#!/usr/bin/env python3

import argparse, sys, shutil, os, hashlib

sys.path.append(os.path.dirname(__file__) + '/lib')

import tamarin, system, rkt

def configure_args_parser():

    profile_names = tamarin.get_available_profile_names()

    parser = argparse.ArgumentParser(description="Generate packages for various GNU/Linux distribution")

    # Define available/required arguments and flags
    parser.add_argument("project_path", help="The path to your project to package")
    parser.add_argument("-p", "--profile", help="The profile to use to package this project (default: debian)", choices=profile_names, default='debian')
    parser.add_argument("--rebuild", help="Ignore cache and rebuild container's image", action="store_true", default=False)

    return parser

if __name__ == "__main__":

    parser = configure_args_parser()
    args = parser.parse_args()

    # Load build profile
    profile = tamarin.load_profile(args.profile)

    workspace = tamarin.get_workspace_dir()
    workspace_tmp = tamarin.get_workspace_subdir('tmp')

    local_rkt_dir = tamarin.get_workspace_subdir('rkt')
    if not system.which('rkt', local_rkt_dir):
        # Download and extract rkt
        rkt_archive_path = tamarin.download_rkt()
        system.extract_tar(rkt_archive_path, workspace_tmp)
        rkt_archive_dir = tamarin.get_rkt_achive_dest_dir()
        shutil.rmtree(local_rkt_dir, ignore_errors=True)
        os.rename(rkt_archive_dir, local_rkt_dir)

    local_acbuild_dir = tamarin.get_workspace_subdir('acbuild')
    if not system.which('acbuild', local_acbuild_dir):
        # Download and extract acbuild
        acbuild_archive_path = tamarin.download_acbuild()
        system.extract_tar(acbuild_archive_path, workspace_tmp)
        acbuild_archive_dir = tamarin.get_acbuild_achive_dest_dir()
        shutil.rmtree(local_acbuild_dir, ignore_errors=True)
        os.rename(acbuild_archive_dir, local_acbuild_dir)

    pid = os.getpid()
    build_workspace = tamarin.get_workspace_subdir('tmp/build_{:d}'.format(pid))

    rkt_store = tamarin.get_workspace_subdir('store')
    rkt_flags = ["--dir={:s}".format(rkt_store)]

    base_image = profile['profile']['default_image']
    # If the base image is Docker-based, preload it and get its name from the store
    if base_image.startswith('docker://'):
        rkt.run([
            "fetch",
            "--insecure-options=image",
            base_image
        ] + rkt_flags)

    aci_file = os.path.join(os.sep, build_workspace, 'image.aci')
    acbuild_flags = ["--modify", aci_file, "--work-path", build_workspace]

    # Use cached image base on base_image and containerbuild hooks
    containerbuild_hooks = profile['containerbuild']['hooks']
    hasher = hashlib.sha1()
    hasher.update(base_image.encode())
    hasher.update(containerbuild_hooks.encode())
    image_hash = hasher.hexdigest()
    cache_dir = tamarin.get_workspace_subdir('cache')
    cached_image_file = os.path.join(os.sep, cache_dir, '{:s}.aci'.format(image_hash[:12]));

    if not args.rebuild and os.path.exists(cached_image_file):
      # Copy cached image
      shutil.copyfile(cached_image_file, aci_file)
    else:
      # Find and export base image from rkt' store
      name_pattern = base_image.split('/')[-1] + '$'
      image = rkt.find_image_by_name(name_pattern, rkt_flags=rkt_flags)
      rkt.export_image(image['id'], aci_file, rkt_flags=rkt_flags);

      # Build image
      tamarin.run_acbuild(acbuild_flags+["set-name", "image_{:d}".format(pid)])
      tamarin.run_acbuild(acbuild_flags+["copy-to-dir", tamarin.get_hooks_dir(), '/tamarin'])
      tamarin.run_acbuild(acbuild_flags+["copy-to-dir", tamarin.get_lib_dir(), '/tamarin'])

      # Execute containerbuild hooks
      cpb_hooks_env = os.environ.copy()
      cpb_hooks_env["PATH"] = os.environ['PATH'] + ':' + local_acbuild_dir
      cpb_hooks_env["TAMARIN_ACBUILD"] = " ".join([system.which('acbuild', local_acbuild_dir)]+acbuild_flags)
      tamarin.run_profile_hooks(profile, 'containerbuild', cwd=build_workspace, env=cpb_hooks_env)

      # Cache image
      shutil.copyfile(aci_file, cached_image_file)

    # Start container
    rkt.run(rkt_flags+[
        "run",
        "--insecure-options=image",
        aci_file, "--net=host",
        "--exec", "/usr/bin/python3", "--", "/tamarin/lib/build.py"
    ], as_root=True)

    # Cleanup

    rkt.run([
        "gc",
        "--grace-period=0"
    ] + rkt_flags, as_root=True)

    rkt.run([
        "image",
        "gc"
    ] + rkt_flags, as_root=True)

    shutil.rmtree(build_workspace, ignore_errors=True)