import sys
import re
from subprocess import Popen, PIPE
from collections import deque
from hashlib import sha1
from deltas.tokenizers import wikitext_split
from mwxml import Dump
import mwpersistence
import mwreverts
from urllib.parse import quote
from urllib.parse import unquote
from deltas import SequenceMatcher

TO_ENCODE = ('title', 'editor')
PERSISTENCE_RADIUS = 7

def try_unquote(obj):
    if type(obj) is str:
        obj = unquote(obj)
        return obj.strip('\"')
    else:
        return

def calculate_persistence(tokens_added):
    return(sum([(len(x.revisions)-1) for x in tokens_added]),
           len(tokens_added))

class WikiqIterator():
    def __init__(self, fh, collapse_user=False):
        self.fh = fh
        self.collapse_user = collapse_user
        self.mwiterator = Dump.from_file(self.fh)
        self.namespace_map = { ns.id : ns.name for ns in
                               self.mwiterator.site_info.namespaces }
        self.__pages = self.load_pages()

    def load_pages(self):
        for page in self.mwiterator:
            yield WikiqPage(page,
                            namespace_map = self.namespace_map,
                            collapse_user=self.collapse_user)

    def __iter__(self):
        return self.__pages

    def __next__(self):
        return next(self._pages)


class WikiqPage():
    __slots__ = ('id', 'title', 'namespace', 'redirect',
                 'restrictions', 'mwpage', '__revisions',
                 'collapse_user')
    
    def __init__(self, page, namespace_map, collapse_user=False):
        self.id = page.id
        self.namespace = page.namespace
        if page.namespace != 0:
            self.title = ':'.join([namespace_map[page.namespace], page.title])
        else:
            self.title = page.title
        self.restrictions = page.restrictions
        self.collapse_user = collapse_user
        self.mwpage = page
        self.__revisions = self.rev_list()

    def rev_list(self):
        # Outline for how we want to handle collapse_user=True
        # iteration   rev.user   prev_rev.user   add prev_rev?
        #         0          A            None           Never
        #         1          A               A           False
        #         2          B               A            True
        #         3          A               B            True
        #         4          A               A           False
        # Post-loop                          A          Always
        for i, rev in enumerate(self.mwpage):
            # never yield the first time
            if i == 0:
                if self.collapse_user: 
                    collapsed_revs = 1
                    rev.collapsed_revs = collapsed_revs

            else:
                if self.collapse_user:
                    # yield if this is the last edit in a seq by a user and reset
                    # also yield if we do know who the user is

                    if rev.deleted.user or prev_rev.deleted.user:
                        yield prev_rev
                        collapsed_revs = 1
                        rev.collapsed_revs = collapsed_revs

                    elif not rev.user.text == prev_rev.user.text:
                        yield prev_rev
                        collapsed_revs = 1
                        rev.collapsed_revs = collapsed_revs
                    # otherwise, add one to the counter
                    else:
                        collapsed_revs += 1
                        rev.collapsed_revs = collapsed_revs
                # if collapse_user is false, we always yield
                else:
                    yield prev_rev

            prev_rev = rev

        # also yield the final time
        yield prev_rev

    def __iter__(self):
        return self.__revisions

    def __next__(self):
        return next(self.__revisions)

class WikiqParser():

    def __init__(self, input_file, output_file, collapse_user=False, persist=False, urlencode=False, persist_legacy=False):
        
        self.input_file = input_file
        self.output_file = output_file
        self.collapse_user = collapse_user
        self.persist = persist
        self.persist_legacy = persist_legacy
        self.printed_header = False
        self.namespaces = []
        self.urlencode = urlencode
        
    def __get_namespace_from_title(self, title):
        default_ns = None

        for ns in self.namespaces:
            # skip if the namespace is not defined
            if ns == None:
                default_ns = self.namespaces[ns]
                continue

            if title.startswith(ns + ":"):
                return self.namespaces[ns]

        # if we've made it this far with no matches, we return the default namespace
        return default_ns

    def process(self):

        # create a regex that creates the output filename
        # output_filename = re.sub(r'^.*/(enwiki\-\d+)\-.*p(\d+)p.*$',
        #                         r'output/wikiq-\1-\2.tsv',
        #                         input_filename)

