from pathlib import Path

from config import STORAGE_DIR, PROJECTS_DIR, PROJECT_ROOT

TOPICS_DIR = STORAGE_DIR / "topics"


def _safe(name: str) -> str:
    return name.replace("/", "_").replace("\x00", "")


def topic_dir(topic: str) -> Path:
    return TOPICS_DIR / _safe(topic)


def arbeit_dir(topic: str) -> Path:
    return topic_dir(topic) / "arbeit"


def blocks_path(topic: str) -> Path:
    return topic_dir(topic) / "blocks.md"


def subblocks_path(topic: str) -> Path:
    """Sidecar: the subblocks with level per block (shared by all guides)."""
    return topic_dir(topic) / "subblocks.json"


def question_pattern_path(topic: str) -> Path:
    """Sidecar: predefined question patterns per block (subblock × type → example question)."""
    return topic_dir(topic) / "question_pattern.json"


def source_path(topic: str) -> Path:
    """Persisted source choice per topic: {type, location, spec}."""
    return topic_dir(topic) / "source.json"


def source_crawl_dir(topic: str) -> Path:
    """Target folder for crawled link sources (pages + PDF .txt)."""
    return topic_dir(topic) / "source"


def safe_folder(location: str) -> Path | None:
    """Folder path relative to the repo root, sandboxed. None if empty/escaping (../, absolute outside)."""
    if not location or not location.strip():
        return None
    p = (PROJECT_ROOT / location.strip()).resolve()
    try:
        p.relative_to(PROJECT_ROOT)
    except ValueError:
        return None
    return p


def guide_content_path(topic: str, format_name: str) -> Path:
    return topic_dir(topic) / "guides" / f"{format_name}.json"


def blocks_topics() -> list[str]:
    """Topics for which a topic folder exists."""
    if not TOPICS_DIR.is_dir():
        return []
    return [d.name for d in TOPICS_DIR.iterdir() if d.is_dir()]


def project_dir(name: str) -> Path:
    return PROJECTS_DIR / name