#!/usr/bin/python3
"""
Assembles the tree into a tar archive named `filename`.

Uses the buildhost's `tar` command, like: `tar -cf $FILENAME -C $TREE`

The compression of the tar archive if determined by the suffix, i.e.
the `--auto-compress` option is used. See tar(1) for details.

By default POSIX ACLs, SELinux contexts and extended attributes are included,
in order to preserve the tree as closely as possible. It is possible to opt
out of any of those by supplying the corresponding option.

Buildhost commands used: `tar` and any needed compression program.
"""

import os
import subprocess
import sys

import osbuild.api


SCHEMA_2 = """
"options": {
  "additionalProperties": false,
  "required": ["filename"],
  "properties": {
    "filename": {
      "description": "Filename for tar archive",
      "type": "string"
    },
    "acls": {
      "description": "Enable support for POSIX ACLs",
       "type": "boolean",
       "default": true
    },
    "selinux": {
      "description": "Enable support for SELinux contexts",
      "type": "boolean",
      "default": true
    },
    "xattrs": {
      "description": "Enable support for extended attributes",
      "type": "boolean",
      "default": true
    }
  }
},
"inputs": {
  "type": "object",
  "additionalProperties": false,
  "required": ["tree"],
  "properties": {
    "tree": {
      "type": "object",
      "additionalProperties": true
    }
  }
}
"""


def main(inputs, output_dir, options):
    tree = inputs["tree"]["path"]
    filename = options["filename"].lstrip("/")

    extra_args = []
    # Set environment variables for the tar operation.
    tar_env = {
        # Speed up xz by allowing it to use all CPU cores for compression.
        "XZ_OPT": "--threads 0"
    }

    # SELinux context, ACLs and extended attributes
    if options.get("acls", True):
        extra_args += ["--acls"]

    if options.get("selinux", True):
        extra_args += ["--selinux"]

    if options.get("xattrs", True):
        extra_args += ["--xattrs", "--xattrs-include", "*"]

    # Set up the tar command.
    tar_cmd = [
        "tar",
        "--auto-compress",
        *extra_args,
        "-cf", os.path.join(output_dir, filename),
        "-C", tree,
        "."
    ]

    # Make a tarball of the tree.
    subprocess.run(
        tar_cmd,
        stdout=subprocess.DEVNULL,
        check=True,
        env=tar_env
    )

    return 0


if __name__ == '__main__':
    args = osbuild.api.arguments()
    r = main(args["inputs"], args["tree"], args["options"])
    sys.exit(r)