initialize

backend/app/services/tasks.py

@@ -0,0 +1,124 @@
+import threading
+import uuid
+from dataclasses import dataclass, field
+from datetime import datetime
+from pathlib import Path
+from queue import Queue
+from typing import Dict, List, Optional
+
+from app.schemas import TaskCreateRequest, TaskResult
+from app.services.media import generate_cover, generate_hls, transcode_to_mp4
+from app.services.storage import get_upload_path
+
+
+def now_iso() -> str:
+    return datetime.utcnow().replace(microsecond=0).isoformat() + "Z"
+
+
+@dataclass
+class TaskRecord:
+    task_id: str
+    file_id: str
+    options: TaskCreateRequest
+    status: str = "queued"
+    result: TaskResult = field(default_factory=TaskResult)
+    error: Optional[str] = None
+    created_at: str = field(default_factory=now_iso)
+    updated_at: str = field(default_factory=now_iso)
+
+    def touch(self) -> None:
+        self.updated_at = now_iso()
+
+
+class TaskManager:
+    def __init__(self) -> None:
+        self.tasks: Dict[str, TaskRecord] = {}
+        self.queue: Queue = Queue()
+        self.lock = threading.Lock()
+        self.worker = threading.Thread(target=self._worker_loop, daemon=True)
+        self.worker_started = False
+
+    def start(self) -> None:
+        if not self.worker_started:
+            self.worker.start()
+            self.worker_started = True
+
+    def create_task(self, payload: TaskCreateRequest) -> TaskRecord:
+        task_id = uuid.uuid4().hex[:12]
+        record = TaskRecord(task_id=task_id, file_id=payload.file_id, options=payload)
+        with self.lock:
+            self.tasks[task_id] = record
+        self.queue.put(task_id)
+        return record
+
+    def get_task(self, task_id: str) -> Optional[TaskRecord]:
+        return self.tasks.get(task_id)
+
+    def list_tasks(self) -> List[TaskRecord]:
+        return sorted(self.tasks.values(), key=lambda task: task.created_at, reverse=True)
+
+    def _update_status(self, task: TaskRecord, status: str) -> None:
+        with self.lock:
+            task.status = status
+            task.touch()
+
+    def _append_log(self, task: TaskRecord, message: str) -> None:
+        with self.lock:
+            task.result.log.append(message)
+            task.touch()
+
+    def _fail_task(self, task: TaskRecord, error: str) -> None:
+        with self.lock:
+            task.status = "failed"
+            task.error = error
+            task.touch()
+
+    def _worker_loop(self) -> None:
+        while True:
+            task_id = self.queue.get()
+            task = self.tasks.get(task_id)
+            if task is None:
+                self.queue.task_done()
+                continue
+
+            try:
+                self._process_task(task)
+            except Exception as exc:  # noqa: BLE001
+                self._fail_task(task, str(exc))
+            finally:
+                self.queue.task_done()
+
+    def _process_task(self, task: TaskRecord) -> None:
+        source_path = get_upload_path(task.file_id)
+        if not source_path.exists():
+            raise FileNotFoundError(f"uploaded file not found: {task.file_id}")
+
+        self._update_status(task, "processing")
+        working_source: Path = source_path
+
+        if task.options.transcode_mp4:
+            self._append_log(task, "Transcoding to MP4 with optional clipping and watermark")
+            mp4_path = transcode_to_mp4(
+                source=source_path,
+                task_id=task.task_id,
+                clip_seconds=task.options.clip_seconds,
+                watermark_text=task.options.watermark_text,
+            )
+            task.result.mp4_url = f"/media/processed/{mp4_path.name}"
+            working_source = mp4_path
+
+        if task.options.generate_cover:
+            self._append_log(task, "Generating cover image")
+            cover_path = generate_cover(working_source, task.task_id)
+            task.result.cover_url = f"/media/covers/{cover_path.name}"
+
+        if task.options.generate_hls:
+            self._append_log(task, "Generating HLS playlist")
+            playlist = generate_hls(working_source, task.task_id)
+            task.result.hls_url = f"/media/hls/{task.task_id}/{playlist.name}"
+
+        self._append_log(task, "Task completed")
+        self._update_status(task, "completed")
+
+
+task_manager = TaskManager()