feat: Import-API mit Vorschau, Saldo-Pruefung und Duplikat-Schutz

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

finance/app/services/importer.py

@@ -0,0 +1,99 @@
+from pathlib import Path
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.config import get_settings
+from app.models.tables import Account, Statement, Transaction
+from app.parsers.base import ParserError
+from app.parsers.registry import parse_pdf
+from app.parsers.validate import balance_difference, dedup_hash
+from app.services.categorize import apply_rules
+
+
+def _find_or_create_account(session: Session, bank: str, iban: str | None, filename: str) -> Account:
+    if iban:
+        acc = session.execute(select(Account).where(Account.iban == iban)).scalar()
+        if acc is not None:
+            return acc
+    else:
+        iban = f"UNBEKANNT-{filename}"
+    acc = Account(bank=bank, iban=iban, name=iban, type="giro")
+    session.add(acc)
+    session.flush()
+    return acc
+
+
+def process_pdf(session: Session, path: Path) -> Statement:
+    settings = get_settings()
+    filename = path.name
+
+    try:
+        parsed = parse_pdf(path)
+    except ParserError as exc:
+        stmt = Statement(filename=filename, bank="unbekannt", account_id=None,
+                         status="error", error_message=str(exc))
+        session.add(stmt)
+        session.commit()
+        session.refresh(stmt)
+        return stmt
+
+    account = _find_or_create_account(session, parsed.bank, parsed.iban, filename)
+
+    stmt = Statement(
+        filename=filename,
+        bank=parsed.bank,
+        account_id=account.id,
+        period_start=parsed.period_start,
+        period_end=parsed.period_end,
+        opening_balance=parsed.opening_balance,
+        closing_balance=parsed.closing_balance,
+        status="draft",
+    )
+    session.add(stmt)
+    session.flush()
+
+    diff = balance_difference(parsed)
+    if diff != 0:
+        stmt.status = "error"
+        stmt.error_message = f"Saldo-Differenz {diff} EUR"
+        session.commit()
+        session.refresh(stmt)
+        return stmt
+
+    drafts = []
+    for t in parsed.transactions:
+        h = dedup_hash(account.id, t.booking_date, t.amount, t.purpose)
+        is_duplicate = session.execute(
+            select(Transaction).where(
+                Transaction.dedup_hash == h,
+                Transaction.status == "confirmed",
+            )
+        ).scalar() is not None
+        tx = Transaction(
+            account_id=account.id,
+            statement_id=stmt.id,
+            booking_date=t.booking_date,
+            value_date=t.value_date,
+            amount=t.amount,
+            purpose=t.purpose,
+            counterparty=t.counterparty,
+            status="draft",
+            dedup_hash=h,
+            is_duplicate=is_duplicate,
+        )
+        session.add(tx)
+        drafts.append(tx)
+
+    session.flush()
+    apply_rules(session, drafts)
+
+    stmt.status = "draft"
+    session.commit()
+    session.refresh(stmt)
+
+    uploads_dir = settings.uploads_dir
+    uploads_dir.mkdir(parents=True, exist_ok=True)
+    path.replace(uploads_dir / filename)
+
+    return stmt