From 90762897db2c1e9df7b80a51e7d9bf273fd3d6d8 Mon Sep 17 00:00:00 2001
From: Nolan Lawson <nolan@nolanlawson.com>
Date: Thu, 18 Jan 2018 20:25:34 -0800
Subject: [PATCH] first stab at online mode

---
 package-lock.json                    |  5 ---
 package.json                         |  1 -
 routes/_components/Layout.html       |  9 ++--
 routes/_components/Timeline.html     | 45 +++++++++++++++----
 routes/_utils/database/database.js   |  2 -
 routes/_utils/database/idb-keyval.js | 57 ------------------------
 routes/_utils/database/statuses.js   | 65 ++++++++++++++++++++++++++++
 routes/_utils/mastodon/oauth.js      | 19 --------
 routes/_utils/mastodon/timelines.js  | 20 +++++++++
 routes/_utils/statuses.js            | 33 ++++++++++++++
 10 files changed, 159 insertions(+), 97 deletions(-)
 delete mode 100644 routes/_utils/database/database.js
 delete mode 100644 routes/_utils/database/idb-keyval.js
 create mode 100644 routes/_utils/database/statuses.js
 create mode 100644 routes/_utils/mastodon/timelines.js
 create mode 100644 routes/_utils/statuses.js

diff --git a/package-lock.json b/package-lock.json
index 85fae1c1..f5a85226 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3282,11 +3282,6 @@
         }
       }
     },
-    "idb": {
-      "version": "2.0.4",
-      "resolved": "https://registry.npmjs.org/idb/-/idb-2.0.4.tgz",
-      "integrity": "sha512-Nw4ykKrrVje6YODRiRm/k2ucFEQeoY+zrkszfOuzVmxx8yyBMtZh2KLaRCKk9r5GzhuF0QlNCVjBewP2n5OZ7Q=="
-    },
     "ieee754": {
       "version": "1.1.8",
       "resolved": "https://registry.npmjs.org/ieee754/-/ieee754-1.1.8.tgz",
diff --git a/package.json b/package.json
index 6d953475..3a3d94d8 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,6 @@
     "fg-loadcss": "^2.0.1",
     "font-awesome-svg-png": "^1.2.2",
     "glob": "^7.1.2",
-    "idb": "^2.0.4",
     "intersection-observer": "^0.5.0",
     "intl-relativeformat": "^2.1.0",
     "lodash": "^4.17.4",
diff --git a/routes/_components/Layout.html b/routes/_components/Layout.html
index 947ae82c..def3f340 100644
--- a/routes/_components/Layout.html
+++ b/routes/_components/Layout.html
@@ -20,16 +20,17 @@
 	export default {
 	  oncreate() {
       mark('onCreate Layout')
+      let node = this.refs.node
       this.observe('innerHeight', debounce(() => {
         // respond to window resize events
         this.store.set({
-          offsetHeight: this.refs.node.offsetHeight
+          offsetHeight: node.offsetHeight
         })
       }, RESIZE_EVENT_DELAY))
 	    this.store.set({
-        scrollTop: this.refs.node.scrollTop,
-        scrollHeight: this.refs.node.scrollHeight,
-        offsetHeight: this.refs.node.offsetHeight
+        scrollTop: node.scrollTop,
+        scrollHeight: node.scrollHeight,
+        offsetHeight: node.offsetHeight
       })
       stop('onCreate Layout')
     },
diff --git a/routes/_components/Timeline.html b/routes/_components/Timeline.html
index 3a4e06b1..6aa756e4 100644
--- a/routes/_components/Timeline.html
+++ b/routes/_components/Timeline.html
@@ -1,3 +1,4 @@
+<:Window bind:online />
 <div class="timeline" role="feed" aria-label="{{label}}">
   <VirtualList component="{{StatusListItem}}"
                items="{{keyedStatuses}}"
@@ -10,20 +11,32 @@
 </style>
 <script>
   import { store } from '../_utils/store'
-  import { getHomeTimeline } from '../_utils/mastodon/oauth'
+  import { getHomeTimeline } from '../_utils/mastodon/timelines'
   import StatusListItem from './StatusListItem.html'
   import VirtualList from './VirtualList.html'
   import { splice, push } from 'svelte-extras'
+  import {
+    insertStatuses as insertStatusesIntoDatabase,
+    getTimelineAfter as getTimelineFromDatabaseAfter
+  } from '../_utils/database/statuses'
+  import { mergeStatuses } from '../_utils/statuses'
   import { mark, stop } from '../_utils/marks'
 
+  const FETCH_LIMIT = 20
+
   export default {
     async oncreate() {
+      this.observe('online', e => console.log(e))
       let instanceName = this.store.get('currentInstance')
       let instanceData = this.store.get('currentInstanceData')
-      let statuses = await getHomeTimeline(instanceName, instanceData.access_token, null, 10)
-      this.set({
-        statuses: statuses,
-      })
+      let online = this.get('online')
+      let statuses = online ?
