niming_backend/blueprints/article.py

from flask import Blueprint, current_app, request, jsonify, make_response
import hashlib
import time
import magic # apt install libmagic1 libmagic-dev -y
from utils import logger, pgclass, setting_loader
from sqlalchemy.orm import sessionmaker
from sqlalchemy import desc
from protobuf_files import niming_pb2
from google.protobuf.message import DecodeError

"""
TODO:
- IG post ( Po文、刪文、只PO本體文章 )

- log 的方式之後要重新設計 > 正規化
- IP Record (deploy之前配合rev proxy)
- gunicorn
- 檔案完成，但是再看看要不要讓發文者持sha256存取自己發的文的檔案
"""

article = Blueprint('article', __name__)

# 匿名文列表
@article.route('/list', methods = ["GET"])
def listing():
    # variables
    if request.args.get("start") is None or request.args.get("count") is None or \
        request.args.get("start").isdigit()==False or request.args.get("count").isdigit()==False: return "Arguments error", 400
    rst = int(request.args.get("start"))
    count = int(request.args.get("count"))

    # db
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    with Session() as session:
        # get ctx
        table = pgclass.SQLarticle
        ftab = pgclass.SQLfile
        res = session.query(table.id, table.ctx, table.igid, table.created_at, table.mark, table.hash).order_by(desc(table.id)).filter(table.mark == 'visible', table.reference == None).offset(rst).limit(count).all()

        # mapping
        res = [ {"id":r[0], "ctx":r[1], "igid":r[2], "created_at":r[3], "mark":r[4],
                 "files": [ f[0] for f in session.query(ftab.id).filter(ftab.reference == r[5]).all() ] } for r in res ]

        return jsonify(res), 200

# 獲取指定文章
@article.route("/get/<int:id>", methods = ["GET"])
def getarticle(id:int):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    with Session() as session:
        # get ctx
        table = pgclass.SQLarticle
        ftab  = pgclass.SQLfile
        res = session.query(table.id, table.ctx, table.igid, table.created_at, table.mark, table.reference, table.hash).filter(table.id == id).filter(table.mark == 'visible').all()

        # mapping
        resfn = [
            {"id":r[0], "ctx":r[1], "igid":r[2], "created_at":r[3], "mark":r[4], "reference":r[5], # basic
             "comment": [ c[0] for c in session.query(table.id).filter(table.reference == int(r[0]), table.mark == "visible").all() ], # comment
             "files": [ f[0] for f in session.query(ftab.id).filter(ftab.reference == r[6]).all() ]
             } 
             for r in res
        ]

        return jsonify(resfn), 200

# 上傳文章 / 留言
@article.route("/post", methods = ["POST"])
def posting():
    # flow:
    #   ctx -> hash -> reference -> file -> IP -> IG -> mark -> post | -> log
    # db
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLarticle
    # loadset
    opt = setting_loader.loadset()
    chk_before_post = opt["Check_Before_Post"]
    maxword = opt["Niming_Max_Word"]
    # data parse
    recv = niming_pb2.DataMessage()
    try: recv.ParseFromString(request.data)
    except DecodeError: return "Protobuf decode error", 400

    # content
    ctx = str(recv.ctx) # request.json["ctx"]
    # length check
    if len(ctx) == 0 or len(ctx) > maxword: return "no content or too many words", 400

    # hash
    seed = ctx + str(time.time())
    hash = hashlib.sha256(seed.encode()).hexdigest()

    with Session() as session:
        # reference
        ref = int(recv.ref) # request.json["ref"]
        if not (ref == 0):   # 如果ref不是0
            # 檢查是不是指向存在的文章
            chk = session.query(table).filter(table.id == ref, table.mark == "visible").first()
            if chk is None: return "Invalid Reference", 400
            # 檢查指向的文章是否也是留言
            if not(chk.reference is None): return "Invalid Reference", 400
        else:
            ref = None
    
        # file processing
        files = recv.files
        # check - size
        atts = opt["Attachment_Count"]
        sizelimit = opt["Attachment_Size"]
        if len(files) > atts: return "Too many files", 400
        for f in files:
            if len(f) <= 0 or len(f) > sizelimit: return "File size error", 400
        # check - mimetype
        allowed_mime = opt["Allowed_MIME"]
        for f in files:
            mime = magic.Magic(mime=True)
            type = mime.from_buffer(f)
            if not(type in allowed_mime): return "File format error", 400
        # run processor
        ftab = pgclass.SQLfile
        for f in files:
            mime = magic.Magic(mime=True)
            type = mime.from_buffer(f)
            fsql = ftab(reference = hash, binary = f, type = type)
            session.add(fsql)

        # IP
        ip = request.remote_addr

        # ig posting
        if chk_before_post:
            igid = None
        # Go posting
        igid = None
        # Coming Soon...

        # mark
        if chk_before_post: mark = "pending"
        else: mark = "visible"

        # posting
        data = table(hash = hash, ctx = ctx, igid = igid, mark = mark, reference = ref, ip = ip)
        session.add(data)
        session.commit()
        # pg getdata
        res = session.query(table.id, table.ctx, table.igid, table.created_at, table.mark, table.hash, table.reference).filter(table.hash == hash).all()
        fres = session.query(ftab.id).filter(ftab.reference == hash).all()
        res = [ {"id":r[0], "ctx":r[1], "igid":r[2], "created_at":r[3], "mark":r[4], "hash":r[5], "reference":r[6],
                 "files": [f[0] for f in fres]
                 } for r in res ]

    # logger
    logger.logger(db, "newpost", "New post (id=%d point to %s): %s"%(res[0]["id"], ref, mark))
    
    return jsonify(res), 201

# 只有發文者可以看到的獲取指定文章
# 只有發文者可以做到的刪除文章
@article.route("/own/<sha256>", methods = ["GET", "DELETE"])
def owner_getarticle(sha256:str):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLarticle
    ftab = pgclass.SQLfile

    # 獲取指定文章
    if request.method == "GET":
        with Session() as session:
            res = session.query(table.id, table.ctx, table.igid, table.created_at, table.mark, table.hash, table.reference).filter(table.hash == sha256).all()
            resfn = [
                {"id":r[0], "ctx":r[1], "igid":r[2], "created_at":r[3], "mark":r[4], "hash":r[5], "reference":r[6],
                "comment":[ c[0] for c in session.query(table.id).filter(table.reference == int(r[0])).all() ], # comments
                "files":[ f[0] for f in session.query(ftab.id).filter(ftab.reference == r[5]).all() ]} # files
                for r in res
            ]
        return jsonify(resfn), 200
    # 刪除指定文章跟他們的留言、檔案
    elif request.method == "DELETE":
        with Session() as session:
            rcl = []
            res = session.query(table).filter(table.hash == sha256).first()     # 本體
            if res is None: return "Post not found", 400 # 檢查本體是否存在
            # 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)
            # commit
            session.commit()
        # logger
        logger.logger(db, "delpost", "Delete post (id=%d with comments %s): last_status=%s"%(res.id, str(rcl), res.mark))
        return "OK", 200

    session.close()

# 獲取匿名文附檔
@article.route("/file/<int:id>", methods=["GET"])
def getfile(id:int):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)

    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    with Session() as session:
        fres = session.query(ftab).filter(ftab.id == id).first()
        if fres is None: return "File not found", 400       # 檢查檔案是否存在
        article = session.query(table).filter(table.hash == fres.reference, table.mark == 'visible').first()
        if article is None: return "File not found", 400    # 檢查文章本體是否存在/可以閱覽
    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