import XCTest
@testable import suixinkan

/// 回归验证相机配置期间启动、快速关闭和重复启动的顺序。
final class QRCodeCaptureSessionControllerTests: XCTestCase {
    func testStartWaitsForConfigurationCommit() {
        let session = RecordingCaptureSession()
        let queue = DispatchQueue(label: "qr-capture-test")
        let controller = QRCodeCaptureSessionController(session: session, queue: queue)
        let entered = DispatchSemaphore(value: 0)
        let release = DispatchSemaphore(value: 0)
        let completed = expectation(description: "configuration committed")

        controller.configure({
            entered.signal()
            _ = release.wait(timeout: .now() + 5)
            return true
        }, completion: { succeeded in
            XCTAssertTrue(Thread.isMainThread)
            XCTAssertTrue(succeeded)
            completed.fulfill()
        })
        XCTAssertEqual(entered.wait(timeout: .now() + 5), .success)
        controller.setRunning(true)
        release.signal()
        queue.sync {
            XCTAssertEqual(session.events, ["begin", "commit", "start"])
            XCTAssertFalse(session.startedDuringConfiguration)
        }
        wait(for: [completed], timeout: 5)
    }

    func testImmediateCloseStopsPendingStart() {
        let session = RecordingCaptureSession()
        let queue = DispatchQueue(label: "qr-capture-test")
        let controller = QRCodeCaptureSessionController(session: session, queue: queue)
        controller.configure({ true }, completion: { _ in })
        controller.setRunning(true)
        controller.setRunning(false)
        queue.sync {
            XCTAssertEqual(session.events, ["begin", "commit", "start", "stop"])
            XCTAssertFalse(session.isRunning)
        }
    }

    func testRepeatedStartAndStopAreIdempotent() {
        let session = RecordingCaptureSession()
        let queue = DispatchQueue(label: "qr-capture-test")
        let controller = QRCodeCaptureSessionController(session: session, queue: queue)
        controller.configure({ true }, completion: { _ in })
        controller.setRunning(true)
        controller.setRunning(true)
        controller.setRunning(false)
        controller.setRunning(false)
        queue.sync {
            XCTAssertEqual(session.events, ["begin", "commit", "start", "stop"])
        }
    }

    func testFailedConfigurationCommitsButDoesNotStart() {
        let session = RecordingCaptureSession()
        let queue = DispatchQueue(label: "qr-capture-test")
        let controller = QRCodeCaptureSessionController(session: session, queue: queue)
        let completed = expectation(description: "configuration failed")
        controller.configure({ false }, completion: { succeeded in
            XCTAssertFalse(succeeded)
            completed.fulfill()
        })
        controller.setRunning(true)
        queue.sync {
            XCTAssertEqual(session.events, ["begin", "commit"])
            XCTAssertFalse(session.isRunning)
        }
        wait(for: [completed], timeout: 5)
    }
}

/// 记录调用顺序并检测配置事务内启动的会话替身，仅在测试串行队列读写。
private final class RecordingCaptureSession: QRCodeCaptureSession {
    var isRunning = false
    var events: [String] = []
    var startedDuringConfiguration = false
    private var configuring = false

    func beginConfiguration() {
        configuring = true
        events.append("begin")
    }

    func commitConfiguration() {
        configuring = false
        events.append("commit")
    }

    func startRunning() {
        startedDuringConfiguration = configuring
        isRunning = true
        events.append("start")
    }

    func stopRunning() {
        isRunning = false
        events.append("stop")
    }
}