pastExam/app.py

from flask import Flask, request, render_template, send_from_directory, abort, redirect, session, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address

import ipfshttpclient

from datetime import date, datetime
from functools import wraps
import hashlib
import random
import os
from config  import C

app = Flask(__name__)
app.config.from_object('config.C')
app.secret_key = C.session_key

limiter = Limiter(
    app,
    key_func=get_remote_address,
    default_limits=["50 / minute"],
)

db = SQLAlchemy(app)

ipfs_client = ipfshttpclient.connect()

class Paper(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    course = db.Column(db.String(30), index=True)
    teacher = db.Column(db.String(30), index=True)
    year = db.Column(db.Integer, index=True)
    author = db.Column(db.String(30), index=True)
    notes = db.Column(db.String(200))
    anon = db.Column(db.Boolean)
    create_date = db.Column(db.Date)
    like_num = db.Column(db.Integer, index=True, default=0)
    down_num = db.Column(db.Integer, index=True, default=0)
    file_hash = db.Column(db.String(64))

if __name__ == "__main__":
    db.create_all()

def login_required(allow_guest=True):
    def login_required_instance(f):
        @wraps(f)
        def df(*args, **kwargs):
            username = session.get('username')
            if not username or (not allow_guest and username.startswith('guest~')):
                return redirect(url_for('login'))
            return f(*args, **kwargs, username=username)
        return df
    return login_required_instance

@app.route('/pastExam/login/')
def login():
    return app.send_static_file('login/index.html')

@app.route('/pastExam/login/guest/')
def guest_login():
    return render_template('guest-login.html', vs=C.verify, allow_guest_upload=C.allow_guest_upload)

@app.route('/pastExam/login/guest/verify', methods=['POST'])
@limiter.limit("10 / hour")
def guest_login_send():
    for name, ques, hint, ans in C.verify:
        if request.form.get(name) != ans:
            return '错误!', 401

    if 'uid' not in session:
        session['uid'] = random.randint(0, 10000000)

    session['username'] = 'guest~%s' % session['uid']
    session.permanent = True
    return {'r':0}

@app.route('/pastExam/')
@login_required()
def list(username):
    course = request.args.get('course')
    teacher = request.args.get('teacher')
    year = request.args.get('year')
    year = year and year.isdigit() and int(year)

    has_course = course is not None
    has_teacher = teacher is not None
    has_year = year is not None
    ept = not (has_course or has_teacher or has_year) and 'page' not in request.args

    ps = Paper.query

    if course:
        ps = ps.filter_by(course=course)
    if teacher:
        ps = ps.filter_by(teacher=teacher)
    if year or year==0:
        ps = ps.filter_by(year=year)

    ps = ps.order_by(db.desc('like_num'))
    pagination = ps.paginate(max_per_page=100)
    curr_year = date.today().year
    all_courses = [i for i, in db.session.query(Paper.course.distinct()).all()]
    all_teachers = [i for i, in db.session.query(Paper.teacher.distinct()).all()]
    all_years = [i for i, in db.session.query(Paper.year.distinct()).all()]
    ipfs_version = hashlib.sha256(C.ipfs_base_url.encode('utf-8')).hexdigest()
    return render_template('list.html', **locals())

def check_length(x, limit=30, allow_null=False):
    return (x and len(x) <= limit) or (allow_null and not x)

@app.route('/pastExam/upload', methods=['POST'])
@limiter.limit("10 / hour")
@login_required(allow_guest=C.allow_guest_upload)
def upload(username):
    name = request.form.get('name')
    teacher = request.form.get('teacher')
    year = request.form.get('year')
    year = year and year.isdigit() and int(year) or 0
    notes = request.form.get('notes', '')
    anon = request.form.get('anon') == 'on'

    if not (check_length(name) and check_length(teacher) and check_length(notes, 200, True)):
        abort(422)

    files = request.files.getlist('files[]')

    dir_name = username + str(datetime.now())
    base_path = os.path.join('/tmp', dir_name)
    os.mkdir(base_path)
    for f in files:
        filename = f.filename.replace('/','_')
        f.save(os.path.join(base_path, filename))

    res = ipfs_client.add(base_path)
    file_hash = ''
    for r in res:
        if r.get('Name') == dir_name:
            file_hash = r.get('Hash')

    if not file_hash:
        abort(500)

    paper = Paper(
                course=name,
                teacher=teacher,
                year=year,
                notes=notes,
                anon=anon,
                author=username,
                create_date=date.today(),
                file_hash=file_hash
            )
    db.session.add(paper)
    db.session.commit()

    return redirect('.#part2')

@app.route('/pastExam/<pid>/download')
@login_required()
def download(pid, username):
    p = Paper.query.get_or_404(pid)
    # TODO: download number
    return redirect(C.ipfs_base_url + p.file_hash, code=301) # 301减少不必要的请求

# TODO like