from __future__ import print_function
from future import standard_library
standard_library.install_aliases()
from builtins import zip
from builtins import str

from codecs import open
from configparser import RawConfigParser as ConfigParser, NoOptionError
import csv
from datetime import datetime, timedelta
from functools import partial
from importlib import import_module
from io import StringIO
import json
import itertools
import math
import os.path
from pkg_resources import resource_filename
import re
import socket
import sys
from urllib.parse import unquote
import webbrowser

from bottle import request, response, route, run, static_file, Bottle
from topicexplorer.lib.color import get_topic_colors, rgb2hex
from topicexplorer.lib.ssl import SSLWSGIRefServer
from topicexplorer.lib.util import int_prompt, bool_prompt, is_valid_filepath, is_valid_configfile

from vsm.corpus import Corpus
from vsm.model.lda import LDA
from vsm.viewer.ldacgsviewer import LdaCgsViewer as LDAViewer
from vsm.viewer.wrappers import doc_label_name

import random
import pystache

__all__ = ['populate_parser', 'main', '_set_acao_headers', 'Application']

def get_static_resource_path(path):
    if os.path.exists(path):
        return os.path.abspath(path)
    elif os.path.exists(os.path.join(sys.prefix, path)):
        return os.path.abspath(os.path.join(sys.prefix, path))
    elif os.path.exists(resource_filename(__name__, path)):
        return resource_filename(__name__, path)
    else:
        raise OSError("File not found: {}".format(path))
    

def _set_acao_headers(f):
    """
    Decorator to set Access-Control-Allow-Origin headers to enable cross-InPhO
    embedding of Topic Explorer bars.
    """
    def set_header(*args, **kwargs):
        host = request.get_header('Origin')
        if host and 'cogs.indiana.edu' in host:
            response.headers['Access-Control-Allow-Origin'] = host
        elif host and 'codepen.io' in host:
            response.headers['Access-Control-Allow-Origin'] = host
        return f(*args, **kwargs)
    return set_header


def _cache_date(days=1):
    """
    Helper function to return the date for the cache header.
    """
    time = datetime.now() + timedelta(days=days)
    return time.strftime("%a, %d %b %Y %I:%M:%S GMT")


class Application(Bottle):
    """
    This is the primary Bottle application for the Topic Explorer.
    Each Application corresponds to a single Corpus object, but may
    have multiple LDA model objects.
    """

    def __init__(self, corpus_file='', model_pattern='', topic_range=None,
                 context_type='', label_module=None, config_file='',
                 fulltext=False, corpus_path='', **kwargs):
        super(Application, self).__init__()

        self.config_file = config_file

        # setup routes
        self.renderer = pystache.Renderer(escape=lambda u: u,
            string_encoding='utf8')
        self.icons = kwargs.get('icons', 'link')
        if fulltext:
            self._serve_fulltext(corpus_path)
        self._setup_routes(**kwargs)

        # load corpus
        self.context_type = context_type
        self.label_name = self.context_type + '_label'
        self._load_label_module(label_module, config_file)
        self._load_corpus(corpus_file)

        # load viewers
        self.v = dict()
        self.topic_range = topic_range
        self.colors = dict()
        self._load_viewers(model_pattern)

    def _load_label_module(self, label_module, config_file):
        try:
            label_module = import_module(label_module)
            print("imported label module")
            label_module.init(self, config_file)
        except (ImportError, NoOptionError, AttributeError):
            pass

        try:
            self.label = label_module.label
            print("imported label function")
        except (AttributeError, UnboundLocalError):
            self.label = lambda x: x
            print("using default label function")

        try:
            self.id_fn = label_module.id_fn
            print("imported id function")
        except (AttributeError, UnboundLocalError):
            self.id_fn = lambda metadata: metadata[self.label_name]
            print("using default id function")

    def _load_corpus(self, corpus_file):
        self.c = Corpus.load(corpus_file)
        self.labels = self.c.view_metadata(self.context_type)[self.label_name]

    def _load_viewers(self, model_pattern):
        self.id_fn = lambda md: md[self.label_name]
        for k in self.topic_range:
            m = LDA.load(model_pattern.format(k))
            self.v[k] = LDAViewer(self.c, m)
            self.colors[k] = dict(get_topic_colors(self.v[k]))
            self.v[k].dist_doc_doc = partial(
                self.v[k].dist_doc_doc, label_fn=self.id_fn)
            self.v[k].dist_top_doc = partial(
                self.v[k].dist_top_doc, label_fn=self.id_fn)

    def _setup_routes(self, **kwargs):
        @self.route('/<k:int>/doc_topics/<doc_id>')
        @_set_acao_headers
        def doc_topic_csv(k, doc_id):
            response.content_type = 'text/csv; charset=UTF8'

            doc_id = unquote(doc_id).decode('utf-8')

            data = self.v[k].doc_topics(doc_id)

            output = StringIO()
            writer = csv.writer(output)
            writer.writerow(['topic', 'prob'])
            writer.writerows([(t, "%6f" % p) for t, p in data])

            return output.getvalue()

