# Natural Language Toolkit: Collocations Application
# Much of the GUI code is imported from concordance.py; We intend to merge these tools together
# Copyright (C) 2001-2018 NLTK Project
# Author: Sumukh Ghodke <sghodke@csse.unimelb.edu.au>
# URL: <http://nltk.org/>
# For license information, see LICENSE.TXT
#


from __future__ import division

import threading

from six.moves import queue as q
from six.moves.tkinter_font import Font
from six.moves.tkinter import (Button, END, Frame, IntVar, LEFT, Label, Menu,
                               OptionMenu, SUNKEN, Scrollbar, StringVar,
                               Text, Tk)

from nltk.corpus import (cess_cat, brown, nps_chat, treebank, sinica_treebank, alpino,
                         indian, floresta, mac_morpho, machado, cess_esp)
from nltk.util import in_idle
from nltk.probability import FreqDist


CORPUS_LOADED_EVENT = '<<CL_EVENT>>'
ERROR_LOADING_CORPUS_EVENT = '<<ELC_EVENT>>'
POLL_INTERVAL = 100

_DEFAULT = 'English: Brown Corpus (Humor)'
_CORPORA = {
            'Catalan: CESS-CAT Corpus':
                lambda: cess_cat.words(),
            'English: Brown Corpus':
                lambda: brown.words(),
            'English: Brown Corpus (Press)':
                lambda: brown.words(categories=['news', 'editorial', 'reviews']),
            'English: Brown Corpus (Religion)':
                lambda: brown.words(categories='religion'),
            'English: Brown Corpus (Learned)':
                lambda: brown.words(categories='learned'),
            'English: Brown Corpus (Science Fiction)':
                lambda: brown.words(categories='science_fiction'),
            'English: Brown Corpus (Romance)':
                lambda: brown.words(categories='romance'),
            'English: Brown Corpus (Humor)':
                lambda: brown.words(categories='humor'),
            'English: NPS Chat Corpus':
                lambda: nps_chat.words(),
            'English: Wall Street Journal Corpus':
                lambda: treebank.words(),
            'Chinese: Sinica Corpus':
                lambda: sinica_treebank.words(),
            'Dutch: Alpino Corpus':
                lambda: alpino.words(),
            'Hindi: Indian Languages Corpus':
                lambda: indian.words(files='hindi.pos'),
            'Portuguese: Floresta Corpus (Portugal)':
                lambda: floresta.words(),
            'Portuguese: MAC-MORPHO Corpus (Brazil)':
                lambda: mac_morpho.words(),
            'Portuguese: Machado Corpus (Brazil)':
                lambda: machado.words(),
            'Spanish: CESS-ESP Corpus':
                lambda: cess_esp.words()
           }

class CollocationsView:
    _BACKGROUND_COLOUR='#FFF' #white

    def __init__(self):
        self.queue = q.Queue()
        self.model = CollocationsModel(self.queue)
        self.top = Tk()
        self._init_top(self.top)
        self._init_menubar()
        self._init_widgets(self.top)
        self.load_corpus(self.model.DEFAULT_CORPUS)
        self.after = self.top.after(POLL_INTERVAL, self._poll)

    def _init_top(self, top):
        top.geometry('550x650+50+50')
        top.title('NLTK Collocations List')
        top.bind('<Control-q>', self.destroy)
        top.protocol('WM_DELETE_WINDOW', self.destroy)
        top.minsize(550,650)

    def _init_widgets(self, parent):
        self.main_frame = Frame(parent, dict(background=self._BACKGROUND_COLOUR, padx=1, pady=1, border=1))
        self._init_corpus_select(self.main_frame)
        self._init_results_box(self.main_frame)
        self._init_paging(self.main_frame)
        self._init_status(self.main_frame)
        self.main_frame.pack(fill='both', expand=True)

    def _init_corpus_select(self, parent):
        innerframe = Frame(parent, background=self._BACKGROUND_COLOUR)
        self.var = StringVar(innerframe)
        self.var.set(self.model.DEFAULT_CORPUS)
        Label(innerframe, justify=LEFT, text=' Corpus: ', background=self._BACKGROUND_COLOUR, padx = 2, pady = 1, border = 0).pack(side='left')

        other_corpora = list(self.model.CORPORA.keys()).remove(self.model.DEFAULT_CORPUS)
        om = OptionMenu(innerframe, self.var, self.model.DEFAULT_CORPUS, command=self.corpus_selected, *self.model.non_default_corpora())
        om['borderwidth'] = 0
        om['highlightthickness'] = 1
        om.pack(side='left')
        innerframe.pack(side='top', fill='x', anchor='n')