+        await getHomeTimeline(instanceName, instanceData.access_token, null, FETCH_LIMIT) :
+        await getTimelineFromDatabaseAfter(null, FETCH_LIMIT)
+      if (!online) {
+        insertStatusesIntoDatabase(statuses)
+      }
+      this.addStatuses(statuses)
     },
     data: () => ({
       target: 'home',
@@ -55,16 +68,30 @@
         let lastStatusId = this.get('lastStatusId')
         let instanceName = this.store.get('currentInstance')
         let instanceData = this.store.get('currentInstanceData')
-        let newStatuses = await getHomeTimeline(instanceName, instanceData.access_token, lastStatusId, 10)
+        let online = this.get('online')
+        let newStatuses = online ?
+          await getHomeTimeline(instanceName, instanceData.access_token, lastStatusId, FETCH_LIMIT) :
+          await getTimelineFromDatabaseAfter(lastStatusId, FETCH_LIMIT)
+        if (online) {
+          insertStatusesIntoDatabase(newStatuses)
+        }
         let statuses = this.get('statuses')
         if (statuses) {
-          this.addItems(newStatuses)
+          this.addStatuses(newStatuses)
         }
         this.set({ runningUpdate: false })
         stop('onScrollToBottom')
       },
-      addItems(items) {
-        this.splice('statuses', this.get('statuses').length, 0, ...items)
+      addStatuses(newStatuses) {
+        if (process.env.NODE_ENV !== 'production') {
+          console.log('addStatuses()')
+        }
+        let statuses = this.get('statuses')
+        if (!statuses) {
+          return
+        }
+        let merged = mergeStatuses(statuses, newStatuses)
+        this.set({ statuses: merged })
       }
     }
   }
diff --git a/routes/_utils/database/database.js b/routes/_utils/database/database.js
deleted file mode 100644
index ccd53e75..00000000
--- a/routes/_utils/database/database.js
+++ /dev/null
@@ -1,2 +0,0 @@
-import keyval from './idb-keyval'
-
diff --git a/routes/_utils/database/idb-keyval.js b/routes/_utils/database/idb-keyval.js
deleted file mode 100644
index 765dbcc1..00000000
--- a/routes/_utils/database/idb-keyval.js
+++ /dev/null
@@ -1,57 +0,0 @@
-import idb from 'idb'
-
-// copypasta'd from https://github.com/jakearchibald/idb#keyval-store
-
-const dbPromise = idb.open('keyval-store', 1, upgradeDB => {
-  upgradeDB.createObjectStore('keyval')
-})
-
-const idbKeyval = {
-  get(key) {
-    return dbPromise.then(db => {
-      return db.transaction('keyval').objectStore('keyval').get(key)
-    })
-  },
-  set(key, val) {
-    return dbPromise.then(db => {
-      const tx = db.transaction('keyval', 'readwrite')
-      tx.objectStore('keyval').put(val, key)
-      return tx.complete
-    })
-  },
-  delete(key) {
-    return dbPromise.then(db => {
-      const tx = db.transaction('keyval', 'readwrite')
-      tx.objectStore('keyval').delete(key)
-      return tx.complete
-    })
-  },
-  clear() {
-    return dbPromise.then(db => {
-      const tx = db.transaction('keyval', 'readwrite')
-      tx.objectStore('keyval').clear()
-      return tx.complete
-    })
-  },
-  keys() {
-    return dbPromise.then(db => {
-      const tx = db.transaction('keyval')
-      const keys = []
-      const store = tx.objectStore('keyval')
-      // This would be store.getAllKeys(), but it isn't supported by Edge or Safari.
