import curses
import sys
import webbrowser
from requests.exceptions import HTTPError

from .errors import SubredditNameError
from .page import BasePage
from .submission import SubmissionPage
from .content import SubredditContent
from .utils import LoadScreen, text_input, display_message, Color, ESCAPE

class SubredditPage(BasePage):

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

        self.reddit = reddit
        self.name = name
        self.loader = LoadScreen(stdscr)

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

    def loop(self):

        self.draw()
        while True:
            cmd = self.stdscr.getch()

            if cmd in (curses.KEY_UP, ord('k')):
                self.move_cursor_up()
                self.clear_input_queue()

            elif cmd in (curses.KEY_DOWN, ord('j')):
                self.move_cursor_down()
                self.clear_input_queue()

            # View submission
            elif cmd in (curses.KEY_RIGHT, curses.KEY_ENTER, ord('l')):
                self.open_submission()
                self.draw()

            elif cmd == ord('o'):
                self.open_link()

            # Enter edit mode to change subreddit
            elif cmd == ord('/'):
                self.prompt_subreddit()
                self.draw()

            # Refresh page
            elif cmd in (curses.KEY_F5, ord('r')):
                self.refresh_content()
                self.draw()

            elif cmd == curses.KEY_RESIZE:
                self.draw()

            # Quit
            elif cmd == ord('q'):
                sys.exit()

            else:
                curses.beep()

    def refresh_content(self, name=None):

        name = name or self.name

        try:
            self.content = SubredditContent.from_name(
                self.reddit, name, self.loader)

        except (SubredditNameError, HTTPError):
            display_message(self.stdscr, 'Invalid Subreddit')

        else:
            self.nav.page_index, self.nav.cursor_index = 0, 0
            self.nav.inverted = False
            self.name = name

    def prompt_subreddit(self):

        attr = curses.A_BOLD | Color.MAGENTA
        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(n_rows-1, len(prompt))
        window.attrset(attr)

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

    def open_submission(self):
        "Select the current submission to view posts"

        submission = self.content.get(self.nav.absolute_index)['object']
        page = SubmissionPage(self.stdscr, self.reddit, submission=submission)
        page.loop()

    @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:
                attr = curses.A_BOLD
                win.addstr(row, 1, text, attr)

        row = n_title + offset
        if row in valid_rows:
            attr = curses.A_UNDERLINE | Color.BLUE
            text = '{url}'.format(**data)
            win.addnstr(row, 1, text, n_cols-1, attr)

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

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

    def open_link(self):
        url = self.content.get(self.nav.absolute_index)['url']
        webbrowser.open_new_tab(url)