        @self.route('/<k:int>/docs/<doc_id>')
        @_set_acao_headers
        def doc_csv(k, doc_id, threshold=0.2):
            response.content_type = 'text/csv; charset=UTF8'

            doc_id = unquote(doc_id).decode('utf-8')

            data = self.v[k].dist_doc_doc(doc_id)

            output = StringIO()
            writer = csv.writer(output)
            writer.writerow(['doc', 'prob'])
            writer.writerows([(d, "%6f" % p) for d, p in data if p > threshold])

            return output.getvalue()

        @self.route('/<k:int>/topics/<topic_no:int>.json')
        @_set_acao_headers
        def topic_json(k, topic_no, N=40):
            response.content_type = 'application/json; charset=UTF8'
            try:
                N = int(request.query.n)
            except:
                pass

            if N > 0:
                data = self.v[k].dist_top_doc([topic_no])[:N]
            else:
                data = self.v[k].dist_top_doc([topic_no])[N:]
                data = reversed(data)

            docs = [doc for doc, prob in data]
            doc_topics_mat = self.v[k].doc_topics(docs)
            docs = self.get_docs(docs, id_as_key=True)

            js = []
            for doc_prob, topics in zip(data, doc_topics_mat):
                doc, prob = doc_prob
                struct = docs[doc]
                struct.update({'prob': float(1 - prob),
                               'topics': dict([(str(t), float(p)) for t, p in topics])})
                js.append(struct)

            return json.dumps(js)

        @self.route('/<k:int>/docs_topics/<doc_id:path>.json')
        @_set_acao_headers
        def doc_topics(k, doc_id, N=40):
            try:
                N = int(request.query.n)
            except:
                pass

            doc_id = unquote(doc_id)

            response.content_type = 'application/json; charset=UTF8'

            if N > 0:
                data = self.v[k].dist_doc_doc(doc_id)[:N]
            else:
                data = self.v[k].dist_doc_doc(doc_id)[N:]
                data = reversed(data)

            docs = [doc for doc, prob in data]
            doc_topics_mat = self.v[k].doc_topics(docs)
            docs = self.get_docs(docs, id_as_key=True)

            js = []
            for doc_prob, topics in zip(data, doc_topics_mat):
                doc, prob = doc_prob
                struct = docs[doc]
                struct.update({'prob': float(1 - prob),
                               'topics': dict([(str(t), float(p)) for t, p in topics])})
                js.append(struct)

            return json.dumps(js)

        @self.route('/<k:int>/word_docs.json')
        @_set_acao_headers
        def word_docs(k, N=40):
            import numpy as np
            try:
                N = int(request.query.n)
            except:
                pass
            try:
                query = request.query.q.lower()
                if self.c.words.dtype.type == np.string_:
                    query = query.encode('ascii', 'ignore')
                
                query = query.split('|')
            except:
                raise Exception('Must specify a query')

            response.content_type = 'application/json; charset=UTF8'

            query = [word for word in query if word in self.c.words]

            # abort if there are no terms in the query
            if not query:
                response.status = 400  # Bad Request
                return "Search terms not in model"

            topics = self.v[k].dist_word_top(query, show_topics=False)
            data = self.v[k].dist_top_doc(topics['i'],
                                          weights=(topics['value'].max() - topics['value']))

            if N > 0:
                data = data[:N]
            else:
                data = data[N:]
                data = reversed(data)

            docs = [doc for doc, prob in data]
            doc_topics_mat = self.v[k].doc_topics(docs)
            docs = self.get_docs(docs, id_as_key=True)

            js = []
            for doc_prob, topics in zip(data, doc_topics_mat):
                doc, prob = doc_prob
                struct = docs[doc]
                struct.update({'prob': float(1 - prob),
                               'topics': dict([(str(t), float(p)) for t, p in topics])})
                js.append(struct)

            return json.dumps(js)

        @self.route('/<k:int>/topics.json')
        @_set_acao_headers
        def topics(k):
            from topicexplorer.lib.color import rgb2hex

            response.content_type = 'application/json; charset=UTF8'
            response.set_header('Expires', _cache_date())
            response.set_header('Cache-Control', 'max-age=86400')
            
