//
//  SplashCoordinator.swift
//  suixinkan
//
//  Created by Codex on 2026/6/29.
//

import Combine
import Foundation

@MainActor
/// 启动页时序协调器，并行执行冷启动 bootstrap，Splash 结束时机以 bootstrap 完成为准。
final class SplashCoordinator: ObservableObject {
    @Published private(set) var isFinished = false

    private let minimumDisplayDuration: TimeInterval
    private let skipsMinimumDuration: Bool

    /// 创建启动页协调器；默认无最短展示时长，测试可注入自定义 delay。
    init(
        minimumDisplayDuration: TimeInterval = 0,
        skipsMinimumDuration: Bool = AppUITestLaunchState.isRunningUITests
    ) {
        self.minimumDisplayDuration = minimumDisplayDuration
        self.skipsMinimumDuration = skipsMinimumDuration
    }

    /// 并行执行 bootstrap 与可选最短展示时长，两者都完成后结束 Splash。
    func start(bootstrap: @escaping () async -> Void) async {
        guard !isFinished else { return }

        async let minimumDelay: Void = waitForMinimumDisplayDuration()
        async let bootstrapWork: Void = bootstrap()

        _ = await (minimumDelay, bootstrapWork)
        isFinished = true
    }

    /// 等待最短展示时长；UI Test 模式下直接返回。
    private func waitForMinimumDisplayDuration() async {
        guard !skipsMinimumDuration else { return }
        let nanoseconds = UInt64(max(minimumDisplayDuration, 0) * 1_000_000_000)
        try? await Task.sleep(nanoseconds: nanoseconds)
    }
}