From 10689d9ef9e05e9cda6c814fbcdccb674f77bcd0 Mon Sep 17 00:00:00 2001
From: thecodrr <thecodrr@protonmail.com>
Date: Mon, 24 Aug 2020 13:07:16 +0500
Subject: [PATCH] feat: implement direct syncing using sse (experimental)

---
 packages/core/api/index.js      |  3 ++-
 packages/core/api/sync/index.js | 23 ++++++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/packages/core/api/index.js b/packages/core/api/index.js
index cd015e79d..9b87016dd 100644
--- a/packages/core/api/index.js
+++ b/packages/core/api/index.js
@@ -92,7 +92,8 @@ class Database {
           this.ev.publish("user:upgraded", data);
           break;
         case "sync":
-          this.ev.publish("db:sync");
+          await this.syncer.eventMerge(data);
+          this.ev.publish("db:refresh");
           break;
       }
     };
diff --git a/packages/core/api/sync/index.js b/packages/core/api/sync/index.js
index 07f8ccc40..aad1bb6bf 100644
--- a/packages/core/api/sync/index.js
+++ b/packages/core/api/sync/index.js
@@ -52,7 +52,7 @@ export default class Sync {
     return await response.json();
   }
 
-  async start() {
+  async _performChecks() {
     let user = await this._db.user.get();
     let token = await this._db.user.token();
     if (!user || !token) throw new Error("You need to login to sync.");
@@ -62,6 +62,13 @@ export default class Sync {
     await this._db.conflicts.check();
 
     let lastSynced = user.notesnook.lastSynced || 0;
+
+    return { user, lastSynced, token };
+  }
+
+  async start() {
+    let { user, lastSynced, token } = await this._performChecks();
+
     let serverResponse = await this._fetch(lastSynced, token);
 
     // we prepare local data before merging so we always have correct data
@@ -82,6 +89,20 @@ export default class Sync {
     }
   }
 
+  async eventMerge(serverResponse) {
+    let { user, lastSynced } = await this._performChecks();
+    // merge the server response
+    await this._merger.merge(serverResponse, lastSynced);
+
+    // check for conflicts and throw
+    await this._db.conflicts.check();
+
+    // update our lastSynced time
+    if (lastSynced) {
+      await this._db.user.set({ notesnook: { ...user.notesnook, lastSynced } });
+    }
+  }
+
   async _send(data, token) {
     let response = await fetch(`${HOST}/sync`, {
       method: "POST",