import copy
import os
import re
import json
import requests
import tarfile
import shutil
import scss
import markdown
import bs4
import werkzeug # mainly for isinstance checks
import click
import flask

from flask import flash, abort, redirect

app = flask.Flask(__name__)

app.config.from_object('defaults')
app.config.from_object('config')

if 'RESOURCE_DIR' not in app.config:
    app.config['RESOURCE_DIR'] = os.path.join(os.getcwd(), 'resources')
if 'ARTICLE_DIR' not in app.config:
    app.config['ARTICLE_DIR'] = os.path.join(os.getcwd(), 'articles')

scss_compiler = scss.Compiler()
markdown_compiler = markdown.Markdown(extensions=['tables', 'footnotes'])


class ExposedException(Exception):

    def __init__(self, message, status=500):
        self.message = message
        self.status = status

def headline_address(text):

    text = text.lower()
    text = text.replace(' ', '-')

    # purge everything that's not 'a' to 'z' or '-' with fire
    text = re.sub(r'[^a-z0-9-]', '', text)

    return text

def replace_thingamabob(value, invite_info, os, client, installer):

    # FIXME: Brain up a less shitty name for this.
    # Data preprocessing for invite_main

    client_info = app.config['CLIENT_INFO'][client]
    installer_info = app.config['INSTALLER_INFO'][os][installer]

    if '{invite.uri}' in value:
        value = value.replace('{invite.uri}', invite_info['uri'])
    if '{invite.register_url}' in value:
        value = value.replace('{invite.register_url}', flask.url_for('.invite_register', token=invite_info['token'], client=client))
    if '{client.name}' in value:
        value = value.replace('{client.name}', client_info['title'])

    if installer_info['url_support']:
        if os in client_info['installer_magic']:
            if '{client.url_magic}' in value:
                value = value.replace('{client.url_magic}', client_info['installer_magic'][os][installer]['url'])
        if '{client.url_install}' in value:
            value = value.replace('{client.url_install}', client_info['installer_manual'][os][installer]['url'])

    if installer_info['pkgname_support']:
        if '{client.pkgname}' in value:
            value = value.replace('{client.pkgname}', client_info['installer_manual'][os][installer]['pkgname'])
    if 'guide' in installer_info:
        if '{installer.guide}' in value:
            value = value.replace('{installer.guide}', installer_info['guide'])

    if '{installer.step_install}' in value:
        if client_info['installer_manual'][os][installer]['gratis']:
            step = installer_info['step_install']['gratis']
        else:
            step = installer_info['step_install']['paid']
        value = value.replace('{installer.step_install}', step)

    if '{register}' in value:
        if 'invites' in client_info['features']:
            text = app.config['REGISTER_INFO']['client']
        else:
            text = app.config['REGISTER_INFO']['web']
        value = value.replace('{register}', replace_thingamabob(text, invite_info, os, client, installer))

    return value


def page(f):

    template_candidates = [
        f"{f.__name__}.jinja",
        "main.jinja",
    ]

    def wrapper(*args, **kwargs):

        env = {
            'claim': app.config['CLAIM'],
            'support_address': app.config['SUPPORT_ADDRESS'],
            'menu': menu('main'),
            'messages': flask.get_flashed_messages(with_categories=True),
        }

        try:
            r = f(*args, **kwargs)
        except ExposedException as e:
            app.logger.error(f"Caught error: {e.message}")
            return flask.render_template('error.jinja', error=e, **env), e.status
        except Exception as e:
            app.logger.error(f"Caught unplanned error:")
            app.log_exception(e)
            return flask.render_template('error.jinja', error=ExposedException('Something went wrong. :('), **env), 500

        if isinstance(r, werkzeug.wrappers.Response):
            return r # directly pass constructed Responses (like redirects) through
        if isinstance(r, dict):
            env.update(r)
        else:
            env['content']: r

        try:
            rendered = flask.render_template(template_candidates, **env)
        except Exception as e:
            app.logger.error(f"Caught templating error.")
            app.log_exception(e)
            return flask.render_template('error.jinja', error=ExposedException('Something went wrong because of a broken template. :('), **env)

