niming_backend/blueprints/article.py

import time
import hashlib
import secrets

import magic
from flask import Blueprint, request, jsonify
from google.protobuf.message import DecodeError

from utils import logger, pgclass, setting_loader
from utils.dbhelper import db, solo_article_fetcher, multi_article_fetcher, solo_file_fetcher, solo_article_remover
from utils.misc import error, error_proto, internal_json2protobuf
from protobuf_files import niming_pb2

"""
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():
    res, code = multi_article_fetcher("general", request.args.get("page"), 30)
    return res, code


# 獲取匿名文附檔
@article.route("/file/<int:id>", methods=["GET"])
def getfile(id:int):
    resp, code = solo_file_fetcher("general", id)
    return resp, code


# 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/<int:id>", methods = ["GET", "DELETE"])
def owner_getarticle(id:int):
    # arguments
    sha256 = request.args.get("hash", None)
    if not sha256:
        return error("Arguments error"), 400
    sha256 = str(sha256)

    # 獲取指定文章
    if request.method == "GET":
        resfn, code = solo_article_fetcher("owner", key=(sha256, id))
        if code == 200: 
            return internal_json2protobuf(resfn), code
        return resfn, code
    # 刪除指定文章跟他們的留言、檔案
    elif request.method == "DELETE":
        result, code = solo_article_remover("owner", hash=sha256, id=id)
        if not code == 200: 
            return result, code

        logger.logger("delpost", "Delete post (id=%d): last_status=%s"
                      %(result["id"], str(result["mark"])))
        return niming_pb2.FetchResponse(
            status = niming_pb2.Status.Success,
            posts = [ niming_pb2.FetchResponse.Message(id = result["id"], mark = result["mark"]) ]
        ).SerializeToString(), 200


# 獲取指定文章
@article.route("/<int:id>", methods = ["GET"])
def getarticle(id:int):
    resfn, code = solo_article_fetcher("general", key=id)
    if code == 200:
        return internal_json2protobuf(resfn), code
    return resfn, code


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

    # content and check
    ctx = str(recv.content)
    if len(ctx) == 0 or len(ctx) > maxword: # length check
        return error_proto("post", "no content or too many words"), 400

    # hash
    seed = ctx + str(time.time()) + str(secrets.token_urlsafe(nbytes=16))
    hash = hashlib.sha256(seed.encode()).hexdigest()

    # reference and check
    ref = int(recv.ref)
    if ref != 0:
        # 檢查指向的文章是否也是留言
        reftg, code = solo_article_fetcher(role="general", key=ref)
        if code != 200 or reftg["reference"]:
            return error_proto("post", "Invalid Reference"), 400
    else:
        ref = None
    
    # file processing and check
    files = recv.files
    # check - size
    atts = opt["Attachment_Count"]
    sizelimit = opt["Attachment_Size"]
    if len(files) > atts: return error_proto("post", "Too many files"), 400
    for f in files:
        if len(f) <= 0 or len(f) > sizelimit: return error_proto("post", "File size error"), 400
    # check - mimetype
    allowed_mime = opt["Allowed_MIME"]
    fmimes = []
    for f in files:
        mime = magic.Magic(mime=True)
        type = mime.from_buffer(f)
        if not(type in allowed_mime): return error_proto("post", "File format error"), 400
        fmimes.append(type)

    # 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
    table = pgclass.SQLarticle
    ftab = pgclass.SQLfile
    try:
        with db.getsession() as session:
            # post
            data = table(hash = hash, content = ctx, igid = igid, mark = mark, reference = ref, ip = ip)
            session.add(data)
            # file processor
            fmidx = 0
            fidarr = []
            for f in files:
                fsql = ftab(reference = hash, binary = f, type = fmimes[fmidx])
                fidarr.append(fsql)
                session.add(fsql)
                fmidx += 1
            # first commit
            session.commit()
            # set file list
            data.file_list = [ fid.id for fid in fidarr ]
            session.commit() # second commit
            result_id = data.id
    except:
        return error_proto("post", "Create new post failed"), 400
    
    # logger
    logger.logger("newpost", "New post (id=%d point to %s): %s"%(result_id, ref, mark))
    
    # to protobuf & return
    proto_stres = niming_pb2.PostResponse(
        status = niming_pb2.Status.Success,
        hash = hash,
        id = int(result_id)
    ).SerializeToString()
    return proto_stres, 200

# 介面全部改成protobuf傳輸
# 檔案傳輸加低畫質版本(縮圖)