#! /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 email.Utils import formatdate
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()
### or from a shell : python -c "import mail; print mail.generate('bienvenue', {'From':'respbats@crans.org', 'To':'admin@genua.fr', 'lang_info':'English version below'})"

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)
        msg['Date']=formatdate(localtime=True)

    return msg