put CompleteSecurity state management in store

and split off a child component (SetupCrossSigningBody) that can
be reused from the "Verify this session" toast.

src/stores/SetupEncryptionStore.js

@@ -0,0 +1,147 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import EventEmitter from 'events';
+import { MatrixClientPeg } from '../MatrixClientPeg';
+import { accessSecretStorage, AccessCancelledError } from '../CrossSigningManager';
+
+export const PHASE_INTRO = 0;
+export const PHASE_BUSY = 1;
+export const PHASE_DONE = 2;    //final done stage, but still showing UX
+export const PHASE_CONFIRM_SKIP = 3;
+export const PHASE_FINISHED = 4; //UX can be closed
+
+/**
+ * Holds the active "Complete Security" session
+ */
+export class SetupEncryptionStore extends EventEmitter {
+    static sharedInstance() {
+        if (!global.mx_SetupEncryptionStore) global.mx_SetupEncryptionStore = new SetupEncryptionStore();
+        return global.mx_SetupEncryptionStore;
+    }
+
+    start() {
+        if (this._started) {
+            return;
+        }
+        this._started = true;
+        this.phase = PHASE_INTRO;
+        this.verificationRequest = null;
+        this.backupInfo = null;
+        MatrixClientPeg.get().on("crypto.verification.request", this.onVerificationRequest);
+    }
+
+    stop() {
+        if (!this._started) {
+            return;
+        }
+        this._started = false;
+        if (this.verificationRequest) {
+            this.verificationRequest.off("change", this.onVerificationRequestChange);
+        }
+        if (MatrixClientPeg.get()) {
+            MatrixClientPeg.get().removeListener("crypto.verification.request", this.onVerificationRequest);
+        }
+    }
+
+    async usePassPhrase() {
+        this.phase = PHASE_BUSY;
+        this.emit("update");
+        const cli = MatrixClientPeg.get();
+        try {
+            const backupInfo = await cli.getKeyBackupVersion();
+            this.backupInfo = backupInfo;
+            this.emit("update");
+            // The control flow is fairly twisted here...
+            // For the purposes of completing security, we only wait on getting
+            // as far as the trust check and then show a green shield.
+            // We also begin the key backup restore as well, which we're
+            // awaiting inside `accessSecretStorage` only so that it keeps your
+            // passphase cached for that work. This dialog itself will only wait
+            // on the first trust check, and the key backup restore will happen
+            // in the background.
+            await new Promise((resolve, reject) => {
+                try {
+                    accessSecretStorage(async () => {
+                        await cli.checkOwnCrossSigningTrust();
+                        resolve();
+                        if (backupInfo) {
+                            // A complete restore can take many minutes for large
+                            // accounts / slow servers, so we allow the dialog
+                            // to advance before this.
+                            await cli.restoreKeyBackupWithSecretStorage(backupInfo);
+                        }
+                    }).catch(reject);
+                } catch (e) {
+                    console.error(e);
+                    reject(e);
+                }
+            });
+
+            if (cli.getCrossSigningId()) {
+                this.phase = PHASE_DONE;
+                this.emit("update");
+            }
+        } catch (e) {
+            if (!(e instanceof AccessCancelledError)) {
+                console.log(e);
+            }
+            // this will throw if the user hits cancel, so ignore
+            this.phase = PHASE_INTRO;
+            this.emit("update");
+        }
+    }
+
+    onVerificationRequest = async (request) => {
+        if (request.otherUserId !== MatrixClientPeg.get().getUserId()) return;
+
+        if (this.verificationRequest) {
+            this.verificationRequest.off("change", this.onVerificationRequestChange);
+        }
+        this.verificationRequest = request;
+        await request.accept();
+        request.on("change", this.onVerificationRequestChange);
+        this.emit("update");
+    }
+
+    onVerificationRequestChange = () => {
+        if (this.verificationRequest.cancelled) {
+            this.verificationRequest.off("change", this.onVerificationRequestChange);
+            this.verificationRequest = null;
+            this.emit("update");
+        }
+    }
+
+    skip() {
+        this.phase = PHASE_CONFIRM_SKIP;
+        this.emit("update");
+    }
+
+    skipConfirm() {
+        this.phase = PHASE_FINISHED;
+        this.emit("update");
+    }
+
+    returnAfterSkip() {
+        this.phase = PHASE_INTRO;
+        this.emit("update");
+    }
+
+    done() {
+        this.phase = PHASE_FINISHED;
+        this.emit("update");
+    }
+}