            # populate word values
            data = self.v[k].topics()

            js = {}
            wordmax = 10  # for alphabetic languages
            if kwargs.get('lang', None) == 'cn':
                wordmax = 25  # for ideographic languages

            for i, topic in enumerate(data):
                js[str(i)] = {
                    "color": rgb2hex(self.colors[k][i]),
                    'words': dict([(str(w), float(p))
                                       for w, p in topic[:wordmax]])
                    }

            return json.dumps(js)

        @self.route('/topics.json')
        @_set_acao_headers
        def word_topic_distance():
            import numpy as np
            response.content_type = 'application/json; charset=UTF8'

            # parse query
            try:
                if '|' in request.query.q:
                    query = request.query.q.lower()
                    if self.c.words.dtype.type == np.string_:
                        query = query.encode('ascii', 'ignore')
                
                    query = query.split('|')
                else:
                    query = request.query.q.lower()
                    if self.c.words.dtype.type == np.string_:
                        query = query.encode('ascii', 'ignore')
                
                    query = query.split(' ')
            except:
                raise Exception('Must specify a query')

            stopped_words = [word for word in query 
                                 if word in self.c.stopped_words]
            query = [word for word in query if word in self.c.words]

            # abort if there are no terms in the query
            if not query and stopped_words:
                response.status = 410  # Gone
                return "Search terms removed using stoplist: " + ' '.join(query)
            elif not query:
                response.status = 404  # Not Found
                return "Search terms not in corpus"


            # calculate distances
            distances = dict()
            for k, viewer in self.v.items():
                d = viewer.dist_word_top(query, show_topics=False)
                distances[k] = np.fromiter(
                    ((k, row['i'], row['value']) for row in d),
                    dtype=[('k', '<i8'), ('i', '<i8'), ('value', '<f8')])

            # merge and sort all topics across all models
            merged_similarity = np.hstack(list(distances.values()))
            sorted_topics = merged_similarity[np.argsort(merged_similarity['value'])]

            # return data
            data = [{'k' : int(t['k']),
                     't' : int(t['i']),
                     'distance' : float(t['value']) } for t in sorted_topics]
            return json.dumps(data)


        @self.route('/topics')
        @_set_acao_headers
        def view_clusters():
            with open(get_static_resource_path('www/master.mustache.html'),
                      encoding='utf-8') as tmpl_file:
                template = tmpl_file.read()

            tmpl_params = {'body' : _render_template('cluster.mustache.html'),
                           'topic_range': self.topic_range}
            return self.renderer.render(template, tmpl_params)


        @self.route('/docs.json')
        @_set_acao_headers
        def docs(docs=None, q=None):
            response.content_type = 'application/json; charset=UTF8'
            response.set_header('Expires', _cache_date())

            try:
                if request.query.q:
                    q = unquote(request.query.q).decode('utf-8')
            except:
                pass

            try:
                if request.query.id:
                    docs = [unquote(request.query.id).decode('utf-8')]
            except:
                pass

            try:
                response.set_header('Expires', 0)
                response.set_header('Pragma', 'no-cache')
                response.set_header('Cache-Control', 'no-cache, no-store, must-revalidate')
                if request.query.random:
                    docs = [random.choice(self.labels)]
            except:
                pass

            js = self.get_docs(docs, query=q)

            return json.dumps(js)

        @self.route('/icons.js')
        def icons():
            with open(get_static_resource_path('www/icons.js')) as icons:
                text = '{0}\n var icons = {1};'\
                    .format(icons.read(), json.dumps(self.icons))
            return text

        def _render_template(page):
            response.set_header('Expires', _cache_date())

            with open(get_static_resource_path('www/' + page),
                      encoding='utf-8') as tmpl_file:
                template = tmpl_file.read()

            tmpl_params = {'corpus_name': kwargs.get('corpus_name', ''),
                           'corpus_link': kwargs.get('corpus_link', ''),
                           'context_type': self.context_type,
                           'topic_range': self.topic_range,
                           'doc_title_format': kwargs.get('doc_title_format', '{0}'),
                           'doc_url_format': kwargs.get('doc_url_format', ''),
                           'home_link': kwargs.get('home_link', '/')}
            return self.renderer.render(template, tmpl_params)

        @self.route('/<k:int>/')
        def index(k):
            with open(get_static_resource_path('www/master.mustache.html'),
                      encoding='utf-8') as tmpl_file:
                template = tmpl_file.read()

            tmpl_params = {'body' : _render_template('bars.mustache.html'),
                           'topic_range': self.topic_range}
            return self.renderer.render(template, tmpl_params)