        # Construct dump file iterator
        dump = WikiqIterator(self.input_file, collapse_user=self.collapse_user)

        # extract list of namspaces
        self.namespaces = {ns.name : ns.id for ns in dump.mwiterator.site_info.namespaces}

        page_count = 0
        rev_count = 0


        # Iterate through pages
        for page in dump:
            rev_detector = mwreverts.Detector()

            if self.persist or self.persist_legacy:
                window = deque(maxlen=PERSISTENCE_RADIUS)

                if not self.persist_legacy:
                    state = mwpersistence.DiffState(SequenceMatcher(tokenizer = wikitext_split),
                                                    revert_radius=PERSISTENCE_RADIUS)

                else:
                    from mw.lib import persistence
                    state = persistence.State()

            # Iterate through a page's revisions
            for rev in page:

                rev_data = {'revid' : rev.id,
                            'date_time' : rev.timestamp.strftime('%Y-%m-%d %H:%M:%S'),
                            'articleid' : page.id,
                            'editor_id' : "" if rev.deleted.user == True or rev.user.id is None else rev.user.id,
                            'title' : '"' + page.title + '"',
                            'namespace' : page.namespace if page.namespace is not None else self.__get_namespace_from_title(page.title),
                            'deleted' : "TRUE" if rev.deleted.text else "FALSE" } 

                # if revisions are deleted, /many/ things will be missing
                if rev.deleted.text:
                    rev_data['text_chars'] = ""
                    rev_data['sha1'] = ""
                    rev_data['revert'] = ""
                    rev_data['reverteds'] = ""

                else:
                    # rev.text can be None if the page has no text
                    if not rev.text:
                        rev.text = ""
                    # if text exists, we'll check for a sha1 and generate one otherwise

                    if rev.sha1:
                        text_sha1 = rev.sha1
                    else:

                        text_sha1 = sha1(bytes(rev.text, "utf8")).hexdigest()
                    
                    rev_data['sha1'] = text_sha1

                    # TODO rev.bytes doesn't work.. looks like a bug
                    rev_data['text_chars'] = len(rev.text)
               
                    # generate revert data
                    revert = rev_detector.process(text_sha1, rev.id)
                    
                    if revert:
                        rev_data['revert'] = "TRUE"
                        rev_data['reverteds'] = '"' + ",".join([str(x) for x in revert.reverteds]) + '"'
                    else:
                        rev_data['revert'] = "FALSE"
                        rev_data['reverteds'] = ""

                # if the fact that the edit was minor can be hidden, this might be an issue
                rev_data['minor'] = "TRUE" if rev.minor else "FALSE"

                if not rev.deleted.user:
                    # wrap user-defined editors in quotes for fread
                    rev_data['editor'] = '"' + rev.user.text + '"'
                    rev_data['anon'] = "TRUE" if rev.user.id == None else "FALSE"
                    
                else:
                    rev_data['anon'] = ""
                    rev_data['editor'] = ""

                #if re.match(r'^#redirect \[\[.*\]\]', rev.text, re.I):
                #    redirect = True
                #else:
                #    redirect = False
                
                #TODO missing: additions_size deletions_size
                
                # if collapse user was on, lets run that
                if self.collapse_user:
                    rev_data['collapsed_revs'] = rev.collapsed_revs

                if self.persist or self.persist_legacy:
                    if rev.deleted.text:

                        for k in ["token_revs", "tokens_added", "tokens_removed", "tokens_window"]:
                            old_rev_data[k] = None
                    else:

                        if not self.persist_legacy:
                            _, tokens_added, tokens_removed = state.update(rev.text, rev.id)

                        else:
                            _, tokens_added, tokens_removed = state.process(rev.text, rev.id, text_sha1)
                            
                        window.append((rev.id, rev_data, tokens_added, tokens_removed))
                        
                        if len(window) == PERSISTENCE_RADIUS:
                            old_rev_id, old_rev_data, old_tokens_added, old_tokens_removed = window[0]
                            
                            num_token_revs, num_tokens = calculate_persistence(old_tokens_added)

