import curses
import time
import requests
import praw

from .exceptions import SubredditError
from .page import BasePage, Navigator, BaseController
from .submission import SubmissionPage
from .content import SubredditContent
from .helpers import clean, open_browser, open_editor
from .docs import SUBMISSION_FILE
from .curses_helpers import (BULLET, UARROW, DARROW, Color, LoadScreen,
                             text_input, show_notification)

__all__ = ['opened_links', 'SubredditController', 'SubredditPage']

# Used to keep track of browsing history across the current session
opened_links = set()


class SubredditController(BaseController):
    character_map = {}


class SubredditPage(BasePage):

    def __init__(self, stdscr, reddit, name):

        self.controller = SubredditController(self)
        self.loader = LoadScreen(stdscr)

        content = SubredditContent.from_name(reddit, name, self.loader)
        super(SubredditPage, self).__init__(stdscr, reddit, content)

    def loop(self):
        while True:
            self.draw()
            cmd = self.stdscr.getch()
            self.controller.trigger(cmd)

    @SubredditController.register(curses.KEY_F5, 'r')
    def refresh_content(self, name=None):
        name = name or self.content.name

        try:
            self.content = SubredditContent.from_name(
                self.reddit, name, self.loader)
        except SubredditError:
            show_notification(self.stdscr, ['Invalid subreddit'])
        except requests.HTTPError:
            show_notification(self.stdscr, ['Could not reach subreddit'])
        else:
            self.nav = Navigator(self.content.get)

    @SubredditController.register('/')
    def prompt_subreddit(self):
        "Open a prompt to type in a new subreddit"

        attr = curses.A_BOLD | Color.CYAN
        prompt = 'Enter Subreddit: /r/'
        n_rows, n_cols = self.stdscr.getmaxyx()
        self.stdscr.addstr(n_rows - 1, 0, prompt, attr)
        self.stdscr.refresh()
        window = self.stdscr.derwin(1, n_cols - len(prompt),
                                    n_rows - 1, len(prompt))
        window.attrset(attr)

        out = text_input(window)
        if out is not None:
            self.refresh_content(name=out)

    @SubredditController.register(curses.KEY_RIGHT, 'l')
    def open_submission(self):
        "Select the current submission to view posts"

        data = self.content.get(self.nav.absolute_index)
        page = SubmissionPage(self.stdscr, self.reddit, url=data['permalink'])
        page.loop()

        if data['url'] == 'selfpost':
            global opened_links
            opened_links.add(data['url_full'])

    @SubredditController.register(curses.KEY_ENTER, 10, 'o')
    def open_link(self):
        "Open a link with the webbrowser"

        url = self.content.get(self.nav.absolute_index)['url_full']
        open_browser(url)

        global opened_links
        opened_links.add(url)

    @SubredditController.register('p')
    def post_submission(self):
        # Abort if user isn't logged in
        if not self.reddit.is_logged_in():
            show_notification(self.stdscr, ['Login to reply'])
            return

        subreddit = self.reddit.get_subreddit(self.content.name)

        # Make sure it is a valid subreddit for submission
        sub = str(subreddit)
        if '+' in sub or sub == '/r/all' or sub == '/r/front':
            message = 'Can\'t post to {0}'.format(sub)
            show_notification(self.stdscr, [message])
            return

        # Open the submission window
        submission_info = SUBMISSION_FILE.format(name=sub)
        curses.endwin()
        submission_text = open_editor(submission_info)
        curses.doupdate()

        # Abort if there is no content
        if not submission_text:
            curses.flash()
            return
        try:
            title, content = submission_text.split('\n', 1)
            self.reddit.submit(subreddit, title, text=content)
        except praw.errors.APIException as e:
            show_notification(self.stdscr, [e.message])
        else:
            time.sleep(0.5)
            self.refresh_content()

    @staticmethod
    def draw_item(win, data, inverted=False):

        n_rows, n_cols = win.getmaxyx()
        n_cols -= 1  # Leave space for the cursor in the first column

        # Handle the case where the window is not large enough to fit the data.
        valid_rows = range(0, n_rows)
        offset = 0 if not inverted else -(data['n_rows'] - n_rows)

        n_title = len(data['split_title'])
        for row, text in enumerate(data['split_title'], start=offset):
            if row in valid_rows:
                text = clean(text)
                win.addnstr(row, 1, text, n_cols - 1, curses.A_BOLD)

        row = n_title + offset
        if row in valid_rows:
            seen = (data['url_full'] in opened_links)
            link_color = Color.MAGENTA if seen else Color.BLUE
            attr = curses.A_UNDERLINE | link_color
            text = clean('{url}'.format(**data))
            win.addnstr(row, 1, text, n_cols - 1, attr)

        row = n_title + offset + 1
        if row in valid_rows:
            text = clean('{score} '.format(**data))
            win.addnstr(row, 1, text, n_cols - 1)

            if data['likes'] is None:
                text, attr = BULLET, curses.A_BOLD
            elif data['likes']:
                text, attr = UARROW, curses.A_BOLD | Color.GREEN
            else:
                text, attr = DARROW, curses.A_BOLD | Color.RED
            win.addnstr(text, n_cols - win.getyx()[1], attr)

            text = clean(' {created} {comments}'.format(**data))
            win.addnstr(text, n_cols - win.getyx()[1])

        row = n_title + offset + 2
        if row in valid_rows:
            text = clean('{author}'.format(**data))
            win.addnstr(row, 1, text, n_cols - 1, curses.A_BOLD)
            text = clean(' {subreddit}'.format(**data))
            win.addnstr(text, n_cols - win.getyx()[1], Color.YELLOW)
            text = clean(' {flair}'.format(**data))
            win.addnstr(text, n_cols - win.getyx()[1], Color.RED)