#!/usr/bin/env python3
import hashlib
import requests
import os
import shutil
import sys

# Initalize from config
INSTALL_DIR = ""
with open("pack-location.txt", "r") as f:
    INSTALL_DIR = f.read().strip()


def apply_updates():
    print("Updating pack...")
    # (fname, url)
    mods = []
    # Set of jar file names
    names = set()

    with open("downloads.txt", "r") as f:
        for line in f:
            dl = line.strip().split(" ")
            if len(line) > 3 and len(dl) == 2 and line[0] != '#':
                dl[0] = dl[0].strip()
                dl[1] = dl[1].strip()
                mods.append(dl)
                names.add(dl[0])
    for mod in mods:
        if mod[0] in os.listdir(INSTALL_DIR):
            print("Skipping " + mod[0] + ", already up to date")
        else:
            print("Installing " + mod[0] + " from " + mod[1] + "...")
            download_obj = requests.get(mod[1], stream=True)
            with open(os.path.join(INSTALL_DIR, mod[0]), "wb") as write_file:
                shutil.copyfileobj(download_obj.raw, write_file)
            print("Done!")

    print("\nRemoving old versions...")
    for jar in os.listdir(INSTALL_DIR):
        if jar not in names and os.path.splitext(jar)[1] == ".jar":
            os.remove(os.path.join(INSTALL_DIR, jar))
            print(f"Removing '{jar}'")

    print("\nFinished updating pack!")

def find_updates():
    print("Reading update file...")
    mods = set()
    with open('updates.txt') as f:
        for line in f:
            mod = line.strip().split()
            if len(line) > 3 and len(mod) == 2 and line[0] != '#':
                # run strip on each element
                mod = tuple(map(lambda x: x.strip(), mod))
                mods.add(mod)
    print("Downloading new versions of all mods...")
    with open('downloads.txt', 'w') as f:
        f.write('# Format: <jarname> <hex digested sha1> <direct download url>\n')
        for mod in mods:
            resp = requests.get(mod[1])
            hsh = hashlib.sha1(resp.content)
            f.write(f'{mod[0]} {hsh.hexdigest()} {resp.url}\n')


if len(sys.argv) < 2:
    print(f"Usage: {sys.argv[0]} <update|find_updates>")
    sys.exit(-1)
elif sys.argv[1] == 'update':
    update()
elif sys.argv[1] == 'find_updates':
    find_updates()
else:
    print(f"Usage: {sys.argv[0]} <update|find_updates>")
    sys.exit(-1)