from flask import Flask, Response, redirect, url_for, request, session, abort, render_template, send_file
from flask_login import LoginManager, UserMixin, login_required, login_user, logout_user, current_user
from PIL import Image, ImageFont, ImageDraw
import qrcode
from io import BytesIO
import json, random, re, string, hashlib, base64

app = Flask(__name__)
systemURL = 'http://192.168.0.11:5000/' #FULL URL with a '/' at the end
systemURL = 'http://10.0.1.115:5000/'
randomchars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789' #note the lack of zero

# flask-login
login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = "login"

admins={}
class Admin(UserMixin):
	def __init__(self, name, password):
		self.id = name
		self.password = password
		admins[name] = self

with open('links.json', 'r') as infile:
	links = json.load(infile)

with open('admins.json', 'r') as infile:
	adminfile = json.load(infile)
	for key, value in adminfile.items():
		if key=='secret_key':
			app.secret_key = value
		elif key=='secret_cookie':
			secret_cookie = value.encode('utf-8')
		else:
			a = Admin(key, value['password'])


def saveFile():
	with open('links.json', 'w') as outfile:
		json.dump(links, outfile)

def randomToken():
	code = ""
	for i in range(0,6):
		code += random.choice(randomchars)
	return code

def codeValidation(code):
	if len(code) not in range (3,10):
		return False
	if re.match('^[\w-]+$', code) is None:
		return False
	return True

def codeLink(code):
	global links
	if code not in links:
		return False
	if len(links[code]['url'])==0:
		return None
	return links[code]['url']

def createNewCode():
	code=randomToken()
	while code in links: #danger!
		code=randomToken()
	links[code]={'url':''}
	return code

def serveImage(img):
    img_io = BytesIO()
    img.save(img_io, 'PNG')
    img_io.seek(0)
    return send_file(img_io, mimetype='image/png')

@app.route('/code/<code>')
def serveCode(code):
	code = code[:code.find('.')]
	if codeValidation(code) is False:
		return send_file('static/invalid.png', mimetype='image/png')
	qr = qrcode.QRCode(
    	version=1,
    	error_correction=qrcode.constants.ERROR_CORRECT_M,
    	box_size=8,
    	border=3,
	)
	qr.add_data(systemURL + code)
	qr.make(fit=True)
	img = qr.make_image(fill_color="black", back_color="white")
	return serveImage(img)

@app.route("/edit", methods=['GET', 'POST'])
def edit():
	code = request.form.get("code") if request.form.get("code") is not None else request.args.get("code")
	url = request.form.get("url")

	if codeLink(code) is False:
		return render_template('invalid.html', code=code)
	if current_user.is_authenticated:
		if url==None:
			return render_template('editlink.html', code=code, url=codeLink(code), admin=current_user.is_authenticated)
		else:
			if url=='remove':
				url = ''
			links[code]['url']=url
			saveFile()
			return render_template('message.html', message="Done Mr. Admin person")
	else:
		if codeLink(code) is not None:
			return render_template('cantedit.html', url=codeLink(code))
	
	if url is None:
		return render_template('editlink.html', code=code, url='', admin=current_user.is_authenticated)
	
	#Saving the link:
	if url.lower().startswith('https://') is False and url.lower().startswith('http://') is False:
		return render_template('message.html', message="Only http:// and https:// links alowed. Plz fix your link!")
	if len(url)>1000:
		return render_template('message.html', message="This link is too long! It probably contains tracking data or other crap. Please find a shorter link.")
	links[code]['url']=url
	saveFile()
	return render_template('success.html')

@app.route("/admin")
@login_required
def admin():
	return render_template('admin.html')

# somewhere to login
@app.route("/login", methods=["GET", "POST"])
def login():
	if request.method == 'POST':
		username = request.form['username']
		password = request.form['password']
		hasher = hashlib.sha256()
		hasher.update(password.encode('utf-8'))
		hasher.update(secret_cookie)
		hashedpassword = base64.b64encode(hasher.digest()).decode('utf-8')
		if admins[username].password == hashedpassword:
			login_user(admins[username])
			return redirect(request.args.get("next"))
		return abort(401)
	else:
		return render_template('login.html')

@app.route("/logout")
@login_required
def logout():
    logout_user()
    return redirect('/')

# callback to reload the user object        
@login_manager.user_loader
def load_user(userid):
    return admins[userid]

@app.route("/generate", methods=['GET', 'POST'])
def generate():
	howmany = request.form.get("howmany")
	if howmany is None:
		return render_template('generate.html')
	codes = []
	for i in range(0, int(howmany)):
		codes.append(createNewCode())
	columns = 4
	codesarray = [codes[i:i+columns] for i in range(0, len(codes), columns)]
	saveFile()
	humanSystemURL = systemURL[systemURL.find('//')+2:]
	return render_template("printlabels.html", codes=codesarray, systemURL=humanSystemURL, codegenURL=systemURL+'code/', format='.png')

@app.route("/list")
@login_required
def list():
	linklist = []
	for key, value in links.items():
		if len(value['url'])>0:
			linklist.append({'code':key, 'url':value['url']})
	return render_template('list.html', linklist=linklist, count=len(linklist))

@app.route("/empty")
@login_required
def showEmptyCodes():
	linklist = []
	for key, value in links.items():
		if value['url']=='':
			linklist.append({'code':key, 'url':value['url']})
	return render_template('listempty.html', linklist=linklist, count=len(linklist))

@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def catch_all(path):
	if len(path)==0:
		return render_template('welcome.html')
	if path in links:
		if codeLink(path) is not None:
			return redirect(links[path]['url'], code=302)
		else:
			return render_template('newcode.html', code=path)
	else:
		return render_template('invalid.html', code=path)