# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

import base64
import collections
import logging
import random
import re
import socket
import threading
import time
from email.utils import getaddresses
from urllib.parse import urlparse

import idna
import markupsafe
from lxml import etree
from lxml.html import clean
from werkzeug import urls

import odoo
from odoo.loglevels import ustr
from odoo.tools import misc

_logger = logging.getLogger(__name__)

#----------------------------------------------------------
# HTML Sanitizer
#----------------------------------------------------------

tags_to_kill = ['base', 'embed', 'frame', 'head', 'iframe', 'link', 'meta',
                'noscript', 'object', 'script', 'style', 'title']

tags_to_remove = ['html', 'body']

# allow new semantic HTML5 tags
allowed_tags = clean.defs.tags | frozenset('article bdi section header footer hgroup nav aside figure main'.split() + [etree.Comment])
safe_attrs = clean.defs.safe_attrs | frozenset(
    ['style',
     'data-o-mail-quote',  # quote detection
     'data-oe-model', 'data-oe-id', 'data-oe-field', 'data-oe-type', 'data-oe-expression', 'data-oe-translation-id', 'data-oe-nodeid',
     'data-publish', 'data-id', 'data-res_id', 'data-interval', 'data-member_id', 'data-scroll-background-ratio', 'data-view-id',
     'data-class', 'data-mimetype', 'data-original-src', 'data-original-id', 'data-gl-filter', 'data-quality', 'data-resize-width',
     'data-shape', 'data-shape-colors', 'data-file-name', 'data-original-mimetype',
     ])


class _Cleaner(clean.Cleaner):

    _style_re = re.compile(r'''([\w-]+)\s*:\s*((?:[^;"']|"[^";]*"|'[^';]*')+)''')

    _style_whitelist = [
        'font-size', 'font-family', 'font-weight', 'background-color', 'color', 'text-align',
        'line-height', 'letter-spacing', 'text-transform', 'text-decoration', 'opacity',
        'float', 'vertical-align', 'display',
        'padding', 'padding-top', 'padding-left', 'padding-bottom', 'padding-right',
        'margin', 'margin-top', 'margin-left', 'margin-bottom', 'margin-right',
        'white-space',
        # box model
        'border', 'border-color', 'border-radius', 'border-style', 'border-width', 'border-top', 'border-bottom',
        'height', 'width', 'max-width', 'min-width', 'min-height',
        # tables
        'border-collapse', 'border-spacing', 'caption-side', 'empty-cells', 'table-layout']

    _style_whitelist.extend(
        ['border-%s-%s' % (position, attribute)
            for position in ['top', 'bottom', 'left', 'right']
            for attribute in ('style', 'color', 'width', 'left-radius', 'right-radius')]
    )

    strip_classes = False
    sanitize_style = False

    def __call__(self, doc):
        # perform quote detection before cleaning and class removal
        for el in doc.iter(tag=etree.Element):
            self.tag_quote(el)

        super(_Cleaner, self).__call__(doc)

        # if we keep attributes but still remove classes
        if not getattr(self, 'safe_attrs_only', False) and self.strip_classes:
            for el in doc.iter(tag=etree.Element):
                self.strip_class(el)

        # if we keep style attribute, sanitize them
        if not self.style and self.sanitize_style:
            for el in doc.iter(tag=etree.Element):
                self.parse_style(el)

    def tag_quote(self, el):
        def _create_new_node(tag, text, tail=None, attrs=None):
            new_node = etree.Element(tag)
            new_node.text = text
            new_node.tail = tail
            if attrs:
                for key, val in attrs.items():
                    new_node.set(key, val)
            return new_node

        def _tag_matching_regex_in_text(regex, node, tag='span', attrs=None):
            text = node.text or ''
            if not re.search(regex, text):
                return

            child_node = None
            idx, node_idx = 0, 0
            for item in re.finditer(regex, text):
                new_node = _create_new_node(tag, text[item.start():item.end()], None, attrs)
                if child_node is None:
                    node.text = text[idx:item.start()]
                    new_node.tail = text[item.end():]
                    node.insert(node_idx, new_node)
                else:
                    child_node.tail = text[idx:item.start()]
                    new_node.tail = text[item.end():]
                    node.insert(node_idx, new_node)
                child_node = new_node
                idx = item.end()
                node_idx = node_idx + 1

        el_class = el.get('class', '') or ''
        el_id = el.get('id', '') or ''