        return rendered

    wrapper.__name__ = f.__name__ # i sure hope this doesn't fuck shit up
    return wrapper


def ensure_token(token):

    try:
        invite_info = get_invite_info(token)
    except ValueError:
        raise ExposedException("Couldn't get info for this token - are you sure it's valid?", 410)
    except RuntimeError:
        raise ExposedException('Something seems to have gone wrong on our side.<img src="/resources/sorry.gif" alt="Sorry…" title="Sorry…" />')

    if invite_info['type'] != 'register':
        raise ExposedException(f"""You have some kind of invite for this service, but
        this site doesn't handle this specific invite type: {invite_info['type']}.
        Feel free to contact {app.config['SUPPORT_ADDRESS']}.""", 204)

    return invite_info

def best_os_guess(request):

    agent = request.headers["User-Agent"]
    if "Android" in agent:
        return "android"
    elif "iPhone" in agent:
        return "ios"
    elif "Windows" in agent:
        return "windows"
    elif "Mac OS" in agent:
        return "macos"
    elif "Linux" in agent:
        return "linux"
    elif "FreeBSD" in agent:
        return "freebsd"
    elif "OpenBSD" in agent:
        return "openbsd"
    elif "NetBSD" in agent:
        return "netbsd"
    return "other"


def get_invite_info(token):

    try:
        r = requests.get(f"{app.config['API_BASE_URL']}/invite/{token}")
    except requests.exceptions.ConnectionError:
        raise RuntimeError("Unable to establish connection to XMPP server!")
    if r.status_code == 200:
        return json.loads(r.text)
    elif r.status_code >= 400 and r.status_code <= 499:
        raise ValueError("Invalid data!")
    elif r.status_code >= 500 and r.status_code <= 599:
        raise RuntimeError("Server-side error indicated!")
    else:
        raise RuntimeError(f"Non-specific error: {r.text}")


def register_with_invite(username, password, token):

    data = {
        'username': username,
        'password': password,
        'token': token,
    }

    payload = json.dumps(data)

    r = requests.post(f"{app.config['API_BASE_URL']}/register", payload, headers={'Content-Type': 'application/json'})

    if r.status_code == 200:
        return
    elif r.status_code == 409:
        raise ValueError("A user with this name already exists!")
    elif r.status_code >= 400 and r.status_code <= 499:
        raise ValueError("Invalid data!")
    elif r.status_code >= 500 and r.status_code <= 599:
        raise RuntimeError("Server-side error indicated!")
    else:
        raise RuntimeError(f"Non-specific error: {r.text}")


def any_in(value, candidates):

    return any(
        map(
            lambda x: x.lower() in value.lower(),
            candidates
        )
    )

#                                    ,- words that are considered a match
#                                    |
#                                    |              ,- end of string or nonword
#                                    |              |  char guarantees matched
#                                    |              |  words stand on their own
#                                    ↓              ↓
match_good = re.compile('^(good|yes|positive|true)($|\W)', re.IGNORECASE)
match_bad = re.compile('^(bad|no|negative|false)($|\W)', re.IGNORECASE)
match_meh = re.compile('^(meh|partial|unverified|mild)($|\W)', re.IGNORECASE)
def article_load(name):

    article_path = os.path.join(app.config['ARTICLE_DIR'], name + '.md')
    if os.path.exists(article_path):

        with open(article_path, 'r', encoding='UTF-8') as fd:
            text = fd.read()

        text = markdown_compiler.convert(text)
        markdown_compiler.reset()

        soup = bs4.BeautifulSoup(text, 'html.parser')

        # Extract title and subtitle for specialized presentation
        header = False
        title = None
        subtitle = None

        scan_offset = 0
        for element in soup.children:
            if isinstance(element, bs4.Tag):
                if title is None and element.name == 'h1':
                    title = element.text
                    element.decompose()
                    scan_offset += 1
                    continue # skip to next loop iteration
                elif title != None and subtitle is None and element.name == 'h2':
                    subtitle = element.text
                    element.decompose()
                    scan_offset += 1
                    break # terminate loop
                else:
                    # terminate loop, if first tag isn't h1 we don't have to
                    # scan the rest of the document
                    break

