//
//  InterceptAjaxRequestsJS.swift
//  flutter_inappwebview
//
//  Created by Lorenzo Pichilli on 16/02/21.
//

import Foundation

let INTERCEPT_AJAX_REQUEST_JS_PLUGIN_SCRIPT_GROUP_NAME = "IN_APP_WEBVIEW_INTERCEPT_AJAX_REQUEST_JS_PLUGIN_SCRIPT"
let FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE = "window.\(JAVASCRIPT_BRIDGE_NAME)._useShouldInterceptAjaxRequest"


let FLAG_VARIABLE_FOR_INTERCEPT_ONLY_ASYNC_AJAX_REQUESTS_JS_SOURCE = "window.\(JAVASCRIPT_BRIDGE_NAME)._interceptOnlyAsyncAjaxRequests";

let INTERCEPT_AJAX_REQUEST_JS_PLUGIN_SCRIPT = PluginScript(
    groupName: INTERCEPT_AJAX_REQUEST_JS_PLUGIN_SCRIPT_GROUP_NAME,
    source: INTERCEPT_AJAX_REQUEST_JS_SOURCE,
    injectionTime: .atDocumentStart,
    forMainFrameOnly: false,
    requiredInAllContentWorlds: true,
    messageHandlerNames: [])

func createInterceptOnlyAsyncAjaxRequestsPluginScript(onlyAsync: Bool) -> PluginScript {
    return PluginScript(groupName: INTERCEPT_AJAX_REQUEST_JS_PLUGIN_SCRIPT_GROUP_NAME,
        source: "\(FLAG_VARIABLE_FOR_INTERCEPT_ONLY_ASYNC_AJAX_REQUESTS_JS_SOURCE) = \(onlyAsync);",
        injectionTime: .atDocumentStart,
        forMainFrameOnly: false,
        requiredInAllContentWorlds: true,
        messageHandlerNames: []
    );
}