        # gmail or yahoo // # outlook, html // # msoffice
        if 'gmail_extra' in el_class or \
                'divRplyFwdMsg' in el_id or \
                ('SkyDrivePlaceholder' in el_class or 'SkyDrivePlaceholder' in el_class):
            el.set('data-o-mail-quote', '1')
            if el.getparent() is not None:
                el.getparent().set('data-o-mail-quote-container', '1')

        if (el.tag == 'hr' and ('stopSpelling' in el_class or 'stopSpelling' in el_id)) or \
           'yahoo_quoted' in el_class:
            # Quote all elements after this one
            el.set('data-o-mail-quote', '1')
            for sibling in el.itersiblings(preceding=False):
                sibling.set('data-o-mail-quote', '1')

        # html signature (-- <br />blah)
        signature_begin = re.compile(r"((?:(?:^|\n)[-]{2}[\s]?$))")
        if el.text and el.find('br') is not None and re.search(signature_begin, el.text):
            el.set('data-o-mail-quote', '1')
            if el.getparent() is not None:
                el.getparent().set('data-o-mail-quote-container', '1')

        # text-based quotes (>, >>) and signatures (-- Signature)
        text_complete_regex = re.compile(r"((?:\n[>]+[^\n\r]*)+|(?:(?:^|\n)[-]{2}[\s]?[\r\n]{1,2}[\s\S]+))")
        if not el.get('data-o-mail-quote'):
            _tag_matching_regex_in_text(text_complete_regex, el, 'span', {'data-o-mail-quote': '1'})

        if el.tag == 'blockquote':
            # remove single node
            el.set('data-o-mail-quote-node', '1')
            el.set('data-o-mail-quote', '1')
        if el.getparent() is not None and (el.getparent().get('data-o-mail-quote') or el.getparent().get('data-o-mail-quote-container')) and not el.getparent().get('data-o-mail-quote-node'):
            el.set('data-o-mail-quote', '1')

    def strip_class(self, el):
        if el.attrib.get('class'):
            del el.attrib['class']

    def parse_style(self, el):
        attributes = el.attrib
        styling = attributes.get('style')
        if styling:
            valid_styles = collections.OrderedDict()
            styles = self._style_re.findall(styling)
            for style in styles:
                if style[0].lower() in self._style_whitelist:
                    valid_styles[style[0].lower()] = style[1]
            if valid_styles:
                el.attrib['style'] = '; '.join('%s:%s' % (key, val) for (key, val) in valid_styles.items())
            else:
                del el.attrib['style']


def html_sanitize(src, silent=True, sanitize_tags=True, sanitize_attributes=False, sanitize_style=False, sanitize_form=True, strip_style=False, strip_classes=False):
    if not src:
        return src
    src = ustr(src, errors='replace')
    # html: remove encoding attribute inside tags
    doctype = re.compile(r'(<[^>]*\s)(encoding=(["\'][^"\']*?["\']|[^\s\n\r>]+)(\s[^>]*|/)?>)', re.IGNORECASE | re.DOTALL)
    src = doctype.sub(u"", src)

    logger = logging.getLogger(__name__ + '.html_sanitize')

