"""
GraphRAGRetriever — full pipeline retriever stub.
Constitutional Hash: 608508a9bd224290
"""

from __future__ import annotations

from dataclasses import dataclass, field

from .models import GraphNode, TraversalResult


@dataclass
class _Score:
    total_score: float = 0.0


@dataclass
class _RankedContext:
    node: GraphNode
    score: _Score = field(default_factory=_Score)


@dataclass
class _AssembledContext:
    text: str = ""


@dataclass
class _RAGResult:
    ranked_contexts: list[_RankedContext] = field(default_factory=list)
    assembled_context: _AssembledContext = field(default_factory=_AssembledContext)


class GraphRAGRetriever:
    """
    Full retrieval pipeline: relevance ranking + context assembly.

    This stub implementation is used when no production retriever is injected.
    It passes through the traversal nodes in the order received, assigning
    decreasing scores based on position.
    """

    async def retrieve(
        self,
        query: str,
        graph_results: TraversalResult,
        query_embedding: list[float] | None = None,
    ) -> _RAGResult:
        ranked = [
            _RankedContext(
                node=node,
                score=_Score(total_score=1.0 - i * 0.1),
            )
            for i, node in enumerate(graph_results.nodes)
        ]
        assembled_text = " ".join(n.text_content for n in graph_results.nodes)
        return _RAGResult(
            ranked_contexts=ranked,
            assembled_context=_AssembledContext(text=assembled_text),
        )
