#!/usr/bin/env python3

import datetime
import os
import subprocess
import sys

import inotify.adapters

def extract_zip(path, dest):
    p = subprocess.run(['unzip', '-o', '-qq', path, '-d', dest])
    if p.returncode != 0:
        raise Exception('failed to extract ' + path)

def extract_rar(path, dest):
    if not dest.endswith('/'):
        dest += '/'
    p = subprocess.run(['unrar', 'x', '-idq', '-y', path, dest])
    if p.returncode != 0:
        raise Exception('failed to extract ' + path)

def extract_tar_gz(path, dest):
    if not dest.endswith('/'):
        dest += '/'
    p = subprocess.run([
        'tar',
        '-C', dest, # goes first cuz reasons?
        '-x', '-z',
        '-f', path])
    if p.returncode != 0:
        raise Exception('failed to extract ' + path)

ARCHIVE_HANDLERS = {
    '.zip': extract_zip,
    '.rar': extract_rar,
    '.tar.gz': extract_tar_gz
}

def convert_name(path):
    base = os.path.basename(path)
    date = str(datetime.date.today())
    return str(date) + '-' + ''.join(c for c in base if c.isalpha())

def process_file(path, extractdir):
    filename = os.path.basename(path)
    for (ext, handler) in ARCHIVE_HANDLERS.items():
        if path.endswith(ext):
            # Set up the directory
            destdir = os.path.realpath(os.path.join(extractdir, convert_name(path)))
            os.makedirs(destdir, exist_ok=True)

            # Actually extract it
            print('Processing', filename, '...')
            handler(path, destdir)
            print('Extracted', filename, 'to', destdir)
            return True

    # If we did nothing, just ignore it.
    print('File', filename, 'doesn\'t seem to be an archive, ignoring')
    return False

def main(args):
    if len(args) != 3:
        print('usage: ./crowsnest.py <watchdir(s)> <extractdir>')
        return 1

    # Do setup and sanity checking
    watchdirs = args[1].split(',')
    extractdir = args[2]
    for d in watchdirs:
        if not os.path.exists(d):
            print('This watch path does not exist:', d)
            return 1
    if not os.path.exists(extractdir):
        print('extract path does not exist')
        return 1

    # Set up the watch
    watch = inotify.adapters.Inotify()
    for d in watchdirs:
        real = os.path.realpath(d)
        watch.add_watch(real)
        print('Added watch for:', real)

    # Start watching
    for event in watch.event_gen(yield_nones=False):
        (_, type_names, path, filename) = event

        fullpath = os.path.join(path, filename)
        if os.path.isdir(fullpath):
            print('Found new directory created:', filename)
            continue

        # Do some checking to see if it was something we care about.
        wasimportant = False
        for tn in type_names:
            if tn == 'IN_CLOSE_WRITE' or tn == 'IN_MOVED_TO':
                wasimportant = True
        if not wasimportant:
            continue

        # Actually deal with it.
        try:
            did_something = process_file(fullpath, extractdir)
            if did_something:
                os.remove(fullpath)
        except Exception as err:
            print('Failed to process file:', str(err))

    # Probs won't get here.
    return 0

if __name__ == '__main__':
    sys.exit(main(sys.argv))