linkulator2/linkulator

#!/usr/bin/env python3

## If this script contains bugs, blame cmccabe.

import glob
import getpass
import os
from pathlib import Path
from shutil import which
import signal
import sys
import subprocess
import time

username = getpass.getuser()

browser = "lynx"

help_text = """
options: -h or --help; -p or --post; or no option to browse links.

Linkulator is a minimalist, commandline link aggregator for small, trusting shell communities.

A few important points about Linkulator:
* Your username is associated with everything you post.  No real anonymity.
* You may ignore other users by adding their username to your ~/.linkulator/ignore file,
  followed by an optional description of why you're ignoring them.
* Link post categories are created dynamically.  Think before you create a new category and
  don't litter the board.
* No files are stored centrally. Each users' contributions are stored in ~/.linkulator/,
  meaning that you may always edit or delete your own files.  Please don't use this ability
  to deceive others.
* Link/reply threads disappear if the original link poster deletes their post; or if you
  put their username in your ignore file.
* Your ~/.linkulator/linkulator_data file must be readable by others, or nobody else will
  see your contributions.
* Linkulator may not work outside of Linux systems.
"""

pipe_count = 4 ## A PROPERLY FORMATED LINE IN linkulator.data HAS EXACTLY FOUR PIPES.

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


# READS THE CURRENT USER'S IGNORE FILE AND ADDS ANY ENTRIES TO THE GLOBAL VARIABLE
# IGNORE NAMES.
def parse_ignore_file():
    global ignore_names
    p = Path(Path.home(), '.linkulator/ignore')
    if p.exists():
        s = p.read_text()
        l = s.splitlines()
        for line in l:
            name = line.split(" ")[0]
            ignore_names.append(name)


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')

    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]
                if file_owner in ignore_names:
                    continue ## IGNORE NAMES IN ignore_file
                for line in f:
                    if line.count("|") != pipe_count:
                        continue ## IGNORE LINES THAT AREN'T FORMATTED PROPERLY.
                    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

    ## THIS IS SUPPOSED TO SORT ALL LINKS BY CREATION DATE.  NEED TO CONFIRM THAT IT WORKS.
    link_data.sort(key=lambda x: x[2])

    global categories
    global category_counts
    categories = []
    category_counts.clear() ## CLEAR SO WE DON'T DOUBLE-COUNT IF FNC RUN MORE THAN ONCE.
    for line in link_data:
        if line[4] not in categories and line[4] != "":
            categories.append(line[4])
            category_counts[line[4]] = 1
        elif line[4] in categories:
            category_counts[line[4]] = category_counts[line[4]] + 1


def print_categories():
    print("Current link post categories include: ")
    for i in categories:
        print(" * " + i + "(" + str(category_counts[i]) + ")")
#    print(categories)
    view_category_contents()


def view_category_contents():
    view_cat = ""
    while view_cat not in categories:
        view_cat = input("View category (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.")

    for line in link_data:
        if line[4] == view_cat:
            print("ID:", line[0], "|", line[6], "|", line[5], "|", line[1])

    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, no thread found with that ID.")
        print_categories() ## 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:
            ftime = time.strftime("%b %d %Y", time.gmtime(float(parent_timestamp)))  ## UGGHH...
            print("\nLink: ", line[6] + " (" + line[5] + "),\n posted by " + line[1] + " on " + ftime)

    print("\nReplies:")
    i = 0
    for line in link_data:
        if line[3] == parent_id:
            print(line[1] + ": " + line[6])
            i = i+1
    if i == 0:
        print("(No replies yet.  Be the first!)\n")

    next_step = input("Type 'R' to reply, 'B' to view in " + browser + ", '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):
    if which(browser) is None:
        print("Sorry, " + browser + " is not installed on your system.  Ask your sysadmin to install it.")
        view_thread(post_id)

    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://")
        tryAnyway = input("Do you want to try it in", browser, "anyway? Y/[N] ")
        if tryAnyway == "Y" or tryAnyway == "y":
            subprocess.call(['lynx', url])
    view_thread(post_id)


def post_link():
    print("Enter link information here.  Leaving any field blank aborts post.")

    link_url = ""
    while link_url == "":
        link_url = input("URL: ")
        if "|" in link_url:
            print("Pipes, \"|\", are illegal characters in Linkulator.  Please try again.")
            link_url = ""
        elif link_url == "":
            graceful_exit()
            
    link_category = ""
    while link_category == "":
        link_category = input("Category: ")
        if "|" in link_category:
            print("Pipes, \"|\", are illegal characters in Linkulator.  Please try again.")
            link_category = ""
        elif link_category == "":
            graceful_exit()

    link_title = ""
    while link_title == "":
        link_title = input("Title: ")
        if "|" in link_title:
            print("Pipes, \"|\", are illegal characters in Linkulator.  Please try again.")
            link_title = ""
        elif link_title == "":
            graceful_exit()

    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 + "\n")
    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:
         timestamp = str(time.time())
         file.write(timestamp + '|' + owner + "+" + tstamp + '|||' + comment + "\r")

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

def search(keyword):
    print("Doesn't work yet. Would be searching title, category, comment for ", keyword)

##  PSEUDOCODE:
##    results_found = ""
##    for line in link_data:
##        if keyword in link_data[title] or keyword in link_data[category] or keyword in link_data[comment]:
##            results_found = "yes"
##            if line is parent post:
##                print line
##            elif line is reply:
##                get parentID
##                print(line[parentID])
##    if results_found == "":
##        print("No results found")
##    else:
##        next_step = input("Enter ID to view thread, "M" for main menu, or [Enter] to quit: ")
##        if next_step...

def graceful_exit():
    print("\n\nThank you for linkulating.  Goodbye.\n")
    exit(0)


def signal_handler(sig, frame):
    graceful_exit()
signal.signal(signal.SIGINT, signal_handler)


def parse_command():
    args = sys.argv[1:]
    if not len(args):
        print("----------")
        print("LINKULATOR")
        print("----------")
        parse_ignore_file()
        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()