        @self.route('/cluster.csv')
        @_set_acao_headers
        def cluster_csv(second=False):
            filename = kwargs.get('cluster_path')
            print("Retrieving cluster.csv:", filename)
            if not filename or not os.path.exists(filename):
                import topicexplorer.train
                filename = topicexplorer.train.cluster(10, self.config_file)
                kwargs['cluster_path'] = filename

            root, filename = os.path.split(filename)
            return static_file(filename, root=root)
        
        @self.route('/description.md')
        @_set_acao_headers
        def description():
            filename = kwargs.get('corpus_desc')
            if not filename:
                response.status = 404
                return "File not found"
            root, filename = os.path.split(filename)
            return static_file(filename, root=root)
        
        @self.route('/')
        @_set_acao_headers
        def cluster():
            with open(get_static_resource_path('www/master.mustache.html'),
                      encoding='utf-8') as tmpl_file:
                template = tmpl_file.read()

            tmpl_params = {'body' : _render_template('splash.mustache.html'),
                           'topic_range': self.topic_range}
            return self.renderer.render(template, tmpl_params)

        @self.route('/<filename:path>')
        @_set_acao_headers
        def send_static(filename):
            return static_file(filename, root=get_static_resource_path('www/'))

    def _serve_fulltext(self, corpus_path):
        @self.route('/fulltext/<doc_id:path>')
        @_set_acao_headers
        def get_doc(doc_id):
            doc_id = doc_id.decode('utf-8')
            pdf_path = os.path.join(corpus_path, re.sub('txt$', 'pdf', doc_id))
            if os.path.exists(pdf_path.encode('utf-8')):
                doc_id = re.sub('txt$', 'pdf', doc_id)
            # here we deal with case where corpus_path and doc_id overlap
            (fdirs, lastdir) = os.path.split(corpus_path)
            pattern = lastdir.decode('utf-8')
            fdirs = fdirs.decode('utf-8')
            if re.match('^' + pattern, doc_id):
                return static_file(doc_id, root=fdirs)
            else:
                return static_file(doc_id, root=corpus_path)

    def get_docs(self, docs=None, id_as_key=False, query=None):
        ctx_md = self.c.view_metadata(self.context_type)

        if docs:
            # filter to metadata for selected docs
            ids = [self.c.meta_int(self.context_type, {self.label_name: doc}) for doc in docs]
            ctx_md = ctx_md[ids]
        else:
            # get metadata for all documents
            docs = self.labels

        js = dict() if id_as_key else list()

        for doc, md in zip(docs, ctx_md):
            if query is None or query.lower() in self.label(doc).lower():
                struct = {
                    'id': doc,
                    'label': self.label(doc),
                    'metadata': dict(zip(md.dtype.names, (str(m) for m in md)))}
                if id_as_key:
                    js[doc] = struct
                else:
                    js.append(struct)

        return js


def get_host_port(args):
    """
    Returns the hostname and port number
    """
    config = ConfigParser({'port': '8000', 'host': '0.0.0.0'})
    with open(args.config, encoding='utf8') as configfile:
        config.read_file(configfile)

    # automatic port assignment
    def test_port(port):
        try:
            host = args.host or config.get("www", "host")
            if host == '0.0.0.0':
                host = 'localhost'
            try:
                s = socket.create_connection((host, port), 2)
                s.close()
                raise IOError("Socket connectable on port {0}".format(port))
            except socket.error:
                pass
            return port
        except IOError:
            if not args.quiet:
                port = int_prompt(
                    "Conflict on port {0}. Enter new port:".format(port))
                return test_port(port)
            else:
                raise IOError(
                    "Conflict on port {0}. Try running with -p to manually set new port.".format(port))

    port = args.port or int(config.get('www', 'port').format(0))
    port = test_port(port)

    # prompt to save
    if (int(config.get("www", "port").format(0))) != port:
        if not args.quiet and bool_prompt(
            "Change default baseport to {0}?".format(port), default=True):
            config.set("www", "port", str(port))

            # create deep copy of configuration
            # see http://stackoverflow.com/a/24343297
            config_string = StringIO()
            config.write(config_string)

            # skip DEFAULT section
            config_string.seek(0)
            idx = config_string.getvalue().index("[main]")
            config_string.seek(idx)

            # read deep copy
            new_config = ConfigParser()
            config.read_file(config_string)

            # write deep copy without DEFAULT section
            # this preserves DEFAULT for rest of program
            with open(args.config, 'w') as configfh:
                new_config.write(configfh)