let INTERCEPT_AJAX_REQUEST_JS_SOURCE = """
\(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) = true;
(function(ajax) {
  var send = ajax.prototype.send;
  var open = ajax.prototype.open;
  var setRequestHeader = ajax.prototype.setRequestHeader;
  ajax.prototype._flutter_inappwebview_url = null;
  ajax.prototype._flutter_inappwebview_method = null;
  ajax.prototype._flutter_inappwebview_isAsync = null;
  ajax.prototype._flutter_inappwebview_user = null;
  ajax.prototype._flutter_inappwebview_password = null;
  ajax.prototype._flutter_inappwebview_password = null;
  ajax.prototype._flutter_inappwebview_already_onreadystatechange_wrapped = false;
  ajax.prototype._flutter_inappwebview_request_headers = {};
  function convertRequestResponse(request, callback) {
    if (request.response != null && request.responseType != null) {
      switch (request.responseType) {
        case 'arraybuffer':
          callback(new Uint8Array(request.response));
          return;
        case 'blob':
          const reader = new FileReader();
          reader.addEventListener('loadend', function() {
            callback(new Uint8Array(reader.result));
          });
          reader.readAsArrayBuffer(blob);
          return;
        case 'document':
          callback(request.response.documentElement.outerHTML);
          return;
        case 'json':
          callback(request.response);
          return;
      };
    }
    callback(null);
  };
  ajax.prototype.open = function(method, url, isAsync, user, password) {
    isAsync = (isAsync != null) ? isAsync : true;
    this._flutter_inappwebview_url = url;
    this._flutter_inappwebview_method = method;
    this._flutter_inappwebview_isAsync = isAsync;
    this._flutter_inappwebview_user = user;
    this._flutter_inappwebview_password = password;
    this._flutter_inappwebview_request_headers = {};
    open.call(this, method, url, isAsync, user, password);
  };
  ajax.prototype.setRequestHeader = function(header, value) {
    this._flutter_inappwebview_request_headers[header] = value;
    setRequestHeader.call(this, header, value);
  };
  function handleEvent(e) {
    var self = this;
    if (\(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == null || \(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == true) {
      var headers = this.getAllResponseHeaders();
      var responseHeaders = {};
      if (headers != null) {
        var arr = headers.trim().split(/[\\r\\n]+/);
        arr.forEach(function (line) {
          var parts = line.split(': ');
          var header = parts.shift();
          var value = parts.join(': ');
          responseHeaders[header] = value;
        });
      }
      convertRequestResponse(this, function(response) {
        var ajaxRequest = {
          method: self._flutter_inappwebview_method,
          url: self._flutter_inappwebview_url,
          isAsync: self._flutter_inappwebview_isAsync,
          user: self._flutter_inappwebview_user,
          password: self._flutter_inappwebview_password,
          withCredentials: self.withCredentials,
          headers: self._flutter_inappwebview_request_headers,
          readyState: self.readyState,
          status: self.status,
          responseURL: self.responseURL,
          responseType: self.responseType,
          response: response,
          responseText: (self.responseType == 'text' || self.responseType == '') ? self.responseText : null,
          responseXML: (self.responseType == 'document' && self.responseXML != null) ? self.responseXML.documentElement.outerHTML : null,
          statusText: self.statusText,
          responseHeaders, responseHeaders,
          event: {
            type: e.type,
            loaded: e.loaded,
            lengthComputable: e.lengthComputable,
            total: e.total
          }
        };
        window.\(JAVASCRIPT_BRIDGE_NAME).callHandler('onAjaxProgress', ajaxRequest).then(function(result) {
          if (result != null) {
            switch (result) {
              case 0:
                self.abort();
                return;
            };
          }
        });
      });
    }
  };
  ajax.prototype.send = function(data) {
    var self = this;
    var canBeIntercepted = self._flutter_inappwebview_isAsync || \(FLAG_VARIABLE_FOR_INTERCEPT_ONLY_ASYNC_AJAX_REQUESTS_JS_SOURCE) === false;
    if (canBeIntercepted && (\(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == null || \(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == true)) {
      if (!this._flutter_inappwebview_already_onreadystatechange_wrapped) {
        this._flutter_inappwebview_already_onreadystatechange_wrapped = true;
        var onreadystatechange = this.onreadystatechange;
        this.onreadystatechange = function() {
          if (\(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == null || \(FLAG_VARIABLE_FOR_SHOULD_INTERCEPT_AJAX_REQUEST_JS_SOURCE) == true) {
            var headers = this.getAllResponseHeaders();
            var responseHeaders = {};
            if (headers != null) {
              var arr = headers.trim().split(/[\\r\\n]+/);
              arr.forEach(function (line) {
                var parts = line.split(': ');
                var header = parts.shift();
                var value = parts.join(': ');
                responseHeaders[header] = value;
              });
            }
            convertRequestResponse(this, function(response) {
              var ajaxRequest = {
                method: self._flutter_inappwebview_method,
                url: self._flutter_inappwebview_url,
                isAsync: self._flutter_inappwebview_isAsync,
                user: self._flutter_inappwebview_user,
                password: self._flutter_inappwebview_password,
                withCredentials: self.withCredentials,
                headers: self._flutter_inappwebview_request_headers,
                readyState: self.readyState,
                status: self.status,
                responseURL: self.responseURL,
                responseType: self.responseType,
                response: response,
                responseText: (self.responseType == 'text' || self.responseType == '') ? self.responseText : null,
                responseXML: (self.responseType == 'document' && self.responseXML != null) ? self.responseXML.documentElement.outerHTML : null,
                statusText: self.statusText,
                responseHeaders: responseHeaders
              };
              window.\(JAVASCRIPT_BRIDGE_NAME).callHandler('onAjaxReadyStateChange', ajaxRequest).then(function(result) {
                if (result != null) {
                  switch (result) {
                    case 0:
                      self.abort();
                      return;
                  };
                }
                if (onreadystatechange != null) {
                  onreadystatechange();
                }
              });
            });
          } else if (onreadystatechange != null) {
            onreadystatechange();
          }
        };
      }
      this.addEventListener('loadstart', handleEvent);
      this.addEventListener('load', handleEvent);
      this.addEventListener('loadend', handleEvent);
      this.addEventListener('progress', handleEvent);
      this.addEventListener('error', handleEvent);
      this.addEventListener('abort', handleEvent);
      this.addEventListener('timeout', handleEvent);
      \(JAVASCRIPT_UTIL_VAR_NAME).convertBodyRequest(data).then(function(data) {
          var ajaxRequest = {
            data: data,
            method: self._flutter_inappwebview_method,
            url: self._flutter_inappwebview_url,
            isAsync: self._flutter_inappwebview_isAsync,
            user: self._flutter_inappwebview_user,
            password: self._flutter_inappwebview_password,
            withCredentials: self.withCredentials,
            headers: self._flutter_inappwebview_request_headers,
            responseType: self.responseType
          };
          window.\(JAVASCRIPT_BRIDGE_NAME).callHandler('shouldInterceptAjaxRequest', ajaxRequest).then(function(result) {
            if (result != null) {
              switch (result) {
                case 0:
                  self.abort();
                  return;
              };
              if (result.data != null && !\(JAVASCRIPT_UTIL_VAR_NAME).isString(result.data) && result.data.length > 0) {
                var bodyString = \(JAVASCRIPT_UTIL_VAR_NAME).arrayBufferToString(result.data);
                if (\(JAVASCRIPT_UTIL_VAR_NAME).isBodyFormData(bodyString)) {
                  var formDataContentType = \(JAVASCRIPT_UTIL_VAR_NAME).getFormDataContentType(bodyString);
                  if (result.headers != null) {
                    result.headers['Content-Type'] = result.headers['Content-Type'] == null ? formDataContentType : result.headers['Content-Type'];
                  } else {
                    result.headers = { 'Content-Type': formDataContentType };
                  }
                }
              }
              if (\(JAVASCRIPT_UTIL_VAR_NAME).isString(result.data) || result.data == null) {
                data = result.data;
              } else if (result.data.length > 0) {
                data = new Uint8Array(result.data);
              }
              self.withCredentials = result.withCredentials;
              if (result.responseType != null && self._flutter_inappwebview_isAsync) {
                self.responseType = result.responseType;
              };
              if (result.headers != null) {
                for (var header in result.headers) {
                  var value = result.headers[header];
                  var flutter_inappwebview_value = self._flutter_inappwebview_request_headers[header];
                  if (flutter_inappwebview_value == null) {
                    self._flutter_inappwebview_request_headers[header] = value;
                  } else {
                    self._flutter_inappwebview_request_headers[header] += ', ' + value;
                  }
                  setRequestHeader.call(self, header, value);
                };
              }
              if ((self._flutter_inappwebview_method != result.method && result.method != null) ||
                  (self._flutter_inappwebview_url != result.url && result.url != null) ||
                  (self._flutter_inappwebview_isAsync != result.isAsync && result.isAsync != null) ||
                  (self._flutter_inappwebview_user != result.user && result.user != null) ||
                  (self._flutter_inappwebview_password != result.password && result.password != null)) {
                self.abort();
                self.open(result.method, result.url, result.isAsync, result.user, result.password);
              }
            }
            send.call(self, data);
          });
      });
    } else {
      send.call(this, data);
    }
  };
})(window.XMLHttpRequest);
"""