import argparse, os, glob, sys, json, email.utils, logging
import xml.etree.ElementTree as et
from datetime import datetime
import regex as re

nn = 0
logging.basicConfig(level=logging.CRITICAL)

xml_re = re.compile('[^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD]')
nl_re = re.compile('\n\n\n')
ind_re = re.compile('--------------------------------------------------------------------------')

def format_subject(s):
	return ' '.join(s.split())

def format_content(c):

	c = c.strip()

	# new lines 
	c = re.sub(nl_re, '\n', c)

	## weird stuff

	# 1. indesign automatic overset... (? dunno why ?)
	# ex: Sat, 22 Nov 1997 18:23:59 -0500 (The Mattel Crackdown -- Nettime)
	c = re.sub(ind_re, '', c)

	return c


	return c.strip().replace("\n\n\n", "\n")

# See for Nevejan?s research
def remove_invalid_xml_characters(s):
	return re.sub(xml_re, '', s)
    # return re.sub(r'[^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD]', '', s)
    # return re.sub(r'\p{Cc}-[\r\n\t]+', '', s)

def parse_date_file(fname):
	return datetime.strptime(fname, '%B_%Y.json')

# returns utc timestamp
def parse_date_msg(msg):
	date_str = msg['date']
	time_tz = None
	try:
		date_tz = email.utils.parsedate_tz(date_str)
		time_tz = email.utils.mktime_tz(date_tz) #utc timestamp
	except TypeError:
		logging.warning("Format Date TypeError")
		loggin.warning("  > " + date_str)
		return None
	except ValueError:
		loggin.warning("Format Date ValueError")
		loggin.warning("  > " + date_str)
		return None
	except Exception as ex:
		print(ex)
	finally:
		return time_tz

# recursive
def index_follow_up(msg):
	r = []
	if 'follow-up' in msg:
		for m in msg['follow-up']:
			d = parse_date_msg(m)
			if d is None:
				d = parse_date_msg(msg) # same as parent
			r.append((d, m))
			r += index_follow_up(m)
	return r

def emit_mail_xml(msg, xmlel):

	global nn
	nn += 1

	mail = et.SubElement(xmlel, 'mail')

	subject = et.SubElement(mail, 'subject')
	subject.text = format_subject(msg['subject'])

	to = et.SubElement(mail, 'to')
	if 'to' in msg: 
		to.text = msg['to']
	else:
		to.text = 'n/a'

	from_ = et.SubElement(mail, 'from')
	from_.text = msg['from']

	date = et.SubElement(mail, 'date')
	date.text = msg['date']

	content = et.SubElement(mail, 'content')
	content.text = format_content(msg['content'])

	# recursuve "follow-up"
	if 'follow-up' in msg:
		followups = index_follow_up(msg)
		followups.sort(key=lambda tup: tup[0])
		for d, f in followups:
			emit_mail_xml(f, xmlel)


def export_file(f, fout):

	with open(f) as fp:
		d = json.load(fp)

	all_mail = et.Element('all')
	for t in d['threads']:
		emit_mail_xml(t, all_mail)		

	fout.write(et.tostring(all_mail).decode('utf-8', 'ignore'))		

def export_year(d, dt, fout):

	dir_files = [f for f in glob.glob(os.path.join(d, "*.json"))]

	chapter = et.Element('chapter')
	year = et.SubElement(chapter, 'year')
	year.text = dt.strftime('%Y')

	# SORT MONTHS BEFORE WRITING TO XML
	dates = []
	for f in dir_files:

		fdt = parse_date_file(os.path.basename(f))
		if dt.year != fdt.year:
			continue

		dates.append((fdt, f))

	dates.sort(key=lambda tup: tup[0])

	for d, f in dates:

		logging.debug(f)

		section = et.SubElement(chapter, 'section')
		month = et.SubElement(section, 'month')
		month.text = d.strftime('%B')

		with open(f) as fp:
			dj = json.load(fp)

		mails = et.SubElement(section, 'mails')
		for t in dj['threads']:
			emit_mail_xml(t, mails)		

	# write utf8 to file (et.tostring are bytes)
	# fout.write(et.tostring(chapter).decode('utf-8', 'ignore'))
	fout.write(remove_invalid_xml_characters(et.tostring(chapter).decode('utf-8', 'ignore')))

if __name__ == "__main__":

	p = argparse.ArgumentParser(description='Mailinglists are dead. Long live mailinglists!')
	p.add_argument('file', metavar="f", help="mailinglist file(s) or dir(s) to export", nargs="+")
	p.add_argument('--year', '-y', metavar='y', type=str, help='year of archive')
	p.add_argument('--interval', '-i', metavar='i', type=str, help='years interval')
	p.add_argument('--output', '-o', metavar='o', type=str, help='output directory')

	args = p.parse_args()

	years = []

	if args.year:
		years.append(datetime.strptime(args.year, '%Y'))

	if args.interval:
		r = args.interval.split('-')
		years = list(map(lambda x: datetime.strptime(str(x), '%Y'), range(int(r[0]), int(r[1]) + 1)))

	if not args.file:
		sys.exit('No file(s). Aborting.')

# with open("out.xml", "w") as fout:
	for f in args.file:
		if not os.path.isdir(f):
			logging.warning(f + ' is not a valid directory.')
			continue
		if len(years) > 0:
			for y in years:
				yn = y.strftime('%Y')
				foutname = os.path.basename(f) + "_" + yn + ".xml"	
				if args.output and os.path.isdir(args.output):
					foutname = os.path.join(args.output, foutname)
				with open(foutname, "w") as fout:
					sys.stdout.write("Processing - " + yn)
					export_year(f, y, fout)
					print(" - nbr of message exported: " + str(nn))
					nn = 0
		else:
			if not os.path.isfile(f):
				sys.exit(f + ' is not a valid file. Aborting.')			
			export_file(f, fout)