    # html encode mako tags <% ... %> to decode them later and keep them alive, otherwise they are stripped by the cleaner
    src = src.replace(u'<%', misc.html_escape(u'<%'))
    src = src.replace(u'%>', misc.html_escape(u'%>'))

    kwargs = {
        'page_structure': True,
        'style': strip_style,              # True = remove style tags/attrs
        'sanitize_style': sanitize_style,  # True = sanitize styling
        'forms': sanitize_form,            # True = remove form tags
        'remove_unknown_tags': False,
        'comments': False,
        'processing_instructions': False
    }
    if sanitize_tags:
        kwargs['allow_tags'] = allowed_tags
        if etree.LXML_VERSION >= (2, 3, 1):
            # kill_tags attribute has been added in version 2.3.1
            kwargs.update({
                'kill_tags': tags_to_kill,
                'remove_tags': tags_to_remove,
            })
        else:
            kwargs['remove_tags'] = tags_to_kill + tags_to_remove

    if sanitize_attributes and etree.LXML_VERSION >= (3, 1, 0):  # lxml < 3.1.0 does not allow to specify safe_attrs. We keep all attributes in order to keep "style"
        if strip_classes:
            current_safe_attrs = safe_attrs - frozenset(['class'])
        else:
            current_safe_attrs = safe_attrs
        kwargs.update({
            'safe_attrs_only': True,
            'safe_attrs': current_safe_attrs,
        })
    else:
        kwargs.update({
            'safe_attrs_only': False,  # keep oe-data attributes + style
            'strip_classes': strip_classes,  # remove classes, even when keeping other attributes
        })

    try:
        # some corner cases make the parser crash (such as <SCRIPT/XSS SRC=\"http://ha.ckers.org/xss.js\"></SCRIPT> in test_mail)
        cleaner = _Cleaner(**kwargs)
        cleaned = cleaner.clean_html(src)
        assert isinstance(cleaned, str)
        # MAKO compatibility: $, { and } inside quotes are escaped, preventing correct mako execution
        cleaned = cleaned.replace(u'%24', u'$')
        cleaned = cleaned.replace(u'%7B', u'{')
        cleaned = cleaned.replace(u'%7D', u'}')
        cleaned = cleaned.replace(u'%20', u' ')
        cleaned = cleaned.replace(u'%5B', u'[')
        cleaned = cleaned.replace(u'%5D', u']')
        cleaned = cleaned.replace(u'%7C', u'|')
        cleaned = cleaned.replace(u'&lt;%', u'<%')
        cleaned = cleaned.replace(u'%&gt;', u'%>')
        # html considerations so real html content match database value
        cleaned.replace(u'\xa0', u'&nbsp;')
    except etree.ParserError as e:
        if 'empty' in str(e):
            return u""
        if not silent:
            raise
        logger.warning(u'ParserError obtained when sanitizing %r', src, exc_info=True)
        cleaned = u'<p>ParserError when sanitizing</p>'
    except Exception:
        if not silent:
            raise
        logger.warning(u'unknown error obtained when sanitizing %r', src, exc_info=True)
        cleaned = u'<p>Unknown error when sanitizing</p>'

    # this is ugly, but lxml/etree tostring want to put everything in a 'div' that breaks the editor -> remove that
    if cleaned.startswith(u'<div>') and cleaned.endswith(u'</div>'):
        cleaned = cleaned[5:-6]

    return markupsafe.Markup(cleaned)

# ----------------------------------------------------------
# HTML/Text management
# ----------------------------------------------------------

URL_REGEX = r'(\bhref=[\'"](?!mailto:|tel:|sms:)([^\'"]+)[\'"])'
TEXT_URL_REGEX = r'https?://[\w@:%.+&~#=/-]+(?:\?\S+)?'
# retrieve inner content of the link
HTML_TAG_URL_REGEX = URL_REGEX + r'([^<>]*>([^<>]+)<\/)?'


def validate_url(url):
    if urls.url_parse(url).scheme not in ('http', 'https', 'ftp', 'ftps'):
        return 'http://' + url

    return url


def is_html_empty(html_content):
    """Check if a html content is empty. If there are only formatting tags with style
    attributes or a void content  return True. Famous use case if a
    '<p style="..."><br></p>' added by some web editor.