        # Split rest of content into sections based on h2 elements
        first_scanned_element = soup.contents[scan_offset]
        if type(first_scanned_element) == bs4.element.Tag and first_scanned_element.name == 'section':
            header = str(first_scanned_element) # if the text (after title and subtitle) begins with a <section>, treat it as dedicated header
            first_scanned_element.decompose()

        section = soup.new_tag('section')
        section['class'] = 'text'
        soup.contents[scan_offset].insert_before(section)
        for element in soup.contents[scan_offset:]:
            if type(element) == bs4.element.Tag:
                if element != section:

                    if element.name in ['h2', 'h3', 'h4', 'h5', 'h6']:
                        name = headline_address(element.text)
                        link = soup.new_tag('a')
                        link['name'] = name
                        link['href'] = f'#{name}'
                        link.append(element.text)
                        element.clear()
                        element.append(link)

                    if element.name == 'h2' and len(section):
                        section = soup.new_tag('section')
                        section['class'] = 'text'
                        element.insert_before(section)
                    elif element.name == 'section':
                        # let existing sections stand on their own, start new section afterwards
                        section = soup.new_tag('section')
                        section['class'] = 'text'
                        element.insert_after(section)
                        continue # skip rest of the loop, do not add this section

                    section.append(element.extract())

        for td in soup.find_all('td'):

            if len(td) and isinstance(td.contents[0], bs4.NavigableString):
                subject = td.contents[0].string
            else:
                subject = td.text

            if match_bad.match(subject):
                td['class'] = 'bad'
            elif match_good.match(subject):
                td['class'] = 'good'
            elif match_meh.match(subject):
                td['class'] = 'meh'

        for a in soup.find_all('a'):
            if a['href'].startswith('http://'):
                a['href'] = 'https://' + a['href'][7:]

            if a['href'].startswith('https://'):
                a['target'] = '_blank'
                a['rel'] = 'noreferrer'

        text = str(soup)

        return {
            'title': title,
            'subtitle': subtitle,
            'header': header,
            'text': text
        }

    abort(404, "No such content. *sad server noises*")


def menu(name=None):
    links = [
        {
            'url': '/',
            'caption': 'Home',
        },
        {
            'url': flask.url_for('.article', name='chatcontrol'),
            'caption': 'ChatControl',
        },
        {
            'url': flask.url_for('.article', name='x-as-in-freedom'),
            'caption': '<em>X</em> as in <em>freedom</em>',
        },
        {
            'url': flask.url_for('.article', name='foss-socialism'),
            'caption': 'Why FOSS is Socialism',
        },
        #{
        #    'url': flask.url_for('.article', name='adversaries'),
        #    'caption': 'Adversaries'
        #},
        {
            'url': flask.url_for('.clients'),
            'caption': 'Supported clients',
        },
        {
            'url': flask.url_for('.client'),
            'caption': 'Web client',
        },
    ]

    for link in links:
        if flask.request.path == link['url']:
            link['active'] = True # propagates to links[idx]['active']
        else:
            link['active'] = False # dito

    return flask.render_template('menu.jinja', links=links, name=name)


@app.cli.command()
@click.option('--version', default='9.1.1')
def install_conversejs(version):

    directory = 'resources/converse'
    directory_dist = f'{directory}/dist'
    version_name = f'converse.js-{version}'
    file_name = f'{version_name}.tgz'
    file_path = f'{directory}/{file_name}'
    archive_url = f'https://github.com/conversejs/converse.js/releases/download/v{version}/{file_name}'

    if not os.path.exists(directory):
        click.secho(f"Created directory {directory}.", fg='green')
        os.mkdir(directory)

    if not os.path.isdir(directory):
        click.secho(f"Not a directory: {directory}", fg='red')

    click.secho(f"Downloading archive '{file_name}'…")
    response = requests.get(archive_url)

    if response.status_code == 200:
        click.secho("Success!", fg='green')

        click.secho("Saving…")
        with open(file_path, 'wb') as file:
            file.write(response.content)

        click.secho("Extracting archive…")
        member_whitelist = []
        with tarfile.open(file_path) as tar:
            for member in tar.getmembers():

                if member.name.startswith('package/dist'):
                    member_whitelist.append(member)

            tar.extractall(directory_dist, members=member_whitelist)

        for extracted_name in os.listdir(f'{directory_dist}/package/dist'):
            shutil.move(
                f'{directory_dist}/package/dist/{extracted_name}',
                f'{directory_dist}/{extracted_name}'
            )

        shutil.rmtree(f'{directory_dist}/package')



