#!/usr/bin/env python3
import os
import sys

if hasattr(sys, '_MEIPASS'): # we're running in a bundle, go to where we have our bundled assets
    os.chdir(sys._MEIPASS)

import argparse
import shutil
import requests
import pathlib
import hashlib
from configparser import RawConfigParser

import util
from util import config

# Apply updates to the actual mod pack
def install():
    mods_location = os.path.join(config["pack"]["location"], "mods")
    whitelist = config["pack"]["whitelist"]

    # Actual download links are stored in pack-lock.ini, so we need to read it in here
    pack_lock = RawConfigParser()
    pack_lock.read('pack-lock.ini')

    print(f"Updating pack with version {pack_lock['global']['pack_version']}...")

    # create the mods folder if it doesn't already exist
    pathlib.Path(mods_location).mkdir(parents=True, exist_ok=True)

    names = set(f'{mod}.jar' for mod in pack_lock['mod_versions'].keys())
    # whitelist client mods (e.g. optifine)
    names.update(whitelist)

    i = 0
    for entry in pack_lock['mod_versions'].items():
        name = f'{entry[0]}.jar'
        checksum, url = entry[1].split(',')
        mod_path = os.path.join(mods_location, name)
        i += 1
        if os.path.exists(mod_path) and os.path.isfile(mod_path) and \
        hashlib.sha1(open(mod_path, 'rb').read()).hexdigest() == checksum:
            print(f"Skipping {name}, already up to date")
        else:
            print(f'Installing {name} from {url}...')
            print(f' ({i} of {len(pack_lock["mod_versions"])})', end='\r')
            download_obj = requests.get(url, stream=True)
            with open(mod_path, "wb") as write_file:
                shutil.copyfileobj(download_obj.raw, write_file)
            print("Done!" + " " * 8)

    # Remove any old mods that might be stuck in the mods folder
    print()
    print("Removing old mods...")
    for jar in os.listdir(mods_location):
        if jar not in names and os.path.splitext(jar)[1] == ".jar":
            os.remove(os.path.join(mods_location, jar))
            print(f"Removing '{jar}'")


    print('\nInstalling configs...')
    # For config files, we don't need to remove any extras, as they
    # will simply be ignored by Forge
    if not os.path.exists('config'):
        raise RuntimeError("Error: config folder must exist!")

    mc_config_folder = os.path.join(config['pack']['location'], 'config')
    if not os.path.exists(mc_config_folder):
        os.mkdir(mc_config_folder)
    for cfg in os.listdir('config'):
        shutil.copyfile(os.path.join('config', cfg), os.path.join(mc_config_folder, cfg))

    print()
    print("Finished installing mods!")



def apply_updates():
    """
    Using the URLs defined in pack.ini, update all mods to the latest 
    compatible version and write them out to pack-lock.ini
    """
    print("Populating version file...")
    print("Getting new versions of all mods...")
    mod_urls = util.find_updated_urls([x for x in config['mods'].values()], config['pack']['game_version'], threads=16)
    print("Downloading and checksumming all mods...")
    checksums = util.find_checksums(mod_urls)

    # Write the updated mods list out to pack-lock.ini
    pack_lock = RawConfigParser()
    pack_lock.read('pack-lock.ini')
    pack_lock['global']['pack_version'] = str(int(pack_lock['global']['pack_version']) + 1)
    # This is only needed for the self-update feature
    pack_lock['global']['config_files'] = ','.join(os.listdir('config'))
    pack_lock['mods'] = {name: f'{checksum},{url}' for name, checksum, url in zip(config['mods'].keys(), checksums, mod_urls)}
    with open('pack-lock.ini', 'w') as f:
        pack_lock.write(f)

    print()
    print("Done!")
    print("Updates applied to pack-lock.ini")
    print(f"New pack version is {pack_lock['global']['pack_version']}")
    print("[!] No mods were installed. To update your mods folder, run 'update.py install'")


# Find if any updates are available
def check_updates(mods, version_file, version=(2, 0, 0)):
    pack_version = util.get_version_from_file(version_file)
    print("Checking for updates to version " + str(pack_version) + "...")
    latest = [(k, mods[k]) for k in mods.keys()]
    old = util.read_file(version_file)
    old_urls = [mod[2] for mod in old]
    num_updates = 0

    print("Checking updates...")
    ffx = util.firefox()

    for mod in latest:
        print("Checking for updates to {mod[0]}...".format(mod=mod), end="")
        sys.stdout.flush()  # takes care of line-buffered terminals
        if 'curseforge' in mod[1]:
            url = util.find_cdn(ffx, mod[1], version)
        else:
            url = requests.get(mod[1]).url
        if url in old_urls:
            print(" No updates")
        else:
            print(" Found update: " + url.split('/')[-1])
            num_updates += 1
    ffx.close()
    
    print("Finished checking for updates.  {num} mods can be updated".format(num=num_updates))
    if num_updates >= 0:
        print("Run 'python update.py apply_updates' to create a new version with these updates applied.")


parser = argparse.ArgumentParser(
    description="A Simple Git-Based Modpack Manager",
    formatter_class=argparse.RawDescriptionHelpFormatter,
    epilog='''\
Available commands:
    install          : Downloads mods listed in version.txt and populates the mods folder specified in pack-location.txt
    apply_updates    : Using the urls in mods.txt, repopulates version.txt to reflect the most recent mod versions
    check_updates    : Compares version.txt and mods.txt to see if any mods can be updated
''')

parser.add_argument('command',
    nargs='?',
    default='install',
    help="The action to perform (default: install)")

if __name__ == "__main__":
    args = parser.parse_args()
    mods = config['mods']
    pack = config['pack']

    # run the command
    if args.command == "install":
        install()
    elif args.command == "apply_updates":
        apply_updates()
    elif args.command == "check_updates":
        check_updates(config['mods'], "version.txt", config['pack']["game_version"])
    else:
        print("Error: command \"" + args.command + "\" does not exist")
        parser.print_help()
        sys.exit(1)