import Ember from 'ember';
import { inject as service } from '@ember/service';
import Component from './outer-html';
import { later } from '@ember/runloop';
import { task, timeout, waitForEvent } from 'ember-concurrency';
import { computed } from '@ember/object';
import { waitFor } from '@ember/test-waiters';

const WAIT_TIME = 500;
const ERROR_WINDOW_CLOSED =
  'The provider window was closed before authentication was complete.  Please click Sign In to try again.';
const ERROR_MISSING_PARAMS =
  'The callback from the provider did not supply all of the required parameters.  Please click Sign In to try again. If the problem persists, you may want to contact your administrator.';
const ERROR_JWT_LOGIN = 'OIDC login is not configured for this mount';
export { ERROR_WINDOW_CLOSED, ERROR_MISSING_PARAMS, ERROR_JWT_LOGIN };

export default Component.extend({
  store: service(),
  featureFlagService: service('featureFlag'),
  selectedAuthPath: null,
  selectedAuthType: null,
  roleName: null,
  role: null,
  errorMessage: null,
  onRoleName() {},
  onLoading() {},
  onError() {},
  onToken() {},
  onNamespace() {},

  didReceiveAttrs() {
    this._super();
    let { oldSelectedAuthPath, selectedAuthPath } = this;
    let shouldDebounce = !oldSelectedAuthPath && !selectedAuthPath;
    if (oldSelectedAuthPath !== selectedAuthPath) {
      this.set('role', null);
      this.onRoleName(this.roleName);
      this.fetchRole.perform(null, { debounce: false });
    } else if (shouldDebounce) {
      this.fetchRole.perform(this.roleName);
    }
    this.set('errorMessage', null);
    this.set('oldSelectedAuthPath', selectedAuthPath);
  },

  // Assumes authentication using OIDC until it's known that the mount is
  // configured for JWT authentication via static keys, JWKS, or OIDC discovery.
  isOIDC: computed('errorMessage', function () {
    return this.errorMessage !== ERROR_JWT_LOGIN;
  }),

  getWindow() {
    return this.window || window;
  },

  fetchRole: task(
    waitFor(function* (roleName, options = { debounce: true }) {
      if (options.debounce) {
        this.onRoleName(roleName);
        // debounce
        yield timeout(Ember.testing ? 0 : WAIT_TIME);
      }
      let path = this.selectedAuthPath || this.selectedAuthType;
      let id = JSON.stringify([path, roleName]);
      let role = null;
      try {
        role = yield this.store.findRecord('role-jwt', id, { adapterOptions: { namespace: this.namespace } });
      } catch (e) {
        // throwing here causes failures in tests
        if ((!e.httpStatus || e.httpStatus !== 400) && !Ember.testing) {
          throw e;
        }
        if (e.errors && e.errors.length > 0) {
          this.set('errorMessage', e.errors[0]);
        }
      }
      this.set('role', role);
    })
  ).restartable(),

  handleOIDCError(err) {
    this.onLoading(false);
    this.prepareForOIDC.cancelAll();
    this.onError(err);
  },

  prepareForOIDC: task(function* (oidcWindow) {
    const thisWindow = this.getWindow();
    // show the loading animation in the parent
    this.onLoading(true);
    // start watching the popup window and the current one
    this.watchPopup.perform(oidcWindow);
    this.watchCurrent.perform(oidcWindow);
    // wait for message posted from oidc callback
    // see issue https://github.com/hashicorp/vault/issues/12436
    // ensure that postMessage event is from expected source
    while (true) {
      const event = yield waitForEvent(thisWindow, 'message');
      if (event.origin !== thisWindow.origin || !event.isTrusted) {
        return this.handleOIDCError();
      }
      if (event.data.source === 'oidc-callback') {
        return this.exchangeOIDC.perform(event.data, oidcWindow);
      }
      // continue to wait for the correct message
    }
  }),

  watchPopup: task(function* (oidcWindow) {
    while (true) {
      yield timeout(WAIT_TIME);
      if (!oidcWindow || oidcWindow.closed) {
        return this.handleOIDCError(ERROR_WINDOW_CLOSED);
      }
    }
  }),

  watchCurrent: task(function* (oidcWindow) {
    // when user is about to change pages, close the popup window
    yield waitForEvent(this.getWindow(), 'beforeunload');
    oidcWindow.close();
  }),

  closeWindow(oidcWindow) {
    this.watchPopup.cancelAll();
    this.watchCurrent.cancelAll();
    oidcWindow.close();
  },

  exchangeOIDC: task(function* (oidcState, oidcWindow) {
    if (oidcState === null || oidcState === undefined) {
      return;
    }
    this.onLoading(true);

    let { namespace, path, state, code } = oidcState;

    // The namespace can be either be passed as a query paramter, or be embedded
    // in the state param in the format `<state_id>,ns=<namespace>`. So if
    // `namespace` is empty, check for namespace in state as well.
    if (namespace === '' || this.featureFlagService.managedNamespaceRoot) {
      let i = state.indexOf(',ns=');
      if (i >= 0) {
        // ",ns=" is 4 characters
        namespace = state.substring(i + 4);
        state = state.substring(0, i);
      }
    }

    // defer closing of the window, but continue executing the task
    later(() => {
      this.closeWindow(oidcWindow);
    }, WAIT_TIME);
    if (!path || !state || !code) {
      return this.handleOIDCError(ERROR_MISSING_PARAMS);
    }
    let adapter = this.store.adapterFor('auth-method');
    this.onNamespace(namespace);
    let resp;
    // do the OIDC exchange, set the token on the parent component
    // and submit auth form
    try {
      resp = yield adapter.exchangeOIDC(path, state, code);
    } catch (e) {
      return this.handleOIDCError(e);
    }
    let token = resp.auth.client_token;
    this.onSelectedAuth('token');
    this.onToken(token);
    yield this.onSubmit();
  }),

  actions: {
    async startOIDCAuth(data, e) {
      this.onError(null);
      if (e && e.preventDefault) {
        e.preventDefault();
      }
      if (!this.isOIDC || !this.role || !this.role.authUrl) {
        return;
      }

      await this.fetchRole.perform(this.roleName, { debounce: false });
      let win = this.getWindow();

      const POPUP_WIDTH = 500;
      const POPUP_HEIGHT = 600;
      let left = win.screen.width / 2 - POPUP_WIDTH / 2;
      let top = win.screen.height / 2 - POPUP_HEIGHT / 2;
      let oidcWindow = win.open(
        this.role.authUrl,
        'vaultOIDCWindow',
        `width=${POPUP_WIDTH},height=${POPUP_HEIGHT},resizable,scrollbars=yes,top=${top},left=${left}`
      );

      this.prepareForOIDC.perform(oidcWindow);
    },
  },
});