linkulator2/linkulator

#!/usr/bin/env python3

## If this script contains bugs, blame cmccabe.

import glob
import getpass
import os
import time
import sys
import subprocess

## TO DO:
##    PARSE/USE IGNORE FILE
##    VALIDATE INPUT FROM linkulator.data FILE
##    "POST" COMMAND LINE ARG SHOULD TAKE AN OPTIONAL LINK ARGUMENT
##    CAPTURE CTRL-C AND GRACEFULLY EXIT
##    NEED TO VALIDATE THAT LYNX IS INSTALLED, AND DON'T OFFER OPEN-IN-BROWSER IF NOT

## FUTURE, TO DO:
##    LINK/REPLIES TREE SHOULD BE A SINGLE DATA STRUCTURE

username = getpass.getuser()

help_text = "options: -h or --help for help, -p or --post to post a link, and no argument to browse links."

link_data = []
## username, datestamp, parent-id, category, link-url, link-title
categories = []

def build_menu():
    ## WHENEVER THIS FUNCTION IS CALLED, THE DATA IS REFRESHED FROM FILES. SINCE
    ## DISK IO IS PROBABLY THE HEAVIEST PART OF THIS SCRIPT, DON'T DO THIS OFTEN.

    linkulator_files = glob.glob('/home/*/.linkulator/linkulator.data')
    ignore_file = glob.glob('/home/' + username + '/.linkulator/ignore')

    if len(linkulator_files) == 0:
        print("It looks link there are no links yet. Run 'linkulator -p' to add one.")
        exit()

    else:

        global link_data
        linkulator_lines = []
        for filename in linkulator_files:
            with open(filename) as f:
                file_owner = filename.split('/')[2]
                for line in f:
                    line = line.rstrip('\n')
                    split_line = line.split('|')
                    split_line.insert(0,file_owner)
                    linkulator_lines.append(split_line) ## creating a list of lists

        i=1
        for idx, line in enumerate(linkulator_lines):
            if line[2] == "": # CREATE/INSERT PARENT ID:
                linkulator_lines[idx].insert(0, i)
                i=i+1
            else: ## NOT PARENT, SO NO PARENT ID
                linkulator_lines[idx].insert(0,"")
        link_data = linkulator_lines

    global categories
    for line in link_data:
        if line[4] not in categories and line[4] != "":
            categories.append(line[4])


def print_categories():
    print("Current link post categories include: ")
    print(categories)
    view_category_contents()


def view_category_contents():
    view_cat = ""
    while view_cat not in categories:
        view_cat = input("Type a category to view its posts or hit [Enter] to quit: ")
        if view_cat == "":
            graceful_exit()
        if view_cat not in categories:
            print("Sorry, that category does not exist.  Try again, or hit [Enter] to quit.")

    for line in link_data:
        if line[4] == view_cat:
            print(line)

    pid = input("Enter a post ID to see its thread, \"m\" to return to the main menu, or hit [Enter] to quit: ")
    if pid == "":                                       ## HARMLESS BUT UNINTENDED 
        graceful_exit()                                 ## ABILITY HERE IS THAT USERS
    elif pid =="m" or pid == "M":                       ## CAN PUT ANY PID IN, NOT JUST
        print_categories()                              ## FROM WITHIN THIS CATEGORY.
        return()
    else:
        view_thread(pid)


def view_thread(post_id):

    parent_id = ""
    url = ""
    for line in link_data:
        if str(line[0]) == post_id:
            parent_id = line[1] + "+" + str(line[2])
            parent_user = line[1]
            parent_timestamp = line[2]
            url = line[5]

    if parent_id == "":
        print("Sorry, thread found with that ID.")
        return() ## THIS IS NOT A GOOD END POINT. SHOULD ASK USER TO RE-ENTER THEIR CHOICE.

    for line in link_data:
        if line[1] == parent_user and line[2] == parent_timestamp:
            print("Parent post:")
            print(line)

    print("Replies:")    
    i = 0
    for line in link_data:
        if line[3] == parent_id:
            print(line)
            i = i+1
    if i == 0:
        print("(No replies yet.  Be the first!)")

    next_step = input("Type 'R' to reply, 'B' to view in Lynx, 'M' for main menu, or anything else to quit: ")
    if next_step == "M" or next_step == "m":
        print_categories()
    elif next_step =="B" or next_step == "b":
        view_link_in_browser(url, post_id)
    elif next_step == "R" or next_step == "r":
        reply(parent_user, parent_timestamp, post_id)
    else:
        graceful_exit()


def view_link_in_browser(url, post_id):
    print("URL = " + url)
    if url.startswith("gopher://") or url.startswith("https://") or url.startswith("http://"):
        subprocess.call(['lynx', url])
    else:
        print("Sorry, that url doesn't start with gopher://, http:// or https://")
    view_thread(post_id)


def post_link():
    link_url = input("URL: ")
    link_category = input("Category: ")
    link_title = input("Title: ")
    timestamp = str(time.time())
    filename = '/home/' + username + '/.linkulator/linkulator.data'
    if os.path.exists(filename):
        append_write = 'a' # append if already exists
    else:
        append_write = 'w' # make a new file if not
    with open(filename, append_write) as file:
         file.write(timestamp + '||' + link_category + '|' + link_url + '|' + link_title + "\r")
    print("Link added!")
    graceful_exit()


def reply(owner, tstamp, post_id):
    global username

    comment = input("Enter your comment: ")

    filename = '/home/' + username + '/.linkulator/linkulator.data'
    if os.path.exists(filename):
        append_write = 'a' # append if already exists
    else:
        append_write = 'w' # make a new file if not
    with open(filename, append_write) as file:
         file.write('|' + owner + "+" + tstamp + '|||' + comment + "\r")

    x = input('Reply added.  Hit [Enter] to return to thread.')
    build_menu()
    view_thread(post_id)
    

def graceful_exit():
    print("Thank you for linkulating.  Goodbye.")
    exit()


def parse_command():
    args = sys.argv[1:]
    if not len(args):
        print("----------")
        print("LINKULATOR")
        print("----------")
        build_menu()
        print_categories()
    elif args[0] in ["-h", "--help", "help"]:
        print(help_text)
    elif args[0] in ["-p", "--post", "-p"]:
        post_link()
    else:
        print("Unknown command: {}".format(args[0]))


if __name__ == '__main__':
    parse_command()