pdf-ocr-hotfolder/pdf_ocr_hotfolder/config.py

"""Konfigurations-Loader (TOML)."""
from __future__ import annotations

import tomllib
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any


class ConfigError(RuntimeError):
    """Konfigurationsdatei ist unvollständig oder fehlerhaft."""


@dataclass
class Paths:
    incoming: Path
    outgoing: Path
    working: Path
    error: Path


@dataclass
class OcrConfig:
    languages: str = "deu+eng"
    jobs: int = 4
    skip_text: bool = True
    oversample: int = 300
    # Default bewusst leer: pdfa_level + skip_text zerschießt OCR mit
    # Ghostscript 10.0.0-10.02.0 (Debian-12-Default), siehe Issue #3
    pdfa_level: str = ""
    deskew: bool = True
    clean: bool = False
    max_workers: int = 2
    # Max. Sekunden, die Tesseract pro Seite laufen darf (0 = kein eigenes Limit)
    timeout: int = 300


@dataclass
class OutputConfig:
    # "prefix" | "suffix" | "none"
    name_mode: str = "prefix"
    # Tag-String, verbatim eingefügt (Leerstring = kein Tag)
    name_tag: str = "OCR_"
    # "delete" | "archive"
    original_on_success: str = "delete"
    # Absoluter Pfad; Pflicht wenn original_on_success == "archive"
    archive_dir: str = ""


@dataclass
class VeraPdfConfig:
    enabled: bool = False
    binary: str = "/opt/verapdf/verapdf"
    flavour: str = "1b"


@dataclass
class FolderUpload:
    enabled: bool = True
    target: str = ""


@dataclass
class NextcloudUpload:
    enabled: bool = False
    url: str = ""
    username: str = ""
    password: str = ""
    remote_path: str = ""
    verify_ssl: bool = True


@dataclass
class SftpUpload:
    enabled: bool = False
    host: str = ""
    port: int = 22
    username: str = ""
    key_file: str = ""
    password: str = ""
    remote_path: str = ""


@dataclass
class EmailNotify:
    enabled: bool = False
    smtp_host: str = ""
    smtp_port: int = 587
    smtp_user: str = ""
    smtp_password: str = ""
    use_starttls: bool = True
    from_addr: str = ""
    to_addrs: list[str] = field(default_factory=list)
    on: str = "errors"  # always | errors | never


@dataclass
class Config:
    paths: Paths
    ocr: OcrConfig
    output: OutputConfig
    verapdf: VeraPdfConfig
    folder: FolderUpload
    nextcloud: NextcloudUpload
    sftp: SftpUpload
    email: EmailNotify
    log_level: str = "INFO"


def _section(data: dict[str, Any], *keys: str) -> dict[str, Any]:
    cur: Any = data
    for k in keys:
        cur = cur.get(k, {}) if isinstance(cur, dict) else {}
    return cur if isinstance(cur, dict) else {}


def _require_path(p: dict[str, Any], key: str, cfg_path: Path) -> Path:
    """Holt einen Pflicht-Pfad aus der [paths]-Sektion.

    Wirft ConfigError mit klarer Meldung statt eines nackten KeyError.
    """
    value = p.get(key)
    if value is None or (isinstance(value, str) and not value.strip()):
        raise ConfigError(
            f"{cfg_path}: In der Sektion [paths] fehlt der Eintrag '{key}' "
            f"(oder er ist leer). Bitte ergänzen, z.B. "
            f'{key} = "/var/lib/pdf-ocr-hotfolder/{key}" '
            f"— siehe config.example.toml."
        )
    return Path(str(value))


def load_config(path: str | Path) -> Config:
    path = Path(path)
    with path.open("rb") as f:
        data = tomllib.load(f)

    if not isinstance(data.get("paths"), dict):
        raise ConfigError(
            f"{path}: Die Sektion [paths] fehlt (oder ist keine Tabelle). "
            "Sie muss die Einträge incoming, outgoing, working und error "
            "enthalten — siehe config.example.toml."
        )

    p = _section(data, "paths")
    paths = Paths(
        incoming=_require_path(p, "incoming", path),
        outgoing=_require_path(p, "outgoing", path),
        working=_require_path(p, "working", path),
        error=_require_path(p, "error", path),
    )

    ocr = OcrConfig(**{k: v for k, v in _section(data, "ocr").items()
                       if k in OcrConfig.__annotations__})
    output = OutputConfig(**{k: v for k, v in _section(data, "output").items()
                             if k in OutputConfig.__annotations__})
    verapdf = VeraPdfConfig(**{k: v for k, v in _section(data, "verapdf").items()
                               if k in VeraPdfConfig.__annotations__})
    folder = FolderUpload(**{k: v for k, v in _section(data, "upload", "folder").items()
                             if k in FolderUpload.__annotations__})
    nextcloud = NextcloudUpload(**{k: v for k, v in _section(data, "upload", "nextcloud").items()
                                   if k in NextcloudUpload.__annotations__})
    sftp = SftpUpload(**{k: v for k, v in _section(data, "upload", "sftp").items()
                         if k in SftpUpload.__annotations__})
    email = EmailNotify(**{k: v for k, v in _section(data, "notify", "email").items()
                           if k in EmailNotify.__annotations__})

    log_level = _section(data, "logging").get("level", "INFO")

    return Config(
        paths=paths, ocr=ocr, output=output, verapdf=verapdf,
        folder=folder, nextcloud=nextcloud, sftp=sftp, email=email,
        log_level=log_level,
    )