                            old_rev_data["token_revs"] = num_token_revs
                            old_rev_data["tokens_added"] = num_tokens
                            old_rev_data["tokens_removed"] = len(old_tokens_removed)
                            old_rev_data["tokens_window"] = PERSISTENCE_RADIUS-1

                            self.print_rev_data(old_rev_data)

                else:
                    self.print_rev_data(rev_data)

                rev_count += 1

            if self.persist or self.persist_legacy:
                # print out metadata for the last RADIUS revisions
                for i, item in enumerate(window):
                    # if the window was full, we've already printed item 0
                    if len(window) == PERSISTENCE_RADIUS and i == 0:
                        continue

                    rev_id, rev_data, tokens_added, tokens_removed = item
                    num_token_revs, num_tokens = calculate_persistence(tokens_added)

                    rev_data["token_revs"] = num_token_revs
                    rev_data["tokens_added"] = num_tokens
                    rev_data["tokens_removed"] = len(tokens_removed)
                    rev_data["tokens_window"] = len(window)-(i+1)
                    
                    self.print_rev_data(rev_data)

            page_count += 1

        print("Done: %s revisions and %s pages." % (rev_count, page_count),
              file=sys.stderr)

    def print_rev_data(self, rev_data):
        # if it's the first time through, print the header
        if self.urlencode:
            for field in TO_ENCODE:
                rev_data[field] = quote(str(rev_data[field]))

        if not self.printed_header:
            print("\t".join([str(k) for k in sorted(rev_data.keys())]), file=self.output_file)
            self.printed_header = True
        
        print("\t".join([str(v) for k, v in sorted(rev_data.items())]), file=self.output_file)


def open_input_file(input_filename):
    if re.match(r'.*\.7z$', input_filename):
        cmd = ["7za", "x", "-so", input_filename, '*'] 
    elif re.match(r'.*\.gz$', input_filename):
        cmd = ["zcat", input_filename] 
    elif re.match(r'.*\.bz2$', input_filename):
        cmd = ["bzcat", "-dk", input_filename] 

    try:
        input_file = Popen(cmd, stdout=PIPE).stdout
    except NameError:
        input_file = open(input_filename, 'r')

    return input_file

def open_output_file(input_filename):
    # create a regex that creates the output filename
    output_filename = re.sub(r'\.(7z|gz|bz2)?$', '', input_filename)
    output_filename = re.sub(r'\.xml', '', output_filename)
    output_filename = output_filename + ".tsv"
    output_file = open(output_filename, "w")

    return output_file


class IPCheck(object):

    # IP address regexes taken from https://gist.github.com/mnordhoff/2213179
    ipv4_address = re.compile('^(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$')

    ipv6_address_or_addrz = re.compile('^(?:(?:[0-9A-Fa-f]{1,4}:){6}(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|::(?:[0-9A-Fa-f]{1,4}:){5}(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){4}(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){3}(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:(?:[0-9A-Fa-f]{1,4}:){,2}[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:){2}(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:(?:[0-9A-Fa-f]{1,4}:){,3}[0-9A-Fa-f]{1,4})?::[0-9A-Fa-f]{1,4}:(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:(?:[0-9A-Fa-f]{1,4}:){,4}[0-9A-Fa-f]{1,4})?::(?:[0-9A-Fa-f]{1,4}:[0-9A-Fa-f]{1,4}|(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))|(?:(?:[0-9A-Fa-f]{1,4}:){,5}[0-9A-Fa-f]{1,4})?::[0-9A-Fa-f]{1,4}|(?:(?:[0-9A-Fa-f]{1,4}:){,6}[0-9A-Fa-f]{1,4})?::)(?:%25(?:[A-Za-z0-9\\-._~]|%[0-9A-Fa-f]{2})+)?$')

    @staticmethod
    def is_ip(username):
        if not type(username) is str:
            return False

        '''Check if a username is an ip (v4 or v6) address. We use this as
        a marker of whether the user is anonymous.'''
        if IPCheck.ipv4_address.match(username) or  IPCheck.ipv6_address_or_addrz.match(username):
            return True
        else:
            return False