Merge branch 'tag-history-date' into 'develop'

Trends: fill in empty tag histories

Closes #29

See merge request soapbox-pub/ditto!3

src/controllers/api/trends.ts

@@ -3,6 +3,7 @@ import { Conf } from '@/config.ts';
 import { z } from '@/deps.ts';
 import { trends } from '@/trends.ts';
 import { Time } from '@/utils.ts';
+import { stripTime } from '@/utils/time.ts';
 
 const limitSchema = z.coerce.number().catch(10).transform((value) => Math.min(Math.max(value, 0), 20));
 
@@ -14,6 +15,7 @@ const trendingTagsController: AppController = (c) => {
   const yesterday = new Date(now.getTime() - Time.days(1));
   const lastWeek = new Date(now.getTime() - Time.days(7));
 
+  /** Most used hashtags within the past 24h. */
   const tags = trends.getTrendingTags({
     since: yesterday,
     until: now,
@@ -24,8 +26,10 @@ const trendingTagsController: AppController = (c) => {
     name,
     url: Conf.local(`/tags/${name}`),
     history: [
+      // Use the full 24h query for the current day. Then use `offset: 1` to adjust for this below.
+      // This result is more accurate than what Mastodon returns.
       {
-        day: String(Math.floor(now.getTime() / 1000)),
+        day: String(Math.floor(stripTime(now).getTime() / 1000)),
         accounts: String(accounts),
         uses: String(uses),
       },
@@ -36,6 +40,7 @@ const trendingTagsController: AppController = (c) => {
         limit: 6,
         offset: 1,
       }).map((history) => ({
+        // For some reason, Mastodon wants these to be strings... oh well.
         day: String(Math.floor(history.day.getTime() / 1000)),
         accounts: String(history.accounts),
         uses: String(history.uses),

src/trends.ts

@@ -1,6 +1,7 @@
 import { Sqlite } from '@/deps.ts';
 import { hashtagSchema, hexIdSchema } from '@/schema.ts';
-import { Time } from './utils.ts';
+import { Time } from '@/utils.ts';
+import { generateDateRange } from '@/utils/time.ts';
 
 interface GetTrendingTagsOpts {
   since: Date;
@@ -43,6 +44,7 @@ class TrendsDB {
     cleanup();
   }
 
+  /** Gets the most used hashtags between the date range. */
   getTrendingTags({ since, until, limit = 10, threshold = 3 }: GetTrendingTagsOpts) {
     return this.#db.query<string[]>(
       `
@@ -62,10 +64,14 @@ class TrendsDB {
     }));
   }
 
+  /**
+   * Gets the tag usage count for a specific tag.
+   * It returns an array with counts for each date between the range.
+   */
   getTagHistory({ tag, since, until, limit = 7, offset = 0 }: GetTagHistoryOpts) {
-    return this.#db.query<string[]>(
+    const result = this.#db.query<string[]>(
       `
-      SELECT inserted_at, COUNT(DISTINCT pubkey8), COUNT(*)
+      SELECT date(inserted_at), COUNT(DISTINCT pubkey8), COUNT(*)
         FROM tag_usages
         WHERE tag = ? AND inserted_at >= ? AND inserted_at < ?
         GROUP BY date(inserted_at)
@@ -79,6 +85,18 @@ class TrendsDB {
       accounts: Number(row[1]),
       uses: Number(row[2]),
     }));
+
+    /** Full date range between `since` and `until`. */
+    const dateRange = generateDateRange(
+      new Date(since.getTime() + Time.days(1)),
+      new Date(until.getTime() - Time.days(offset)),
+    ).reverse();
+
+    // Fill in missing dates with 0 usages.
+    return dateRange.map((day) => {
+      const data = result.find((item) => item.day.getTime() === day.getTime());
+      return data || { day, accounts: 0, uses: 0 };
+    });
   }
 
   addTagUsages(pubkey: string, hashtags: string[], date = new Date()): void {

src/utils/time.test.ts

@@ -0,0 +1,23 @@
+import { assertEquals } from '@/deps-test.ts';
+
+import { generateDateRange } from './time.ts';
+
+Deno.test('generateDateRange', () => {
+  const since = new Date('2023-07-03T16:30:00.000Z');
+  const until = new Date('2023-07-07T09:01:00.000Z');
+
+  const expected = [
+    new Date('2023-07-03T00:00:00.000Z'),
+    new Date('2023-07-04T00:00:00.000Z'),
+    new Date('2023-07-05T00:00:00.000Z'),
+    new Date('2023-07-06T00:00:00.000Z'),
+    new Date('2023-07-07T00:00:00.000Z'),
+  ];
+
+  const result = generateDateRange(since, until);
+
+  assertEquals(
+    result.map((d) => d.getTime()),
+    expected.map((d) => d.getTime()),
+  );
+});

src/utils/time.ts

@@ -9,4 +9,24 @@ const Time = {
   years: (y: number) => y * Time.days(365),
 };
 
-export { Time };
+/** Strips the time off the date, giving 12am UTC. */
+function stripTime(date: Date): Date {
+  return new Date(Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate()));
+}
+
+/** Strips times off the dates and generates all 24h intervals between them, inclusive of both inputs. */
+function generateDateRange(since: Date, until: Date): Date[] {
+  const dates = [];
+
+  const sinceDate = stripTime(since);
+  const untilDate = stripTime(until);
+
+  while (sinceDate <= untilDate) {
+    dates.push(new Date(sinceDate));
+    sinceDate.setUTCDate(sinceDate.getUTCDate() + 1);
+  }
+
+  return dates;
+}
+
+export { generateDateRange, stripTime, Time };