import Foundation
import XuqmCoreSDK
#if canImport(UIKit)
import UIKit
#endif

/// JSBridge 标准处理器 — 提供 xuqm.* 命名空间的标准桥接方法。
/// 类型在所有平台可见；UIKit 依赖的实现仅在 iOS 上编译。
@MainActor
public final class XWebViewStandardHandlers {

    #if canImport(UIKit)
    private weak var viewController: UIViewController?
    private var onClose: (() -> Void)?

    public init(viewController: UIViewController? = nil, onClose: (() -> Void)? = nil) {
        self.viewController = viewController
        self.onClose = onClose
    }
    #else
    public init() {}
    #endif

    // MARK: - Message Dispatch

    public func handleMessage(_ message: [String: Any]) -> Bool {
        #if canImport(UIKit)
        guard let action = message["action"] as? String else { return false }
        let callbackId = message["callbackId"] as? String
        switch action {
        case "xuqm.getDeviceInfo": handleGetDeviceInfo(callbackId: callbackId); return true
        case "xuqm.getToken":      handleGetToken(callbackId: callbackId);      return true
        case "xuqm.getUserInfo":   handleGetUserInfo(callbackId: callbackId);   return true
        case "xuqm.closeWebView":  onClose?();                                  return true
        case "xuqm.showToast":     handleShowToast(message: message);           return true
        default:                   return false
        }
        #else
        return false
        #endif
    }

    // MARK: - Handlers (UIKit only)

    #if canImport(UIKit)
    private func handleGetDeviceInfo(callbackId: String?) {
        guard let callbackId else { return }
        let device = UIDevice.current
        callCallback(callbackId, data: [
            "model": device.model,
            "osVersion": "iOS \(device.systemVersion)",
            "platform": "IOS",
            "deviceId": device.identifierForVendor?.uuidString ?? "",
        ])
    }

    private func handleGetToken(callbackId: String?) {
        guard let callbackId else { return }
        callCallback(callbackId, data: ["token": XuqmSDK.shared.token ?? ""])
    }

    private func handleGetUserInfo(callbackId: String?) {
        guard let callbackId else { return }
        // userId is @MainActor; we post empty now — override in app layer if needed
        callCallback(callbackId, data: ["userId": XuqmSDK.shared.userId ?? ""])
    }

    private func handleShowToast(message: [String: Any]) {
        guard let msg = message["message"] as? String else { return }
        DispatchQueue.main.async { [weak self] in
            guard let vc = self?.viewController else { return }
            let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
            vc.present(alert, animated: true)
            DispatchQueue.main.asyncAfter(deadline: .now() + 2) { alert.dismiss(animated: true) }
        }
    }

    private func callCallback(_ callbackId: String, data: [String: Any]) {
        guard let jsonData = try? JSONSerialization.data(withJSONObject: data),
              let jsonString = String(data: jsonData, encoding: .utf8) else { return }
        let js = "window[\"\(callbackId)\"](\(jsonString))"
        NotificationCenter.default.post(name: .xWebViewCallJs, object: nil, userInfo: ["js": js])
    }
    #endif

    // MARK: - Injected JS (all platforms)

    public nonisolated static var injectedJavaScript: String {
        """
        (function() {
          window.xuqm = window.xuqm || {};

          window.xuqm.getDeviceInfo = function(callback) {
            var callbackId = 'cb_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
            window[callbackId] = function(data) { if (callback) callback(data); delete window[callbackId]; };
            window.ReactNativeWebView.postMessage(JSON.stringify({ action: 'xuqm.getDeviceInfo', callbackId: callbackId }));
          };

          window.xuqm.getToken = function(callback) {
            var callbackId = 'cb_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
            window[callbackId] = function(data) { if (callback) callback(data.token); delete window[callbackId]; };
            window.ReactNativeWebView.postMessage(JSON.stringify({ action: 'xuqm.getToken', callbackId: callbackId }));
          };

          window.xuqm.getUserInfo = function(callback) {
            var callbackId = 'cb_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
            window[callbackId] = function(data) { if (callback) callback(data); delete window[callbackId]; };
            window.ReactNativeWebView.postMessage(JSON.stringify({ action: 'xuqm.getUserInfo', callbackId: callbackId }));
          };

          window.xuqm.closeWebView = function() {
            window.ReactNativeWebView.postMessage(JSON.stringify({ action: 'xuqm.closeWebView' }));
          };

          window.xuqm.showToast = function(message) {
            window.ReactNativeWebView.postMessage(JSON.stringify({ action: 'xuqm.showToast', message: message }));
          };
        })();
        true;
        """
    }
}

// MARK: - Notification Name (UIKit only, used by WKWebView coordinator)

#if canImport(UIKit)
extension Notification.Name {
    static let xWebViewCallJs = Notification.Name("xWebViewCallJs")
}
#endif