# coding=utf-8

# Nemubot is a modulable IRC bot, built around XML configuration files.
# Copyright (C) 2012  Mercier Pierre-Olivier
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from html.entities import name2codepoint
import http.client
import json
import re
import socket
from urllib.parse import quote
from urllib.parse import urlparse
from urllib.request import urlopen

import xmlparser

def isURL(url):
    """Return True if the URL can be parsed"""
    o = urlparse(url)
    return o.scheme == "" and o.netloc == "" and o.path == ""

def getScheme(url):
    """Return the protocol of a given URL"""
    o = urlparse(url)
    return o.scheme

def getHost(url):
    """Return the domain of a given URL"""
    return urlparse(url).netloc

def getPort(url):
    """Return the port of a given URL"""
    return urlparse(url).port

def getPath(url):
    """Return the page request of a given URL"""
    return urlparse(url).path

def getUser(url):
    """Return the page request of a given URL"""
    return urlparse(url).username
def getPassword(url):
    """Return the page request of a given URL"""
    return urlparse(url).password


# Get real pages

def getURLContent(url, timeout=15):
    """Return page content corresponding to URL or None if any error occurs"""
    o = urlparse(url)
    if o.netloc == "":
        o = urlparse("http://" + url)

    if o.scheme == "http":
        conn = http.client.HTTPConnection(o.netloc, port=o.port, timeout=timeout)
    elif o.scheme == "https":
        conn = http.client.HTTPSConnection(o.netloc, port=o.port, timeout=timeout)
    elif o.scheme is None or o.scheme == "":
        conn = http.client.HTTPConnection(o.netloc, port=80, timeout=timeout)
    else:
        return None
    try:
        if o.query != '':
            conn.request("GET", o.path + "?" + o.query, None, {"User-agent": "Nemubot v3"})
        else:
            conn.request("GET", o.path, None, {"User-agent": "Nemubot v3"})
    except socket.timeout:
        return None
    except socket.gaierror:
        print ("<tools.web> Unable to receive page %s on %s from %s."
               % (o.path, o.netloc, url))
        return None

    try:
        res = conn.getresponse()
        size = int(res.getheader("Content-Length", 200000))
        cntype = res.getheader("Content-Type")

        if size > 200000 or (cntype[:4] != "text" and cntype[:4] != "appl"):
            return None

        data = res.read(size)

        # Decode content
        charset = "utf-8"
        lcharset = res.getheader("Content-Type").split(";")
        if len(lcharset) > 1:
            for c in charset:
                ch = c.split("=")
                if ch[0].strip().lower() == "charset" and len(ch) > 1:
                    cha = ch[1].split(".")
                    if len(cha) > 1:
                        charset = cha[1]
                    else:
                        charset = cha[0]
    except http.client.BadStatusLine:
        return None
    finally:
        conn.close()

    if res.status == http.client.OK or res.status == http.client.SEE_OTHER:
        return data.decode(charset)
    elif (res.status == http.client.FOUND or res.status == http.client.MOVED_PERMANENTLY) and res.getheader("Location") != url:
        return getURLContent(res.getheader("Location"), timeout)
    else:
        return None

def getXML(url, timeout=15):
    """Get content page and return XML parsed content"""
    cnt = getURLContent(url, timeout)
    if cnt is None:
        return None
    else:
        return xmlparser.parse_string(cnt)

def getJSON(url, timeout=15):
    """Get content page and return JSON content"""
    cnt = getURLContent(url, timeout)
    if cnt is None:
        return None
    else:
        return json.loads(cnt.decode())

# Other utils

def htmlentitydecode(s):
    """Decode htmlentities"""
    return re.sub('&(%s);' % '|'.join(name2codepoint),
                  lambda m: chr(name2codepoint[m.group(1)]), s)

def striphtml(data):
    """Remove HTML tags from text"""
    p = re.compile(r'<.*?>')
    return htmlentitydecode(p.sub('', data).replace("&#x28;", "/(").replace("&#x29;", ")/").replace("&#x22;", "\""))