#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#
#    umfrage - einfache web-basierte Meinungsabfragen
#    Copyright (C) 2012 - Lars Kruse <devel@sumpfralle.de>
#
#    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 of the License, 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 this program.  If not, see <http://www.gnu.org/licenses/>.
#


import os
# the basedir is the parent dir of the location of this script
BASE_DIR = os.path.dirname(os.path.abspath(os.path.join(__file__, os.path.pardir)))
# add the project directory to the python search path
import sys
sys.path.insert(0, os.path.join(BASE_DIR, "src"))


from dataset import DEFINITION_OPTIONS, DEFINITION_QUALITY_RANGES, \
        DEFINITION_QUESTIONS

import ConfigParser
import uuid
import re
import smtplib
import email.mime.text
import email.utils
import sqlobject
import bobo
import genshi
import genshi.template
import genshi.filters


CONFIG_FILE = os.path.join(BASE_DIR, "umfrage.conf")
MAIL_ADDRESS_REGEX = r"^([\w\-\.]+@(\w[\w\-]+\.)+[\w\-]+)$"
# Set the INIT_DB_UMFRAGE environment setting in order to clean up the
# database during the first initial run. All tables are removed and
# initialized again based on the content of src/dataset.py
# e.g. run the following:
#    INIT_DB_UMFRAGE=1 python src/umfrage.py
RUN_FIRST_DB_INIT = "INIT_DB_UMFRAGE" in os.environ

config = ConfigParser.SafeConfigParser()
config.read(CONFIG_FILE)
db_uri = config.get("database", "uri")
sqlobject.sqlhub.processConnection = sqlobject.connectionForURI(db_uri)
loader = genshi.template.TemplateLoader(os.path.join(BASE_DIR, 'templates'), auto_reload=False)


class Session(sqlobject.SQLObject):
    created = sqlobject.DateTimeCol(default=sqlobject.DateTimeCol.now)
    name = sqlobject.UnicodeCol(default=lambda: uuid.uuid4().hex)


class Question(sqlobject.SQLObject):
    text = sqlobject.UnicodeCol()
    weight = sqlobject.IntCol()
    quality_levels = sqlobject.PickleCol()


class Option(sqlobject.SQLObject):
    title = sqlobject.UnicodeCol()
    text = sqlobject.UnicodeCol()
    image = sqlobject.UnicodeCol()
    weight = sqlobject.IntCol()


class Answer(sqlobject.SQLObject):
    text = sqlobject.UnicodeCol(default="")
    quality = sqlobject.UnicodeCol(default="")
    question = sqlobject.ForeignKey("Question")
    option = sqlobject.ForeignKey("Option")
    session = sqlobject.ForeignKey("Session")


class Submission(sqlobject.SQLObject):
    session = sqlobject.ForeignKey("Session")
    timestamp = sqlobject.DateTimeCol(default=sqlobject.DateTimeCol.now)
    to_default_destination = sqlobject.BoolCol()
    title = sqlobject.UnicodeCol()
    text = sqlobject.UnicodeCol()


def get_default_values(**kwargs):
    value_dict = {}
    # we always need "options" (e.g. on frontpage)
    value_dict["options"] = list(Option.select())
    value_dict["options"].sort(key=lambda item: item.weight)
    # useful values for different pages
    value_dict["base_url"] = config.get("hosting", "full_url")
    value_dict["to_address"] = config.get("content", "to_address")
    value_dict["errors"] = []
    # the base_url is expected to end with a slash
    if not value_dict["base_url"].endswith("/"):
        value_dict["base_url"] += "/"
    for key, value in kwargs.items():
        value_dict[key] = value
    return value_dict


def render(filename, input_data=None, **values):
    stream = loader.load(filename).generate(**values)
    if not input_data is None:
        stream |= genshi.filters.HTMLFormFiller(data=input_data)
    return stream.render("html", doctype="html")


def get_previous_question(question):
    questions = Question.select().orderBy("-weight")
    for one_q in questions:
        if one_q.weight < question.weight:
            return one_q
    return None


def get_next_question(question):
    questions = Question.select().orderBy("weight")
    for one_q in questions:
        if one_q.weight > question.weight:
            return one_q
    return None

def get_last_question():
    questions = list(Question.select().orderBy("weight"))
    if questions:
        return questions[-1]
    else:
        return None


