import os
import json
from flask import Flask, request, render_template, redirect
from urllib.request import urlopen
from urllib.parse import urlencode

# To sanitize Flask input fields
from flask import escape

# To sanitize Markdown input
import markdown
import bleach

APP = Flask(__name__)
APP.config.from_object("config.Config")

# ---

def get_pad_content(pad_name, ext=""):
	if ext:
		pad_name = f'{ pad_name }{ ext }'

	print(pad_name)

	arguments = { 
		'padID' : pad_name,
		'apikey' : APP.config['PAD_API_KEY']
	}
	api_call = 'getText'
	response = json.load(urlopen(f"{ APP.config['PAD_API_URL'] }{ api_call }", data=urlencode(arguments).encode()))
	
	# create pad in case it does not yet exist
	if response['code'] == 1 and 'padID does not exist' == response['message']:
		api_call = 'createPad'
		urlopen(f"{ APP.config['PAD_API_URL'] }{ api_call }", data=urlencode(arguments).encode())
		api_call = 'getText'
		response = json.load(urlopen(f"{ APP.config['PAD_API_URL'] }{ api_call }", data=urlencode(arguments).encode()))

	content = response['data']['text']
	return content

def all_pads():
	arguments = { 
		'apikey' : APP.config['PAD_API_KEY'],
	}
	api_call = 'listAllPads'
	response = json.load(urlopen(f"{ APP.config['PAD_API_URL'] }{ api_call }", data=urlencode(arguments).encode()))

	return response

def create_pad_on_first_run(name, ext):
	pads = all_pads()
	pad = name+ext

	if pad not in pads['data']['padIDs']:

		# Select default template
		if 'md' in ext:
			default_template = 'templates/default.md'
		elif 'css' in ext:
			default_template = 'templates/default.css'
		default_template = open(default_template).read()

		# Create pad and add the default template
		arguments = { 
			'padID' : pad,
			'apikey' : APP.config['PAD_API_KEY'],
			'text' : default_template
		}
		api_call = 'createPad'
		json.load(urlopen(f"{ APP.config['PAD_API_URL'] }{ api_call }", data=urlencode(arguments).encode()))

def md_to_html(md_pad_content):
	# Convert Markdown to HTML
	html = markdown.markdown(md_pad_content, extensions=['meta'])
	
	# Sanitize the Markdown
	# html = bleach.clean(html)
	
	# Another way to Sanitize
	from markupsafe import Markup
	html = Markup(html) # Maybe not safe enough?
	
	return html

def get_md_metadata(md_pad_content):
	# Read the metadata from the Markdown
	md = markdown.Markdown(extensions=['meta'])
	md.convert(md_pad_content)
	metadata = md.Meta

	return metadata

# ---

@APP.route('/', methods=['GET', 'POST'])
def index():
	name = False
	if request.values.get('name'):
		name = escape(request.values.get('name')) # Returns a Markup() object, which is "None" when False
	if name: 
		# This is when the environment is "created"
		# The pads are filled with the default templates (pad, stylesheet, template)
		exts = ['.md', '.css']
		for ext in exts:
			create_pad_on_first_run(name, ext)
		return redirect(f'/{ name }/')
	else:
		return render_template('start.html')

@APP.route('/<name>/', methods=['GET'])
def main(name):
	return redirect(f'/{ name }/pad/')

@APP.route('/<name>/pad/')
def pad(name):
	pad_name = f'{ name }.md'
	url = os.path.join(APP.config['PAD_URL'], pad_name)
	return render_template('iframe.html', url=url, name=name.strip())

@APP.route('/<name>/stylesheet/', methods=['GET'])
def stylesheet(name):
	pad_name = f'{ name }.css'
	url = os.path.join(APP.config['PAD_URL'], pad_name)
	return render_template('iframe.html', url=url, name=name.strip())

@APP.route('/<name>/html/')
def html(name):
	path = os.path.join(f'/{ name }/', 'preview.html')
	return render_template('iframe.html', url=path, name=name.strip())

@APP.route('/<name>/pdf/')
def pdf(name):
	path = os.path.join(f'/{ name }/', 'pagedjs.html')
	return render_template('pdf.html', url=path, name=name.strip())

# //////////////////
# RENDERED RESOURCES 
# //////////////////
# (These are not saved as a file on the server)

@APP.route('/<name>/stylesheet.css')
def css(name):
	css = get_pad_content(name, '.css')
	# Insert CSS sanitizer here.
	
	return css, 200, {'Content-Type': 'text/css; charset=utf-8'}

@APP.route('/<name>/preview.html')
def preview(name):
	# TO GENERATE THE PREVIEW WEBPAGE
	md_pad_content = get_pad_content(name, ext='.md')
	html = md_to_html(md_pad_content)
	metadata = get_md_metadata(md_pad_content)
	lang = metadata['language'][0]
	
	return render_template('preview.html', name=name.strip(), pad_content=html, lang=lang)

@APP.route('/<name>/pagedjs.html')
def pagedjs(name):
	# TO GENERATE THE PAGED.JS WEBPAGE
	md_pad_content = get_pad_content(name, ext='.md')
	html = md_to_html(md_pad_content)
	metadata = get_md_metadata(md_pad_content)
	lang = metadata['language'][0]
	
	return render_template('pagedjs.html', name=name.strip(), pad_content=html, lang=lang)

# //////////////////

if __name__ == '__main__':
	APP.debug=True
	APP.run(host="0.0.0.0", port=f'{ APP.config["PORTNUMBER"] }', threaded=True)