@app.route('/resources/<path:name>')
def serve_resource(name):

    resource_path = os.path.join(app.config['RESOURCE_DIR'], name)
    if os.path.exists(resource_path):
        extension = name.split('.')[-1]

        if extension == 'scss':
            return flask.Response(scss_compiler.compile(resource_path), mimetype='text/css')
        return flask.send_file(resource_path)
    else:
        return flask.Response("No such resource.", status=404)


@app.route('/')
@page
def home():

    return article_load('home')

@app.route('/article/<string:name>')
@page
def article(name):
    return article_load(name)

@app.route('/clients/')
@page
def clients():

    client_info = {}
    for client_name, info in app.config['CLIENT_INFO'].items():
        #current_client_info = {}
        current_client_info = info
        if os.path.exists(os.path.join(app.config['RESOURCE_DIR'], 'third-party-logos', f'{client_name}.svg')):
            current_client_info['logo'] = f'/resources/third-party-logos/{client_name}.svg'

        client_info[client_name] = current_client_info

    os_info = {}
    for os_name, info in app.config['OS_INFO'].items():
        current_os_info = info
        if os.path.exists(os.path.join(app.config['RESOURCE_DIR'], 'third-party-logos', f'{os_name}.svg')):
            current_os_info['logo'] = f'/resources/third-party-logos/{os_name}.svg'

        os_info[os_name] = current_os_info

    return {
        'client_info': client_info,
        'feature_info': app.config['FEATURE_INFO'],
        'installer_info': app.config['INSTALLER_INFO'],
        'os_info': os_info
    }

@app.route('/invite/<string:token>/')
@page
def invite_main(token):

    invite_info = ensure_token(token)

    welcome_msg = f'''You have been invited to register on {app.config['SERVICE_NAME']}<br /> <span class="claim">{app.config['CLAIM']}</span>'''

    probable_os = best_os_guess(flask.request)

    # redirect to #fragment of detected OS
    # ?r acts as marker that we already redirected, to avoid looping
    if not 'r' in flask.request.args:
        return redirect(f'?r#{probable_os}')

    processed_info = {}
    for os_name, os_info in app.config['OS_INFO'].items():

        current_os_info = {
            'title': os_info['title'],
            'client_recommend': os_info['client_recommend'],
            'client_other': [],
            'clients': {},
        }

        for client_name, client_info in app.config['CLIENT_INFO'].items():

            if os_name in client_info['os']:

                if client_name != current_os_info['client_recommend']:
                    current_os_info['client_other'].append(client_name)

                current_client_info = {
                    'title': client_info['title'],
                    'description': client_info['description'],
                    'features': client_info['features'],
                    'project_url': client_info['project_url'],
                    'os': client_info['os'],
                    'installer_recommend': client_info['installer_recommend'][os_name],
                }

                if os.path.exists(os.path.join(app.config['RESOURCE_DIR'], 'third-party-logos', f'{client_name}.svg')):
                    current_client_info['logo'] = f'/resources/third-party-logos/{client_name}.svg'

                if 'help_url' in client_info:
                    current_client_info['help_url'] = client_info['help_url']

                if os_name in client_info['installer_magic']:
                    current_client_info['installer_magic'] = client_info['installer_magic'][os_name]
                    for magic_installer in current_client_info['installer_magic']:
                        # string replacement to inject invite redirect in magic installer URLs
                        current_client_info['installer_magic'][magic_installer]['url'] = current_client_info['installer_magic'][magic_installer]['url'].replace('{invite.uri}', flask.helpers.url_quote(invite_info['uri'])) # this line is a monster

                current_client_info['installer_manual'] = client_info['installer_manual'][os_name]