    :param str html_content: html content, coming from example from an HTML field
    :returns: bool, True if no content found or if containing only void formatting tags
    """
    if not html_content:
        return True
    tag_re = re.compile(r'\<\s*\/?(?:p|div|span|br|b|i|font)(?:(?=\s+\w*)[^/>]*|\s*)/?\s*\>')
    return not bool(re.sub(tag_re, '', html_content).strip())

def html_keep_url(text):
    """ Transform the url into clickable link with <a/> tag """
    idx = 0
    final = ''
    link_tags = re.compile(r"""(?<!["'])((ftp|http|https):\/\/(\w+:{0,1}\w*@)?([^\s<"']+)(:[0-9]+)?(\/|\/([^\s<"']))?)(?![^\s<"']*["']|[^\s<"']*</a>)""")
    for item in re.finditer(link_tags, text):
        final += text[idx:item.start()]
        final += '<a href="%s" target="_blank" rel="noreferrer noopener">%s</a>' % (item.group(0), item.group(0))
        idx = item.end()
    final += text[idx:]
    return final


def html2plaintext(html, body_id=None, encoding='utf-8'):
    """ From an HTML text, convert the HTML to plain text.
    If @param body_id is provided then this is the tag where the
    body (not necessarily <body>) starts.
    """
    ## (c) Fry-IT, www.fry-it.com, 2007
    ## <peter@fry-it.com>
    ## download here: http://www.peterbe.com/plog/html2plaintext

    html = ustr(html)

    if not html.strip():
        return ''

    tree = etree.fromstring(html, parser=etree.HTMLParser())

    if body_id is not None:
        source = tree.xpath('//*[@id=%s]' % (body_id,))
    else:
        source = tree.xpath('//body')
    if len(source):
        tree = source[0]

    url_index = []
    i = 0
    for link in tree.findall('.//a'):
        url = link.get('href')
        if url:
            i += 1
            link.tag = 'span'
            link.text = '%s [%s]' % (link.text, i)
            url_index.append(url)

    html = ustr(etree.tostring(tree, encoding=encoding))
    # \r char is converted into &#13;, must remove it
    html = html.replace('&#13;', '')

    html = html.replace('<strong>', '*').replace('</strong>', '*')
    html = html.replace('<b>', '*').replace('</b>', '*')
    html = html.replace('<h3>', '*').replace('</h3>', '*')
    html = html.replace('<h2>', '**').replace('</h2>', '**')
    html = html.replace('<h1>', '**').replace('</h1>', '**')
    html = html.replace('<em>', '/').replace('</em>', '/')
    html = html.replace('<tr>', '\n')
    html = html.replace('</p>', '\n')
    html = re.sub('<br\s*/?>', '\n', html)
    html = re.sub('<.*?>', ' ', html)
    html = html.replace(' ' * 2, ' ')
    html = html.replace('&gt;', '>')
    html = html.replace('&lt;', '<')
    html = html.replace('&amp;', '&')

    # strip all lines
    html = '\n'.join([x.strip() for x in html.splitlines()])
    html = html.replace('\n' * 2, '\n')

    for i, url in enumerate(url_index):
        if i == 0:
            html += '\n\n'
        html += ustr('[%s] %s\n') % (i + 1, url)

    return html.strip()

def plaintext2html(text, container_tag=False):
    """ Convert plaintext into html. Content of the text is escaped to manage
        html entities, using misc.html_escape().
        - all \n,\r are replaced by <br />
        - enclose content into <p>
        - convert url into clickable link
        - 2 or more consecutive <br /> are considered as paragraph breaks

        :param string container_tag: container of the html; by default the
            content is embedded into a <div>
    """
    text = misc.html_escape(ustr(text))

    # 1. replace \n and \r
    text = re.sub(r'(\r\n|\r|\n)', '<br/>', text)

    # 2. clickable links
    text = html_keep_url(text)

    # 3-4: form paragraphs
    idx = 0
    final = '<p>'
    br_tags = re.compile(r'(([<]\s*[bB][rR]\s*/?[>]\s*){2,})')
    for item in re.finditer(br_tags, text):
        final += text[idx:item.start()] + '</p><p>'
        idx = item.end()
    final += text[idx:] + '</p>'

    # 5. container
    if container_tag: # FIXME: validate that container_tag is just a simple tag?
        final = '<%s>%s</%s>' % (container_tag, final, container_tag)
    return markupsafe.Markup(final)

def append_content_to_html(html, content, plaintext=True, preserve=False, container_tag=False):
    """ Append extra content at the end of an HTML snippet, trying
        to locate the end of the HTML document (</body>, </html>, or
        EOF), and converting the provided content in html unless ``plaintext``
        is False.
        Content conversion can be done in two ways:
        - wrapping it into a pre (preserve=True)
        - use plaintext2html (preserve=False, using container_tag to wrap the
            whole content)
        A side-effect of this method is to coerce all HTML tags to
        lowercase in ``html``, and strip enclosing <html> or <body> tags in
        content if ``plaintext`` is False.

