#!/usr/bin/env python3

import requests
import argparse
import json
import os
import re
import shutil
import tarfile

MW_API_URL = 'https://www.mediawiki.org/w/api.php'
DEBUG = False

def get_filename_from_cd(cd):
	"""
	Get filename from content-disposition
	"""
	if not cd:
		return None
	fname = re.findall('filename=(.+)', cd)
	if len(fname) == 0:
		return None
	return fname[0]

def find_nearest_small_value(key, sorted_li):
	return max(i for i in sorted_li if i <= key)

def download(name, url, path):
	if url == None:
		return
	if DEBUG:
		print(f'    ↪ Downloading { name } from { url } to "{ path }"')
	else:
		print(f' ↪ Downloading { name }')
	r = requests.get(url, allow_redirects = True)
	filename = get_filename_from_cd(r.headers.get('content-disposition'))
	if filename == None and url.find('/'):
		filename = url.rsplit('/', 1)[1]
	if DEBUG:
		print( f'    ↪ Writing to {os.path.join( path, filename )}' )
	open(os.path.join( path, filename ), 'wb').write(r.content)
	if DEBUG:
		print( f'    ↪ Decompressing to {os.path.join( path, name )}' )
	tgz = tarfile.open( os.path.join( path, filename ) )
	tgz.extractall( path )
	tgz.close

def get_url(release, item, degrade):
	if release in item:
		return item[release]
	elif degrade:
		prv = find_nearest_small_value(release, list(item.keys()))
		return item[prv]
	else:
		return None

def ensure_path(path):
	if os.path.exists(path):
		if os.path.isdir(path):
			if os.access(path, os.W_OK):
				return True
			else:
				return False
		else:
			return False
	else:
		os.mkdir( path, mode=0o770 )
		if os.getuid == 0:
			shutil.chown(path, user='www-data', group='www-data')

def get_path(path):
	if os.path.exists(path):
		if os.path.isdir(path):
			if os.access(path, os.W_OK):
				return path
			elif path != './':
				print(f'"{path}" is not writable. Trying current directory.')
				return( get_path('./') )
			else:
				print(f'Cannot write to {path}. Terminating.')
				exit(3)
		else:
			print(f'"{path}" is not a directory. Trying current directory.')
			return( get_path('./') )
	else:
		print(f'"{path}" does not exist. Trying current directory.')
		return( get_path('./') )

def init():
	global DEBUG
	parser = argparse.ArgumentParser(
		prog="SkinAndExtendMediawiki",
		description="It's all in the name, skinning and extending Mediawiki",
		epilog="Skins and extensions respectively will be downloaded into 'skins' and 'extensions' subdirectory of the -p/--path given."
	)
	parser.add_argument("-p","--path", help="installation path\nExamples:-p /var/www/mediawiki/\n--path /srv/mediawiki", type=str, default='./')
	parser.add_argument("-r","--release", help="Mediawiki release, use release 'list' to list available release tags.", type=str, default="list")
	parser.add_argument("-d","--degrade", help="degrade Mediawiki release if no download for the selected release exists (source → master → REL… → REL-1 …), otherwise will be skipped", action='store_true')
	parser.add_argument("-s","--skins", help="install one or more Mediawiki skins", type=str, dest='skins', nargs='+')
	parser.add_argument("-e","--extensions", help="install one or more Mediawiki extensions", type=str, dest='extensions', nargs='+')
	parser.add_argument("-v", "--verbose", help="increase output verbosity", action="store_true")
	
	args = parser.parse_args()
	if args.verbose:
		DEBUG = True
	if DEBUG:
		print(args)
	payload = { 'action': 'query', 'list': 'extdistbranches', 'format': 'json' }
	r = requests.get( MW_API_URL, params=( payload | { 'edbskins': 'Vector'} ) )
	if r.status_code == 200:
		response = json.loads(r.text)
		vector_keys = list( response['query']['extdistbranches']['skins']['Vector'].keys() )
		list_message = f'\nAvailable release tags: { vector_keys }.'
	else:
		list_message = f'Cannot retrieve release tags, received HTTP { r.status_code}.'
	if args.release == 'list':
		parser.print_help()
		print(list_message)
		exit(1)
	elif args.release in vector_keys:
		print(f'Using release tag { args.release }.')
	else:
		print(f'Invalid release tag { args.release }.')
		exit(2)

	final_payload = payload.copy()
	if args.skins != None:
		final_payload |= { 'edbskins': '|'.join(args.skins) }
	if args.extensions != None:
		final_payload |= { 'edbexts': '|'.join(args.extensions) }
	
	#print( json.dumps(final_payload, indent=4) )
	r = requests.get( MW_API_URL, params=final_payload )
	response = json.loads(r.text)
	edb = response['query']['extdistbranches']
	path = get_path( os.path.join( args.path, '' ) )
	for dl_type in list(response['query']['extdistbranches'].keys()):
		print(f'Processing { dl_type }.')
		ensure_path( os.path.join( path, dl_type ) )
		for item in edb[dl_type]:
			if DEBUG:
				print( f' ↪ {item}: { get_url( args.release, edb[dl_type][item], args.degrade )}' )
			download(item, get_url( args.release, edb[dl_type][item], args.degrade ), os.path.join( path, dl_type ) )
		

if __name__ == "__main__":
    init()