                # collect non-recommended installers for this OS
                # we assume 'installer_manual' to hold *all* installers for this OS
                current_client_info['installer_other'] = set(current_client_info['installer_manual'].keys())
                current_client_info['installer_other'].remove(current_client_info['installer_recommend'])

                if os_name in client_info['installer_magic'] and current_client_info['installer_recommend'] in current_client_info['installer_magic']:
                    current_client_info['action_recommend'] = 'installer_magic'
                else:
                    current_client_info['action_recommend'] = 'installer_manual'

                current_client_info['installers'] = {}
                for installer_name, installer_info in app.config['INSTALLER_INFO'][os_name].items():

                    if installer_name in client_info['installer_manual'][os_name]:

                        current_installer_info = {
                            'title': installer_info['title'],
                            'gratis': current_client_info['installer_manual'][installer_name]['gratis'],
                            'url_support': installer_info['url_support'],
                            'magic_support': installer_info['magic_support'],
                            'pkgname_support': installer_info['pkgname_support'],
                            'guide_package': installer_info['guide_package'],
                        }

                        # list of keys over whose values we want to run string replacement
                        keys_replace = ['guide_package']

                        if installer_info['magic_support']:
                            current_installer_info['guide_magic'] = installer_info['guide_magic']
                            keys_replace.append('guide_magic')


                        if 'guide' in installer_info: # pre-installed installers don't have 'guide'
                            current_installer_info['guide'] = installer_info['guide']
                            # prepend 'guide'; has to come first so guide with
                            # replacements is available in 'guide_package'.
                            keys_replace = ['guide'] + keys_replace

                        for k in keys_replace:

                            value = replace_thingamabob(current_installer_info[k], invite_info, os_name, client_name, installer_name)
                            current_installer_info[k] = value

                        current_client_info['installers'][installer_name] = current_installer_info

                current_os_info['clients'][client_name] = current_client_info

        processed_info[os_name] = current_os_info

    return {
        'probable_os': probable_os,
        'welcome_msg': welcome_msg,
        'info': processed_info,
        'feature_info': app.config['FEATURE_INFO'],
    }

@app.route('/invite/<string:token>/register/', methods=['GET', 'POST'])
@page
def invite_register(token):

    invite_info = ensure_token(token)

    fakepost = 'fakepost' in flask.request.args

    if flask.request.method == 'POST' or fakepost:
        if ('username' in flask.request.form and 'password' in flask.request.form) or fakepost:

            if fakepost:
                username = "FNORD"
                password = "FNORD"
            else:
                username = flask.request.form['username']
                password = flask.request.form['password']

            try:
                if not fakepost:
                    register_with_invite(username, password, token)
            except ValueError as e:
                return e.args[0]
            except RuntimeError as e:
                return { 'message': "Sorry, that didn't work. Please try again." }
            else:

                data = {
                    'help': app.config['HELP_INFO'],
                    'message':  """Congratulations, your account
                                is ready for use!""",
                    'username': username,
                    'password': password,
                    'jid':      f"{ username }@{ app.config['XMPP_DOMAIN']}",
                }

                if 'client' in flask.request.args:
                    data['client'] = flask.request.args['client']
                    data['client_info'] = app.config['CLIENT_INFO'][data['client']]

                flask.session['jid'] = data['jid']
                flask.session['password'] = data['password']

                return data
        else:
            return { 'message': "Malformatted data." }
    else:
        return {
            'help': app.config['HELP_INFO'],
            'message': "Almost there! Just tell us what your new identity should be.",
            'domain': app.config['XMPP_DOMAIN'],
            'form': True,
        }


@app.route('/client')
@page
def client():
    return {
        'bosh_url': app.config.get('BOSH_URL'),
        'websocket_url': app.config.get('WEBSOCKET_URL'),
        'jid': flask.session['jid'] if 'jid' in flask.session else None,
        'password': flask.session['password'] if 'password' in flask.session else None,
    }


if __name__ == '__main__':
    app.config['DEBUG'] = True
    app.run('0.0.0.0')