feat: retry, semaphore, and download concurrency/retry config (#13 3/5)

apps/backend/drizzle/0001_tearful_the_fallen.sql

@@ -0,0 +1 @@
+ALTER TABLE `downloads` ADD `attempts` integer DEFAULT 0 NOT NULL;

apps/backend/drizzle/meta/0001_snapshot.json

@@ -0,0 +1,195 @@
+{
+  "version": "6",
+  "dialect": "sqlite",
+  "id": "0e170273-951e-4b46-b8be-8d77d6188596",
+  "prevId": "7511a5bb-12b1-4836-8099-498542b3d20d",
+  "tables": {
+    "downloads": {
+      "name": "downloads",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "torrent_filename": {
+          "name": "torrent_filename",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "peer_id": {
+          "name": "peer_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "peer_name": {
+          "name": "peer_name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "item_id": {
+          "name": "item_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "filename": {
+          "name": "filename",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "dest_path": {
+          "name": "dest_path",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "part_path": {
+          "name": "part_path",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "release_size": {
+          "name": "release_size",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "release_json": {
+          "name": "release_json",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expected_bytes": {
+          "name": "expected_bytes",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "expected_bytes_source": {
+          "name": "expected_bytes_source",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "expected_bytes_mismatch": {
+          "name": "expected_bytes_mismatch",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "downloaded_bytes": {
+          "name": "downloaded_bytes",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "attempts": {
+          "name": "attempts",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "started_at": {
+          "name": "started_at",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "completed_at": {
+          "name": "completed_at",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "error": {
+          "name": "error",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "downloads_status_idx": {
+          "name": "downloads_status_idx",
+          "columns": [
+            "status"
+          ],
+          "isUnique": false
+        },
+        "downloads_updated_at_idx": {
+          "name": "downloads_updated_at_idx",
+          "columns": [
+            "updated_at"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {
+        "downloads_status_check": {
+          "name": "downloads_status_check",
+          "value": "\"downloads\".\"status\" in ('downloading', 'completed', 'failed', 'import_queued')"
+        },
+        "downloads_expected_bytes_source_check": {
+          "name": "downloads_expected_bytes_source_check",
+          "value": "\"downloads\".\"expected_bytes_source\" is null or \"downloads\".\"expected_bytes_source\" = 'content_length'"
+        }
+      }
+    }
+  },
+  "views": {},
+  "enums": {},
+  "_meta": {
+    "schemas": {},
+    "tables": {},
+    "columns": {}
+  },
+  "internal": {
+    "indexes": {}
+  }
+}

apps/backend/drizzle/meta/_journal.json

@@ -8,6 +8,13 @@
       "when": 1780589033291,
       "tag": "0000_mysterious_vin_gonzales",
       "breakpoints": true
+    },
+    {
+      "idx": 1,
+      "version": "6",
+      "when": 1780707145431,
+      "tag": "0001_tearful_the_fallen",
+      "breakpoints": true
     }
   ]
 }

apps/backend/src/__tests__/config.test.ts

@@ -277,4 +277,22 @@ describe('appConfig parsing', () => {
     })
     expect(result.success).toBe(false)
   })
+
+  test('defaults the downloads hardening knobs', () => {
+    const parsed = AppConfig.parse({
+      downloads: { watchPath: '/w', completedPath: '/c' },
+    })
+    expect(parsed.downloads).toMatchObject({
+      maxConcurrentDownloads: 3,
+      maxDownloadAttempts: 5,
+      retryBaseDelayMs: 1000,
+      retryMaxDelayMs: 60_000,
+    })
+  })
+
+  test('respects an explicit maxConcurrentDownloads and rejects non-positive values', () => {
+    const parsed = AppConfig.parse({ downloads: { watchPath: '/w', completedPath: '/c', maxConcurrentDownloads: 8 } })
+    expect(parsed.downloads?.maxConcurrentDownloads).toBe(8)
+    expect(AppConfig.safeParse({ downloads: { watchPath: '/w', completedPath: '/c', maxConcurrentDownloads: 0 } }).success).toBe(false)
+  })
 })

