From 5c62938dbbf3fe4146bf18a10827cd51a4157049 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Josep=20Mar=C3=AD?= <xusoo@users.noreply.github.com>
Date: Wed, 12 Aug 2020 21:59:59 +0200
Subject: [PATCH] Add new method for cycling through every login (#142)

* Add new method for cycling through every login

To be used from browser extension when autofilling.
Related PR: https://github.com/bitwarden/browser/pull/956

* Cache sorted ciphers by URL and invalidate them after a period of 5 seconds

* Move file to models
---
 src/abstractions/cipher.service.ts      |  1 +
 src/models/domain/sortedCiphersCache.ts | 60 +++++++++++++++++++++++++
 src/services/cipher.service.ts          | 27 ++++++++---
 3 files changed, 82 insertions(+), 6 deletions(-)
 create mode 100644 src/models/domain/sortedCiphersCache.ts

diff --git a/src/abstractions/cipher.service.ts b/src/abstractions/cipher.service.ts
index 3c55b2cdbf..8ec886e240 100644
--- a/src/abstractions/cipher.service.ts
+++ b/src/abstractions/cipher.service.ts
@@ -24,6 +24,7 @@ export abstract class CipherService {
     getAllDecryptedForUrl: (url: string, includeOtherTypes?: CipherType[]) => Promise<CipherView[]>;
     getAllFromApiForOrganization: (organizationId: string) => Promise<CipherView[]>;
     getLastUsedForUrl: (url: string) => Promise<CipherView>;
+    getNextCipherForUrl: (url: string) => Promise<CipherView>;
     updateLastUsedDate: (id: string) => Promise<void>;
     saveNeverDomain: (domain: string) => Promise<void>;
     saveWithServer: (cipher: Cipher) => Promise<any>;
diff --git a/src/models/domain/sortedCiphersCache.ts b/src/models/domain/sortedCiphersCache.ts
new file mode 100644
index 0000000000..6976904d9d
--- /dev/null
+++ b/src/models/domain/sortedCiphersCache.ts
@@ -0,0 +1,60 @@
+import { CipherView } from '../view';
+
+const CacheTTL = 5000;
+
+export class SortedCiphersCache {
+    private readonly sortedCiphersByUrl: Map<string, Ciphers> = new Map<string, Ciphers>();
+    private readonly timeouts: Map<string, any> = new Map<string, any>();
+
+    constructor(private readonly comparator: (a: CipherView, b: CipherView) => number) { }
+
+    isCached(url: string) {
+        return this.sortedCiphersByUrl.has(url);
+    }
+
+    addCiphers(url: string, ciphers: CipherView[]) {
+        ciphers.sort(this.comparator);
+        this.sortedCiphersByUrl.set(url, new Ciphers(ciphers));
+        this.resetTimer(url);
+    }
+
+    getLastUsed(url: string) {
+        this.resetTimer(url);
+        return this.isCached(url) ? this.sortedCiphersByUrl.get(url).getLastUsed() : null;
+    }
+
+    getNext(url: string) {
+        this.resetTimer(url);
+        return this.isCached(url) ? this.sortedCiphersByUrl.get(url).getNext() : null;
+    }
+
+    clear() {
+        this.sortedCiphersByUrl.clear();
+        this.timeouts.clear();
+    }
+
+    private resetTimer(url: string) {
+        clearTimeout(this.timeouts.get(url));
+        this.timeouts.set(url, setTimeout(() => {
+            this.sortedCiphersByUrl.delete(url);
+            this.timeouts.delete(url);
+        }, CacheTTL));
+    }
+}
+
+class Ciphers {
+    lastUsedIndex = -1;
+
+    constructor(private readonly ciphers: CipherView[]) { }
+
+    getLastUsed() {
+        this.lastUsedIndex = Math.max(this.lastUsedIndex, 0);
+        return this.ciphers[this.lastUsedIndex];
+    }
+
+    getNext() {
+        const nextIndex = (this.lastUsedIndex + 1) % this.ciphers.length;
+        this.lastUsedIndex = nextIndex;
+        return this.ciphers[nextIndex];
+    }
+}
diff --git a/src/services/cipher.service.ts b/src/services/cipher.service.ts
index 5145f519b5..fe661bdeea 100644
--- a/src/services/cipher.service.ts
+++ b/src/services/cipher.service.ts
@@ -35,6 +35,8 @@ import { FieldView } from '../models/view/fieldView';
 import { PasswordHistoryView } from '../models/view/passwordHistoryView';
 import { View } from '../models/view/view';
 
+import { SortedCiphersCache } from '../models/domain/sortedCiphersCache';
+
 import { ApiService } from '../abstractions/api.service';
 import { CipherService as CipherServiceAbstraction } from '../abstractions/cipher.service';
 import { CryptoService } from '../abstractions/crypto.service';
@@ -63,6 +65,8 @@ export class CipherService implements CipherServiceAbstraction {
     // tslint:disable-next-line
     _decryptedCipherCache: CipherView[];
 
+    private sortedCiphersCache: SortedCiphersCache = new SortedCiphersCache(this.sortCiphersByLastUsed);
+
     constructor(private cryptoService: CryptoService, private userService: UserService,
         private settingsService: SettingsService, private apiService: ApiService,
         private storageService: StorageService, private i18nService: I18nService,
@@ -85,6 +89,7 @@ export class CipherService implements CipherServiceAbstraction {
 
     clearCache(): void {
         this.decryptedCipherCache = null;
+        this.sortedCiphersCache.clear();
     }
 
     async encrypt(model: CipherView, key?: SymmetricCryptoKey, originalCipher: Cipher = null): Promise<Cipher> {
@@ -437,13 +442,11 @@ export class CipherService implements CipherServiceAbstraction {
     }
 
     async getLastUsedForUrl(url: string): Promise<CipherView> {
-        const ciphers = await this.getAllDecryptedForUrl(url);
-        if (ciphers.length === 0) {
-            return null;
-        }
+        return this.getCipherForUrl(url, true);
+    }
 
-        const sortedCiphers = ciphers.sort(this.sortCiphersByLastUsed);
-        return sortedCiphers[0];
+    async getNextCipherForUrl(url: string): Promise<CipherView> {
+        return this.getCipherForUrl(url, false);
     }
 
     async updateLastUsedDate(id: string): Promise<void> {
@@ -1002,4 +1005,16 @@ export class CipherService implements CipherServiceAbstraction {
                 throw new Error('Unknown cipher type.');
         }
     }
+
+    private async getCipherForUrl(url: string, lastUsed: boolean): Promise<CipherView> {
+        if (!this.sortedCiphersCache.isCached(url)) {
+            const ciphers = await this.getAllDecryptedForUrl(url);
+            if (!ciphers) {
+                return null;
+            }
+            this.sortedCiphersCache.addCiphers(url, ciphers);
+        }
+
+        return lastUsed ? this.sortedCiphersCache.getLastUsed(url) : this.sortedCiphersCache.getNext(url);
+    }
 }