"""章节封面是否可入队（与 Celery 任务共享，避免循环 import）。"""

from __future__ import annotations

from typing import Any

from app.core.config import settings
from app.features.memoir.asset_resolver import (
    parse_asset_refs,
    strip_image_placeholders,
)
from app.features.memoir.memoir_images.schema import (
    IMAGE_STATUS_FAILED,
    IMAGE_STATUS_PENDING,
)


def chapter_has_story_links(chapter: Any) -> bool:
    return any(
        getattr(link, "story", None)
        for link in getattr(chapter, "story_links", None) or []
    )


def effective_chapter_markdown_for_cover_gates(chapter: Any) -> str:
    """
     用于封面闸门计数：优先 DB canonical；若为空且已挂 stories，则用内存物化串
    （与列表/详情在 compose_dirty 时的临时正文对齐，避免「有图但 canonical 未落库」导致永不出封面）。
    """
    md = (getattr(chapter, "canonical_markdown", None) or "").strip()
    if md:
        return md
    if chapter_has_story_links(chapter):
        from app.features.memoir.chapter_markdown_compose import (
            materialize_chapter_markdown_from_loaded_chapter,
        )

        try:
            alt = (
                materialize_chapter_markdown_from_loaded_chapter(chapter) or ""
            ).strip()
        except Exception:
            return ""
        return alt
    return ""


def count_chapter_inline_body_images(
    chapter: Any, *, markdown: str | None = None
) -> int:
    """统计 asset:// 插图次数；未传 markdown 时用 effective_chapter_markdown_for_cover_gates。"""
    source = (
        markdown
        if markdown is not None
        else effective_chapter_markdown_for_cover_gates(chapter)
    )
    return len(parse_asset_refs(source))


def chapter_eligible_for_cover_by_inline_body_image_count(
    chapter: Any, *, markdown: str | None = None
) -> bool:
    """正文内 asset:// 数量 ≥ 配置阈值时允许封面；markdown 非 None 时仅用该串计数。"""
    min_required = int(settings.memoir_min_inline_images_for_chapter_cover)
    return count_chapter_inline_body_images(chapter, markdown=markdown) >= min_required


def primary_chapter_memoir_image(chapter: Any) -> Any | None:
    """章节级 MemoirImage（封面槽位）：按 order_index 最小取第一条。"""
    imgs = sorted(
        getattr(chapter, "images", None) or [],
        key=lambda m: getattr(m, "order_index", 0),
    )
    return imgs[0] if imgs else None


def chapter_needs_cover_enqueue(chapter) -> bool:
    """尚无 cover_asset、有正文、且正文内 asset 插图达到 env 阈值时，可派发 generate_chapter_cover。"""
    if not chapter:
        return False
    if not chapter_has_story_links(chapter):
        return False
    if getattr(chapter, "cover_asset_id", None):
        return False
    view = effective_chapter_markdown_for_cover_gates(chapter)
    body = strip_image_placeholders(view).strip()
    if not body:
        return False
    return chapter_eligible_for_cover_by_inline_body_image_count(chapter, markdown=view)


def chapter_has_cover_to_generate(chapter) -> bool:
    """章节是否有待生成的封面图（任一条 chapter 级 MemoirImage 为 pending/failed）。"""
    for m in getattr(chapter, "images", None) or []:
        status = (m.status or "").strip()
        if status in (IMAGE_STATUS_PENDING, IMAGE_STATUS_FAILED):
            return True
    return False


def cover_memoir_image_pending_or_failed(chapter: Any) -> Any | None:
    """用于补图任务：按 order_index 找到第一条 pending/failed 的章节配图行。"""
    images = sorted(
        getattr(chapter, "images", None) or [],
        key=lambda m: getattr(m, "order_index", 0),
    )
    for m in images:
        st = (m.status or "").strip()
        if st in (IMAGE_STATUS_PENDING, IMAGE_STATUS_FAILED):
            return m
    return None