schort/schort.py

74 lines
2.8 KiB
Python
Executable File

#!/usr/bin/env python3
from flask import Flask, render_template, url_for, request, redirect, abort
import sqlite3, random, string, time, hashlib, base64
app = Flask(__name__)
@app.route('/', methods=['GET', 'POST'])
@app.route('/<shortLink>', methods=['GET', 'POST'])
def short(shortLink=""):
if request.method == "GET":
conn = sqlite3.connect("links.sqlite")
c = conn.cursor()
result = c.execute('SELECT * FROM links WHERE shortLink=?', (shortLink, )).fetchone()
if result:
return redirect(result[1], code=301) # Redirect to long URL saved in the database
else:
message = ""
if len(shortLink) > 0:
message = "Enter long URL for "+ request.url_root + shortLink+":"
return render_template("index.html", name=shortLink, message=message, message_type="info") # Does the user wish to create a personel short link?
elif request.method == "POST": # Someone submitted a new link to short
wishId = request.form["wishId"]
longUrl = request.form["url"]
if not wishId:
databaseId = insertIdUnique("", longUrl)
else:
databaseId = insertIdUnique(wishId, longUrl)
return request.url_root + databaseId # TODO: Give the user a nice site where he can see his short URL
def insertIdUnique(idToCheck, longUrl):
hashUrl = hashlib.sha256(longUrl.encode()).digest()
base64Url = base64.urlsafe_b64encode(hashUrl).decode()
if len(idToCheck) == 0:
idToCheck = base64Url[:4]
conn = sqlite3.connect("links.sqlite")
c = conn.cursor()
try:
c.execute('INSERT INTO links VALUES (?, ?, ?, ?, ?)', (idToCheck, longUrl, int(time.time()), request.remote_addr, "default" ))
databaseId = idToCheck
conn.commit()
conn.close()
except sqlite3.IntegrityError as e:
print("Hash already exists, does the long URL matches?")
longUrlDb = c.execute('SELECT * FROM links WHERE shortLink=?', (idToCheck, )).fetchone()
if longUrl == longUrlDb[1]:
print(longUrl + " is already in database with id " + idToCheck + ". Serving old id…")
databaseId = idToCheck
else:
print("Found real hash collision for " + longUrl + " and " + longUrlDb[1])
conn.commit()
conn.close()
if len(base64Url) - 1 >= len(idToCheck) + 1:
databaseId = insertIdUnique(base64Url[:len(idToCheck)+1], longUrl)
else:
print("Can't produce a long enough hash from the new link to be unique. This should never happen")
print("Bailing out, you are on your own. Good luck.")
print("=========================================================================================")
abort(500)
return databaseId
def initDB():
conn = sqlite3.connect("links.sqlite")
c = conn.cursor()
c.execute('''CREATE TABLE IF NOT EXISTS links (shortLink UNIQUE NOT NULL, longLink, timestamp, ip, redirectMethod);''')
conn.commit()
conn.close()
print("DB init")
if __name__ == '__main__':
initDB()
# app.run(debug=True)
app.run(debug=False)