def get_session(session_id):
    session = None
    if session_id:
        sessions = Session.selectBy(name=session_id)
        if sessions.count() > 0:
            session = sessions[0]
    return session


def send_mail(to_address, from_address, subject, text, sender=None):
    msg = email.mime.text.MIMEText(unicode(text), _charset="utf-8")
    msg["Subject"] = unicode(subject)
    msg["From"] = from_address
    msg["To"] = to_address
    if sender:
        msg["Sender"] = sender
    msg["Date"] = email.utils.formatdate()
    use_ssl = config.get("mail", "use_ssl", "no")
    use_ssl = use_ssl.lower() in ("1", "true", "yes", "on", "enabled")
    host = config.get("mail", "host", "localhost")
    if use_ssl:
        # see http://bugs.python.org/issue11927 (Python 2.7 uses port 25 instead of 465 by default)
        s = smtplib.SMTP_SSL(host, port=465)
    else:
        s = smtplib.SMTP(host)
    s.sendmail(from_address, [to_address], msg.as_string())
    s.quit()

@bobo.query('/submit')
def do_submit(session_id=None, subject=None, from_address=None,
        to_address=None, summary_text=None, go_backward=None):
    session = get_session(session_id)
    if go_backward:
        return render_question(session, get_last_question())
    input_data = {}
    params = get_default_values()
    if not session:
        return bobo.redirect(params["base_url"])
    params["session"] = session
    if not subject:
        params["errors"].append(u"Bitte tragen Sie einen Email-Titel (Betreff) ein!")
    else:
        input_data["subject"] = subject
    if from_address:
        # even with invalid input: store it for another attempt
        input_data["from_address"] = from_address
    if from_address and re.match(MAIL_ADDRESS_REGEX, from_address):
        pass
    elif from_address:
        params["errors"].append(u"Die Absende-Emailadresse scheint ungültig zu sein. Bitte korrigieren Sie dies!")
    else:
        params["errors"].append(u"Bitte tragen Sie eine Email-Adresse als Absender ein!")
    if to_address:
        # even with invalid input: store it for another attempt
        input_data["to_address"] = to_address
    if to_address and re.match(MAIL_ADDRESS_REGEX, to_address):
        pass
    elif to_address:
        params["errors"].append(u"Die Ziel-Emailadresse scheint ungültig zu sein. Bitte korrigieren Sie dies!")
    else:
        params["errors"].append(u"Bitte tragen Sie eine Ziel-Adresse für die Email " + \
                "ein (Vorgabe: %s)!" % params["to_address"])
    if not summary_text:
        params["errors"].append(u"Die Email darf nicht leer sein. Kehren Sie " + \
                "zurück zum Fragebogen und klicken Sie erneut auf " + \
                "'Abschließen' um den Vorgabetext wiederherzustellen!")
    else:
        input_data["summary_text"] = summary_text
    if params["errors"]:
        return render("summary.html", input_data=input_data, **params)
    else:
        admin_address = config.get("mail", "admin_address", "")
        try:
            send_mail(to_address, admin_address or from_address, subject, summary_text, sender=from_address)
        except smtplib.SMTPException, err_msg:
            params["errors"] = "Der Versand der Mail schlug fehl: %s" % err_msg
            return render("summary.html", input_data=input_data, **params)
        try:
            if admin_address:
                send_mail(from_address, admin_address, subject, summary_text)
        except smtplib.SMTPException, err_msg:
            pass
        submission = Submission(session=session,
                to_default_destination=(to_address == params["to_address"]),
                title=subject, text=summary_text)
        return render("submitted.html", **params)


def get_quality_text(question, quality):
    for key, text in question.quality_levels:
        if key == quality:
            return text
    return None


def get_answer_lines(answer):
    is_empty = True
    lines = []
    lines.append("")
    lines.append("## %s" % answer.option.title)
    if answer.quality:
        is_empty = False
        lines.append("Bewertung: %s (%s)" % (answer.quality,
            get_quality_text(answer.question, answer.quality)))
    if answer.text.strip():
        is_empty = False
        lines.append("Kommentar:")
        for line in answer.text.splitlines():
            if line.strip():
                lines.append("* %s" % line.strip())
    if is_empty:
        return []
    else:
        return lines


