#!/usr/bin/env python

#  todo-email-scraper.py - Watch an email address for TODOs and add them to an org file
#
# Copyright (c) 2014 Free Software Foundation, Inc.
#
# Authors:
#          Anthony Lander <anthony.lander@gmail.com>
#
# Version: 1.0
# Keywords: org, todo, email
#
# This file is not part of GNU Emacs.
#
# This program is free software# you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation# either version 3, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY# without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
#
# Commentary:
#
# - Email subject is the TODO line, and body is the TODO body.
# - Add a property line :TODO-TARGET: true to the parent heading where TODOs should be dropped
# - Configure email address, diary file, password below.
# - You can schedule this to run every 30 minutes in a cron job.

# - The scraper scrapes all emails from a designated address (so only you can
# - send yourself todos). as such, it is best to set up a todo email address to
# - receive only todo emails.


import sys
from os import rename
from datetime import datetime
from string import replace
import imaplib
import StringIO
from email.parser import Parser

# ### Configuration
diary_file = "/path/to/org_file.org"  # Replace with your org file
server = 'imap.gmail.com'             # Replace with your imap mail server
username = 'tasklist@gmail.com'       # Replace with the email address that receives todos
password = 'passowrd'                 # Replace with the password for the above email address
authorized_sender = 'you@gmail.com'   # Replace with the email address from which you send todos


def is_diary_file_available():
    try:
        file = open(diary_file, "r")
    except IOError:
        return False
    file.close()
    return True

    
def get_todos():

    imap = imaplib.IMAP4_SSL(server)
    imap.login(username, password)
    imap.select()

    search_criteria = '(UNSEEN FROM "' + authorized_sender + '")'
    typ, data = imap.search(None, search_criteria)

    todos = []
    for num in data[0].split():
        todo_subject = ""
        todo_body = []
        typ, data = imap.fetch(num, '(RFC822)')

        file = StringIO.StringIO(data[0][1])
        message = Parser().parse(file)
        todo_subject = message['subject']
#        print message['Subject'] + "\n"

        body = ""
        for part in message.walk():
            t = part.get_content_type()
            if t and t.lower() == "text/plain":
                # Found the first text/plain part 
                body = part.get_payload(decode=True)
                break
        
 #       print ">", body, "<"
        long_line = ""
        for line in [line.strip() for line in body.splitlines() if len(line) > 0]:
            if line[-1:] == "=":
                long_line += line[:-1]
            else:
                if len(long_line) > 0:  # There is a long line waiting to be written
#                    print "long line: ", long_line
                    todo_body.append(long_line)
                    long_line = ""
                else:
#                    print "line: ", line
                    todo_body.append(line)
                    long_line = ""
                
        if len(long_line) > 0:
#            print "long line (final): ", long_line
            todo_body.append(long_line)
        todos.append({'subject' : todo_subject, 'body' : todo_body})
                
    imap.close()
    imap.logout()
    return todos
    
    
def new_diary_lines_with_todos(todos):
    try:
        file = open(diary_file, "rt+")
        found = False
        done = False
        stars = ""
        timestamp = datetime.now().strftime("[%Y-%m-%d %a %H:%M]")
        log_lines = [":LOGBOOK:", '- State "TODO"       from ""           ' + timestamp, ":END:"]
        
        lines = []
        while not done:
            line = file.readline()
            if len(line) == 0:
                done = True
            else:
                lines.append(line)

                if not found:
                    if line[0] == "*":
                        stars = line.split()[0]

                    if line.strip() == ":TODO-TARGET: true":
                        found = True

                        line = ""
                        while not line.strip() == ":END:":
                            line = file.readline()
                            lines.append(line)

                        for todo in todos:
                            line = "%s%s%s%s" % (stars, "** TODO ", todo['subject'], "\n")
                            lines.append(line)
                            spaces = replace(stars + "** ", "*", " ")
                            for line in log_lines:
                                lines.append(spaces + line + "\n")

                            for line in todo['body']:
                                lines.append(spaces + line + "\n")
        file.close()
    except:
        print "Unexpected error:", sys.exc_info()[0]
        file.close()
        raise
    return lines


def write_todo_file(filename, todos):
    try:
        file = open(filename, "w")
        for todo in todos:
            file.write(todo)
        file.close()
        return True
    except:
        print "Unexpected error:", sys.exc_info()[0]
        file.close()
        raise

    return False

def scrape_todos():
    if not is_diary_file_available():
        print "No diary file available - aborting."
        sys.exit(-1)

    todos = get_todos()
    if len(todos) > 0:
        new_lines = new_diary_lines_with_todos(todos)
        try:
            now = datetime.now().strftime(".%Y-%m-%d-%H-%M")
            diary_backup = diary_file + now + ".orig"
#            print "renaming", diary_file, " to ", diary_backup
            rename(diary_file, diary_backup)
        except:
            print "Unexpected error while renaming:", sys.exc_info()[0]
            raise
        
        write_todo_file(diary_file, new_lines)
        print "Added ", len(todos), " todos at ", now


if __name__ == '__main__':
    scrape_todos()
    sys.exit(0)