function _extends() {
  _extends = Object.assign || function (target) {
    for (var i = 1; i < arguments.length; i++) {
      var source = arguments[i];

      for (var key in source) {
        if (Object.prototype.hasOwnProperty.call(source, key)) {
          target[key] = source[key];
        }
      }
    }

    return target;
  };

  return _extends.apply(this, arguments);
}

/**
 * Actions represent the type of change to a location value.
 *
 * @see https://github.com/remix-run/history/tree/main/docs/api-reference.md#action
 */
var Action;

(function (Action) {
  /**
   * A POP indicates a change to an arbitrary index in the history stack, such
   * as a back or forward navigation. It does not describe the direction of the
   * navigation, only that the current index changed.
   *
   * Note: This is the default action for newly created history objects.
   */
  Action["Pop"] = "POP";
  /**
   * A PUSH indicates a new entry being added to the history stack, such as when
   * a link is clicked and a new page loads. When this happens, all subsequent
   * entries in the stack are lost.
   */

  Action["Push"] = "PUSH";
  /**
   * A REPLACE indicates the entry at the current index in the history stack
   * being replaced by a new one.
   */

  Action["Replace"] = "REPLACE";
})(Action || (Action = {}));

var readOnly = process.env.NODE_ENV !== "production" ? function (obj) {
  return Object.freeze(obj);
} : function (obj) {
  return obj;
};

function warning(cond, message) {
  if (!cond) {
    // eslint-disable-next-line no-console
    if (typeof console !== 'undefined') console.warn(message);

    try {
      // Welcome to debugging history!
      //
      // This error is thrown as a convenience so you can more easily
      // find the source for a warning that appears in the console by
      // enabling "pause on exceptions" in your JavaScript debugger.
      throw new Error(message); // eslint-disable-next-line no-empty
    } catch (e) {}
  }
}

var BeforeUnloadEventType = 'beforeunload';
var PopStateEventType = 'popstate';
/**
 * Browser history stores the location in regular URLs. This is the standard for
 * most web apps, but it requires some configuration on the server to ensure you
 * serve the same app at multiple URLs.
 *
 * @see https://github.com/remix-run/history/tree/main/docs/api-reference.md#createbrowserhistory
 */

function createBrowserHistory(options) {
  if (options === void 0) {
    options = {};
  }

  var _options = options,
      _options$window = _options.window,
      window = _options$window === void 0 ? document.defaultView : _options$window;
  var globalHistory = window.history;

  function getIndexAndLocation() {
    var _window$location = window.location,
        pathname = _window$location.pathname,
        search = _window$location.search,
        hash = _window$location.hash;
    var state = globalHistory.state || {};
    return [state.idx, readOnly({
      pathname: pathname,
      search: search,
      hash: hash,
      state: state.usr || null,
      key: state.key || 'default'
    })];
  }

  var blockedPopTx = null;

  function handlePop() {
    if (blockedPopTx) {
      blockers.call(blockedPopTx);
      blockedPopTx = null;
    } else {
      var nextAction = Action.Pop;

      var _getIndexAndLocation = getIndexAndLocation(),
          nextIndex = _getIndexAndLocation[0],
          nextLocation = _getIndexAndLocation[1];

      if (blockers.length) {
        if (nextIndex != null) {
          var delta = index - nextIndex;

          if (delta) {
            // Revert the POP
            blockedPopTx = {
              action: nextAction,
              location: nextLocation,
              retry: function retry() {
                go(delta * -1);
              }
            };
            go(delta);
          }
        } else {
          // Trying to POP to a location with no index. We did not create
          // this location, so we can't effectively block the navigation.
          process.env.NODE_ENV !== "production" ? warning(false, // TODO: Write up a doc that explains our blocking strategy in
          // detail and link to it here so people can understand better what
          // is going on and how to avoid it.
          "You are trying to block a POP navigation to a location that was not " + "created by the history library. The block will fail silently in " + "production, but in general you should do all navigation with the " + "history library (instead of using window.history.pushState directly) " + "to avoid this situation.") : void 0;
        }
      } else {
        applyTx(nextAction);
      }
    }
  }

  window.addEventListener(PopStateEventType, handlePop);
  var action = Action.Pop;

  var _getIndexAndLocation2 = getIndexAndLocation(),
      index = _getIndexAndLocation2[0],
      location = _getIndexAndLocation2[1];

  var listeners = createEvents();
  var blockers = createEvents();

  if (index == null) {
    index = 0;
    globalHistory.replaceState(_extends({}, globalHistory.state, {
      idx: index
    }), '');
  }

  function createHref(to) {
    return typeof to === 'string' ? to : createPath(to);
  } // state defaults to `null` because `window.history.state` does


  function getNextLocation(to, state) {
    if (state === void 0) {
      state = null;
    }

    return readOnly(_extends({
      pathname: location.pathname,
      hash: '',
      search: ''
    }, typeof to === 'string' ? parsePath(to) : to, {
      state: state,
      key: createKey()
    }));
  }

