#!/usr/bin/env python
# -*- coding: utf-8 -*-

from typing import Any, List

from fastapi import Depends, Query, Path
from sqlalchemy import text
from sqlalchemy.ext.asyncio import AsyncSession

from common.const import PERIODS, SUBJECTS, RESOURCE_TYPES, WORK_RESOURCE_TYPES
from crud.base import CrudManager
from crud.resource import crud_work_category, crud_exam_category
from models.user import SysUser
from schemas.resource import NewCategory, UpdateCategory
from utils.depends import get_async_db, get_current_user


# 学段列表
async def get_periods(current_user: SysUser = Depends(get_current_user)):
    data = [{"name": item} for item in PERIODS]
    return {"data": data}


# 学科列表
async def get_subjects(current_user: SysUser = Depends(get_current_user)):
    data = [{"name": item} for item in SUBJECTS]
    return {"data": data}


async def get_work_types(current_user: SysUser = Depends(get_current_user)):
    data = [{"name": item} for item in WORK_RESOURCE_TYPES]
    return {"data": data}


# 分类
async def get_category_tree(crud: CrudManager,
                            db: AsyncSession = Depends(get_async_db),
                            root: List[Any] = None):
    for item in root:
        children = await crud.fetch_all(db, filters=[text(f"pid={item.id}")])
        item.children = children
        await get_category_tree(crud, db, item.children)


async def get_categories(ctype: str = Query(...,
                                            description="资源类型，exam / work"),
                         db: AsyncSession = Depends(get_async_db),
                         current_user: SysUser = Depends(get_current_user)):
    if ctype not in RESOURCE_TYPES:
        return {"errcode": 400, "mess": "资源类型错误!"}
    crud = crud_work_category if ctype == "work" else crud_exam_category
    root = await crud.fetch_all(db, filters=[text("pid = 0")])
    await get_category_tree(crud, db, root)
    return {"data": root}


# 创建资源分类
async def create_category(info: NewCategory,
                          db: AsyncSession = Depends(get_async_db),
                          current_user: SysUser = Depends(get_current_user)):
    # 判断提交参数是否为空
    info_dict = info.dict(exclude_none=True)
    if not info_dict:
        return {"errcode": 400, "mess": "提交参数为空!"}

    # 分类
    crud = crud_work_category if info.ctype == "work" else crud_exam_category
    filters = {
        "name": info.name,
        "period": info.period,
        "subject": info.subject
    }
    if info.pid:    # 判断上级分类是否存在
        category = await crud.find_one(db, filters={"id": info.pid})
        if not category:
            return {"errcode": 404, "mess": "上级分类不存在!"}
        else:
            info.pname = category.name

    # 判断同级分类是否存在重复
    existed = await crud.count(db, filters=filters)
    if existed:
        return {"errcode": 400, "mess": "存在同名分类!"}

    # 创建
    delattr(info, "ctype")
    db_obj = await crud.insert_one(db, info)
    return {"data": db_obj}


# 更新资源分类
async def update_category(info: UpdateCategory,
                          cid: int = Path(..., description="分类ID"),
                          db: AsyncSession = Depends(get_async_db),
                          current_user: SysUser = Depends(get_current_user)):
    # 判断提交参数是否为空
    info_dict = info.dict(exclude_none=True)
    if not info_dict:
        return {"errcode": 400, "mess": "提交参数为空!"}

    # 判断分类是否存在
    crud = crud_work_category if info.ctype == "work" else crud_exam_category
    db_obj = await crud.find_one(db, filters={"id": cid})
    if not db_obj:
        return {"errcode": 404, "mess": "分类不存在!"}

    # 判断上级分类是否存在
    if ("pid" in info_dict) or ("pname" in info_dict):
        if bool(info.pid) ^ bool(info.pname):
            return {"errcode": 400, "mess": "缺少上级分类ID或名称"}
        existed = await crud.count(db,
                                   filters={
                                       "id": info.pid,
                                       "name": info.pname
                                   })
        if not existed:
            return {"errcode": 404, "mess": "上级分类不存在!"}

    # 判断同级分类是否存在重复
    if "name" in info_dict:
        existed = await crud.count(
            db,
            filters=[
                text(f"id != {cid} AND name = '{info.name}'"),
                text(f"pid = {info.pid} AND pname = '{info.pname}'")
            ])
        if existed:
            return {"errcode": 400, "mess": "存在同名分类!"}

    # 更新
    db_obj = await crud.update(db, db_obj, info)
    return {"data": db_obj}


# 删除资源分类
async def delete_category(cid: int = Path(..., description="资源分类ID"),
                          ctype: str = Query(...,
                                             description="分类类型，exam / work"),
                          db: AsyncSession = Depends(get_async_db),
                          current_user: SysUser = Depends(get_current_user)):
    if ctype not in RESOURCE_TYPES:
        return {"errcode": 400, "mess": "分类类型错误!"}

    crud = crud_work_category if ctype == "work" else crud_exam_category
    existed = await crud.count(db, {"id": cid})
    if not existed:
        return {"errcode": 404, "mess": "分类不存在!"}
    else:
        await crud.delete(db, obj_id=cid)
        # TODO: 删除关联数据
        # bg_task.add_task(delete_related_object, db, cid=id)
        return {"data": None}