-      // openKeyCursor isn't supported by Safari, so we fall back
-      const iterate = store.iterateKeyCursor || store.iterateCursor
-      iterate.call(store, cursor => {
-        if (!cursor) {
-          return
-        }
-        keys.push(cursor.key)
-        cursor.continue()
-      })
-
-      return tx.complete.then(() => keys)
-    })
-  }
-}
-
-export default idbKeyval
\ No newline at end of file
diff --git a/routes/_utils/database/statuses.js b/routes/_utils/database/statuses.js
new file mode 100644
index 00000000..d88852fa
--- /dev/null
+++ b/routes/_utils/database/statuses.js
@@ -0,0 +1,65 @@
+import cloneDeep from 'lodash/cloneDeep'
+
+const STORE = 'statuses'
+
+const dbPromise = new Promise((resolve, reject) => {
+  let req = indexedDB.open(STORE, 1)
+  req.onerror = reject
+  req.onblocked = () => {
+    console.log('idb blocked')
+  }
+  req.onupgradeneeded = () => {
+    let db = req.result;
+    let oStore = db.createObjectStore(STORE, {
+      keyPath: 'id'
+    })
+    oStore.createIndex('created_at', 'created_at')
+    oStore.createIndex('pinafore_id_as_negative_big_int', 'pinafore_id_as_negative_big_int')
+    oStore.createIndex('pinafore_id_as_big_int', 'pinafore_id_as_big_int')
+  }
+  req.onsuccess = () => resolve(req.result)
+})
+
+function transformStatusForStorage(status) {
+  status = cloneDeep(status)
+  status.pinafore_id_as_big_int = parseInt(status, 10)
+  status.pinafore_id_as_negative_big_int = -parseInt(status, 10)
+  status.pinafore_stale = true
+  return status
+}
+
+export async function getTimelineAfter(max_id = null, limit = 20) {
+  const db = await dbPromise
+  return await new Promise((resolve, reject) => {
+    const tx = db.transaction(STORE, 'readonly')
+    const store = tx.objectStore(STORE)
+    const index = store.index('pinafore_id_as_negative_big_int')
+    let res
+    let sinceAsNegativeBigInt = max_id === null ? null : -parseInt(max_id, 10)
+    let query = sinceAsNegativeBigInt === null ? null : IDBKeyRange.lowerBound(sinceAsNegativeBigInt, false)
+
+    index.getAll(query, limit).onsuccess = (e) => {
+      console.log('done calling getAll()')
+      res = e.target.result
+    }
+
+    tx.oncomplete = () => {
+      console.log('complete')
+      resolve(res)
+    }
+    tx.onerror = reject
+  })
+}
+
+export async function insertStatuses(statuses) {
+  const db = await dbPromise
+  return await new Promise((resolve, reject) => {
+    const tx = db.transaction(STORE, 'readwrite')
+    const store = tx.objectStore(STORE)
+    for (let status of statuses) {
+      store.put(transformStatusForStorage(status))
+    }
+    tx.oncomplete = resolve
+    tx.onerror = reject
+  })
+}
\ No newline at end of file
diff --git a/routes/_utils/mastodon/oauth.js b/routes/_utils/mastodon/oauth.js
index 1e751758..8911dd8c 100644
--- a/routes/_utils/mastodon/oauth.js
+++ b/routes/_utils/mastodon/oauth.js
@@ -32,23 +32,4 @@ export function getAccessTokenFromAuthCode(instanceName, clientId, clientSecret,
     grant_type: 'authorization_code',
     code: code
   })
-}
-
-export function getHomeTimeline(instanceName, accessToken, since, limit) {
-  let url = `https://${instanceName}/api/v1/timelines/home`
-
-  let params = {}
-  if (since) {
-    params[since] = since
-  }
-
-  if (limit) {
-    params[limit] = limit
-  }
-
-  url += '?' + paramsString(params)
-
-  return get(url, {
-    'Authorization': `Bearer ${accessToken}`
-  })
 }
\ No newline at end of file
diff --git a/routes/_utils/mastodon/timelines.js b/routes/_utils/mastodon/timelines.js
new file mode 100644
index 00000000..2ad3093f
--- /dev/null
+++ b/routes/_utils/mastodon/timelines.js
@@ -0,0 +1,20 @@
+import { get, paramsString } from '../ajax'
+
+export function getHomeTimeline(instanceName, accessToken, maxId, since) {
+  let url = `https://${instanceName}/api/v1/timelines/home`
+
+  let params = {}
+  if (since) {
+    params.since = since
+  }
+
+  if (maxId) {
+    params.max_id = maxId
+  }
+
+  url += '?' + paramsString(params)
+
+  return get(url, {
+    'Authorization': `Bearer ${accessToken}`
+  })
+}
\ No newline at end of file
diff --git a/routes/_utils/statuses.js b/routes/_utils/statuses.js
new file mode 100644
index 00000000..93654556
--- /dev/null
+++ b/routes/_utils/statuses.js
@@ -0,0 +1,33 @@
+// Merge two lists of statuses for the same timeline, e.g. one from IDB
+// and another from the network. In case of duplicates, prefer the fresh.
+export function mergeStatuses(leftStatuses, rightStatuses) {
+  let leftIndex = 0
+  let rightIndex = 0
+  let merged = []
+  while (leftIndex < leftStatuses.length || rightIndex < rightStatuses.length) {
+    if (leftIndex === leftStatuses.length) {
+      merged.push(rightStatuses[rightIndex])
+      rightIndex++
+      continue
+    }
+    if (rightIndex === rightStatuses.length) {
+      merged.push(leftStatuses[leftIndex])
+      leftIndex++
+      continue
+    }
+    let left = leftStatuses[leftIndex]
+    let right = rightStatuses[rightIndex]
+    if (right.id === left.id) {
+      merged.push(right.pinafore_stale ? left : right)
+      rightIndex++
+      leftIndex++
+    } else if (parseInt(right.id, 10) > parseInt(left.id, 10)) {
+      merged.push(right)
+      rightIndex++
+    } else {
+      merged.push(left)
+      leftIndex++
+    }
+  }
+  return merged
+}
\ No newline at end of file