#! /usr/bin/env python
# -*- coding: utf-8 -*-

import os
import jinja2
import sys
from email.header import Header
from email.message import Message
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from markdown import markdown

sys.path.append('/usr/scripts/')
from gestion.email_tools import format_sender
sys.path.pop()

default_language = 'fr'
template_path = '/usr/scripts/gestion/mail/template/'
html_template = template_path + 'html'
html_mutilang_template = template_path + 'html_multilang'
text_mutilang_template = template_path + 'text_multilang'

templateLoader = jinja2.FileSystemLoader( searchpath=["/", template_path]  )
templateEnv = jinja2.Environment( loader=templateLoader )


# file extension to rendering function map
markup = {
  'md' : markdown
}

### For an example: 
### print generate('bienvenue', {'From':'respbats@crans.org', 'To':'admin@genua.fr', 'lang_info':'English version below'}).as_string()


def submessage(playload, type, charset='utf-8'):
    """Renvois un sous message à mettre dans un message multipart"""
    submsg=MIMEText('', type, charset)
    del(submsg['Content-Transfer-Encoding'])
    submsg['Content-Transfer-Encoding']='8bit'
    submsg.set_payload(playload)
    return submsg

def get_lang(mail, part, lang, lang_fallback):
    for l in [lang, lang_fallback]:
        for ext in markup.keys():
            if os.path.isfile(template_path + mail + '/' + part + '/' + l + '.' + ext):
                return l, ext, template_path + mail + '/' + part + '/' + l + '.' + ext
        if os.path.isfile(template_path + mail + '/' + part + '/' + l):
            return l, None, template_path + mail + '/' + part + '/' + l
    raise ValueError("Language %s nor %s found" % (lang, lang_fallback))
    
def body(mail, lang1, lang2, mk, params, charset):
    file1 = template_path + mail + '/body/' + lang1
    file2 = template_path + mail + '/body/' + lang2
    if mk:
        file1 = file1 + '.' + mk
        file2 = file2 + '.' + mk
    if lang1 == lang2 or not os.path.isfile(file2): # No alt language
        txt = templateEnv.get_template(file1).render(params)
        ret = [ submessage(txt.encode(charset), 'plain', charset) ]
        if mk: # compute the html version
            html = templateEnv.get_template(html_template).render({'body': markup[mk](txt)})
            ret.append(submessage(html.encode(charset), 'html', charset))
    else:
        txt1 = templateEnv.get_template(file1).render(params)
        txt2 = templateEnv.get_template(file2).render(params)
        params_txt=dict(params)
        params_txt.update({'body1': txt1, 'body2':txt2})
        txt = templateEnv.get_template(text_mutilang_template).render(params_txt)
        ret=[ submessage(txt.encode(charset), 'plain', charset) ]
        if mk: # compute the html version
            params_html=dict(params)
            params_html.update({'lang1':lang1, 'lang2':lang2, 'body1': markup[mk](txt1), 'body2': markup[mk](txt2)})
            html = templateEnv.get_template(html_mutilang_template).render(params_html)
            ret.append(submessage(html.encode(charset), 'html', charset))
    return ret

def generate(mail, params, lang=default_language, lang_fallback=default_language, lang_alt='en', charset='utf-8'):
    """Génère un message multipart"""
    msg = MIMEMultipart('alternative')
    if os.path.isdir(template_path + mail):
        for filename in [dir for dir in os.listdir(template_path + mail) if os.path.isdir(template_path + mail + '/' + dir)]:
            lang_tmp, mk, file = get_lang(mail, filename, lang, lang_fallback)

            if filename == 'body': 
                for part in body(mail, lang_tmp, lang_alt, mk, params, charset):
                    msg.attach(part)
            else:
                txt = templateEnv.get_template(file).render(params)
                if filename in ['From', 'To', 'Cc', 'Bcc']:
                    msg[filename] = format_sender(txt, charset)
                else:
                    msg[filename]=Header(txt.encode(charset), charset)

    return msg