From 0e380a26ba009c8b9bdea0a76146d29272c609de Mon Sep 17 00:00:00 2001
From: Lynn Smeria <ae@cephea.de>
Date: Wed, 18 Mar 2020 01:30:56 +0200
Subject: [PATCH] Collect & simulate hooks

---
 hooks.js     | 38 +++++++++++++++++++++++++++++++++
 index.js     | 59 +++++++++++++++++++++++++++++++++++++++++++++++-----
 package.json |  3 ++-
 yarn.lock    |  5 +++++
 4 files changed, 99 insertions(+), 6 deletions(-)
 create mode 100644 hooks.js

diff --git a/hooks.js b/hooks.js
new file mode 100644
index 0000000..d5614f1
--- /dev/null
+++ b/hooks.js
@@ -0,0 +1,38 @@
+const fs = require('fs').promises;
+const ms = require('ms');
+const os = require('os');
+const path = require('path');
+
+const getHooksRoot = () => path.join(os.homedir(), '/.syncthing-hooks');
+
+const readHooksRoot = async root => {
+  try {
+    const files = await fs.readdir(root);
+    return files;
+  } catch {
+    return [];
+  }
+};
+
+const parseHooks = (root, hooks) =>
+  hooks
+    .map(x => ({
+      path: path.join(root, x),
+      match: x.match(/(?<folder>.{11})-(?<time>.*)/),
+    }))
+    .filter(x => x.match)
+    .map(x => ({
+      path: x.path,
+      folder: x.match.groups.folder,
+      time: ms(x.match.groups.time),
+    }));
+
+const collectHooks = async () => {
+  const root = getHooksRoot();
+  const hooks = await readHooksRoot(root);
+  return parseHooks(root, hooks);
+};
+
+module.exports = {
+  collectHooks,
+};
diff --git a/index.js b/index.js
index 4d2c171..00a1f65 100644
--- a/index.js
+++ b/index.js
@@ -1,13 +1,62 @@
 const { fetchNewEvents } = require('./api');
+const { collectHooks } = require('./hooks');
 
 require('dotenv').config();
 
-const state = {};
+const state = {
+  seenIds: null,
+  mostRecentEventForFolder: null,
+};
+
+const getMostRecentEvents = (events, monitoredFolders) => {
+  const mostRecentEventForFolder = events
+    .filter(x => x.data && x.data.folder)
+    .filter(x => monitoredFolders.has(x.data.folder))
+    .reduce(
+      (acc, x) => {
+        const date = new Date(x.time);
+        const existingDate = acc[x.data.folder];
+        acc[x.data.folder] =
+          existingDate && existingDate > date ? existingDate : date;
+        return acc;
+      },
+      state.mostRecentEventForFolder
+        ? { ...state.mostRecentEventForFolder }
+        : {}
+    );
+  state.mostRecentEventForFolder = mostRecentEventForFolder;
+  return mostRecentEventForFolder;
+};
+
+const convertRecentEventDatesToDelta = () => {
+  const now = new Date().getTime();
+  return Object.entries(state.mostRecentEventForFolder)
+    .map(([folder, date]) => [folder, now - date.getTime()])
+    .reduce((acc, [path, delta]) => {
+      acc[path] = delta;
+      return acc;
+    }, {});
+};
 
 setInterval(async () => {
   const { events, seenIds } = await fetchNewEvents(state.seenIds);
+  const hooks = await collectHooks();
+  const monitoredFolders = new Set(hooks.map(x => x.folder));
+  const deltaForFolders =
+    getMostRecentEvents(events, monitoredFolders) &&
+    convertRecentEventDatesToDelta();
+
+  hooks
+    .filter(x => deltaForFolders[x.folder])
+    .forEach(hook => {
+      const timeToWait = hook.time - deltaForFolders[hook.folder];
+      console.log(timeToWait);
+      if (timeToWait < 0) {
+        delete state.mostRecentEventForFolder[hook.folder];
+        console.log('running hook', hook);
+      }
+    });
+
+  console.warn(deltaForFolders);
   state.seenIds = seenIds;
-  events.forEach(event => {
-    console.log(event);
-  });
-}, 1000);
+}, 2000);
diff --git a/package.json b/package.json
index 296d15a..58db71b 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "dotenv": "8.2.0",
-    "got": "10.6.0"
+    "got": "10.6.0",
+    "ms": "2.1.2"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index 2849ffc..0b4a9df 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -164,6 +164,11 @@ mimic-response@^2.0.0, mimic-response@^2.1.0:
   resolved "https://registry.yarnpkg.com/mimic-response/-/mimic-response-2.1.0.tgz#d13763d35f613d09ec37ebb30bac0469c0ee8f43"
   integrity sha512-wXqjST+SLt7R009ySCglWBCFpjUygmCIfD790/kVbiGmUgfYGuB14PiTd5DwVxSV4NcYHjzMkoj5LjQZwTQLEA==
 
+ms@2.1.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
+  integrity sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==
+
 normalize-url@^4.1.0:
   version "4.5.0"
   resolved "https://registry.yarnpkg.com/normalize-url/-/normalize-url-4.5.0.tgz#453354087e6ca96957bd8f5baf753f5982142129"