"""章节阅读片段物化：与 canonical 同一生成时机写入 reading_segments_json（无签名 URL）。"""

from __future__ import annotations

from typing import Any

from app.features.memoir.asset_resolver import (
    collect_asset_ids_from_markdown,
    resolve_asset_refs_in_markdown,
)
from app.features.memoir.markdown_sanitize import sanitize_story_for_chapter_compose
from app.features.memoir.models import Chapter


def _primary_story_intent_asset_id(story: Any) -> str | None:
    for it in getattr(story, "image_intents", None) or []:
        if getattr(it, "intent_role", None) == "primary":
            aid = getattr(it, "asset_id", None)
            return str(aid) if aid else None
    return None


def _cover_intent_snapshot_from_story(story: Any) -> dict | None:
    """primary intent 元数据（无 url），供 JSON 持久化。"""
    intents = getattr(story, "image_intents", None) or []
    primary = None
    for it in intents:
        if getattr(it, "intent_role", None) == "primary":
            primary = it
            break
    if not primary:
        return None
    aid = getattr(primary, "asset_id", None)
    if not aid:
        return None
    status = getattr(primary, "status", None) or "pending"
    return {
        "asset_id": str(aid),
        "status": status,
        "description": getattr(primary, "caption", None) or "故事配图",
        "prompt": getattr(primary, "prompt_brief", None),
        "style": getattr(primary, "style_profile", None),
        "error": getattr(primary, "error", None),
        "created_at": primary.created_at.isoformat() if primary.created_at else None,
        "updated_at": primary.updated_at.isoformat() if primary.updated_at else None,
    }


def _cover_dict_from_snapshot_row(
    snap: dict[str, Any], asset_url_map: dict[str, str]
) -> dict:
    aid = snap.get("asset_id")
    url = asset_url_map.get(str(aid)) if aid else None
    return {
        "placeholder": "",
        "description": snap.get("description") or "故事配图",
        "index": 0,
        "status": snap.get("status") or "pending",
        "prompt": snap.get("prompt"),
        "url": url,
        "storage_key": None,
        "provider": None,
        "style": snap.get("style"),
        "size": None,
        "error": snap.get("error"),
        "retryable": None,
        "created_at": snap.get("created_at"),
        "updated_at": snap.get("updated_at"),
    }


def build_reading_segments_snapshot(ch: Chapter) -> list[dict[str, Any]]:
    """
    物化阅读片段快照：body 保留 asset://；cover 仅存 intent 元数据（正文已含同 asset 则省略）。
    与 append_chapter_compose_version 同路径写入。
    """
    links = sorted(
        list(getattr(ch, "story_links", None) or []),
        key=lambda x: getattr(x, "order_index", 0),
    )
    out: list[dict[str, Any]] = []
    for link in links:
        st = getattr(link, "story", None)
        if st is None:
            continue
        title = (getattr(st, "title", None) or "").strip()
        raw = (getattr(st, "canonical_markdown", None) or "").strip()
        body = sanitize_story_for_chapter_compose(raw, title)
        if not body:
            continue
        primary_aid = _primary_story_intent_asset_id(st)
        inline_ids = set(collect_asset_ids_from_markdown(body))
        cover: dict | None = None
        if primary_aid and primary_aid not in inline_ids:
            cover = _cover_intent_snapshot_from_story(st)
        out.append(
            {
                "story_id": st.id,
                "body_markdown": body,
                "cover_asset": cover,
            }
        )
    return out


def hydrate_reading_segments_from_snapshot(
    ch: Chapter,
    asset_url_map: dict[str, str] | None = None,
) -> list[dict[str, Any]]:
    """将持久化快照解析为 API 形态（签名 URL）。"""
    from app.features.memoir import helpers as h

    asset_url_map = asset_url_map or {}
    resolve = lambda aid: asset_url_map.get(aid)  # noqa: E731
    rows = getattr(ch, "reading_segments_json", None) or []
    out: list[dict[str, Any]] = []
    for row in rows:
        body = resolve_asset_refs_in_markdown(row["body_markdown"], resolve)
        ci = row.get("cover_asset")
        if ci:
            img_raw = _cover_dict_from_snapshot_row(ci, asset_url_map)
            img_norm = h.first_normalized_image_for_api(img_raw)
        else:
            img_norm = None
        out.append(
            {
                "story_id": row["story_id"],
                "body_markdown": body,
                "cover_asset": img_norm,
            }
        )
    return out


def resolve_reading_segments_for_chapter_detail(
    ch: Chapter,
    asset_url_map: dict[str, str] | None = None,
) -> list[dict[str, Any]]:
    """章节详情：仅读取已物化快照。"""
    asset_url_map = asset_url_map or {}
    if getattr(ch, "reading_segments_json", None) is None:
        return []
    return hydrate_reading_segments_from_snapshot(ch, asset_url_map=asset_url_map)