from fastapi import APIRouter
from typing import List
from fastapi import APIRouter, HTTPException
from app.schemas.user import ChapterRelationCreate, ChapterRelationResponse
from app.services.user_service import create_chapter_relation, get_graph_relations, search_chapters, \
    get_relations_to_level_simple, get_chapter_relations

router = APIRouter(
    prefix="/chapters",
    tags=["Chapters"],
)

@router.post("/relation/", response_model=ChapterRelationResponse)
def add_chapter_relation(relation: ChapterRelationCreate):
    """
    创建章节之间的关系
    """
    return create_chapter_relation(relation)

@router.get("/relations/", response_model=List[ChapterRelationResponse])
def list_chapter_relations():
    """
    查询所有章节关系
    """
    return get_graph_relations()


@router.get("/search_chapters", response_model=List[ChapterRelationResponse])
def search_chapters_endpoint(q: str):
    """
    API 端点：根据搜索关键字模糊查询章节及其相关章节
    :param q: 搜索关键字
    :return: 匹配的章节关系列表
    """
    if not q:
        raise HTTPException(status_code=400, detail="搜索关键字不能为空")
    results = search_chapters(q)
    if not results:
        raise HTTPException(status_code=404, detail="未找到匹配的章节关系")
    return results
@router.get("/relations/level/{level}", response_model=List[ChapterRelationResponse])
def get_relations_by_level_simple(level: int):
    """
    简化版：根据目标层级查询从 Root 到目标层级的所有节点和关系
    :param level: 目标层级（1 -> Root & Subject, 2 -> Root, Subject, Topic, ..., 5 -> Problem）
    :return: 对应层级的节点和关系
    """
    if level < 0 or level > 5:
        raise HTTPException(status_code=400, detail="层级参数必须在 0 到 5 之间")

    try:
        relations = get_relations_to_level_simple(level)
        if not relations:
            raise HTTPException(status_code=404, detail="未找到相关节点关系")
        return relations
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
@router.get("/{chapter}/relations", response_model=List[ChapterRelationResponse])
async def get_relations_by_chapter(chapter: str):
    """
    根据章节名称获取该章节及其相关关系，但排除 label 为 Subject 的 next_SB 关系
    :param chapter_name: 章节名称
    :return: 章节关系列表
    """
    try:
        relations = get_chapter_relations(chapter)
        if not relations:
            raise HTTPException(status_code=404, detail=f"No relations found for chapter {chapter}")
        return relations
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error fetching relations: {str(e)}")