    # hostname assignment
    host = args.host or config.get('www', 'host')

    return host, port


def main(args, app=None):
    if app is None:
        app = create_app(args)

    host, port = get_host_port(args)

    if args.browser:
        if host == '0.0.0.0':
            link_host = socket.gethostname()
        else:
            link_host = host
        url = "http://{host}:{port}/"
        url = url.format(host=link_host, port=port, k=min(app.topic_range))
        webbrowser.open(url)

        print("TIP: Browser launch can be disabled with the '--no-browser' argument:")
        print("topicexplorer serve --no-browser", args.config, "\n")

    app.run(server='paste', host=host, port=port)


def create_app(args):
    # load in the configuration file
    config = ConfigParser({
        'certfile': None,
        'keyfile': None,
        'ca_certs': None,
        'ssl': False,
        'port': '8000',
        'host': '0.0.0.0',
        'icons': 'link',
        'corpus_link': None,
        'doc_title_format': '{0}',
        'doc_url_format': '',
        'raw_corpus': None,
        'label_module': None,
        'fulltext': 'false',
        'topics': None,
        'cluster': None,
        'corpus_desc' : None,
        'home_link' : '/',
        'lang': None})

    with open(args.config, encoding='utf8') as configfile:
        config.read_file(configfile)

    # path variables
    context_type = config.get('main', 'context_type')
    corpus_file = config.get('main', 'corpus_file')
    model_pattern = config.get('main', 'model_pattern')
    cluster_path = config.get('main', 'cluster')

    # language customization
    lang = config.get('main', 'lang')

    # set topic_range
    if config.get('main', 'topics'):
        topic_range = eval(config.get('main', 'topics'))

    # get icons_list
    config_icons = config.get('www', 'icons').split(",")
    if args.fulltext or config.getboolean('www', 'fulltext'):
        if not any('fulltext' in icon for icon in config_icons):
            config_icons.insert(0, 'fulltext-inline')

    # Create application object
    corpus_name = config.get('www', 'corpus_name')
    corpus_link = config.get('www', 'corpus_link')
    doc_title_format = config.get('www', 'doc_title_format')
    doc_url_format = config.get('www', 'doc_url_format')
    home_link = config.get('www', 'home_link')
    label_module = config.get('main', 'label_module')
    corpus_path = config.get('main', 'raw_corpus')
    corpus_desc = config.get('main', 'corpus_desc')
    fulltext = args.fulltext or config.getboolean('www', 'fulltext')

    app = Application(corpus_file=corpus_file,
                      model_pattern=model_pattern,
                      topic_range=topic_range,
                      context_type=context_type,
                      label_module=label_module,
                      config_file=args.config,
                      corpus_path=corpus_path,
                      fulltext=fulltext,
                      lang=lang,
                      icons=config_icons,
                      corpus_name=corpus_name,
                      corpus_link=corpus_link,
                      doc_title_format=doc_title_format,
                      doc_url_format=doc_url_format,
                      cluster_path=cluster_path,
                      corpus_desc=corpus_desc,
                      home_link=home_link)

    """
    host, port = get_host_port(args) 
    """
    # app.run(host='0.0.0.0', port=8081)
    return app


def populate_parser(parser):
    parser.add_argument('config', type=lambda x: is_valid_configfile(parser, x),
                        help="Configuration file path")
    parser.add_argument('-k', type=int, required=False,
                        help="Number of Topics")
    parser.add_argument('-p', dest='port', type=int,
                        help="Port Number", default=None)
    parser.add_argument('--host', default=None, help='Hostname')
    parser.add_argument('--no-browser', dest='browser', action='store_false')
    parser.add_argument("-q", "--quiet", action="store_true")
    parser.add_argument('--fulltext', action='store_true',
                        help='Serve raw corpus files.')
    parser.add_argument('--bibtex', default=None,
                        type=lambda x: is_valid_filepath(parser, x),
                        help='BibTeX library location')
    parser.add_argument('--ssl', action='store_true',
                        help="Use SSL (must specify certfile, keyfile, and ca_certs in config)")
    parser.add_argument('--ssl-certfile', dest='certfile', nargs="?",
                        const='server.pem', default=None,
                        type=lambda x: is_valid_filepath(parser, x),
                        help="SSL certificate file")
    parser.add_argument('--ssl-keyfile', dest='keyfile', default=None,
                        type=lambda x: is_valid_filepath(parser, x),
                        help="SSL certificate key file")
    parser.add_argument('--ssl-ca', dest='ca_certs', default=None,
                        type=lambda x: is_valid_filepath(parser, x),
                        help="SSL certificate authority file")

if __name__ == '__main__':
    from argparse import ArgumentParser

    # argument parsing
    parser = ArgumentParser()
    populate_parser(parser)
    args = parser.parse_args()

    main(args)
