128 lines
4.7 KiB
Swift
128 lines
4.7 KiB
Swift
import Foundation
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/// 提供 ISO 8601 格式的北京时间字符串（如 `2026-05-07T16:58:00+08:00`），用于 bind / setPlayMode payload 的 `time` 字段。
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///
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/// 三级 fallback：
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/// 1. 苏宁公开时间 API 的 body（`sysTime2` 或 `sysTime1`）
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/// 2. 苏宁 response.headers["Date"]（HTTP RFC 1123）
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/// 3. 本地 `Date()` + 8h
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///
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/// 5 秒内单飞复用，避免 bind/setPlayMode 连发时重复请求。
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final class BeijingTimeProvider {
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private static let suningURL = URL(string: "https://quan.suning.com/getSysTime.do")!
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private static let cacheTTL: TimeInterval = 5
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private static let fetchTimeout: TimeInterval = 3
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private static let beijingOffsetSeconds: TimeInterval = 8 * 3600
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private let session: URLSession
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private let queue = DispatchQueue(label: "duooomi.ble.beijingTime")
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private var cached: (value: String, at: Date)?
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private var inflight: [(String) -> Void] = []
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private var fetching = false
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init(session: URLSession = .shared) {
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self.session = session
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}
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/// 异步获取北京时间字符串。回调一定在主队列触发。
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func fetch(completion: @escaping (String) -> Void) {
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queue.async { [weak self] in
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guard let self = self else { return }
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if let cached = self.cached, Date().timeIntervalSince(cached.at) < Self.cacheTTL {
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self.dispatch(cached.value, to: completion)
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return
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}
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self.inflight.append(completion)
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if self.fetching { return }
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self.fetching = true
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self.performFetch { value in
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self.queue.async {
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self.cached = (value, Date())
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let pending = self.inflight
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self.inflight = []
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self.fetching = false
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pending.forEach { self.dispatch(value, to: $0) }
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}
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}
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}
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}
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private func dispatch(_ value: String, to completion: @escaping (String) -> Void) {
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DispatchQueue.main.async { completion(value) }
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}
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private func performFetch(_ done: @escaping (String) -> Void) {
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var req = URLRequest(url: Self.suningURL)
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req.timeoutInterval = Self.fetchTimeout
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req.httpMethod = "GET"
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session.dataTask(with: req) { [weak self] data, resp, _ in
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guard let self = self else { return }
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if let data = data, let body = try? JSONDecoder().decode(SuningTimeBody.self, from: data),
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let value = self.formatSuningBody(body) {
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done(value)
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return
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}
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if let http = resp as? HTTPURLResponse,
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let dateHeader = http.headerValue(caseInsensitive: "Date"),
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let value = self.formatHTTPDateHeader(dateHeader) {
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done(value)
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return
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}
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done(self.formatLocal())
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}.resume()
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}
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private func formatSuningBody(_ body: SuningTimeBody) -> String? {
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if let s = body.sysTime2,
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s.range(of: #"^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$"#, options: .regularExpression) != nil {
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return s.replacingOccurrences(of: " ", with: "T") + "+08:00"
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}
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if let s = body.sysTime1, s.count == 14, Int(s) != nil {
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let y = s.prefix(4)
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let mo = s.dropFirst(4).prefix(2)
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let d = s.dropFirst(6).prefix(2)
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let h = s.dropFirst(8).prefix(2)
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let mi = s.dropFirst(10).prefix(2)
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let se = s.dropFirst(12).prefix(2)
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return "\(y)-\(mo)-\(d)T\(h):\(mi):\(se)+08:00"
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}
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return nil
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}
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private func formatHTTPDateHeader(_ raw: String) -> String? {
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let formatter = DateFormatter()
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formatter.locale = Locale(identifier: "en_US_POSIX")
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formatter.timeZone = TimeZone(identifier: "GMT")
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formatter.dateFormat = "EEE, dd MMM yyyy HH:mm:ss zzz"
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guard let date = formatter.date(from: raw) else { return nil }
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return Self.formatBeijing(date)
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}
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private func formatLocal() -> String {
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Self.formatBeijing(Date())
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}
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private static func formatBeijing(_ date: Date) -> String {
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var calendar = Calendar(identifier: .gregorian)
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calendar.timeZone = TimeZone(secondsFromGMT: Int(beijingOffsetSeconds))!
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let c = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second], from: date)
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return String(
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format: "%04d-%02d-%02dT%02d:%02d:%02d+08:00",
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c.year ?? 1970, c.month ?? 1, c.day ?? 1,
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c.hour ?? 0, c.minute ?? 0, c.second ?? 0
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)
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}
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}
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private struct SuningTimeBody: Decodable {
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let sysTime1: String?
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let sysTime2: String?
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}
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