hn-cli/hn.py

#!/usr/bin/env python3

import requests
from bs4 import BeautifulSoup as Soup
import curses
import webbrowser
import math

import api

spinner_states = ['-', '\\', '|', '/']

class Client:
    def __init__(self):
        # set up curses
        self.screen = curses.initscr()
        curses.start_color()
        curses.use_default_colors()
        curses.init_pair(1, 255, 208)
        curses.noecho()
        curses.cbreak()
        self.screen.keypad(True)

        self.topstories = api.get_topstories()
        self.loadedstories = []
        self.story_pos = 0
        self.cursor_pos = 0

        self.lines = curses.LINES
        self.cols = curses.COLS
        self.stories_in_a_site = self.lines - 3

    def load_stories(self, from_pos, to_pos):
        for idx, i in enumerate(self.topstories[from_pos:to_pos]):
            self.set_footer(f'[{spinner_states[idx%4]}] Loading { to_pos - from_pos } stories...')
            self.screen.refresh()
            self.loadedstories.append(api.get_story(i))

    def set_footer(self, footer):
        self.screen.addstr(curses.LINES - 1, 0, footer, curses.A_REVERSE)
        self.screen.clrtoeol()

    def draw(self):
        self.screen.clear()
        self.lines = curses.LINES
        self.cols = curses.COLS
        # header, detail, footer:
        self.stories_in_a_site = self.lines - 3

        title_string = '[Y] Hacker News'
        title_string +=' ' * (self.cols - len(title_string) - 1) + '\n'

        self.screen.addstr(title_string, curses.color_pair(1))

        for i, story in enumerate(self.loadedstories[self.story_pos:self.story_pos + self.stories_in_a_site]):
            prefix = '>' if i == self.cursor_pos else ''
            # calculate length of line
            text = f'{prefix} ()\n'
            chars_available = self.cols - len(text)
            max_title_len = min((chars_available//4)*3, len(story.title))
            max_url_len = chars_available - max_title_len

            title = story.title[:max_title_len-1] + "…" if len(story.title) > max_title_len else story.title
            link = story.link.replace('https://', '').replace('http://', '')
            link = link[:max_url_len-1] + "…" if len(link) > max_url_len else link

            self.screen.addstr(prefix)
            if i == self.cursor_pos:
                if story.read:
                    self.screen.addstr(title, curses.A_DIM | curses.A_UNDERLINE)
                else:
                    self.screen.addstr(title, curses.A_UNDERLINE)
                self.screen.addstr(f' ({link})\n', curses.A_DIM )
                detail = f'    by {story.author} | {story.comments} comments | {story.votes} points\n'
                self.screen.addstr(detail)
            else:
                if story.read:
                    self.screen.addstr(title, curses.A_DIM) 
                else:
                    self.screen.addstr(title)
                self.screen.addstr(f' ({link})\n', curses.A_DIM )

        page = int(self.story_pos / self.stories_in_a_site + 1)
        total_pages = math.ceil(len(self.loadedstories)/self.stories_in_a_site)
        self.set_footer(f'Page {page}/{total_pages}, loaded {len(self.loadedstories)} stories.') 

    def handle_input(self):
        c = self.screen.getch()
        if c == ord('q'):  # Quit
            self.exit()
        elif c == curses.KEY_UP:
            self.cursor_pos -= 1
            if self.cursor_pos < 0:
                self.cursor_pos = self.stories_in_a_site-1
                # scroll up a page (:
                self.story_pos -= self.stories_in_a_site
                self.story_pos = 0 if self.story_pos < 0 else self.story_pos

        elif c == curses.KEY_DOWN:
            self.cursor_pos += 1
            if self.cursor_pos >= self.stories_in_a_site:
                self.cursor_pos = 0
                # scroll up down a page :)
                self.story_pos += self.stories_in_a_site
                self.load_more_if_needed()

        elif c == ord('c'):
            webbrowser.open(f'https://news.ycombinator.com/item?id={self.loadedstories[self.story_pos + self.cursor_pos].id}')
        elif c == curses.KEY_ENTER or c == 10:
            if self.loadedstories[self.story_pos + self.cursor_pos].link == 'No URL':
                webbrowser.open(f'https://news.ycombinator.com/item?id={self.loadedstories[self.story_pos + self.cursor_pos].id}')
            else:
                webbrowser.open(self.loadedstories[self.story_pos + self.cursor_pos].link)
            self.loadedstories[self.story_pos + self.cursor_pos].read = True
        elif c == ord('r'):
            self.reload()
        elif c == curses.KEY_RESIZE:
            curses.resize_term(*self.screen.getmaxyx())
            self.lines, self.cols = self.screen.getmaxyx()
            self.stories_in_a_site = self.lines - 3
            self.load_more_if_needed()

    def load_more_if_needed(self):
        if len(self.loadedstories) < self.story_pos + self.stories_in_a_site:
            # load more
            self.load_stories(len(self.loadedstories), self.story_pos + self.stories_in_a_site)

    def run(self):
        self.load_stories(0, self.stories_in_a_site)
        while True:
            self.draw()
            self.handle_input()

    def exit(self):
        curses.endwin()
        import sys
        sys.exit(0)

    def reload(self):
        self.topstories = api.get_topstories()
        self.loadedstories = []
        self.story_pos = 0
        self.cursor_pos = 0
        self.load_more_if_needed()

def main():
    try:
        client = Client()
        client.run()
    except Exception as e:
        curses.endwin()
        raise e

if __name__ == '__main__':
    main()