"""知识库文章 API — P1-3 嵌入功能模块用

提供按关联页面查询知识文章的功能。
"""
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from sqlalchemy import or_
from typing import Optional
from app.database import get_db
from app.auth_middleware import require_role
from app.deps import get_entity_id
from app.models.knowledge_article import KnowledgeArticle

router = APIRouter(prefix="/api/cma/knowledge-articles", tags=["知识库嵌入"],
    dependencies=[Depends(require_role("ceo", "finance", "business", "it"))],
)


def article_to_dict(a: KnowledgeArticle) -> dict:
    return {
        "id": a.id,
        "entity_id": a.entity_id,
        "title": a.title,
        "summary": a.summary,
        "content": a.content,
        "category": a.category,
        "icon": a.icon,
        "related_page": a.related_page,
        "sort_order": a.sort_order,
    }


@router.get("")
def list_articles(
    related_page: Optional[str] = Query(None, description="按关联页面路由筛选"),
    category: Optional[str] = Query(None),
    db: Session = Depends(get_db),
    entity_id: int = Depends(get_entity_id),
):
    """查询知识文章（本企业专属 ∪ 全局共享），可按关联页面或分类筛选

    隔离语义（2026-09-03 多租户分区）：
    - entity_id IS NULL → 全局共享（CMA 系统教学知识，所有企业可见）
    - entity_id == 当前账套 → 企业专属（只本企业可见）
    - 其他企业的专属文章不可见
    """
    q = db.query(KnowledgeArticle).filter(
        or_(
            KnowledgeArticle.entity_id == entity_id,
            KnowledgeArticle.entity_id.is_(None),
        )
    )
    if related_page:
        q = q.filter(KnowledgeArticle.related_page.contains(related_page))
    if category:
        q = q.filter(KnowledgeArticle.category == category)
    articles = q.order_by(KnowledgeArticle.sort_order.asc(), KnowledgeArticle.id.asc()).all()
    return {"data": [article_to_dict(a) for a in articles]}


@router.get("/{article_id}")
def get_article(
    article_id: int,
    db: Session = Depends(get_db),
    entity_id: int = Depends(get_entity_id),
):
    """获取文章详情（企业专属文章仅本企业可见，防跨企业探测）"""
    a = (
        db.query(KnowledgeArticle)
        .filter(KnowledgeArticle.id == article_id)
        .first()
    )
    if not a:
        raise HTTPException(404, "文章不存在")
    if a.entity_id is not None and a.entity_id != entity_id:
        raise HTTPException(404, "文章不存在")
    return article_to_dict(a)