Erste lauffähige Version

app/mailmerge/tasks.py

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+"""
+Celery-Tasks für die PDF-Erzeugung.
+"""
+from __future__ import annotations
+
+import csv
+import io
+import logging
+import tempfile
+from pathlib import Path
+
+from celery import shared_task
+from django.core.files import File
+from django.utils import timezone
+
+from .models import JobLogEntry, MailMergeJob
+from .services.docx_renderer import docx_to_pdf, render_docx
+from .services.pdf_merge import merge_pdfs
+
+logger = logging.getLogger(__name__)
+
+
+def _log(job: MailMergeJob, level: str, msg: str) -> None:
+    JobLogEntry.objects.create(job=job, level=level, message=msg)
+    logger.log(getattr(logging, level.upper(), logging.INFO), "[job %s] %s", job.id, msg)
+
+
+@shared_task(bind=True)
+def run_mailmerge(self, job_id: str) -> str:
+    job = MailMergeJob.objects.select_related("template").get(pk=job_id)
+    job.status = MailMergeJob.Status.RUNNING
+    job.started_at = timezone.now()
+    job.save(update_fields=["status", "started_at"])
+    _log(job, "info", f"Job gestartet (task={self.request.id}).")
+
+    try:
+        # CSV einlesen
+        raw = job.recipients_csv.read().decode("utf-8-sig")
+        reader = csv.DictReader(io.StringIO(raw))
+        rows = list(reader)
+        job.total_rows = len(rows)
+        job.save(update_fields=["total_rows"])
+        _log(job, "info", f"{len(rows)} Empfänger gefunden.")
+
+        if not rows:
+            raise ValueError("CSV enthält keine Datenzeilen.")
+
+        # CSV-Felder vs. Template-Platzhalter prüfen
+        csv_fields = set(reader.fieldnames or [])
+        placeholders = set(job.template.placeholders or [])
+        missing = placeholders - csv_fields
+        if missing:
+            _log(job, "warning",
+                 f"CSV fehlen Spalten: {', '.join(sorted(missing))}")
+
+        # Jeden Brief rendern, alle zu einem PDF zusammenführen
+        with tempfile.TemporaryDirectory(prefix="mailmerge-") as tmpdir:
+            tmp = Path(tmpdir)
+            pdfs: list[Path] = []
+            template_path = Path(job.template.file.path)
+
+            for idx, row in enumerate(rows, start=1):
+                docx_out = tmp / f"letter_{idx:05d}.docx"
+                render_docx(template_path, row, docx_out)
+                pdf = docx_to_pdf(docx_out, tmp / "pdf")
+                pdfs.append(pdf)
+                job.processed_rows = idx
+                job.save(update_fields=["processed_rows"])
+
+            merged = tmp / f"serienbrief_{job.id}.pdf"
+            merge_pdfs(pdfs, merged)
+            with merged.open("rb") as f:
+                job.result_pdf.save(merged.name, File(f), save=False)
+
+        job.status = MailMergeJob.Status.DONE
+        job.finished_at = timezone.now()
+        job.save()
+        _log(job, "info", "Job erfolgreich abgeschlossen.")
+        return str(job.id)
+
+    except Exception as exc:  # noqa: BLE001
+        job.status = MailMergeJob.Status.FAILED
+        job.error_message = str(exc)
+        job.finished_at = timezone.now()
+        job.save()
+        _log(job, "error", f"Job fehlgeschlagen: {exc}")
+        raise