niming_backend/utils/dbhelper.py

from typing import Tuple, Dict, List

from flask import make_response, Response, jsonify
from sqlalchemy.orm import sessionmaker
from sqlalchemy import desc

from utils import pgclass
from utils.misc import error

class db:
    _engine = None

    @classmethod
    def __init__(cls, engine):
        cls._engine = engine

    @classmethod
    def getsession(cls):
        Session = sessionmaker(bind=cls._engine)
        return Session()

# role (general) (owner) (admin)
# 獲取單一文章
def solo_article_fetcher(role:str, key) -> Tuple[Dict,int]: # admin, owner, general
    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    resfn = {}

    with db.getsession() as session:
        # query
        if role == "owner":
            res = session.query(table).filter(table.hash == key).first()
        elif role == "admin":
            res = session.query(table).filter(table.id == key).first()
        elif role == "general":
            res = session.query(table).filter(table.id == key, table.mark == "visible").first()
        if res is None: return {"error":"Post not found"}, 404

        # mapping
        resfn.update({"id": res.id, "ctx": res.ctx, "igid": res.igid, "mark": res.mark, "reference": res.reference})
        if role == "admin": resfn["ip"] = res.ip
        elif role == "owner": resfn["hash"] = res.hash

        # comment
        if role == "owner" or role == "admin":
            resfn["comment"] = [ c[0] for c in session.query(table.id).filter(table.reference == int(res.id)).all() ]
        elif role == "general":
            resfn["comment"] = [ c[0] for c in session.query(table.id).filter(table.reference == int(res.id), table.mark == "visible").all() ]
    
        # file
        resfn["files"] = [ f[0] for f in session.query(ftab.id).filter(ftab.reference == res.hash).all() ]

    return resfn, 200

# 獲取文章列表
def multi_article_fetcher(role:str, start:str, count:str) -> Tuple[Response, int]: # general, admin
    # checker
    if start is None or count is None or \
            not start.isdigit() or not count.isdigit(): 
        return error("Arguments error"), 400
    start = int(start)
    count = int(count)

    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    resfn = []

    with db.getsession() as session:
        # query
        if role == "general":
            res = session.query(table).filter(table.mark == "visible", table.reference == None)
        elif role == "admin":
            res = session.query(table).filter(table.reference == None)
        res = res.order_by(desc(table.id)).offset(start).limit(count).all()

        # mapping
        for r in res:
            rup = {"id":r.id, "ctx":r.ctx, "igid":r.igid, "created_at":r.created_at, "mark":r.mark}
            if role == "admin": rup["ip"] = r.ip # 如果是管理員 多給ip
            rup["files"] = [ f[0] for f in session.query(ftab.id).filter(ftab.reference == r.hash).all() ] # 檔案
            resfn.append(rup)
    
    return jsonify(resfn), 200

# 刪除文章
def solo_article_remover(role:str, hash:str=None, id:int=None) -> Tuple[Dict, int]: # admin, general
    key = None
    if role == "admin": key = id
    elif role == "general": key = hash
    
    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    rcl = []

    with db.getsession() as session:
        # 獲取本體
        if role == "admin":
            res = session.query(table).filter(table.id == key).first()
        elif role == "general":
            res = session.query(table).filter(table.hash == key).first()
        if res is None: # 檢查本體是否存在
            return {"error":"Post not found"}, 404

        # 刪除本體檔案
        session.query(ftab).filter(ftab.reference == res.hash).delete()

        # 刪留言
        resc = session.query(table).filter(table.reference == res.id).all() # 留言
        for c in resc:
            rcl.append(c.id)
            # 刪留言的檔案
            session.query(ftab).filter(ftab.reference == c.hash).delete()
            # 刪留言
            session.delete(c)
        
        # 刪本體
        session.delete(res)
        
        session.commit()
    
    return {"id":res.id, "mark":res.mark, "rcl":rcl}, 200

# 獲取檔案
def solo_file_fetcher(role:str, id:int) -> Tuple[Response, int]: # general, admin
    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile

    with db.getsession() as session:
        fres = session.query(ftab).filter(ftab.id == id).first()
        if fres is None: # 檢查檔案是否存在
            return error("File not found"), 404
        
        if role == "general":
            article = session.query(table).filter(table.hash == fres.reference, table.mark == 'visible').first()
        elif role == "admin":
            article = session.query(table).filter(table.hash == fres.reference).first()
        if article is None: # 檢查文章本體是否存在/可以閱覽
            return error("File not found"), 404
    
    resp = make_response(fres.binary)
    resp.headers.set("Content-Type", fres.type)
    resp.headers.set("Content-Disposition", f"attachment; filename=file{fres.id}")
    return resp, 200