        :param str html: html tagsoup (doesn't have to be XHTML)
        :param str content: extra content to append
        :param bool plaintext: whether content is plaintext and should
            be wrapped in a <pre/> tag.
        :param bool preserve: if content is plaintext, wrap it into a <pre>
            instead of converting it into html
    """
    html = ustr(html)
    if plaintext and preserve:
        content = u'\n<pre>%s</pre>\n' % misc.html_escape(ustr(content))
    elif plaintext:
        content = '\n%s\n' % plaintext2html(content, container_tag)
    else:
        content = re.sub(r'(?i)(</?(?:html|body|head|!\s*DOCTYPE)[^>]*>)', '', content)
        content = u'\n%s\n' % ustr(content)
    # Force all tags to lowercase
    html = re.sub(r'(</?)(\w+)([ >])',
        lambda m: '%s%s%s' % (m.group(1), m.group(2).lower(), m.group(3)), html)
    insert_location = html.find('</body>')
    if insert_location == -1:
        insert_location = html.find('</html>')
    if insert_location == -1:
        return markupsafe.Markup('%s%s' % (html, content))
    return markupsafe.Markup('%s%s%s' % (html[:insert_location], content, html[insert_location:]))


def prepend_html_content(html_body, html_content):
    """Prepend some HTML content at the beginning of an other HTML content."""
    html_content = type(html_content)(re.sub(r'(?i)(</?(?:html|body|head|!\s*DOCTYPE)[^>]*>)', '', html_content))
    html_content = html_content.strip()

    body_match = re.search(r'<body[^>]*>', html_body) or re.search(r'<html[^>]*>', html_body)
    insert_index = body_match.end() if body_match else 0

    return html_body[:insert_index] + html_content + html_body[insert_index:]

#----------------------------------------------------------
# Emails
#----------------------------------------------------------

# matches any email in a body of text
email_re = re.compile(r"""([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,63})""", re.VERBOSE)

# matches a string containing only one email
single_email_re = re.compile(r"""^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,63}$""", re.VERBOSE)

mail_header_msgid_re = re.compile('<[^<>]+>')

email_addr_escapes_re = re.compile(r'[\\"]')


def generate_tracking_message_id(res_id):
    """Returns a string that can be used in the Message-ID RFC822 header field

       Used to track the replies related to a given object thanks to the "In-Reply-To"
       or "References" fields that Mail User Agents will set.
    """
    try:
        rnd = random.SystemRandom().random()
    except NotImplementedError:
        rnd = random.random()
    rndstr = ("%.15f" % rnd)[2:]
    return "<%s.%.15f-openerp-%s@%s>" % (rndstr, time.time(), res_id, socket.gethostname())

def email_split_tuples(text):
    """ Return a list of (name, email) address tuples found in ``text`` . Note
    that text should be an email header or a stringified email list as it may
    give broader results than expected on actual text. """
    if not text:
        return []
    return [(addr[0], addr[1]) for addr in getaddresses([text])
                # getaddresses() returns '' when email parsing fails, and
                # sometimes returns emails without at least '@'. The '@'
                # is strictly required in RFC2822's `addr-spec`.
                if addr[1]
                if '@' in addr[1]]

def email_split(text):
    """ Return a list of the email addresses found in ``text`` """
    if not text:
        return []
    return [email for (name, email) in email_split_tuples(text)]

def email_split_and_format(text):
    """ Return a list of email addresses found in ``text``, formatted using
    formataddr. """
    if not text:
        return []
    return [formataddr((name, email)) for (name, email) in email_split_tuples(text)]

