import Foundation
import UIKit
import XuqmCoreSDK

/// JSBridge 标准处理器
/// 提供 xuqm.* 命名空间的标准桥接方法
public final class XWebViewStandardHandlers {

    private weak var viewController: UIViewController?
    private var onClose: (() -> Void)?

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

    /// 处理 JS 消息
    /// - Returns: 是否已处理
    public func handleMessage(_ message: [String: Any]) -> Bool {
        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":
            handleCloseWebView()
            return true
        case "xuqm.showToast":
            handleShowToast(message: message)
            return true
        default:
            return false
        }
    }

    // MARK: - Handlers

    private func handleGetDeviceInfo(callbackId: String?) {
        guard let callbackId = callbackId else { return }

        let device = UIDevice.current
        let model = device.model
        let osVersion = "iOS \(device.systemVersion)"
        let platform = "IOS"
        let deviceId = device.identifierForVendor?.uuidString ?? ""

        callCallback(callbackId, data: [
            "model": model,
            "osVersion": osVersion,
            "platform": platform,
            "deviceId": deviceId,
        ])
    }

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

    private func handleGetUserInfo(callbackId: String?) {
        guard let callbackId = callbackId else { return }
        let userId = XuqmSDK.shared.currentUserId ?? ""
        callCallback(callbackId, data: ["userId": userId])
    }

    private func handleCloseWebView() {
        onClose?()
    }

    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)
            }
        }
    }

    // MARK: - Callback

    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))"
        // The WebView will execute this JS through its controller
        NotificationCenter.default.post(
            name: .xWebViewCallJs,
            object: nil,
            userInfo: ["js": js]
        )
    }

    /// 生成注入的 JS 代码
    public static var injectedJavaScript: String {
        return """
        (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

extension Notification.Name {
    static let xWebViewCallJs = Notification.Name("xWebViewCallJs")
}