"""上下文装配：StructuredSource + 模板 + 规则 → 有序 GenerationContext 列表（Phase 5）。"""
from __future__ import annotations

from genesis.data_models import StructuredSource
from genesis.services.rag_service import CannedRagService
from genesis.writer.models import ChapterSpec, GenerationContext
from genesis.writer.template_mapper import map_template


def build_contexts(
    structured_source: StructuredSource,
    samples_dir: str = "sample",
    output_language: str = "auto",
) -> list[GenerationContext]:
    specs: list[ChapterSpec] = map_template(structured_source.template)
    rag = CannedRagService(samples_dir=samples_dir)
    out: list[GenerationContext] = []
    for spec in specs:
        # RagService 方法为同步（P5-T3 裁定）
        write_rules = rag.retrieve_write_rules(spec.chapter_id)
        design_rules = rag.retrieve_design_rules(spec.chapter_id)
        used = (structured_source.template.styles or {}).get("used", [])
        out.append(
            GenerationContext(
                chapter_id=spec.chapter_id,
                title=spec.title,
                template_marker=spec,
                structured_source=structured_source,
                write_rules=write_rules,
                design_rules=design_rules,
                template_styles=set(used),
                impact_report=getattr(structured_source, "impact_report", None),
                output_language=output_language,
            )
        )
    return out