    def _init_status(self, parent):
        self.status = Label(parent, justify=LEFT, relief=SUNKEN, background=self._BACKGROUND_COLOUR, border=0, padx = 1, pady = 0)
        self.status.pack(side='top', anchor='sw')

    def _init_menubar(self):
        self._result_size = IntVar(self.top)
        menubar = Menu(self.top)

        filemenu = Menu(menubar, tearoff=0, borderwidth=0)
        filemenu.add_command(label='Exit', underline=1,
                   command=self.destroy, accelerator='Ctrl-q')
        menubar.add_cascade(label='File', underline=0, menu=filemenu)

        editmenu = Menu(menubar, tearoff=0)
        rescntmenu = Menu(editmenu, tearoff=0)
        rescntmenu.add_radiobutton(label='20', variable=self._result_size,
                     underline=0, value=20, command=self.set_result_size)
        rescntmenu.add_radiobutton(label='50', variable=self._result_size,
                     underline=0, value=50, command=self.set_result_size)
        rescntmenu.add_radiobutton(label='100', variable=self._result_size,
                     underline=0, value=100, command=self.set_result_size)
        rescntmenu.invoke(1)
        editmenu.add_cascade(label='Result Count', underline=0, menu=rescntmenu)

        menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
        self.top.config(menu=menubar)

    def set_result_size(self, **kwargs):
        self.model.result_count = self._result_size.get()

    def _init_results_box(self, parent):
        innerframe = Frame(parent)
        i1 = Frame(innerframe)
        i2 = Frame(innerframe)
        vscrollbar = Scrollbar(i1, borderwidth=1)
        hscrollbar = Scrollbar(i2, borderwidth=1, orient='horiz')
        self.results_box = Text(i1,
                    font=Font(family='courier', size='16'),
                    state='disabled', borderwidth=1,
                    yscrollcommand=vscrollbar.set,
                    xscrollcommand=hscrollbar.set, wrap='none', width='40', height = '20', exportselection=1)
        self.results_box.pack(side='left', fill='both', expand=True)
        vscrollbar.pack(side='left', fill='y', anchor='e')
        vscrollbar.config(command=self.results_box.yview)
        hscrollbar.pack(side='left', fill='x', expand=True, anchor='w')
        hscrollbar.config(command=self.results_box.xview)
        #there is no other way of avoiding the overlap of scrollbars while using pack layout manager!!!
        Label(i2, text='   ', background=self._BACKGROUND_COLOUR).pack(side='left', anchor='e')
        i1.pack(side='top', fill='both', expand=True, anchor='n')
        i2.pack(side='bottom', fill='x', anchor='s')
        innerframe.pack(side='top', fill='both', expand=True)

    def _init_paging(self, parent):
        innerframe = Frame(parent, background=self._BACKGROUND_COLOUR)
        self.prev = prev = Button(innerframe, text='Previous', command=self.previous, width='10', borderwidth=1, highlightthickness=1, state='disabled')
        prev.pack(side='left', anchor='center')
        self.next = next = Button(innerframe, text='Next', command=self.__next__, width='10', borderwidth=1, highlightthickness=1, state='disabled')
        next.pack(side='right', anchor='center')
        innerframe.pack(side='top', fill='y')
        self.reset_current_page()

    def reset_current_page(self):
        self.current_page = -1

    def _poll(self):
        try:
            event = self.queue.get(block=False)
        except q.Empty:
            pass
        else:
            if event == CORPUS_LOADED_EVENT:
                self.handle_corpus_loaded(event)
            elif event == ERROR_LOADING_CORPUS_EVENT:
                self.handle_error_loading_corpus(event)
        self.after = self.top.after(POLL_INTERVAL, self._poll)

    def handle_error_loading_corpus(self, event):
        self.status['text'] = 'Error in loading ' + self.var.get()
        self.unfreeze_editable()
        self.clear_results_box()
        self.freeze_editable()
        self.reset_current_page()

    def handle_corpus_loaded(self, event):
        self.status['text'] = self.var.get() + ' is loaded'
        self.unfreeze_editable()
        self.clear_results_box()
        self.reset_current_page()
        #self.next()
        collocations = self.model.next(self.current_page + 1)
        self.write_results(collocations)
        self.current_page += 1