  function getHistoryStateAndUrl(nextLocation, index) {
    return [{
      usr: nextLocation.state,
      key: nextLocation.key,
      idx: index
    }, createHref(nextLocation)];
  }

  function allowTx(action, location, retry) {
    return !blockers.length || (blockers.call({
      action: action,
      location: location,
      retry: retry
    }), false);
  }

  function applyTx(nextAction) {
    action = nextAction;

    var _getIndexAndLocation3 = getIndexAndLocation();

    index = _getIndexAndLocation3[0];
    location = _getIndexAndLocation3[1];
    listeners.call({
      action: action,
      location: location
    });
  }

  function push(to, state) {
    var nextAction = Action.Push;
    var nextLocation = getNextLocation(to, state);

    function retry() {
      push(to, state);
    }

    if (allowTx(nextAction, nextLocation, retry)) {
      var _getHistoryStateAndUr = getHistoryStateAndUrl(nextLocation, index + 1),
          historyState = _getHistoryStateAndUr[0],
          url = _getHistoryStateAndUr[1]; // TODO: Support forced reloading
      // try...catch because iOS limits us to 100 pushState calls :/


      try {
        globalHistory.pushState(historyState, '', url);
      } catch (error) {
        // They are going to lose state here, but there is no real
        // way to warn them about it since the page will refresh...
        window.location.assign(url);
      }

      applyTx(nextAction);
    }
  }

  function replace(to, state) {
    var nextAction = Action.Replace;
    var nextLocation = getNextLocation(to, state);

    function retry() {
      replace(to, state);
    }

    if (allowTx(nextAction, nextLocation, retry)) {
      var _getHistoryStateAndUr2 = getHistoryStateAndUrl(nextLocation, index),
          historyState = _getHistoryStateAndUr2[0],
          url = _getHistoryStateAndUr2[1]; // TODO: Support forced reloading


      globalHistory.replaceState(historyState, '', url);
      applyTx(nextAction);
    }
  }

  function go(delta) {
    globalHistory.go(delta);
  }

  var history = {
    get action() {
      return action;
    },

    get location() {
      return location;
    },

    createHref: createHref,
    push: push,
    replace: replace,
    go: go,
    back: function back() {
      go(-1);
    },
    forward: function forward() {
      go(1);
    },
    listen: function listen(listener) {
      return listeners.push(listener);
    },
    block: function block(blocker) {
      var unblock = blockers.push(blocker);

      if (blockers.length === 1) {
        window.addEventListener(BeforeUnloadEventType, promptBeforeUnload);
      }

      return function () {
        unblock(); // Remove the beforeunload listener so the document may
        // still be salvageable in the pagehide event.
        // See https://html.spec.whatwg.org/#unloading-documents

        if (!blockers.length) {
          window.removeEventListener(BeforeUnloadEventType, promptBeforeUnload);
        }
      };
    }
  };
  return history;
}

function promptBeforeUnload(event) {
  // Cancel the event.
  event.preventDefault(); // Chrome (and legacy IE) requires returnValue to be set.

  event.returnValue = '';
}

function createEvents() {
  var handlers = [];
  return {
    get length() {
      return handlers.length;
    },

    push: function push(fn) {
      handlers.push(fn);
      return function () {
        handlers = handlers.filter(function (handler) {
          return handler !== fn;
        });
      };
    },
    call: function call(arg) {
      handlers.forEach(function (fn) {
        return fn && fn(arg);
      });
    }
  };
}

function createKey() {
  return Math.random().toString(36).substr(2, 8);
}
/**
 * Creates a string URL path from the given pathname, search, and hash components.
 *
 * @see https://github.com/remix-run/history/tree/main/docs/api-reference.md#createpath
 */


function createPath(_ref) {
  var _ref$pathname = _ref.pathname,
      pathname = _ref$pathname === void 0 ? '/' : _ref$pathname,
      _ref$search = _ref.search,
      search = _ref$search === void 0 ? '' : _ref$search,
      _ref$hash = _ref.hash,
      hash = _ref$hash === void 0 ? '' : _ref$hash;
  if (search && search !== '?') pathname += search.charAt(0) === '?' ? search : '?' + search;
  if (hash && hash !== '#') pathname += hash.charAt(0) === '#' ? hash : '#' + hash;
  return pathname;
}
/**
 * Parses a string URL path into its separate pathname, search, and hash components.
 *
 * @see https://github.com/remix-run/history/tree/main/docs/api-reference.md#parsepath
 */

function parsePath(path) {
  var parsedPath = {};

  if (path) {
    var hashIndex = path.indexOf('#');

    if (hashIndex >= 0) {
      parsedPath.hash = path.substr(hashIndex);
      path = path.substr(0, hashIndex);
    }

    var searchIndex = path.indexOf('?');

    if (searchIndex >= 0) {
      parsedPath.search = path.substr(searchIndex);
      path = path.substr(0, searchIndex);
    }

    if (path) {
      parsedPath.pathname = path;
    }
  }

  return parsedPath;
}

/**
 * Create a default instance for the current document.
 */

var browser = createBrowserHistory();

export { browser as default };
//# sourceMappingURL=browser.js.map