"""
FILE: app/core/chunking/chunking_propagation.py
DESCRIPTION: Vererbung von Kanten (Inheritance) über Sektions-Pfade.
"""
from typing import List, Dict, Set
from .chunking_models import Chunk, RawBlock
from .chunking_parser import parse_edges_robust

def propagate_section_edges(chunks: List[Chunk], blocks: List[RawBlock]) -> List[Chunk]:
    """WP-15b: Kanten aus Headings werden an Sub-Chunks vererbt."""
    section_inheritance: Dict[str, Set[str]] = {}
    for b in blocks:
        if b.kind == "heading":
            edges = parse_edges_robust(b.text)
            if edges:
                if b.section_path not in section_inheritance:
                    section_inheritance[b.section_path] = set()
                section_inheritance[b.section_path].update(edges)
    
    for ch in chunks:
        inherited = section_inheritance.get(ch.section_path, set())
        for e_str in inherited:
            kind, target = e_str.split(':', 1)
            ch.candidate_pool.append({"kind": kind, "to": target, "provenance": "inherited"})
    return chunks