XCTAssertNotNil(afterSwipe, "翻页后应能读取状态")
        XCTAssertTrue((afterSwipe?.page ?? 0) > 1, "连续翻页后页码应推进")
    }

    func testEvenWindowSizeRoundsUp() throws {
        // 传 4 应被归一化为 5
        app.launchAndOpenSampleBook(bookTitleQuery: largeBookQuery, resetsReaderState: true, windowSize: 4)
        app.waitForReader(timeout: 20)

        let state = app.waitForDemoReaderState(timeout: 15, description: "偶数窗口向上取奇") { state in
            state.mode == "bookPageMap" && state.windowSize != nil
        }

        XCTAssertEqual(state.windowSize, 5, "windowSize=4 应被归一化为 5")
    }
}