icpc-webprint/server-tx/app/print/views.py

from . import m_print

import requests
import time
from datetime import datetime

from flask import render_template
from flask import redirect
from flask import request
from flask import session
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from io import BytesIO
from app._tools.decorators import auth_required
from app._tools.database import DataManager
from app._tools.database import SessionManager
from app._tools.database import ConfigManager


RENDER_TEMPLATE = {
    "$root$" : "print/print_code_a.html",
    "$tutor$" : "print/print_code_t.html"
}
pdfmetrics.registerFont(TTFont('webprint', ConfigManager.get_config()['font-path']))

def watermark_gen(p : canvas.Canvas, config, user, page) -> None:
    REPLACEMENTS = {
        "$time$": datetime.now().strftime('%d.%m.%Y %H:%M'),
        "$team$": getattr(user, 'team', 'Unknown Team'),
        "$loc$": getattr(user, 'loc', 'Unknown Location'),
        "$page$": str(page)
    }
    wm_format = str(config['print']['watermark'])
    for key, value in REPLACEMENTS.items():
        wm_format = wm_format.replace(key, value)
    p.setFont("webprint", 13)
    p.setFillColorRGB(0.5, 0.5, 0.5)
    p.rotate(45)
    p.drawString(200, 200, wm_format * 10)
    p.rotate(-45)

@m_print.route('/')
@auth_required
def print_code():
    user = DataManager.get_user(SessionManager.get_session(session["token"]).user_id)
    render = 'print/print_code.html'
    if user.team in RENDER_TEMPLATE:
        render = RENDER_TEMPLATE[user.team]
    return render_template(
        f'{render}', user = user
    )

@m_print.route('/printcode', methods=['POST'])
@auth_required
def print_proc():
    user_text = request.form.get('code')
    lines = user_text.split('\n')
    if len(lines) < 4:
        return render_template("error.html", error = "Код, в котором так мало строк, можно запомнить и без печати :)")
    user = DataManager.get_user(SessionManager.get_session(session["token"]).user_id)
    config = ConfigManager.get_config()
    timedelta = int(time.time()) - user.lastprint_ts
    timedelta = config['print']['limits']['seconds-per-request'] - timedelta
    if timedelta > 0:
        return render_template("error.html", error = f"Пожалуйста, подождите ещё {timedelta} с. перед повторным запросом!")
    DataManager.edit_user(user.id, "lastprint_ts", int(time.time()))
    buffer = BytesIO()
    proc_pdf = canvas.Canvas(buffer, pagesize = A4)
    width, height = A4

    left_margin = 15
    top_margin = height - 30
    line_height = 15
    y = top_margin

    pages = 1
    watermark_gen(proc_pdf, config, user, pages)
    proc_pdf.setFillColorRGB(0, 0, 0, 1)
    proc_pdf.setFont("webprint", 9)
    for line in lines:
        line = line.replace('\r', '')
        if y < 30:
            pages += 1
            if (pages > config['print']['limits']['pages-per-request']):
                return render_template(
                    "error.html",
                    error = f"Достигнут лимит на генерацию в {config['print']['limits']['pages-per-request']} страниц за запрос!"
                )
            proc_pdf.showPage()
            watermark_gen(proc_pdf, config, user, pages)
            proc_pdf.setFillColorRGB(0, 0, 0, 1)
            proc_pdf.setFont("webprint", 9)
            y = top_margin
        proc_pdf.drawString(left_margin, y, line)
        y -= line_height
    
    proc_pdf.showPage()
    proc_pdf.save()
    buffer.seek(0)
    proc_pdf = buffer.getvalue()

    try:
        DataManager.edit_user(
            user.id,
            "pages",
            user.pages + pages
        )
        response = requests.post(
            f"http://{config['server']['ip']}:{config['server']['port']}/printfile",
            files = {
                'file' : (f"wp_{user.username}_{user.lastprint_ts}.pdf", proc_pdf)
            },
            data = {
                'secret-key' : config['server']['secret']
            },
            timeout = 10
        )
        if response.status_code == 200:
            return redirect("/")
        else:
            return render_template(
                "error.html",
                error = "Ошибка при отправке PDF файла на печать. Обратитесь к Администратору."
            )
    except Exception as e:
        return render_template(
            "error.html",
            error = f"Ошибка при подключении к серверу печати: {str(e)}"
        )

@m_print.route('/printpdf', methods=['POST'])
@auth_required
def print_pdf_proc():
    user = DataManager.get_user(SessionManager.get_session(session["token"]).user_id)
    config = ConfigManager.get_config()
    if user.team not in RENDER_TEMPLATE:
        return redirect("/")
    samples = 1
    file = request.files.get('file')
    if file.filename == '':
        return render_template("error.html", error = "Не был прикреплён файл!")
    if 'samples' in request.form:
        samples = int(request.form.get('samples'))
    if samples not in range(1, 16):
        return render_template(
            "error.html",
            error = "Допустимый диапазон копий составляет 1..15!"
        )
    DataManager.edit_user(user.id, "lastprint_ts", int(time.time()))
    try:
        response = requests.post(
            f"http://{config['server']['ip']}:{config['server']['port']}/printfile",
            files = {
                'file' : (f"wp_{user.username}_{user.lastprint_ts}.pdf", file)
            },
            data = {
                'secret-key' : config['server']['secret'],
                'samples' : samples
            },
            timeout = 10
        )
        if response.status_code == 200:
            return redirect("/")
        else:
            return render_template(
                "error.html",
                error = "Ошибка при отправке PDF файла на печать. Обратитесь к Администратору."
            )
    except Exception as e:
        return render_template(
            "error.html",
            error = f"Ошибка при подключении к серверу печати: {str(e)}"
        )