def get_summary_text(session):
    lines = []
    prefix = config.get("content", "text_prefix", "")
    if prefix:
        lines.append(prefix)
        lines.append("")
    questions = Question.select().orderBy("weight")
    for question in questions:
        answers = list(Answer.selectBy(session=session, question=question))
        if not answers:
            # no answers: skip this question
            continue
        answers.sort(key=lambda item: item.option.weight)
        lines.append("")
        lines.append("# %s" % question.text)
        for answer in answers:
            lines.extend(get_answer_lines(answer))
        lines.append("")
    lines.append("")
    return os.linesep.join(lines)


def show_summary(session):
    params = get_default_values()
    params["session"] = session
    input_data = {}
    input_data["subject"] = config.get("content", "subject")
    input_data["to_address"] = params["to_address"]
    input_data["summary_text"] = get_summary_text(session)
    return render("summary.html", input_data=input_data, **params)


def render_question(session, question):
    input_data = {}
    for option in Option.select():
        for key in ("text", "quality"):
            dict_key = "option_%s_%s" % (option.id, key)
            answers = list(Answer.selectBy(session=session, question=question,
                    option=option))
            if answers:
                input_data[dict_key] = getattr(answers[0], key)
            else:
                # this seems to be necessary for the input filter of genshi
                input_data[dict_key] = ""
    for answer in Answer.selectBy(session=session, question=question):
        for key in ("text", "quality"):
            input_data["option_%s_%s" % (answer.option.id, key)] = \
                    getattr(answer, key)
    params = get_default_values()
    params.update({"session": session,
            "question": question,
            "next_question": get_next_question(question),
            "previous_question": get_previous_question(question),
    })
    return render("question.html", input_data=input_data, **params)


@bobo.query('/db')
def show_db():
    params = get_default_values()
    params["Session"] = Session
    params["Question"] = Question
    params["Option"] = Option
    params["Answer"] = Answer
    params["Submission"] = Submission
    return render("db.html", **params)


@bobo.query('/')
def update_question(bobo_request, session_id=None, question_id=None,
        go_backward=False):
    kwargs = bobo_request.params
    session = get_session(session_id)
    if not session:
        session = Session()
        params = get_default_values()
        params["session"] = session
        return render("start.html", **params)
    question = None
    if question_id:
        try:
            question = Question.get(int(question_id))
        except ValueError:
            pass
    # any new input values? (update "Answer" objects)
    target_question = None
    if question:
        for option in Option.select():
            opt_params = {}
            for key in ("text", "quality"):
                dict_key = "option_%s_%s" % (option.id, key)
                if (dict_key in kwargs) and kwargs[dict_key]:
                    opt_params[key] = kwargs[dict_key]
            answers = Answer.selectBy(session=session, question=question,
                    option=option)
            # at least one item was found
            if opt_params:
                if answers.count() > 0:
                    answer = answers[0]
                else:
                    # create new one
                    answer = Answer(session=session, question=question,
                        option=option)
                # update one value
                for key in ("text", "quality"):
                    setattr(answer, key, opt_params.get(key, ""))
            else:
                # everything is empty -> delete answer
                if ("option_%s_%s" % (option.id, "text") in kwargs) and \
                        (answers.count() > 0):
                    answers[0].destroySelf()
        if go_backward:
            target_question = get_previous_question(question)
        else:
            target_question = get_next_question(question)
            if not target_question:
                # special case: we are finished
                return show_summary(session)
    if not target_question:
        # start with the first question
        target_question = Question.select().orderBy("weight")[0]
    return render_question(session, target_question)


@bobo.query('')
def redirect_startpage():
    return bobo.redirect(get_default_values()["base_url"])


# initialize the tables (do it only once!)
if RUN_FIRST_DB_INIT:
    tables = (Session, Question, Option, Answer, Submission)
    # drop all
    drop_tables = list(tables)
    drop_tables.reverse()
    for table in drop_tables:
        if table.tableExists():
            table.dropTable()
    for table in tables:
        table.createTable()
    for index, (title, image_url, lines) in enumerate(DEFINITION_OPTIONS):
        Option(title=title, image=image_url,
                text=os.linesep.join(lines), weight=index)
    for index, (text, quality_levels) in enumerate(DEFINITION_QUESTIONS):
        Question(text=text, weight=index, quality_levels=DEFINITION_QUALITY_RANGES[quality_levels])

# this application should be usable with mod_wsgi
application = bobo.Application(bobo_resources=__name__)