implemented a lot of features

database/migrations/1768620764840_add_search_indexes.ts

@@ -0,0 +1,43 @@
+import { BaseSchema } from '@adonisjs/lucid/schema'
+
+/**
+ * Web interface (CONCEPT.md D22): trigram indexes for substring search, and
+ * SQL versions of the "readable name" rule used for filtering.
+ */
+export default class extends BaseSchema {
+  async up() {
+    this.defer(async (db) => {
+      await db.rawQuery('CREATE EXTENSION IF NOT EXISTS pg_trgm')
+      // Per-file suffixes stripped, as in lib/release fileStem.
+      await db.rawQuery(`
+        CREATE OR REPLACE FUNCTION name_stem(name text) RETURNS text IMMUTABLE LANGUAGE sql AS $$
+          SELECT regexp_replace(name,
+            '(\\.(part\\d+\\.rar|r\\d{2,3}|rar|vol\\d+[+-]\\d+\\.par2|par2|7z(\\.\\d{3})?|zip|\\d{3}|nfo|sfv|nzb|tar|zst|gz|xz|mkv|mp4|avi|m4v|ts|iso|img|flac|mp3|epub|pdf|jpg|png))+$',
+            '', 'i')
+        $$`)
+      // Not an obfuscated token (as in ArchiveService.looksRandom).
+      await db.rawQuery(`
+        CREATE OR REPLACE FUNCTION is_readable_name(name text) RETURNS boolean IMMUTABLE LANGUAGE sql AS $$
+          SELECT name IS NOT NULL AND NOT (
+            (name_stem(name) ~ '^[A-Za-z0-9]{16,}$' AND name_stem(name) ~ '\\d'
+              AND name_stem(name) ~ '[a-z]' AND name_stem(name) ~ '[A-Z]')
+            OR name_stem(name) ~* '^[0-9a-f]{16,}$')
+        $$`)
+      await db.rawQuery('CREATE INDEX IF NOT EXISTS releases_name_trgm ON releases USING gin (name gin_trgm_ops)')
+      await db.rawQuery('CREATE INDEX IF NOT EXISTS files_filename_trgm ON files USING gin (filename gin_trgm_ops)')
+      await db.rawQuery('CREATE INDEX IF NOT EXISTS files_real_name_trgm ON files USING gin (real_name gin_trgm_ops)')
+      await db.rawQuery('CREATE INDEX IF NOT EXISTS releases_posted_at_idx ON releases (posted_at DESC NULLS LAST)')
+    })
+  }
+
+  async down() {
+    this.defer(async (db) => {
+      await db.rawQuery('DROP INDEX IF EXISTS releases_posted_at_idx')
+      await db.rawQuery('DROP INDEX IF EXISTS files_real_name_trgm')
+      await db.rawQuery('DROP INDEX IF EXISTS files_filename_trgm')
+      await db.rawQuery('DROP INDEX IF EXISTS releases_name_trgm')
+      await db.rawQuery('DROP FUNCTION IF EXISTS is_readable_name(text)')
+      await db.rawQuery('DROP FUNCTION IF EXISTS name_stem(text)')
+    })
+  }
+}