    def corpus_selected(self, *args):
        new_selection = self.var.get()
        self.load_corpus(new_selection)

    def previous(self):
        self.freeze_editable()
        collocations = self.model.prev(self.current_page - 1)
        self.current_page= self.current_page - 1
        self.clear_results_box()
        self.write_results(collocations)
        self.unfreeze_editable()

    def __next__(self):
        self.freeze_editable()
        collocations = self.model.next(self.current_page + 1)
        self.clear_results_box()
        self.write_results(collocations)
        self.current_page += 1
        self.unfreeze_editable()

    def load_corpus(self, selection):
        if self.model.selected_corpus != selection:
            self.status['text'] = 'Loading ' + selection + '...'
            self.freeze_editable()
            self.model.load_corpus(selection)

    def freeze_editable(self):
        self.prev['state'] = 'disabled'
        self.next['state'] = 'disabled'

    def clear_results_box(self):
        self.results_box['state'] = 'normal'
        self.results_box.delete("1.0", END)
        self.results_box['state'] = 'disabled'

    def fire_event(self, event):
        #Firing an event so that rendering of widgets happen in the mainloop thread
        self.top.event_generate(event, when='tail')

    def destroy(self, *e):
        if self.top is None: return
        self.top.after_cancel(self.after)
        self.top.destroy()
        self.top = None

    def mainloop(self, *args, **kwargs):
        if in_idle(): return
        self.top.mainloop(*args, **kwargs)

    def unfreeze_editable(self):
        self.set_paging_button_states()

    def set_paging_button_states(self):
        if self.current_page == -1 or self.current_page == 0:
            self.prev['state'] = 'disabled'
        else:
            self.prev['state'] = 'normal'
        if self.model.is_last_page(self.current_page):
            self.next['state'] = 'disabled'
        else:
            self.next['state'] = 'normal'

    def write_results(self, results):
        self.results_box['state'] = 'normal'
        row = 1
        for each in results:
            self.results_box.insert(str(row) + '.0', each[0] + " " + each[1] + "\n")
            row += 1
        self.results_box['state'] = 'disabled'

class CollocationsModel:
    def __init__(self, queue):
        self.result_count = None
        self.selected_corpus = None
        self.collocations = None
        self.CORPORA = _CORPORA
        self.DEFAULT_CORPUS = _DEFAULT
        self.queue = queue
        self.reset_results()

    def reset_results(self):
        self.result_pages = []
        self.results_returned = 0

    def load_corpus(self, name):
        self.selected_corpus = name
        self.collocations = None
        runner_thread = self.LoadCorpus(name, self)
        runner_thread.start()
        self.reset_results()

    def non_default_corpora(self):
        copy = []
        copy.extend(list(self.CORPORA.keys()))
        copy.remove(self.DEFAULT_CORPUS)
        copy.sort()
        return copy

    def is_last_page(self, number):
        if number < len(self.result_pages):
            return False
        return self.results_returned + (number - len(self.result_pages)) * self.result_count >= len(self.collocations)

    def next(self, page):
        if (len(self.result_pages) - 1) < page:
            for i in range(page - (len(self.result_pages) - 1)):
                self.result_pages.append(self.collocations[self.results_returned:self.results_returned+self.result_count])
                self.results_returned += self.result_count
        return self.result_pages[page]

    def prev(self, page):
        if page == -1:
            return []
        return self.result_pages[page]

    class LoadCorpus(threading.Thread):
        def __init__(self, name, model):
            threading.Thread.__init__(self)
            self.model, self.name = model, name

        def run(self):
            try:
                words = self.model.CORPORA[self.name]()
                from operator import itemgetter
                text = [w for w in words if len(w) > 2]
                fd = FreqDist(tuple(text[i:i+2]) for i in range(len(text)-1))
                vocab = FreqDist(text)
                scored = [((w1,w2), fd[(w1,w2)] ** 3 / (vocab[w1] * vocab[w2])) for w1, w2 in fd]
                scored.sort(key=itemgetter(1), reverse=True)
                self.model.collocations = list(map(itemgetter(0), scored))
                self.model.queue.put(CORPUS_LOADED_EVENT)
            except Exception as e:
                print(e)
                self.model.queue.put(ERROR_LOADING_CORPUS_EVENT)

#def collocations():
#    colloc_strings = [w1 + ' ' + w2 for w1, w2 in self._collocations[:num]]

def app():
    c = CollocationsView()
    c.mainloop()

if __name__ == '__main__':
    app()

__all__ = ['app']
