//
//  MainScanTabItemTests.swift
//  suixinkanTests
//

import XCTest
@testable import suixinkan_ios

/// 主 TabBar 中间扫码入口测试，覆盖系统 TabBar 槽位配置。
@MainActor
final class MainScanTabItemTests: XCTestCase {

    /// 测试主 Tab 容器加载后包含四个业务 Tab 和中间扫码入口。
    func testMainTabBarControllerLoadsFiveSystemTabItems() {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)

        controller.loadViewIfNeeded()

        XCTAssertEqual(controller.viewControllers?.count, 5)
        for tab in AppTab.allCases {
            XCTAssertNotNil(controller.navigationController(for: tab))
            XCTAssertEqual(
                controller.navigationController(for: tab)?.tabBarItem.accessibilityIdentifier,
                "main.tab.\(tab.rawValue)"
            )
        }
    }

    /// 测试扫码入口位于订单与数据之间，并保留指定无障碍标识。
    func testScanTabItemIsCenteredBetweenOrdersAndStatistics() throws {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)

        controller.loadViewIfNeeded()

        let scanItem = try XCTUnwrap(controller.viewControllers?[2].tabBarItem)
        XCTAssertEqual(scanItem.title, "扫码")
        XCTAssertEqual(scanItem.accessibilityIdentifier, "main.scan")
        XCTAssertEqual(scanItem.accessibilityLabel, "扫码核销")
        XCTAssertNotNil(scanItem.image)
        XCTAssertNotNil(scanItem.selectedImage)
    }

    /// 测试点击扫码槽位会被拦截且不改变当前选中页面。
    func testSelectingScanTabPresentsScannerWithoutSelectingPlaceholder() throws {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)
        var scanTapCount = 0
        controller.onScanTabSelected = {
            scanTapCount += 1
        }

        controller.loadViewIfNeeded()
        controller.selectedIndex = 1

        let scanController = try XCTUnwrap(controller.viewControllers?[2])
        XCTAssertFalse(controller.tabBarController(controller, shouldSelect: scanController))
        XCTAssertEqual(scanTapCount, 1)
        XCTAssertEqual(controller.selectedIndex, 1)
    }

    /// 测试业务 Tab 仍允许系统 TabBar 正常选中。
    func testSelectingBusinessTabIsAllowed() throws {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)

        controller.loadViewIfNeeded()

        let ordersController = try XCTUnwrap(controller.viewControllers?[1])
        XCTAssertTrue(controller.tabBarController(controller, shouldSelect: ordersController))
    }

    /// 测试各 Tab 的图标资源可被加载并挂载到 tabBarItem。
    func testMainTabBarControllerTabBarItemsHaveImages() {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)
        controller.loadViewIfNeeded()

        for tab in AppTab.allCases {
            let item = controller.navigationController(for: tab)?.tabBarItem
            XCTAssertNotNil(item?.image, "tab \(tab.rawValue) image should not be nil")
            XCTAssertNotNil(item?.selectedImage, "tab \(tab.rawValue) selectedImage should not be nil")
            XCTAssertGreaterThan(item?.image?.size.width ?? 0, 0)
            XCTAssertGreaterThan(item?.selectedImage?.size.width ?? 0, 0)
        }
    }

    /// 测试订单角标仍挂载在订单业务导航控制器的系统 TabBarItem 上。
    func testOrderBadgeUsesOrdersNavigationTabBarItem() throws {
        let services = AppServices(apiClient: APIClient(session: MainTabRecordingURLSession()))
        let controller = MainTabBarController(services: services)

        controller.loadViewIfNeeded()

        let ordersNavigationController = try XCTUnwrap(controller.navigationController(for: .orders))
        ordersNavigationController.tabBarItem.badgeValue = "3"

        XCTAssertEqual(controller.viewControllers?[1].tabBarItem.badgeValue, "3")
    }
}

/// 主 Tab 测试使用的空网络会话，确保容器加载不触发真实请求。
private final class MainTabRecordingURLSession: URLSessionProtocol {
    /// 返回空成功响应。
    func data(for request: URLRequest) async throws -> (Data, URLResponse) {
        let response = HTTPURLResponse(
            url: request.url ?? URL(string: "https://example.com")!,
            statusCode: 200,
            httpVersion: nil,
            headerFields: nil
        )!
        return (Data(), response)
    }
}