apps/backend/src/__tests__/database.test.ts

@@ -151,4 +151,65 @@ describe('DownloadsRepository', () => {
     expect(stale.error).toContain('stale')
     handle.close()
   })
+
+  test('increments attempts and records a resume reset', async () => {
+    const handle = await openDatabase({ appConfigPath: join(tempDir, 'config.jsonc') })
+    const repository = new DownloadsRepository(handle.db)
+    const created = repository.create({
+      torrentFilename: 'movie.torrent',
+      peerId: 'peer-1',
+      peerName: 'Friend Jack',
+      itemId: 'movie:1',
+      filename: release.filename,
+      destPath: join(tempDir, release.filename),
+      partPath: join(tempDir, `${release.filename}.part`),
+      releaseSize: release.size,
+      release,
+    })
+
+    expect(repository.incrementAttempts(created.id)).toBe(1)
+    expect(repository.incrementAttempts(created.id)).toBe(2)
+    repository.updateProgress(created.id, 40)
+    repository.markResumeReset(created.id)
+
+    const row = repository.get(created.id)!
+    expect(row.attempts).toBe(2)
+    expect(row.downloadedBytes).toBe(0)
+    expect(row.status).toBe('downloading')
+    expect(row.error).toContain('resume validation failed')
+    handle.close()
+  })
+
+  test('lists stale downloading rows without mutating them', async () => {
+    const handle = await openDatabase({ appConfigPath: join(tempDir, 'config.jsonc') })
+    const repository = new DownloadsRepository(handle.db)
+    const a = repository.create({
+      torrentFilename: 'a.torrent',
+      peerId: 'peer-1',
+      peerName: 'Friend Jack',
+      itemId: 'movie:1',
+      filename: 'A.mkv',
+      destPath: join(tempDir, 'A.mkv'),
+      partPath: join(tempDir, 'A.mkv.part'),
+      releaseSize: 10,
+      release,
+    })
+    const b = repository.create({
+      torrentFilename: 'b.torrent',
+      peerId: 'peer-1',
+      peerName: 'Friend Jack',
+      itemId: 'movie:2',
+      filename: 'B.mkv',
+      destPath: join(tempDir, 'B.mkv'),
+      partPath: join(tempDir, 'B.mkv.part'),
+      releaseSize: 10,
+      release,
+    })
+    repository.markCompleted(b.id, 10)
+
+    const stale = repository.listStaleDownloads()
+    expect(stale.map(r => r.id)).toEqual([a.id])
+    expect(repository.get(a.id)?.status).toBe('downloading')
+    handle.close()
+  })
 })

apps/backend/src/__tests__/downloads-api.test.ts

@@ -1,4 +1,3 @@
-import type { AppConfig } from '../lib/config'
 import type { Envs } from '../lib/envs'
 import type { Release } from '../lib/release'
 import { mkdtemp, rm } from 'node:fs/promises'
@@ -7,6 +6,7 @@ import { join } from 'node:path'
 import { afterEach, beforeEach, describe, expect, test } from 'bun:test'
 import { getApp } from '../app'
 import { openDatabase } from '../database/connection'
+import { AppConfig } from '../lib/config'
 import { DownloadsRepository } from '../modules/downloads/downloads.repository'
 
 const envs: Envs = {
@@ -20,12 +20,12 @@ const envs: Envs = {
   NODE_ENV: 'test',
 }
 
-const config: AppConfig = {
+const config = AppConfig.parse({
   jack: { baseUrl: 'http://localhost:3000', apiKey: 'test-api-key' },
   downloads: { watchPath: '/tmp/watch', completedPath: '/tmp/completed' },
   servers: [],
   peers: [],
-}
+})
 
 const release: Release = {
   id: 'remote:movie:1',