def email_normalize(text):
    """ Sanitize and standardize email address entries.
        A normalized email is considered as :
        - having a left part + @ + a right part (the domain can be without '.something')
        - being lower case
        - having no name before the address. Typically, having no 'Name <>'
        Ex:
        - Possible Input Email : 'Name <NaMe@DoMaIn.CoM>'
        - Normalized Output Email : 'name@domain.com'
    """
    emails = email_split(text)
    if not emails or len(emails) != 1:
        return False
    return emails[0].lower()


def email_domain_extract(email):
    """ Extract the company domain to be used by IAP services notably. Domain
    is extracted from email information e.g:
        - info@proximus.be -> proximus.be
    """
    normalized_email = email_normalize(email)
    if normalized_email:
        return normalized_email.split('@')[1]
    return False

def email_domain_normalize(domain):
    """Return the domain normalized or False if the domain is invalid."""
    if not domain or '@' in domain:
        return False

    return domain.lower()

def url_domain_extract(url):
    """ Extract the company domain to be used by IAP services notably. Domain
    is extracted from an URL e.g:
        - www.info.proximus.be -> proximus.be
    """
    parser_results = urlparse(url)
    company_hostname = parser_results.hostname
    if company_hostname and '.' in company_hostname:
        return '.'.join(company_hostname.split('.')[-2:])  # remove subdomains
    return False

def email_escape_char(email_address):
    """ Escape problematic characters in the given email address string"""
    return email_address.replace('\\', '\\\\').replace('%', '\\%').replace('_', '\\_')

# was mail_thread.decode_header()
def decode_message_header(message, header, separator=' '):
    return separator.join(h for h in message.get_all(header, []) if h)

def formataddr(pair, charset='utf-8'):
    """Pretty format a 2-tuple of the form (realname, email_address).

    If the first element of pair is falsy then only the email address
    is returned.

    Set the charset to ascii to get a RFC-2822 compliant email. The
    realname will be base64 encoded (if necessary) and the domain part
    of the email will be punycode encoded (if necessary). The local part
    is left unchanged thus require the SMTPUTF8 extension when there are
    non-ascii characters.

    >>> formataddr(('John Doe', 'johndoe@example.com'))
    '"John Doe" <johndoe@example.com>'

    >>> formataddr(('', 'johndoe@example.com'))
    'johndoe@example.com'
    """
    name, address = pair
    local, _, domain = address.rpartition('@')

    try:
        domain.encode(charset)
    except UnicodeEncodeError:
        # rfc5890 - Internationalized Domain Names for Applications (IDNA)
        domain = idna.encode(domain).decode('ascii')

    if name:
        try:
            name.encode(charset)
        except UnicodeEncodeError:
            # charset mismatch, encode as utf-8/base64
            # rfc2047 - MIME Message Header Extensions for Non-ASCII Text
            name = base64.b64encode(name.encode('utf-8')).decode('ascii')
            return f"=?utf-8?b?{name}?= <{local}@{domain}>"
        else:
            # ascii name, escape it if needed
            # rfc2822 - Internet Message Format
            #   #section-3.4 - Address Specification
            name = email_addr_escapes_re.sub(r'\\\g<0>', name)
            return f'"{name}" <{local}@{domain}>'
    return f"{local}@{domain}"


def encapsulate_email(old_email, new_email):
    """Change the FROM of the message and use the old one as name.

    e.g.
    * Old From: "Admin" <admin@gmail.com>
    * New From: notifications@odoo.com
    * Output: "Admin" <notifications@odoo.com>
    """
    old_email_split = getaddresses([old_email])
    if not old_email_split or not old_email_split[0]:
        return old_email

    new_email_split = getaddresses([new_email])
    if not new_email_split or not new_email_split[0]:
        return

    old_name, old_email = old_email_split[0]
    if old_name:
        name_part = old_name
    else:
        name_part = old_email.split("@")[0]

    return formataddr((
        name_part,
        new_email_split[0][1],
    ))